Fixed top/up/down/bottom for ZDisplayable

[trakem2.git] / ini / trakem2 / display / DisplayCanvas.java

/**

 TrakEM2 plugin for ImageJ(C).
 Copyright (C) 2005-2009 Albert Cardona and Rodney Douglas.

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation (http://www.gnu.org/licenses/gpl.txt )

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. 

 You may contact Albert Cardona at acardona at ini.phys.ethz.ch
 Institute of Neuroinformatics, University of Zurich / ETH, Switzerland.
 **/

package ini.trakem2.display;

import ij.*;
import ij.gui.*;
import ij.process.ByteProcessor;
import ij.process.ColorProcessor;
import ini.trakem2.Project;
import ini.trakem2.persistence.Loader;
import ini.trakem2.utils.ProjectToolbar;
import ini.trakem2.utils.*;
import ini.trakem2.imaging.*;

import java.awt.event.*;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.geom.Area;
import java.awt.image.BufferedImage;
import java.awt.image.BufferStrategy;
import java.awt.image.VolatileImage;
import java.util.*;
import java.awt.Cursor;
import java.util.concurrent.atomic.AtomicInteger;

import ini.trakem2.utils.Lock;


public final class DisplayCanvas extends ImageCanvas implements KeyListener/*, FocusListener*/, MouseWheelListener {

        private Display display;

        private boolean update_graphics = false;
        private BufferedImage offscreen = null;
        private ArrayList al_top = new ArrayList();

        private final Lock lock_paint = new Lock();

        private Rectangle box = null; // the bounding box of the active

        private FakeImageWindow fake_win;

        private FreeHandProfile freehandProfile = null;
        private Robot r;// used for setting the mouse pointer

        //private RepaintThread rt_old = null;
        /** Any painting operation should wait on this object, set the controling flag to true, and when done set controling to false and controler.notifyAll(). */
        private final Object controler_ob = new Object();
        private boolean controling = false;

        private final Lock offscreen_lock = new Lock();

        private Cursor noCursor;

        private boolean snapping = false;
        private boolean dragging = false;
        private boolean input_disabled = false;
        private boolean input_disabled2 = false;

        private static final int NONE = 0;
        private static final int MOUSE = 1;
        private static final int KEY_MOVE = 2;
        private static final int Z_KEY = 4; // the undo system

        /** Store a copy of whatever data as each Class may define it, one such data object per class.
         * Private to the package. */
        static private Hashtable<Class,Object> copy_buffer = new Hashtable<Class,Object>();

        static void setCopyBuffer(final Class c, final Object ob) { copy_buffer.put(c, ob); }
        static Object getCopyBuffer(final Class c) { return copy_buffer.get(c); }

        static private boolean openglEnabled = false;
        static private boolean quartzEnabled = false;
        static private boolean ddscaleEnabled = false;

        // Private to the display package:
        static final RenderingHints rhints;
 
        /** Adapted code from Wayne Meissner, for gstreamer-java org.gstreamer.swing.GstVideoComponent; */
        static {
                final Map<RenderingHints.Key, Object> hints = new HashMap<RenderingHints.Key, Object>();
                try {
                        String openglProperty = System.getProperty("sun.java2d.opengl");
                        openglEnabled = openglProperty != null && Boolean.parseBoolean(openglProperty);
                } catch (Exception ex) { }
                try {
                        String quartzProperty = System.getProperty("apple.awt.graphics.UseQuartz");
                        quartzEnabled = Boolean.parseBoolean(quartzProperty);
                } catch (Exception ex) { }
                try {
                        String ddscaleProperty = System.getProperty("sun.java2d.ddscale");
                        String d3dProperty = System.getProperty("sun.java2d.d3d");
                        ddscaleEnabled = Boolean.parseBoolean(ddscaleProperty) && Boolean.parseBoolean(d3dProperty);
                } catch (Exception ex) { }

                if (openglEnabled) {
                        // Bilinear interpolation can be accelerated by the OpenGL pipeline
                        hints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
                        hints.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
                        
                } else if (quartzEnabled) {
                        //hints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
                        hints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR);
                        hints.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_SPEED);
                        hints.put(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_OFF);
                        
                } else if (ddscaleEnabled) {
                        hints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
                }

                rhints = new RenderingHints(hints);
        }

        /** Adapted code from Wayne Meissner, for gstreamer-java org.gstreamer.swing.GstVideoComponent; */
        /*
        private ActionListener resourceReaper = new ActionListener() {
                public void actionPerformed(final ActionEvent ae) {
                        if (!frameRendered) {
                                if (volatileImage != null) {
                                        volatileImage.flush();
                                        volatileImage = null;
                                }
                                frameRendered = false;

                                // Stop the timer so we don't wakeup needlessly
                                resourceTimer.stop();
                        }
                }
        };
        */

        private VolatileImage volatileImage;
        //private javax.swing.Timer resourceTimer = new javax.swing.Timer(10000, resourceReaper);
        //private boolean frameRendered = false;
        private boolean invalid_volatile = false;

        /** Adapted code from Wayne Meissner, for gstreamer-java org.gstreamer.swing.GstVideoComponent; */
        private void renderVolatileImage(final BufferedImage bufferedImage, final Displayable active, final Displayable[] top, final Layer active_layer, final int c_alphas, final AffineTransform at, Rectangle clipRect) {
                do {
                        final int w = getWidth(), h = getHeight();
                        final GraphicsConfiguration gc = getGraphicsConfiguration();
                        if (invalid_volatile || volatileImage == null || volatileImage.getWidth() != w 
                                        || volatileImage.getHeight() != h
                                        || volatileImage.validate(gc) == VolatileImage.IMAGE_INCOMPATIBLE) {
                                if (volatileImage != null) {
                                        volatileImage.flush();
                                }
                                volatileImage = gc.createCompatibleVolatileImage(w, h);
                                volatileImage.setAccelerationPriority(1.0f);
                                invalid_volatile = false;
                                clipRect = null; // paint all
                        }
                        // 
                        // Now paint the BufferedImage into the accelerated image
                        //
                        final Graphics2D g = volatileImage.createGraphics();

                        // 0 - set clipRect
                        if (null != clipRect) g.setClip(clipRect);

                        // 1 - Erase any background
                        g.setColor(Color.black);
                        if (null == clipRect) g.fillRect(0, 0, w, h);
                        else g.fillRect(clipRect.x, clipRect.y, clipRect.width, clipRect.height);

                        // 2 - Paint offscreen image
                        g.drawImage(bufferedImage, 0, 0, null);

                        // 3 - Paint the active Displayable and all cached on top
                        if (null != active_layer) {
                                g.setTransform(at);
                                g.setStroke(this.stroke); // AFTER setting the transform
                                // Active has to be painted wherever it is, within al_top
                                //if (null != active && active.getClass() != Patch.class && !active.isOutOfRepaintingClip(magnification, srcRect, clipRect)) active.paint(g, magnification, true, c_alphas, active_layer);
                                if (null != top) {
                                        final Rectangle tmp = null != clipRect ? new Rectangle() : null;
                                        final Rectangle clip = null != clipRect ? new Rectangle((int)(clipRect.x * magnification) - srcRect.x, (int)(clipRect.y * magnification) - srcRect.y, (int)(clipRect.width * magnification), (int)(clipRect.height * magnification)) : null;
                                        for (int i=0; i<top.length; i++) {
                                                if (null != clipRect && !top[i].getBoundingBox(tmp).intersects(clip)) continue;
                                                top[i].paint(g, magnification, top[i] == active, c_alphas, active_layer);
                                        }
                                }
                        }

                        g.dispose();
                } while (volatileImage.contentsLost());
        }

        /** Adapted code from Wayne Meissner, for gstreamer-java org.gstreamer.swing.GstVideoComponent;
         *  Paints (and re-renders, if necessary) the volatile image onto the given Graphics object, which
         *  is that of the DisplayCanvas as provided to the paint(Graphics g) method.
         *
         *  Expects clipRect in screen coordinates
         */
        private void render(final Graphics g, final Displayable active, final Displayable[] top, final Layer active_layer, final int c_alphas, final AffineTransform at, Rectangle clipRect) {
                final Graphics2D g2d = (Graphics2D) g.create();
                g2d.setRenderingHints(rhints);
                do {
                        if (invalid_volatile || null == volatileImage
                         || volatileImage.validate(getGraphicsConfiguration()) != VolatileImage.IMAGE_OK)
                        {
                                // clear clip, remake in full
                                clipRect = null;
                                renderVolatileImage(offscreen, active, top, active_layer, c_alphas, at, clipRect);
                        }
                        if (null != clipRect) g2d.setClip(clipRect);
                        g2d.drawImage(volatileImage, 0, 0, null);
                } while (volatileImage.contentsLost());

                g2d.dispose();

                //
                // Restart the resource reaper timer if neccessary
                //
                /*
                if (!frameRendered) {
                        frameRendered = true;
                        if (!resourceTimer.isRunning()) {
                                resourceTimer.restart();
                        }
                }
                */
        }

        protected void invalidateVolatile() {
                this.invalid_volatile = true;
        }

        /////////////////

        public DisplayCanvas(Display display, int width, int height) {
                super(new FakeImagePlus(width, height, display));
                fake_win = new FakeImageWindow(imp, this, display);
                this.display = display;
                this.imageWidth = width;
                this.imageHeight = height;
                removeKeyListener(IJ.getInstance());
                addKeyListener(this);
                addMouseWheelListener(this);
        }

        public Display getDisplay() { return display; }

        /** Used to constrain magnification so that only snapshots are used for painting when opening a new, large and filled Display. */
        protected void setInitialMagnification(double mag) { // calling this method 'setMagnification' would conflict with the super class homonimous method.
                this.magnification = mag; // don't save in the database. This value is overriden when reopening from the database by calling the setup method.
        }

        /** Used for restoring properties from the database. */
        public void setup(double mag, Rectangle srcRect) {
                this.magnification = mag;
                this.srcRect = (Rectangle)srcRect.clone(); // just in case
                super.setDrawingSize((int)Math.ceil(srcRect.width * mag), (int)Math.ceil(srcRect.height * mag));
                setMagnification(mag);
                display.pack(); // TODO should be run via invokeLater ... need to check many potential locks of invokeLater calling each other.
        }

        /** Does not repaint. */
        public void setDimensions(double width, double height) {
                this.imageWidth = (int)Math.ceil(width);
                this.imageHeight = (int)Math.ceil(height);
                ((FakeImagePlus)imp).setDimensions(imageWidth, imageHeight);
                zoomToFit();
        }

        /** Overriding to disable it. */
        public void handlePopupMenu() {}

        public void update(Graphics g) {
                // overriding to avoid default behaviour in java.awt.Canvas which consists in first repainting the entire drawable area with the background color, and then calling method paint.
                this.paint(g);
        }

        //private AtomicInteger counter = new AtomicInteger(0); // threads' tag

        private long last_paint = 0;

        /** Handles repaint event requests and the generation of offscreen threads. */
        private final AbstractRepaintThread RT = new AbstractRepaintThread(this, "T2-Canvas-Repainter", new OffscreenThread()) {
                protected void handleUpdateGraphics(final Component target, final Rectangle clipRect) {
                        this.off.setProperties(new RepaintProperties(clipRect, display.getLayer(), target.getWidth(), target.getHeight(), display.getActive(), display.getDisplayChannelAlphas()));
                }
        };

        /*
        private final void setRenderingHints(final Graphics2D g) {
                // so slow!! Particularly the first one.
                g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
                //g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
                //g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,  RenderingHints.VALUE_ANTIALIAS_ON); // to smooth edges of the images
                //g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
                //g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
        }
        */

        public void setMagnification(double mag) {
                // ensure a stroke of thickness 1.0 regardless of magnification
                this.stroke = new BasicStroke((float)(1.0/mag), BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER);
                // FIXES MAG TO ImageCanvas.zoomLevel LIMITS!!
                //super.setMagnification(mag);
                // So, manually:
                this.magnification = mag;
                imp.setTitle(imp.getTitle());
        }

        /** Paint lines always with a thickness of 1 pixel. This stroke is modified when the magnification is changed, to compensate. */
        private BasicStroke stroke = new BasicStroke(1.0f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER);

        /** The affine transform representing the srcRect displacement and the magnification. */
        private final AffineTransform atc = new AffineTransform();

        public void paint(final Graphics g) {
                try {
                        synchronized (lock_paint) {
                                lock_paint.lock();
                        }

                        // ensure proper positioning
                        g.translate(0, 0); // ints!

