src/edu/mit/ezyang/gravity/j3d/SmartPickZoomBehavior.java

   1 /*
   2  * To change this template, choose Tools | Templates
   3  * and open the template in the editor.
   4  */
   5 package edu.mit.ezyang.gravity.j3d;
   6
   7 import com.sun.j3d.utils.behaviors.mouse.MouseBehavior;
   8 import com.sun.j3d.utils.behaviors.mouse.MouseBehaviorCallback;
   9 import com.sun.j3d.utils.behaviors.mouse.MouseZoom;
  10 import com.sun.j3d.utils.picking.PickResult;
  11 import com.sun.j3d.utils.picking.behaviors.PickMouseBehavior;
  12 import com.sun.j3d.utils.picking.behaviors.PickingCallback;
  13 import javax.media.j3d.Bounds;
  14 import javax.media.j3d.BranchGroup;
  15 import javax.media.j3d.Canvas3D;
  16 import javax.media.j3d.Transform3D;
  17 import javax.media.j3d.TransformGroup;
  18
  19 /**
  20  * Reimplemented PickZoomBehavior, but uses SmartMouseWheelZoom, which
  21  * has been customized to take into account rotations relative to the surface
  22  * display. Modifications are solely in constructor and new setRotateTransformGroup
  23  * method.
  24  * @author Edward Z. Yang <ezyang@mit.edu>
  25  */
  26 public class SmartPickZoomBehavior extends PickMouseBehavior implements MouseBehaviorCallback {
  27
  28     private SmartMouseZoom zoom;
  29     private PickingCallback callback = null;
  30     private TransformGroup currentTG;
  31
  32     /**
  33      * Propagates rotation transform group to SmartMouseTranslate in order
  34      * to provide appropriate information to transform.
  35      * @note We only support one rotation transform group; this should be
  36      *       enough for people with shallow object graphs.
  37      * @param group TransformGroup with rotation we need to adjust to
  38      */