                        final Rectangle clipRect = g.getClipBounds();

                        final Displayable active = display.getActive();
                        final int c_alphas = display.getDisplayChannelAlphas();

                        final Layer active_layer = display.getLayer();

                        final Graphics2D g2d = (Graphics2D)g;

                        Displayable[] di = null;

                        synchronized (offscreen_lock) {
                                offscreen_lock.lock();
                                try {

                                        // prepare the canvas for the srcRect and magnification
                                        final AffineTransform at_original = g2d.getTransform();
                                        atc.setToIdentity();
                                        atc.scale(magnification, magnification);
                                        atc.translate(-srcRect.x, -srcRect.y);
                                        at_original.preConcatenate(atc);

                                        di = new Displayable[al_top.size()];
                                        al_top.toArray(di);

                                        //Utils.log2("al_top.size(): " + di.length);

                                        if (null != offscreen) {
                                                //g.drawImage(offscreen, 0, 0, null);
                                                if (dragging) invalidateVolatile(); // to update the active at least
                                                render(g, active, di, active_layer, c_alphas, at_original, clipRect);
                                        }

                                        g2d.setTransform(at_original);

                                } catch (Exception e) {
                                        e.printStackTrace();
                                }
                                offscreen_lock.unlock();
                        }

                        g2d.setStroke(this.stroke);

                        // paint a pink frame around selected objects, and a white frame around the active object
                        final Selection selection = display.getSelection();
                        if (null != selection && ProjectToolbar.getToolId() < ProjectToolbar.PENCIL) { // i.e. PENCIL, PEN and ALIGN
                                selection.paint(g2d, srcRect, magnification);
                        }

                        // debug buckets
                        //if (null != display.getLayer().root) display.getLayer().root.paint(g2d, srcRect, magnification, Color.red);
                        //if (null != display.getLayer().getParent().root) display.getLayer().getParent().root.paint(g2d, srcRect, magnification, Color.blue);


                        // reset to identity
                        g2d.setTransform(new AffineTransform());
                        // reset to 1.0 thickness
                        g2d.setStroke(new BasicStroke(1.0f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER));

                        final Align align = null != active_layer ? active_layer.getParent().getAlign() : null;
                        if (null != align) {
                                align.paint(active_layer, g2d, srcRect, magnification);
                        }

                        // paint brush outline for AreaList
                        if (mouse_in && null != active && ProjectToolbar.getToolId() == ProjectToolbar.PEN && active.getClass() == AreaList.class) {
                                int brushSize = ProjectToolbar.getBrushSize();
                                g.setColor(active.getColor());
                                g.drawOval((int)((xMouse -srcRect.x -brushSize/2)*magnification), (int)((yMouse - srcRect.y -brushSize/2)*magnification), (int)(brushSize * magnification), (int)(brushSize * magnification));
                        }

                        final Roi roi = imp.getRoi();
                        if (null != roi) {
                                roi.draw(g);
                        }

                        // Mathias code:
                        if (null != freehandProfile) {
                                freehandProfile.paint(g, magnification, srcRect, true);
                                if(noCursor == null)
                                        noCursor = Toolkit.getDefaultToolkit().createCustomCursor(new BufferedImage(1,1,BufferedImage.TYPE_BYTE_BINARY), new Point(0,0), "noCursor");
                        }

                        final long now = System.currentTimeMillis();
                        //p("interval: " + (now - last_paint));
                        last_paint = now;

                } catch (Exception e) {
                        Utils.log2("DisplayCanvas.paint(Graphics) Error: " + e);
                        IJError.print(e);
                } finally {
                        synchronized (lock_paint) {
                                lock_paint.unlock();
                        }
                }
        }

        public void waitForRepaint() {
                // wait for all offscreen methods to finish painting
                RT.waitForOffs();
                // wait for the paint method to finish painting
                synchronized (lock_paint) {
                        // wait until painting is done
                }
        }

        /** Paints a handle on the screen coords. Adapted from ij.gui.Roi class. */
        static public void drawHandle(final Graphics g, final int x, final int y, final double magnification) {
                final int width5 = (int)Math.round(5 / magnification);
                final int width3 = (int)Math.round(3 / magnification);
                final int corr2 = (int)Math.round(2 / magnification);
                final int corr1 = (int)Math.ceil(1 / magnification);
                g.setColor(Color.white);
                g.drawRect(x - corr2, y - corr2, width5, width5);
                g.setColor(Color.black);
                g.drawRect(x - corr1, y - corr1, width3, width3);
                g.setColor(Color.white);
                g.fillRect(x, y, corr1, corr1);
        }

        /** Paints a handle on the offscreen x,y. Adapted from ij.gui.Roi class. */
        private void drawHandle(Graphics g, double x, double y) {
                g.setColor(Color.black);
                g.fillRect((int) ((x - srcRect.x) * magnification) - 1, (int) ((y - srcRect.y) * magnification) - 1, 3, 3);
                g.setColor(Color.white);
                g.drawRect((int) ((x - srcRect.x) * magnification) - 2, (int) ((y - srcRect.y) * magnification) - 2, 5, 5);
        }

        protected void setDrawingColor(int ox, int oy, boolean setBackground) {
                super.setDrawingColor(ox, oy, setBackground);
        }

        /** As offscreen. */
        private int x_p, y_p, x_d, y_d, x_d_old, y_d_old;

        private boolean popup = false;

        private boolean locked = false; // TODO temporary!

        private int tmp_tool = -1;

        public void mousePressed(MouseEvent me) {

                this.flags = me.getModifiers();

                x_p = x_d = srcRect.x + (int) (me.getX() / magnification); // offScreenX(me.getX());
                y_p = y_d = srcRect.y + (int) (me.getY() / magnification); // offScreenY(me.getY());

                this.xMouse = x_p;
                this.yMouse = y_p;

                // ban if beyond bounds:
                if (x_p < srcRect.x || y_p < srcRect.y || x_p > srcRect.x + srcRect.width || y_p > srcRect.y + srcRect.height) {
                        return;
                }

                // Popup:
                popup = false; // not reset properly in macosx
                if (Utils.isPopupTrigger(me)) {
                        popup = true;
                        display.getPopupMenu().show(this, me.getX(), me.getY());
                        return;
                }

                // reset
                snapping = false;

                int tool = ProjectToolbar.getToolId();

                // pan with middle mouse like in inkscape
                /* // works, but can't use it: the alt button then is useless (so no erasing with areas, and so on)
                if (0 != (flags & InputEvent.BUTTON2_MASK))
                */
                if (me.getButton() == MouseEvent.BUTTON2) {
                        tmp_tool = tool;
                        ProjectToolbar.setTool(Toolbar.HAND);
                        tool = Toolbar.HAND;
                }
                //Utils.log2("button: " + me.getButton() + "  BUTTON2: " + MouseEvent.BUTTON2);

                switch (tool) {
                case Toolbar.MAGNIFIER:
                        if (me.isAltDown()) zoomOut(me.getX(), me.getY());
                        else zoomIn(me.getX(), me.getY());
                        return;
                case Toolbar.HAND:
                        super.setupScroll(x_p, y_p); // offscreen coords.
                        //display.repaintAll();
                        return;
                }

                if (input_disabled) {
                        input_disabled2 = true;
                        Utils.showMessage("Please wait while completing the task.\nOnly the glass and hand tool are enabled.");
                        return; // only zoom and pan are allowed
                }

                Displayable active = display.getActive();


                switch (tool) {
                case Toolbar.WAND:
                        if (null != active && active instanceof Patch) {
                                me.translatePoint(-(int) active.getX(), -(int) active.getY());
                                super.mousePressed(me);
                                repaint();
                                // TODO should use LayerStack virtualization ... then scale back the ROI
                        }
                        return;
                case ProjectToolbar.PENCIL:
                        if (null != active && active.isVisible() && active.getClass() == Profile.class) {
                                Profile prof = (Profile) active;
                                this.freehandProfile = new FreeHandProfile(prof);
                                freehandProfile.mousePressed(x_p, y_p);
                                return;
                        }
                        break;
                case Toolbar.RECTANGLE:
                case Toolbar.OVAL:
                case Toolbar.POLYGON:
                case Toolbar.FREEROI:
                case Toolbar.LINE:
                case Toolbar.POLYLINE:
                case Toolbar.FREELINE:
                case Toolbar.ANGLE:
                case Toolbar.POINT:
                        // pass the mouse event to superclass ImageCanvas.
                        super.mousePressed(me);
                        repaint();
                        return;
                case Toolbar.DROPPER:
                        // The color dropper
                        setDrawingColor(x_p, y_p, me.isAltDown());
                        return;
                }

                // check:
                if (display.isReadOnly()) return;

                switch (tool) {
                case Toolbar.TEXT:
                        // edit a label, or add a new one
                        if (null == active || !active.contains(x_p, y_p)) {
                                // find a Displayable to activate, if any
                                display.choose(me.getX(), me.getY(), x_p, y_p, DLabel.class);
                                active = display.getActive();
                        }
                        if (null != active && active.isVisible() && active instanceof DLabel) {
                                // edit
                                ((DLabel) active).edit();
                        } else {
                                // new
                                DLabel label = new DLabel(display.getProject(), "  ", x_p, y_p);
                                display.getLayer().add(label);
                                label.edit();
                        }
                        return;
                }

                // SPECIFIC for SELECT and above tools

                // no ROIs allowed past this point
                if (tool >= ProjectToolbar.SELECT) imp.killRoi();
                else return;

                Selection selection = display.getSelection();
                if (selection.isTransforming()) {
                        box = selection.getLinkedBox();
                        selection.mousePressed(me, x_p, y_p, magnification);
                        return;
                }
                // select or deselect another active Displayable, or add it to the selection group:
                if (ProjectToolbar.SELECT == tool) {
                        display.choose(me.getX(), me.getY(), x_p, y_p, me.isShiftDown(), null);
                }
                active = display.getActive();
                selection = display.getSelection();

                if (ProjectToolbar.ALIGN == tool) {
                        LayerSet set = display.getLayer().getParent();
                        if (!set.isAligning()) {
                                set.startAlign(display);
                        }
                        set.getAlign().mousePressed(display.getLayer(), me, x_p, y_p, magnification);
                        return;
                }

                if (null == active || !active.isVisible()) return;

                switch (tool) {
                case ProjectToolbar.SELECT:
                        // check if the active is usable:
                        // check if the selection contains locked objects
                        if (selection.isLocked()) {
                                locked = true;
                                return;
                        }
                        if (selection.isEmpty()) {
                                locked = true;
                                return;
                        }
                        // gather initial box (for repainting purposes)
                        box = selection.getLinkedBox();
                        selection.mousePressed(me, x_p, y_p, magnification);
                        break;
                default: // the PEN and PENCIL tools, and any other custom tool
                        display.getLayerSet().addPreDataEditStep(active);
                        box = active.getBoundingBox();
                        active.mousePressed(me, x_p, y_p, magnification);
                        invalidateVolatile();
                        break;
                }
                //Utils.log("locked: " + locked + " popup: " + popup + " input_disabled2: " + input_disabled2);
        }

        public void mouseDragged(MouseEvent me) {
                // ban if beyond bounds:
                if (x_p < srcRect.x || y_p < srcRect.y || x_p > srcRect.x + srcRect.width || y_p > srcRect.y + srcRect.height) {
                        return;
                }

                Selection selection = display.getSelection();
                if (locked && !selection.isEmpty()) {
                        Utils.log("Selection is locked.");
                        return;
                }

                if (popup) return;

                dragging = true;

                this.flags = me.getModifiers();

                x_d_old = x_d;
                y_d_old = y_d;

                x_d = srcRect.x + (int) (me.getX() / magnification); // offscreen
                y_d = srcRect.y + (int) (me.getY() / magnification);

                this.xMouse = x_d;
                this.yMouse = y_d;

                // protection:
                int me_x = me.getX();
                int me_y = me.getY();
                if (me_x < 0 || me_x > this.getWidth() || me_y < 0 || me_y > this.getHeight()) {
                        x_d = x_d_old;
                        y_d = y_d_old;
                        return;
                }

                int tool = ProjectToolbar.getToolId();


                // pan with middle mouse like in inkscape
                /* // works, but can't use it: the alt button then is useless (so no erasing with areas, and so on)
                if (0 != (flags & InputEvent.BUTTON2_MASK)) {
                        tool = Toolbar.HAND;
                }
                */ // so the above has been implemented as a temporary switch to the HAND tool at the mousePressed function.

                switch (tool) {
                case Toolbar.MAGNIFIER: // TODO : create a zooms-area tool
                        return;
                case Toolbar.HAND:
                        int srx = srcRect.x,
                            sry = srcRect.y;
                        scroll(me.getX(), me.getY());
                        if (0 != srx - srcRect.x || 0 != sry - srcRect.y) {
                                update_graphics = true; // update the offscreen images.
                                display.getNavigator().repaint(false);
                                repaint(true);
                        }
                        return;
                }

                if (input_disabled2) return;

                if (null != display.getLayer().getParent().getAlign()) return;


                //debug:
                //Utils.log2("x_d,y_d : " + x_d + "," + y_d + "   x_d_old, y_d_old : " + x_d_old + "," + y_d_old + "  dx, dy : " + (x_d_old - x_d) + "," + (y_d_old - y_d));

                // Code for Matthias' FreehandProfile (TODO this should be done on mousePressed, not on mouseDragged)

                Displayable active = display.getActive();
                if (null != active && active.getClass() == Profile.class) {
                        try {
                                if (r == null) {
                                        r = new Robot(this.getGraphicsConfiguration().getDevice());
                                }
                        } catch (AWTException e) {
                                e.printStackTrace();
                        }
                }

                switch (tool) {
                case ProjectToolbar.PENCIL:
                        if (null != active && active.isVisible() && active.getClass() == Profile.class) {
                                if (freehandProfile == null)
                                        return; // starting painting out of the DisplayCanvas border
                                double dx = x_d - x_d_old;
                                double dy = y_d - y_d_old;
                                freehandProfile.mouseDragged(me, x_d, y_d, dx, dy);
                                repaint();
                                // Point screenLocation = getLocationOnScreen();
                                // mousePos[0] += screenLocation.x;
                                // mousePos[1] += screenLocation.y;
                                // r.mouseMove( mousePos[0], mousePos[1]);
                                return;
                        }
                        break;
                case Toolbar.RECTANGLE:
                case Toolbar.OVAL:
                case Toolbar.POLYGON:
                case Toolbar.FREEROI:
                case Toolbar.LINE:
                case Toolbar.POLYLINE:
                case Toolbar.FREELINE:
                case Toolbar.ANGLE:
                case Toolbar.POINT:
                        // pass the mouse event to superclass ImageCanvas.
                        super.mouseDragged(me);
                        repaint(false);
                        return;
                }
                // no ROIs beyond this point
                if (tool >= ProjectToolbar.SELECT) imp.killRoi();
                else return;

                // check:
                if (display.isReadOnly()) return;

                if (null != active && active.isVisible()) {
                        // prevent dragging beyond the layer limits
                        if (display.getLayer().contains(x_d, y_d, 1)) {
                                Rectangle box2;
                                switch (tool) {
                                case ProjectToolbar.SELECT:
                                        selection.mouseDragged(me, x_p, y_p, x_d, y_d, x_d_old, y_d_old);
                                        box2 = selection.getLinkedBox();
                                        box.add(box2);
                                        // repaint all Displays (where it was and where it is now, hence the sum of both boxes):
                        //TODO//Utils.log2("md: " + box.toString());
                                        Display.repaint(display.getLayer(), Selection.PADDING, box, false, active.isLinked() || active.getClass() == Patch.class);
                                        // box for next mouse dragged iteration
                                        box = box2;
                                        break;
                                case ProjectToolbar.ALIGN:
                                        break; // nothing
                                default:
                                        active.mouseDragged(me, x_p, y_p, x_d, y_d, x_d_old, y_d_old);
                                        // the line above must repaint on its own
                                        break;
                                }
                        } else { 
                                locked = true; // TODO temporary until the snapTo and mouseEntered issues are fixed
                                Utils.log("DisplayCanvas.mouseDragged: preventing drag beyond layer limits.");
                        }
                }
        }

        public void mouseReleased(MouseEvent me) {
                boolean dragging2 = dragging;
                dragging = false;
                if (popup) {
                        popup = false;
                        return;
                }

                // ban if beyond bounds:
                if (x_p < srcRect.x || y_p < srcRect.y || x_p > srcRect.x + srcRect.width || y_p > srcRect.y + srcRect.height) {
                        return;
                }

                int tool = ProjectToolbar.getToolId();

                // pan with middle mouse like in inkscape
                /* // works, but can't use it: the alt button then is useless (so no erasing with areas, and so on)
                if (0 != (flags & InputEvent.BUTTON2_MASK)) {
                        tool = Toolbar.HAND;
                }
                */

                switch (tool) {
                case Toolbar.MAGNIFIER:
                        // display.updateInDatabase("srcRect"); // TODO if the display.frame
                        // is shrinked, the pack() in the zoom methods will also call the
                        // updateInDatabase("srcRect") (so it's going to be done twice)
                        display.updateFrameTitle();
                        return;
                case Toolbar.HAND:
                        display.updateInDatabase("srcRect");
                        if (-1 != tmp_tool) {
                                ProjectToolbar.setTool(tmp_tool);
                                tmp_tool = -1;
                        }
                        if (!dragging2) repaint(true); // TEMPORARY just to allow fixing bad screen when simply cliking with the hand
                        return;
                }

                if (input_disabled2) {
                        input_disabled2 = false; // reset
                        return;
                }

                if (locked) {
                        locked = false;
                        if (dragging2) {
                                String msg = "\nRight-click and select\"";
                                if (null != display.getActive()) {
                                        msg += display.getActive().getClass() == Patch.class ? "Unlock" : "Unlink";
                                }
                                msg += "\" first.";
                                Utils.showMessage("Selection is locked or contains links to a locked object." + msg);
                        }
                        return;
                }

                if (display.getLayer().getParent().isAligning()) {
                        return;
                }

                // pan with middle mouse like in inkscape
                /* // works, but can't use it: the alt button then is useless (so no erasing with areas, and so on)
                if (0 != (flags & InputEvent.BUTTON2_MASK)) {
                        tool = Toolbar.HAND;
                }
                */

                this.flags = me.getModifiers();
                flags &= ~InputEvent.BUTTON1_MASK; // make sure button 1 bit is not set (FOR AreaList brush-like)
                flags &= ~InputEvent.BUTTON2_MASK; // make sure button 2 bit is not set
                flags &= ~InputEvent.BUTTON3_MASK; // make sure button 3 bit is not set

                int x_r = srcRect.x + (int)(me.getX() / magnification);
                int y_r = srcRect.y + (int)(me.getY() / magnification);

                this.xMouse = x_r;
                this.yMouse = y_r;

                Displayable active = display.getActive();

                switch (tool) {
                        case ProjectToolbar.PENCIL:
                                if (null != active && active.isVisible() && active.getClass() == Profile.class) {
                                        if (freehandProfile == null)
                                                return; // starting painting out of the DisplayCanvas boarder
                                        freehandProfile.mouseReleased(me, x_p, y_p, x_d, y_d, x_r, y_r);
                                        freehandProfile = null;
                                        //repaint(true);
                                        Selection selection = display.getSelection();
                                        selection.updateTransform(display.getActive());
                                        Display.repaint(display.getLayer(), selection.getBox(), Selection.PADDING); // repaints the navigator as well
                                        return;
                                }
                                break;
                        case Toolbar.RECTANGLE:
                        case Toolbar.OVAL:
                        case Toolbar.POLYGON:
                        case Toolbar.FREEROI:
                        case Toolbar.LINE:
                        case Toolbar.POLYLINE:
                        case Toolbar.FREELINE:
                        case Toolbar.ANGLE:
                        case Toolbar.POINT:
                                // pass the mouse event to superclass ImageCanvas.
                                super.mouseReleased(me);
                                repaint();
                                // return; // replaced by #SET_ROI
                }

                final Roi roi = imp.getRoi();

                // check:
                if (display.isReadOnly()) return;

                if (tool >= ProjectToolbar.SELECT) {
                        if (null != roi) imp.killRoi();
                } else return; // #SET_ROI

                Selection selection = display.getSelection();

                if (snapping) {
                        // finish dragging
                        selection.mouseReleased(me, x_p, y_p, x_d, y_d, x_r, y_r);
                        box.add(selection.getLinkedBox());
                        Display.repaint(display.getLayer(), box, Selection.PADDING); // repaints the navigator as well
                        StitchingTEM.snap(active, display); // will repaint whatever is appropriate (the visible linked group snapped along)
                        // reset:
                        snapping = false;
                        return;
                }

                if (null != active && active.isVisible()) {
                        switch(tool) {
                        case ProjectToolbar.SELECT:
                                selection.mouseReleased(me, x_p, y_p, x_d, y_d, x_r, y_r);
                                box.add(selection.getLinkedBox());
                                Display.repaint(display.getLayer(), Selection.PADDING, box, !selection.isTransforming(), active.isLinked() || active.getClass() == Patch.class); // does not repaint the navigator
                                break;
                        case ProjectToolbar.PENCIL:
                        case ProjectToolbar.PEN:
                                active.mouseReleased(me, x_p, y_p, x_d, y_d, x_r, y_r); // active, not selection (Selection only handles transforms, not active's data editions)
                                // update active's bounding box
                                selection.updateTransform(active);
                                box.add(selection.getBox());
                                Display.repaint(display.getLayer(), Selection.PADDING, box, !selection.isTransforming(), active.isLinked() || active.getClass() == Patch.class); // does not repaint the navigator
                                //if (!active.getClass().equals(AreaList.class)) Display.repaint(display.getLayer(), box, Selection.PADDING); // repaints the navigator as well
                                // TODO: this last repaint call is unnecessary, if the box was properly repainted on mouse drag for Profile etc.
                                //else 
                                if (null != old_brush_box) {
                                        repaint(old_brush_box, 0, false);
                                        old_brush_box = null; // from mouseMoved
                                }
                                // The current state:
                                display.getLayerSet().addDataEditStep(active);
                                break;
                        }
                }
        }

        // private to the package
        boolean isDragging() {
                if (null == display.getSelection()) {
                        Utils.log2("WARNING DisplayCanvas.isDragging thinks the display.getSelection() gives a null object ?!?");
                        return false;
                }
                return display.getSelection().isDragging();
        }

        private boolean mouse_in = false;

        public void mouseEntered(MouseEvent me) {
                mouse_in = true;
                // try to catch focus if the JFrame is front most
                if (display.isActiveWindow() && !this.hasFocus()) {
                        this.requestFocus();
                }
                // bring dragged point to mouse pointer
                // TODO doesn't work as expected.
                /*
                Displayable active = display.getActive();
                int x = offScreenX(me.getX());
                int y = offScreenY(me.getY());
                if (null != active) {
                        active.snapTo(x, y, x_p, y_p);
                        x_p = x_d = x_d_old = x;
                        y_p = y_d = y_d_old = y;
                }
                */
                //Utils.log2("mouseEntered x,y: " + offScreenX(me.getX()) + "," + offScreenY(me.getY()));
        }

        public void mouseExited(MouseEvent me) {
                mouse_in = false;
                // paint away the circular brush if any
                if (ProjectToolbar.getToolId() == ProjectToolbar.PEN) {
                        Displayable active = display.getActive();
                        if (null != active && active.isVisible() && AreaList.class == active.getClass()) {
                                if (null != old_brush_box) {
                                        this.repaint(old_brush_box, 0);
                                        old_brush_box = null;
                                }
                        }
                }
        }

        /** Sets the cursor based on the current tool and cursor location. */
        public void setCursor(int sx, int sy, int ox, int oy) {
                // copy of ImageCanvas.setCursor without the win==null
                xMouse = ox;
                yMouse = oy;
                Roi roi = imp.getRoi();
                /*
                 * ImageWindow win = imp.getWindow(); if (win==null) return;
                 */
                if (IJ.spaceBarDown()) {
                        setCursor(handCursor);
                        return;
                }
                switch (Toolbar.getToolId()) {
                case Toolbar.MAGNIFIER:
                        if (IJ.isMacintosh())
                                setCursor(defaultCursor);
                        else
                                setCursor(moveCursor);
                        break;
                case Toolbar.HAND:
                        setCursor(handCursor);
                        break;
                case ProjectToolbar.SELECT:
                case ProjectToolbar.PENCIL:
                case ProjectToolbar.ALIGN:
                        setCursor(defaultCursor);
                        break;
                default: // selection tool

                        if (roi != null && roi.getState() != roi.CONSTRUCTING && roi.isHandle(sx, sy) >= 0)
                                setCursor(handCursor);
                        else if (Prefs.usePointerCursor || (roi != null && roi.getState() != roi.CONSTRUCTING && roi.contains(ox, oy)))
                                setCursor(defaultCursor);
                        else
                                setCursor(crosshairCursor);
                        break;
                }
        }
        /** Set the srcRect - used by the DisplayNavigator. */
        protected void setSrcRect(int x, int y, int width, int height) {
                this.srcRect.setRect(x, y, width, height);
                display.updateInDatabase("srcRect");
        }

        public void setDrawingSize(int new_width, int new_height,
                        boolean adjust_srcRect) {
                // adjust srcRect!
                if (adjust_srcRect) {
                        double mag = super.getMagnification();
                        // This method is very important! Make it fit perfectly.
                        if (srcRect.width * mag < new_width) {
                                // expand
                                if (new_width > imageWidth * mag) {
                                        // too large, limit
                                        srcRect.x = 0;
                                        srcRect.width = imageWidth;
                                } else {
                                        srcRect.width = (int) Math.ceil(new_width / mag);
                                        if (srcRect.x + srcRect.width > imageWidth) {
                                                srcRect.x = imageWidth - srcRect.width;
                                        }
                                }
                        } else {
                                // shrink
                                srcRect.width = (int) Math.ceil(new_width / mag);
                        }
                        if (srcRect.height * mag < new_height) {
                                // expand
                                if (new_height > imageHeight * mag) {
                                        // too large, limit
                                        srcRect.y = 0;
                                        srcRect.height = imageHeight;
                                } else {
                                        srcRect.height = (int) Math.ceil(new_height / mag);
                                        if (srcRect.y + srcRect.height > imageHeight) {
                                                srcRect.y = imageHeight - srcRect.height;
                                        }
                                }
                        } else {
                                // shrink
                                srcRect.height = (int) Math.ceil(new_height / mag);
                        }
                }
                super.setDrawingSize(new_width, new_height);
        }

        private void zoomIn2(int x, int y) {
                // copy of ImageCanvas.zoomIn except for the canEnlarge is different and
                // there's no call to the non-existing ImageWindow
                if (magnification >= 32)
                        return;
                double newMag = getHigherZoomLevel2(magnification);

                // zoom at point: correct mag drift
                int cx = getWidth() / 2;
                int cy = getHeight() / 2;
                int dx = (int)(((x - cx) * magnification) / newMag);
                int dy = (int)(((y - cy) * magnification) / newMag);
                x -= dx;
                y -= dy;

                // Adjust the srcRect to the new dimensions
                int w = (int) Math.round(dstWidth / newMag);
                if (w * newMag < dstWidth)
                        w++;
                if (w > imageWidth)
                        w = imageWidth;
                int h = (int) Math.round(dstHeight / newMag);
                if (h * newMag < dstHeight)
                        h++;
                if (h > imageHeight)
                        h = imageHeight;
                x = offScreenX(x);
                y = offScreenY(y);
                final Rectangle r = new Rectangle(x - w / 2, y - h / 2, w, h);
                if (r.x < 0)
                        r.x = 0;
                if (r.y < 0)
                        r.y = 0;
                if (r.x + w > imageWidth)
                        r.x = imageWidth - w;
                if (r.y + h > imageHeight)
                        r.y = imageHeight - h;
                srcRect = r;

                //display.pack();

                setMagnification(newMag);
                display.updateInDatabase("srcRect");
                display.repaintAll2(); // this repaint includes this canvas's repaint as well, but also the navigator, etc. // repaint();
        }

        private void zoomOut2(int x, int y) {
                //if (magnification <= 0.03125)
                //      return;
                double newMag = getLowerZoomLevel2(magnification);

                // zoom at point: correct mag drift
                int cx = getWidth() / 2;
                int cy = getHeight() / 2;
                int dx = (int)(((x - cx) * magnification) / newMag);
                int dy = (int)(((y - cy) * magnification) / newMag);
                x -= dx;
                y -= dy;

                if (imageWidth * newMag > dstWidth || imageHeight * newMag > dstHeight) {
                        int w = (int) Math.round(dstWidth / newMag);
                        if (w * newMag < dstWidth)
                                w++;
                        int h = (int) Math.round(dstHeight / newMag);
                        if (h * newMag < dstHeight)
                                h++;
                        x = offScreenX(x);
                        y = offScreenY(y);
                        Rectangle r = new Rectangle(x - w / 2, y - h / 2, w, h);
                        if (r.x < 0)
                                r.x = 0;
                        if (r.y < 0)
                                r.y = 0;
                        if (r.x + w > imageWidth)
                                r.x = imageWidth - w;
                        if (r.y + h > imageHeight)
                                r.y = imageHeight - h;
                        srcRect = r;
                } else {
                        // Shrink srcRect, but NOT the dstWidth,dstHeight of the canvas, which remain the same:
                        srcRect = new Rectangle(0, 0, imageWidth, imageHeight);
                }

                setMagnification(newMag);
                display.repaintAll2(); // this repaint includes this canvas's repaint
                // as well, but also the navigator, etc.
                // repaint();
                display.updateInDatabase("srcRect");
        }

        /** The minimum amout of pixels allowed for width or height when zooming out. */
        static private final int MIN_DIMENSION = 10; // pixels

        /** Enable zooming out up to the point where the display becomes 10 pixels in width or height. */
        protected double getLowerZoomLevel2(final double currentMag) {
                // if it is 1/72 or lower, then:
                if (Math.abs(currentMag - 1/72.0) < 0.00000001 || currentMag < 1/72.0) { // lowest zoomLevel in ImageCanvas is 1/72.0
                        // find nearest power of two under currentMag
                        // start at level 7, which is 1/128
                        int level = 7;
                        double scale = currentMag;
                        while (scale * srcRect.width > MIN_DIMENSION && scale * srcRect.height > MIN_DIMENSION) {
                                scale = 1 / Math.pow(2, level);
                                // if not equal and actually smaller, break:
                                if (Math.abs(scale - currentMag) != 0.00000001 && scale < currentMag) break;
                                level++;
                        }
                        return scale;
                } else {
                        return ImageCanvas.getLowerZoomLevel(currentMag); 
                }
        }
        protected double getHigherZoomLevel2(final double currentMag) {
                // if it is not 1/72 and its lower, then:
                if (Math.abs(currentMag - 1/72.0) > 0.00000001 && currentMag < 1/72.0) { // lowest zoomLevel in ImageCanvas is 1/72.0
                        // find nearest power of two above currentMag
                        // start at level 14, which is 0.00006103515625 (0.006 %)
                        int level = 14; // this value may be increased in the future
                        double scale = currentMag;
                        while (level >= 0) {
                                scale = 1 / Math.pow(2, level);
                                if (scale > currentMag) break;
                                level--;
                        }
                        return scale;
                } else {
                        return ImageCanvas.getHigherZoomLevel(currentMag);
                }
        }


        /*
         * // OBSOLETE: modified ij.gui.ImageCanvas directly
         public void mouseMoved(MouseEvent e) { if (IJ.getInstance()==null) return; int sx =
         * e.getX(); int sy = e.getY(); int ox = offScreenX(sx); int oy =
         * offScreenY(sy); flags = e.getModifiers(); setCursor(sx, sy, ox, oy);
         * IJ.setInputEvent(e); Roi roi = imp.getRoi(); if (roi!=null &&
         * (roi.getType()==Roi.POLYGON || roi.getType()==Roi.POLYLINE ||
         * roi.getType()==Roi.ANGLE) && roi.getState()==roi.CONSTRUCTING) {
         * PolygonRoi pRoi = (PolygonRoi)roi; pRoi.handleMouseMove(ox, oy); } else {
         * if (ox<imageWidth && oy<imageHeight) { //ImageWindow win =
         * imp.getWindow(); //if (win!=null) win.mouseMoved(ox, oy);
         * imp.mouseMoved(ox, oy); } else IJ.showStatus(""); } }
         */

        private Rectangle old_brush_box = null;

        private MouseMovedThread mouse_moved = new MouseMovedThread();

        private class MouseMovedThread extends Thread {
                private MouseEvent me = null;
                private boolean go = true;
                MouseMovedThread() {
                        super("T2-mouseMoved");
                        setDaemon(true);
                        setPriority(Thread.NORM_PRIORITY);
                        start();
                }
                void dispatch(MouseEvent me) {
                        //Utils.log2("before");
                        synchronized (this) {
                                //Utils.log2("in");
                                this.me = me;
                                notify();
                        }
                }
                void quit() {
                        go = false;
                        synchronized (this) { notify(); }
                }
                public void run() {
                        while (go) {
                                MouseEvent me = null;
                                synchronized (this) {
                                        try { this.wait(); } catch (Exception e) {}
                                        me = this.me;
                                        this.me = null;
                                }
                                try { mouseMoved(me); } catch (Exception e) { IJError.print(e); }
                        }
                }
                private void mouseMoved(MouseEvent me) {
                        if (null == me) return;
                        if (input_disabled || display.getSelection().isDragging()) return;

                        final Displayable active = display.getActive();

                        // only when no mouse buttons are down
                        final int flags = me.getModifiers(); // override, the super fails for some reason
                        if (0 == (flags & InputEvent.BUTTON1_MASK)
                        /* && 0 == (flags & InputEvent.BUTTON2_MASK) */ // this is the alt key down ..
                         && 0 == (flags & InputEvent.BUTTON3_MASK)
                        //if (me.getButton() == MouseEvent.NOBUTTON
                         && ProjectToolbar.getToolId() == ProjectToolbar.PEN && null != active && active.isVisible() && AreaList.class == active.getClass()) {
                                // repaint area where the brush circle is
                                int brushSize = ProjectToolbar.getBrushSize() +2; // +2 padding
                                Rectangle r = new Rectangle( xMouse - brushSize/2,
                                                             yMouse - brushSize/2,
                                                             brushSize+1,
                                                             brushSize+1 );
                                Rectangle copy = (Rectangle)r.clone(); 
                                if (null != old_brush_box) r.add(old_brush_box);
                                old_brush_box = copy;
                                repaint(r, 1); // padding because of painting rounding which would live dirty trails
                        }

                        if (me.isShiftDown()) {
                                // Print a comma-separated list of objects under the mouse pointer
                                final Layer layer = DisplayCanvas.this.display.getLayer();
                                final int x_p = offScreenX(me.getX()),
                                          y_p = offScreenY(me.getY());
                                final ArrayList<Displayable> al = new ArrayList(layer.getParent().findZDisplayables(layer, x_p, y_p, true));
                                final ArrayList al2 = new ArrayList(layer.find(x_p, y_p, true));
                                Collections.reverse(al2); // text labels first
                                al.addAll(al2);
                                if (0 == al.size()) {
                                        Utils.showStatus("", false);
                                        return;
                                }
                                final StringBuilder sb = new StringBuilder();
                                final Project pr = layer.getProject();
                                for (Displayable d : al) sb.append(pr.getShortMeaningfulTitle(d)).append(", ");
                                sb.setLength(sb.length()-2);
                                Utils.showStatus(sb.toString(), false);
                        } else {
                                // set xMouse, yMouse, and print pixel value
                                DisplayCanvas.super.mouseMoved(me);
                        }
                }
        }

        public void mouseMoved(final MouseEvent me) {
                mouse_moved.dispatch(me);
        }

        /** Zoom in using the current mouse position, or the center if the mouse is out. */
        public void zoomIn() {
                if (xMouse < 0 || screenX(xMouse) > dstWidth || yMouse < 0 || screenY(yMouse) > dstHeight) {
                        zoomIn(dstWidth/2, dstHeight/2);
                } else {
                        zoomIn(screenX(xMouse), screenY(yMouse));
                }
        }

        /** Overriding to repaint the DisplayNavigator as well. */
        public void zoomIn(int x, int y) {
                update_graphics = true; // update the offscreen images.
                zoomIn2(x, y);
        }

        /** Zoom out using the current mouse position, or the center if the mouse is out. */
        public void zoomOut() {
                if (xMouse < 0 || screenX(xMouse) > dstWidth || yMouse < 0 || screenY(yMouse) > dstHeight) {
                        zoomOut(dstWidth/2, dstHeight/2);
                } else zoomOut(screenX(xMouse), screenY(yMouse));
        }

        /** Overriding to repaint the DisplayNavigator as well. */
        public void zoomOut(int x, int y) {
                update_graphics = true; // update the offscreen images.
                zoomOut2(x, y);
        }

        /** Center the srcRect around the given object(s) bounding box, zooming if necessary. */
        public void showCentered(Rectangle r) {
                // multiply bounding box dimensions by two
                r.x -= r.width / 2;
                r.y -= r.height / 2;
                r.width += r.width;
                r.height += r.height;
                // compute target magnification
                double magn = getWidth() / (double)r.width;
                // bring bounds within limits of the layer and the canvas' drawing size
                double lw = display.getLayer().getLayerWidth();
                double lh = display.getLayer().getLayerHeight();
                int cw = (int) (getWidth() / magn); // canvas dimensions in offscreen coords
                int ch = (int) (getHeight() / magn);

                // 2nd attempt:
                // fit to canvas drawing size:
                r.y += (r.height - ch) / 2;
                r.width = cw;
                r.height = ch;
                // place within layer bounds
                if (r.x < 0) r.x = 0;
                if (r.y < 0) r.y = 0;
                if (r.width > lw) {
                        r.x = 0;
                        r.width = (int)lw;
                }
                if (r.height > lh) {
                        r.y = 0;
                        r.height = (int)lh;
                }
                if (r.x + r.width > lw) r.x = (int)(lw - cw);
                if (r.y + r.height > lh) r.y = (int)(lh - ch);
                // compute magn again, since the desired width may have changed:
                magn = getWidth() / (double)r.width;

                // set magnification and srcRect
                setup(magn, r);
                try { Thread.sleep(200); } catch (Exception e) {} // swing ... waiting for the display.pack()
                update_graphics = true;
                RT.paint(null, update_graphics);
                display.updateInDatabase("srcRect");
                display.updateFrameTitle();
                display.getNavigator().repaint(false);
        }

        /** Repaint as much as the bounding box around the given Displayable. If the Displayable is null, the entire canvas is repainted, remaking the offscreen images. */
        public void repaint(Displayable d) {
                repaint(d, 0);
        }

        /**
         * Repaint as much as the bounding box around the given Displayable plus the
         * extra padding. If the Displayable is null, the entire canvas is
         * repainted, remaking the offscreen images.
         */
        public void repaint(Displayable displ, int extra) {
                if (null != displ) {
                        Rectangle r = displ.getBoundingBox();
                        r.x = (int) ((r.x - srcRect.x) * magnification) - extra;
                        r.y = (int) ((r.y - srcRect.y) * magnification) - extra;
                        r.width = (int) Math.ceil(r.width * magnification) + extra + extra;
                        r.height = (int) Math.ceil(r.height * magnification) + extra + extra;
                        RT.paint(r, update_graphics);
                } else {
                        // everything
                        repaint(true);
                }
        }

        /**
         * Repaint the clip corresponding to the sum of all boundingboxes of
         * Displayable objects in the hashset.
         */
        // it is assumed that the linked objects are close to each other, otherwise
        // the clip rectangle grows enormously.
        public void repaint(final HashSet hs) {
                if (null == hs) return;
                final Iterator it = hs.iterator();
                int count = 0;
                Rectangle r = new Rectangle();
                final Layer dl = display.getLayer();
                while (it.hasNext()) {
                        final Displayable d = (Displayable) it.next();
                        if (d.getLayer() == dl) {
                                count++;
                                r.add(d.getBoundingBox());
                        }
                }
                if (count > 0) {
                        //repaint(r.x, r.y, r.width, r.height);
                        RT.paint(r, update_graphics);
                }
        }

        /**
         * Repaint the given offscreen Rectangle after transforming its data on the fly to the
         * srcRect and magnification of this DisplayCanvas. The Rectangle is not
         * modified.
         */
        public void repaint(final Rectangle r, final int extra) {
                if (null == r) {
                        //Utils.log2("DisplayCanvas.repaint(Rectangle, int) warning: null r");
                        RT.paint(null, update_graphics);
                        return;
                }
                // repaint((int) ((r.x - srcRect.x) * magnification) - extra, (int) ((r.y - srcRect.y) * magnification) - extra, (int) Math .ceil(r.width * magnification) + extra + extra, (int) Math.ceil(r.height * magnification) + extra + extra);
                RT.paint(new Rectangle((int) ((r.x - srcRect.x) * magnification) - extra, (int) ((r.y - srcRect.y) * magnification) - extra, (int) Math.ceil(r.width * magnification) + extra + extra, (int) Math.ceil(r.height * magnification) + extra + extra), update_graphics);
        }

        /**
         * Repaint the given Rectangle after transforming its data on the fly to the
         * srcRect and magnification of this DisplayCanvas. The Rectangle is not
         * modified.
         * @param box The rectangle to repaint
         * @param extra The extra outbound padding to add to the rectangle
         * @param update_graphics Whether to recreate the offscreen images or not
         */
        public void repaint(Rectangle box, int extra, boolean update_graphics) {
                this.update_graphics = update_graphics;
                repaint(box, extra);
        }

        /** Repaint everything, updating offscreen graphics if so specified. */
        public void repaint(final boolean update_graphics) {
                this.update_graphics = update_graphics | this.update_graphics;
                RT.paint(null, update_graphics);
        }

        /** Overridden to multithread. This method is here basically to enable calls to the FakeImagePlus.draw from the HAND and other tools to repaint properly.*/
        public void repaint() {
                //Utils.log2("issuing thread");
                RT.paint(null, update_graphics);
        }

        /** Overridden to multithread. */
        /* // saved as unoveridden to make sure there are no infinite thread loops when calling super in buggy JVMs
        public void repaint(long ms, int x, int y, int width, int height) {
                RT.paint(new Rectangle(x, y, width, height), update_graphics);
        }
        */

        /** Overridden to multithread. */
        public void repaint(int x, int y, int width, int height) {
                RT.paint(new Rectangle(x, y, width, height), update_graphics);
        }

        public void setUpdateGraphics(boolean b) {
                update_graphics = b;
        }

        /** Release offscreen images and stop threads. */
        public void flush() {
                // cleanup update graphics thread if any
                RT.quit();
                synchronized (offscreen_lock) {
                        offscreen_lock.lock();

                        offscreen = null;
                        // reset for remaking if necessary TODO doesn't work in at least java 1.6 ?
                        update_graphics = true;

                        offscreen_lock.unlock();
                }
        }

        public void destroy() {
                flush();
                WindowManager.setTempCurrentImage(imp); // the FakeImagePlus
                WindowManager.removeWindow(fake_win); // the FakeImageWindow
        }

        public boolean isTransforming() { // TODO: this can fail if the Display is closed quickly after creation
                return display.getSelection().isTransforming();
        }

        public void setTransforming(boolean b) {
                if (ProjectToolbar.getToolId() != ProjectToolbar.SELECT && b) {
                        ProjectToolbar.setTool(ProjectToolbar.SELECT);
                }
                display.getSelection().setTransforming(b);
                //repaint other Displays as well!
                Display.repaint(display.getLayerSet());
        }

        public void cancelTransform() {
                Selection selection = display.getSelection();
                Rectangle box = selection.getLinkedBox();
                selection.cancelTransform();
                box.add(selection.getLinkedBox()); // the restored box now.
                if (!(selection.getNSelected() == 1 && !display.getActive().isLinked())) update_graphics = true;
                repaint(true);
        }

        /*
        public void keyReleased(KeyEvent ke) {
                int key_code = ke.getKeyCode();
                switch (key_code) {
                case KeyEvent.VK_UP:
                case KeyEvent.VK_DOWN:
                case KeyEvent.VK_LEFT:
                case KeyEvent.VK_RIGHT:
                        Selection selection = display.getSelection();
                        Rectangle b = selection.getLinkedBox();
                        selection.resetBox();
                        b.add(selection.getLinkedBox());
                        repaint(b, 0);
                        ke.consume();
                        break;
                }
        }
        */

        public void keyPressed(KeyEvent ke) {

                /*
                // debug shortcut:
                if (ke.getKeyCode() == KeyEvent.VK_D && ke.isShiftDown() && ke.isAltDown() && ke.isControlDown()) {
                        try {
                        java.lang.reflect.Field f = Display.class.getDeclaredField("hs_panels");
                        f.setAccessible(true);
                        Utils.log("Display n_panels:" + ((java.util.HashMap)f.get(display)).size());
                        Utils.log("Display displ.:  " + display.getLayer().getDisplayables().size());
                        ke.consume();
                        } catch (Exception e) {
                                IJError.print(e);
                        }
                        return;
                }
                */

                Displayable active = display.getActive();

                if (null != freehandProfile
                        && ProjectToolbar.getToolId() == ProjectToolbar.PENCIL
                        && ke.getKeyCode() == KeyEvent.VK_ESCAPE
                        && null != freehandProfile)
                {
                        freehandProfile.abort();
                        ke.consume();
                        return;
                }

                /*
                 * TODO screen editor ... TEMPORARY if (active instanceof DLabel) {
                 * active.keyPressed(ke); ke.consume(); return; }
                 */

                int keyCode = ke.getKeyCode();
                int keyChar = ke.getKeyChar();

                boolean used = false;

                switch (keyChar) {
                case '+':
                case '=':
                        zoomIn();
                        used = true;
                        break;
                case '-':
                case '_':
                        zoomOut();
                        used = true;
                        break;
                default:
                        break;
                }


                if (used) {
                        ke.consume(); // otherwise ImageJ would use it!
                        return;
                }

                if (input_disabled) {
                        if (KeyEvent.VK_ESCAPE == keyCode) {
                                // cancel last job if any
                                if (Utils.checkYN("Really cancel job?")) {
                                        display.getProject().getLoader().quitJob(null);
                                        display.repairGUI();
                                }
                        }
                        ke.consume();
                        return; // only zoom is enabled, above
                }

                if (KeyEvent.VK_W == keyCode) {
                        display.remove(false); // will call back the canvas.flush()
                        ke.consume();
                        return;
                } else if (KeyEvent.VK_S == keyCode && 0 == ke.getModifiers() && display.getProject().getLoader().isAsynchronous()) {
                        display.getProject().getLoader().save(display.getProject());
                        ke.consume();
                        return;
                }

                // if display is not read-only, check for other keys:
                switch (keyChar) {
                case '<':
                case ',': // select next Layer up
                        display.previousLayer(ke.getModifiers()); // repaints as well
                        ke.consume();
                        return;
                case '>':
                case '.': // select next Layer down
                        display.nextLayer(ke.getModifiers());
                        ke.consume();
                        return;
                }

                if (null == active && null != imp.getRoi()) {
                        IJ.getInstance().keyPressed(ke);
                        return;
                }

                // end here if display is read-only
                if (display.isReadOnly()) {
                        ke.consume();
                        display.repaintAll();
                        return;
                }

                if (KeyEvent.VK_ENTER == keyCode) {
                        if (display.getSelection().isTransforming()) {
                                setTransforming(false); // will apply transforms and repaint
                                ke.consume();
                                return;
                        } else if (display.getLayer().getParent().isAligning()) {
                                display.getLayer().getParent().applyAlign(false);
                                ke.consume();
                                return;
                        } else {
                                IJ.getInstance().toFront();
                                ke.consume();
                                return;
                        }
                }

                // check preconditions (or the keys are meaningless). Allow 'enter' to
                // bring forward the ImageJ window, and 'v' to paste a patch.
                /*if (null == active && KeyEvent.VK_ENTER != keyCode && KeyEvent.VK_V != keyCode && KeyEvent) {
                        return;
                }*/

                Layer layer = display.getLayer();

                final int mod = ke.getModifiers();

                switch (keyCode) {
                        case KeyEvent.VK_COMMA:
                        case 0xbc: // select next Layer up
                                display.nextLayer(ke.getModifiers());
                                break;
                        case KeyEvent.VK_PERIOD:
                        case 0xbe: // select next Layer down
                                display.previousLayer(ke.getModifiers());
                                break;
                        case KeyEvent.VK_Z:
                                // UNDO: shift+z or ctrl+z
                                if (0 == (mod ^ Event.SHIFT_MASK) || 0 == (mod ^ Utils.getControlModifier())) {
                                        // If it's the last step and the last action was not Z_KEY undo action, then store current:
                                        Bureaucrat.createAndStart(new Worker.Task("Undo") { public void exec() {
                                                if (isTransforming()) display.getSelection().undoOneStep();
                                                else display.getLayerSet().undoOneStep();
                                                Display.repaint(display.getLayerSet());
                                        }}, display.getProject());
                                        ke.consume();
                                // REDO: alt+z or ctrl+shift+z
                                } else if (0 == (mod ^ Event.ALT_MASK) || 0 == (mod ^ (Event.SHIFT_MASK | Utils.getControlModifier())) ) {
                                        Bureaucrat.createAndStart(new Worker.Task("Redo") { public void exec() {
                                                if (isTransforming()) display.getSelection().redoOneStep();
                                                else display.getLayerSet().redoOneStep();
                                                Display.repaint(display.getLayerSet());
                                        }}, display.getProject());
                                        ke.consume();
                                }
                                // else, the 'z' command restores the image using ImageJ internal undo
                                break;
                        case KeyEvent.VK_T:
                                if (null != active && 0 == ke.getModifiers() && !isTransforming()) {
                                        setTransforming(true);
                                        ke.consume();
                                }
                                // else, let ImageJ grab the ROI into the Manager, if any
                                break;
                        case KeyEvent.VK_A:
                                if (0 == (ke.getModifiers() ^ Utils.getControlModifier())) {
                                        display.getSelection().selectAll();
                                        Display.repaint(display.getLayer(), display.getSelection().getBox(), 0);
                                        ke.consume();
                                        break; // INSIDE the 'if' block, so that it can bleed to the default block which forwards to active!
                                } else if (null != active) {
                                        active.keyPressed(ke);
                                        if (ke.isConsumed()) break;
                                        // TODO this is just a hack really. Should just fall back to default switch option.
                                        // The whole keyPressed method needs revision: should not break from it when not using the key.
                                }
                        case KeyEvent.VK_ESCAPE: // cancel transformation
                                if (display.getLayer().getParent().isAligning()) {
                                        display.getLayer().getParent().cancelAlign();
                                        ke.consume();
                                } else if (null != active) {
                                        if (display.getSelection().isTransforming()) cancelTransform();
                                        else {
                                                display.select(null); // deselect
                                                // repaint out the brush if present
                                                if (ProjectToolbar.PEN == ProjectToolbar.getToolId()) {
                                                        repaint(old_brush_box, 0);
                                                }
                                        }
                                        ke.consume();
                                }
                                break;
                        case KeyEvent.VK_SPACE:
                                if (0 == ke.getModifiers()) {
                                        if (null != active) {
                                                invalidateVolatile();
                                                if (Math.abs(active.getAlpha() - 0.5f) > 0.001f) active.setAlpha(0.5f);
                                                else active.setAlpha(1.0f);
                                                display.setTransparencySlider(active.getAlpha());
                                                ke.consume();
                                        }
                                } else {
                                        // ;)
                                        int kem = ke.getModifiers();
                                        if (0 != (kem & KeyEvent.SHIFT_MASK)
                                         && 0 != (kem & KeyEvent.ALT_MASK)
                                         && 0 != (kem & KeyEvent.CTRL_MASK)) {
                                                Utils.showMessage("A mathematician, like a painter or poet,\nis a maker of patterns.\nIf his patterns are more permanent than theirs,\nit is because they are made with ideas.");
                                                ke.consume();
                                         }
                                }
                                break;
                        case KeyEvent.VK_S:
                                if (ke.isAltDown()) {
                                        snapping = true;
                                        ke.consume();
                                } else if (dragging) {
                                        // ignore improper 's' that open ImageJ's save dialog (linux problem ... in macosx, a single dialog opens with lots of 'ssss...' in the text field)
                                        ke.consume();
                                }
                                break;
                        case KeyEvent.VK_H:
                                handleHide(ke);
                                break;
                        case KeyEvent.VK_I:
                                if (ke.isAltDown()) {
                                        if (ke.isShiftDown()) display.importImage();
                                        else display.importNextImage();
                                        ke.consume();
                                }
                                break;
                        case KeyEvent.VK_PAGE_UP: // as in Inkscape
                                if (null != active) {
                                        update_graphics = true;
                                        layer.getParent().move(LayerSet.UP, active);
                                        Display.repaint(layer, active, 5);
                                        Display.updatePanelIndex(layer, active);
                                        ke.consume();
                                }
                                break;
                        case KeyEvent.VK_PAGE_DOWN: // as in Inkscape
                                if (null != active) {
                                        update_graphics = true;
                                        layer.getParent().move(LayerSet.DOWN, active);
                                        Display.repaint(layer, active, 5);
                                        Display.updatePanelIndex(layer, active);
                                        ke.consume();
                                }
                                break;
                        case KeyEvent.VK_HOME: // as in Inkscape
                                if (null != active) {
                                        update_graphics = true;
                                        layer.getParent().move(LayerSet.TOP, active);
                                        Display.repaint(layer, active, 5);
                                        Display.updatePanelIndex(layer, active);
                                        ke.consume();
                                }
                                break;
                        case KeyEvent.VK_END: // as in Inkscape
                                if (null != active) {
                                        update_graphics = true;
                                        layer.getParent().move(LayerSet.BOTTOM, active);
                                        Display.repaint(layer, active, 5);
                                        Display.updatePanelIndex(layer, active);
                                        ke.consume();
                                }
                                break;
                        case KeyEvent.VK_V:
                                if (0 == ke.getModifiers()) {
                                        if (null == active || active.getClass() == Patch.class) {
                                                // paste a new image
                                                ImagePlus clipboard = ImagePlus.getClipboard();
                                                if (null != clipboard) {
                                                        ImagePlus imp = new ImagePlus(clipboard.getTitle() + "_" + System.currentTimeMillis(), clipboard.getProcessor().crop());
                                                        Object info = clipboard.getProperty("Info");
                                                        if (null != info) imp.setProperty("Info", (String)info);
                                                        double x = srcRect.x + srcRect.width/2 - imp.getWidth()/2;
                                                        double y = srcRect.y + srcRect.height/2 - imp.getHeight()/2;
                                                        // save the image somewhere:
                                                        Patch pa = display.getProject().getLoader().addNewImage(imp, x, y);
                                                        display.getLayer().add(pa);
                                                        ke.consume();
                                                } // TODO there isn't much ImageJ integration in the pasting. Can't paste to a selected image, for example.
                                        } else {
                                                // Each type may know how to paste data from the copy buffer into itself:
                                                active.keyPressed(ke);
                                                ke.consume();
                                        }
                                }
                                break;
                        case KeyEvent.VK_C:
                                if (null != active) {
                                        active.keyPressed(ke);
                                }
                                break;
                        case KeyEvent.VK_P:
                                if (0 == ke.getModifiers()) {
                                        final Project pro = display.getProject();
                                        if ("true".equals(pro.getProperty("no_color_cues"))) {
                                                // remove key
                                                pro.setProperty("no_color_cues", null);
                                        } else {
                                                pro.setProperty("no_color_cues", "true");
                                        }
                                        Display.repaint(display.getLayer().getParent());
                                        ke.consume();
                                }
                                break;
                        case KeyEvent.VK_DELETE:
                                if (0 == ke.getModifiers()) {
                                        display.getSelection().deleteAll();
                                }
                                break;
                        case KeyEvent.VK_B:
                                if (0 == ke.getModifiers() && null != active && active.getClass() == Profile.class) {
                                        display.duplicateLinkAndSendTo(active, 0, active.getLayer().getParent().previous(layer));
                                        ke.consume();
                                }
                                break;
                        case KeyEvent.VK_N:
                                if (0 == ke.getModifiers() && null != active && active.getClass() == Profile.class) {
                                        display.duplicateLinkAndSendTo(active, 1, active.getLayer().getParent().next(layer));
                                        ke.consume();
                                }
                                break;
                        case KeyEvent.VK_F1:
                        case KeyEvent.VK_F2:
                        case KeyEvent.VK_F3:
                        case KeyEvent.VK_F4:
                        case KeyEvent.VK_F5:
                        case KeyEvent.VK_F6:
                        case KeyEvent.VK_F7:
                        case KeyEvent.VK_F8:
                        case KeyEvent.VK_F9:
                        case KeyEvent.VK_F10:
                        case KeyEvent.VK_F11:
                        case KeyEvent.VK_F12:
                                ProjectToolbar.keyPressed(ke);
                                break;
                        case KeyEvent.VK_UP:
                        case KeyEvent.VK_DOWN:
                        case KeyEvent.VK_LEFT:
                        case KeyEvent.VK_RIGHT:
                                // bleed to active:
                        default:
                                // forward event to active
                                if (null != active) {
                                        active.keyPressed(ke);
                                        if (ke.isConsumed()) {
                                                Selection selection = display.getSelection();
                                                repaint(selection.getLinkedBox(), Selection.PADDING + 2); // optimization
                                        }
                                }
                }

                if ( !(keyCode == KeyEvent.VK_UNDEFINED || keyChar == KeyEvent.CHAR_UNDEFINED) && !ke.isConsumed() && null != active && active instanceof Patch) {
                        // forward to ImageJ for a final try
                        IJ.getInstance().keyPressed(ke);
                        repaint(active, 5);
                        ke.consume();
                }
                //Utils.log2("keyCode, keyChar: " + keyCode + ", " + keyChar + " ref: " + KeyEvent.VK_UNDEFINED + ", " + KeyEvent.CHAR_UNDEFINED);
        }

        public void keyTyped(KeyEvent ke) {}

        public void keyReleased(KeyEvent ke) {}

        public void zoomToFit() {
                double magw = (double) getWidth() / imageWidth;
                double magh = (double) getHeight() / imageHeight;
                this.magnification = magw < magh ? magw : magh;
                this.srcRect.setRect(0, 0, imageWidth, imageHeight);
                setMagnification(magnification);
                display.updateInDatabase("srcRect"); // includes magnification
        }


        public void setReceivesInput(boolean b) {
                this.input_disabled = !b;
        }

        public boolean isInputEnabled() {
                return !input_disabled;
        }

        public void exportXML(StringBuffer sb_body, String indent, Object any) {
                sb_body.append("<canvas magnification=\"").append(magnification).append("\" srcrect_x=\"").append(srcRect.x).append("\" srcrect_y=\"").append(srcRect.y).append("\" srcrect_width=\"").append(srcRect.width).append("\" srcrect_height=\"").append(srcRect.height).append("\">\n");
        }

        /** CAREFUL: the ImageProcessor of the returned ImagePlus is fake, that is, a 4x4 byte array; but the dimensions that it returns are those of the host LayerSet. Used to retrieve ROIs for example.*/
        public ImagePlus getFakeImagePlus() {
                return this.imp;
        }

        /** Key/Mouse bindings like:
         * - ij.gui.StackWindow: wheel to scroll slices (in this case Layers)
         * - Inkscape: control+wheel to zoom (apple+wheel in macosx, since control+wheel zooms desktop)
         */
        public void mouseWheelMoved(MouseWheelEvent mwe) {
                if (dragging) return; // prevent unexpected mouse wheel movements
                final int modifiers = mwe.getModifiers();
                final int rotation = mwe.getWheelRotation();
                if (0 == (modifiers ^ Utils.getControlModifier())) {
                        // scroll zooom under pointer
                        int x = mwe.getX();
                        int y = mwe.getY();
                        if (x < 0 || y < 0 || x >= getWidth() || y >= getHeight()) {
                                x = getWidth()/2;
                                y = getHeight()/2;
                        }
                        if (rotation > 0) {
                                zoomOut(x, y);
                        } else {
                                zoomIn(x, y);
                        }
                } else if (0 == (modifiers ^ InputEvent.SHIFT_MASK) && ProjectToolbar.getToolId() == ProjectToolbar.PEN) {
                        int brushSize_old = ProjectToolbar.getBrushSize();
                        // resize brush for AreaList painting
                        final int sign = rotation > 0 ? 1 : -1;
                        int brushSize = ProjectToolbar.setBrushSize((int)(5 * sign / magnification)); // the getWheelRotation provides the sign
                        if (brushSize_old > brushSize) brushSize = brushSize_old; // for repainting purposes alnne
                        int extra = (int)(5 / magnification);
                        if (extra < 2) extra = 2;
                        extra += 4;
                        Rectangle r = new Rectangle((int)(mwe.getX() / magnification) + srcRect.x - brushSize/2 - extra, (int)(mwe.getY() / magnification) + srcRect.y - brushSize/2 - extra, brushSize+extra, brushSize+extra);
                        this.repaint(r, 0);
                } else if (0 == modifiers) {
                        // scroll layers
                        if (rotation > 0) display.nextLayer(modifiers);
                        else display.previousLayer(modifiers);
                }
        }

        protected class RepaintProperties implements AbstractOffscreenThread.RepaintProperties {
                final private Layer layer;
                final private int g_width;
                final private int g_height;
                final private Displayable active;
                final private int c_alphas;
                final private Rectangle clipRect;
                final private int mode;
                final private HashMap<Color,Layer> hm;
                final private ArrayList<LayerPanel> blending_list;

                RepaintProperties(final Rectangle clipRect, final Layer layer, final int g_width, final int g_height, final Displayable active, final int c_alphas) {
                        this.clipRect = clipRect;
                        this.layer = layer;
                        this.g_width = g_width;
                        this.g_height = g_height;
                        this.active = active;
                        this.c_alphas = c_alphas;

                        // query the display for repainting mode
                        this.hm = new HashMap<Color,Layer>();
                        this.blending_list = new ArrayList<LayerPanel>();
                        this.mode = display.getPaintMode(hm, blending_list);
                }
        }

        private final class OffscreenThread extends AbstractOffscreenThread {

                OffscreenThread() {
                        super("T2-Canvas-Offscreen");
                }

                public void paint() {
                        try {
                                final Layer layer;
                                final int g_width;
                                final int g_height;
                                final Displayable active;
                                final int c_alphas;
                                final Rectangle clipRect;
                                final Loader loader;
                                final HashMap<Color,Layer> hm;
                                final ArrayList<LayerPanel> blending_list;
                                final int mode;

                                synchronized (this) {
                                        final DisplayCanvas.RepaintProperties rp = (DisplayCanvas.RepaintProperties) this.rp;
                                        layer = rp.layer;
                                        g_width = rp.g_width;
                                        g_height = rp.g_height;
                                        active = rp.active;
                                        c_alphas = rp.c_alphas;
                                        clipRect = rp.clipRect;
                                        loader = layer.getProject().getLoader();
                                        mode = rp.mode;
                                        hm = rp.hm;
                                        blending_list = rp.blending_list;
                                }

                                // flag Loader to do massive flushing if needed
                                loader.setMassiveMode(true);

                                // ALMOST, but not always perfect //if (null != clipRect) g.setClip(clipRect);

                                // prepare the canvas for the srcRect and magnification
                                final AffineTransform atc = new AffineTransform();
                                atc.scale(magnification, magnification);
                                atc.translate(-srcRect.x, -srcRect.y);

                                // Area to which each Patch will subtract from
                                //final Area background =  new Area(new Rectangle(0, 0, g_width, g_height));
                                // bring the area to Layer space
                                //background.transform(atc.createInverse());

                                // the non-srcRect areas, in offscreen coords
                                final Rectangle r1 = new Rectangle(srcRect.x + srcRect.width, srcRect.y, (int)(g_width / magnification) - srcRect.width, (int)(g_height / magnification));
                                final Rectangle r2 = new Rectangle(srcRect.x, srcRect.y + srcRect.height, srcRect.width, (int)(g_height / magnification) - srcRect.height);


                                final ArrayList<Displayable> al_top = new ArrayList<Displayable>();
                                boolean top = false;

                                final ArrayList<Displayable> al_paint = new ArrayList<Displayable>();

                                final ArrayList<Patch> al_patches = new ArrayList<Patch>();

                                // start
                                //final ArrayList al = layer.getDisplayables();
                                layer.getParent().checkBuckets();
                                layer.checkBuckets();
                                final Iterator<Displayable> ital = layer.find(srcRect, true).iterator();
                                final Collection<Displayable> al_zdispl = layer.getParent().findZDisplayables(layer, srcRect, true);
                                final Iterator<Displayable> itzd = al_zdispl.iterator();

                                // Assumes the Layer has its objects in order:
                                // 1 - Patches
                                // 2 - Profiles, Balls
                                // 3 - Pipes and ZDisplayables (from the parent LayerSet)
                                // 4 - DLabels

                                Displayable tmp = null;

                                while (ital.hasNext()) {
                                        final Displayable d = ital.next();
                                        final Class c = d.getClass();
                                        if (DLabel.class == c || LayerSet.class == c) {
                                                tmp = d; // since ital.next() has moved forward already
                                                break;
                                        }
                                        if (Patch.class == c) {
                                                al_paint.add(d);
                                                al_patches.add((Patch)d);
                                        } else {
                                                if (!top && d == active) top = true; // no Patch on al_top ever
                                                if (top) al_top.add(d);
                                                else al_paint.add(d);
                                        }
                                }

                                // preload concurrently as many as possible
                                Loader.preload(al_patches, magnification, false); // must be false; a 'true' would incur in an infinite loop.

                                // paint the ZDisplayables here, before the labels and LayerSets, if any
                                while (itzd.hasNext()) {
                                        final Displayable zd = itzd.next();
                                        if (zd == active) top = true;
                                        if (top) al_top.add(zd);
                                        else al_paint.add(zd);
                                }
                                // paint LayerSet and DLabel objects!
                                if (null != tmp) {
                                        if (tmp == active) top = true;
                                        if (top) al_top.add(tmp);
                                        else al_paint.add(tmp);
                                }
                                while (ital.hasNext()) {
                                        final Displayable d = ital.next();
                                        if (d == active) top = true;
                                        if (top) al_top.add(d);
                                        else al_paint.add(d);
                                }

                                // create new graphics
                                layer.getProject().getLoader().releaseToFit(g_width * g_height * 4 + 1024);
                                final BufferedImage target = getGraphicsConfiguration().createCompatibleImage(g_width, g_height, Transparency.TRANSLUCENT); // creates a BufferedImage.TYPE_INT_ARGB image in my T60p ATI FireGL laptop
                                final Graphics2D g = (Graphics2D)target.getGraphics();

                                g.setTransform(atc); //at_original);

                                //setRenderingHints(g);
                                // always a stroke of 1.0, regardless of magnification; the stroke below corrects for that
                                g.setStroke(stroke);



                                // Testing: removed Area.subtract, now need to fill int background
                                g.setColor(Color.black);
                                g.fillRect(0, 0, g_width - r1.x, g_height - r2.y);


                                // paint:
                                //  1 - background
                                //  2 - images and anything else not on al_top
                                //  3 - non-srcRect areas

                                //Utils.log2("offscreen painting: " + al_paint.size());


                                // Determine painting mode
                                if (Display.REPAINT_SINGLE_LAYER == mode) {
                                        // Direct painting mode, with prePaint abilities
                                        for (final Displayable d : al_paint) {
                                                d.prePaint(g, magnification, d == active, c_alphas, layer);
                                        }
                                } else if (Display.REPAINT_MULTI_LAYER == mode) {
                                        // paint first the current layer Patches only (to set the background)
                                        int count = 0;
                                        for (final Displayable d : al_patches) {
                                                d.paint(g, magnification, d == active, c_alphas, layer);
                                        }

                                        // then blend on top the Patches of the others, in reverse Z order and using the alpha of the LayerPanel
                                        final Composite original = g.getComposite();
                                        // reset
                                        g.setTransform(new AffineTransform());
                                        for (final ListIterator<LayerPanel> it = blending_list.listIterator(blending_list.size()); it.hasPrevious(); ) {
                                                final LayerPanel lp = it.previous();
                                                if (lp.layer == layer) continue;
                                                layer.getProject().getLoader().releaseToFit(g_width * g_height * 4 + 1024);
                                                final BufferedImage bi = getGraphicsConfiguration().createCompatibleImage(g_width, g_height, Transparency.TRANSLUCENT);
                                                final Graphics2D gb = bi.createGraphics();
                                                gb.setTransform(atc);
                                                for (final Displayable d : lp.layer.find(srcRect, true)) {
                                                        if (d.getClass() != Patch.class) continue; // skip non-images
                                                        d.paint(gb, magnification, false, c_alphas, lp.layer);
                                                }
                                                g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, lp.getAlpha()));
                                                g.drawImage(bi, 0, 0, null);
                                                bi.flush();
                                        }
                                        // restore
                                        g.setComposite(original);
                                        g.setTransform(atc);

                                        // then paint the non-Patch objects of the current layer
                                        for (final Displayable d : al_paint.subList(al_patches.size(), al_paint.size())) {
                                                d.paint(g, magnification, d == active, c_alphas, layer);
                                        }
                                } else { // Display.REPAINT_RGB_LAYER == mode
                                        final HashMap<Color,byte[]> channels = new HashMap<Color,byte[]>();
                                        hm.put(Color.green, layer);
                                        for (final Map.Entry<Color,Layer> e : hm.entrySet()) {
                                                final BufferedImage bi = new BufferedImage(g_width, g_height, BufferedImage.TYPE_BYTE_GRAY); //INDEXED, Loader.GRAY_LUT);
                                                final Graphics2D gb = bi.createGraphics();
                                                gb.setTransform(atc);
                                                final Layer la = e.getValue();
                                                if (la == layer && Color.green != e.getKey()) continue; // don't paint current layer in two channels
                                                for (final Displayable d : la.find(srcRect, true)) {
                                                        if (d.getClass() != Patch.class) continue; // skip non-images
                                                        d.paint(gb, magnification, false, c_alphas, la);
                                                }
                                                channels.put(e.getKey(), (byte[])new ByteProcessor(bi).getPixels());
                                        }
                                        final byte[] red, green, blue;
                                        green = channels.get(Color.green);
                                        if (null == channels.get(Color.red)) red = new byte[green.length];
                                        else red = channels.get(Color.red);
                                        if (null == channels.get(Color.blue)) blue = new byte[green.length];
                                        else blue = channels.get(Color.blue);
                                        final int[] pix = new int[green.length];
                                        for (int i=0; i<green.length; i++) {
                                                pix[i] = ((red[i] & 0xff) << 16) + ((green[i] & 0xff) << 8) + (blue[i] & 0xff);
                                        }
                                        // undo transform, is intended for Displayable objects
                                        g.setTransform(new AffineTransform());
                                        final Image img = new ColorProcessor(g_width, g_height, pix).createImage();
                                        g.drawImage(img, 0, 0, null);
                                        img.flush();
                                        // reset
                                        g.setTransform(atc);

                                        // then paint the non-Patch objects of the current layer
                                        for (final Displayable d : al_paint.subList(al_patches.size(), al_paint.size())) {
                                                d.paint(g, magnification, d == active, c_alphas, layer);
                                        }
                                }

                                // finally, paint non-srcRect areas
                                if (r1.width > 0 || r1.height > 0 || r2.width > 0 || r2.height > 0) {
                                        g.setColor(Color.gray);
                                        g.setClip(r1);
                                        g.fill(r1);
                                        g.setClip(r2);
                                        g.fill(r2);
                                }

                                synchronized (offscreen_lock) {
                                        offscreen_lock.lock();
                                        try {
                                                // only on success:
                                                update_graphics = false;
                                                loader.setMassiveMode(false);
                                                if (null != offscreen) offscreen.flush();
                                                offscreen = target;
                                                invalidateVolatile();
                                                DisplayCanvas.this.al_top = al_top;

                                        } catch (Exception e) {
                                                e.printStackTrace();
                                        }

                                        offscreen_lock.unlock();
                                }

                                // Send repaint event, without offscreen graphics
                                RT.paint(clipRect, false);

                        } catch (OutOfMemoryError oome) {
                                // so OutOfMemoryError won't generate locks
                                IJError.print(oome);
                        } catch (Exception e) {
                                IJError.print(e);
                        }
                }
        }

        // added here to prevent flickering, but doesn't help. All it does is avoid a call to imp.redraw()
        protected void scroll(int sx, int sy) {
                int ox = xSrcStart + (int)(sx/magnification);  //convert to offscreen coordinates
                int oy = ySrcStart + (int)(sy/magnification);
                int newx = xSrcStart + (xMouseStart-ox);
                int newy = ySrcStart + (yMouseStart-oy);
                if (newx<0) newx = 0;
                if (newy<0) newy = 0;
                if ((newx+srcRect.width)>imageWidth) newx = imageWidth-srcRect.width;
                if ((newy+srcRect.height)>imageHeight) newy = imageHeight-srcRect.height;
                srcRect.x = newx;
                srcRect.y = newy;
        }

        private void handleHide(final KeyEvent ke) {
                if (ke.isAltDown() && !ke.isShiftDown()) {
                        // show hidden
                        display.getLayer().getParent().setAllVisible(false);
                        //Display.repaint(display.getLayer());
                        Display.update(display.getLayer());
                        ke.consume();
                        return;
                }
                if (ke.isShiftDown()) {
                        // hide deselected
                        display.hideDeselected(ke.isAltDown());
                        ke.consume();
                        return;
                }
                // else, hide selected
                display.getSelection().setVisible(false);
                Display.update(display.getLayer());
                ke.consume();
        }

        private class ScreenImage {
                long layer_id = -1;
                Rectangle srcRect = null;
                double mag = 0;
                Image awt = null;
                final boolean equals(final long layer_id, final Rectangle srcRect, final double mag) {
                        return layer_id == this.layer_id && mag == this.mag && srcRect.equals(this.srcRect);
                }
                /** Flushes the old awt if any. */
                final void set(final Image awt, final long layer_id, final Rectangle srcRect, final double mag) {
                        this.layer_id = layer_id;
                        this.srcRect = (Rectangle)srcRect.clone();
                        if (null != awt && awt != this.awt) this.awt.flush();
                        this.awt = awt;
                        this.mag = mag;
                }
                final void flush() {
                        this.layer_id = -1;
                        this.srcRect = null;
                        if (null != this.awt) this.awt.flush();
                        this.awt = null;
                        this.mag = 0;
                }
                final boolean isFlushed() { return -1 == layer_id; }
        }

        /*** Stores and manages a listing of max 10 recently made offscreen images. The images are actually stored in the loader's cache; this class simply assigns the layer_id to each.  */
        private class ShallowCache {
                final ScreenImage[] sim = new ScreenImage[75];
                int oldest = 0;
                void add(final Image awt, final Layer layer, final Rectangle srcRect, final double mag) {
                        final long layer_id = layer.getId();
                        // Only one awt per layer_id
                        int i = 0;
                        for (;i<sim.length; i++) {
                                if (null == sim[i]) { sim[i] = new ScreenImage(); break; }
                                if (sim[i].isFlushed()) break;
                                if (sim[i].layer_id == layer_id) {
                                        sim[i].set(awt, layer_id, srcRect, mag);
                                        return;
                                }
                        }
                        // ok so set the given image at 'i'
                        int k = i;
                        if (sim.length == i) {
                                // no space, pop oldest
                                // So now oldest is next to oldest;
                                oldest++;
                                if (oldest == sim.length) k = oldest = 0;
                        }
                        // set
                        sim[k].set(awt, layer_id, srcRect, mag);
                        layer.getProject().getLoader().cacheOffscreen(layer, awt);
                }
                Image get(final Layer layer, final Rectangle srcRect, final double mag) {
                        final long layer_id = layer.getId();
                        for (int i=0; i<sim.length; i++) {
                                if (null == sim[i]) return null;
                                if (sim[i].equals(layer_id, srcRect, mag)) {
                                        Image awt = layer.getProject().getLoader().getCached(layer_id, 0);
                                        if (null == awt) sim[i].flush(); // got lost
                                        return awt;
                                }
                        }
                        return null;
                }
                void flush(Layer layer) {
                        final long layer_id = layer.getId();
                        for (int i=0; i<sim.length; i++) {
                                if (sim[i].layer_id == layer_id) {
                                        layer.getProject().getLoader().decacheAWT(layer_id);
                                        sim[i].flush();
                                        break; // only one per layer_id
                                }
                        }
                }
        }
}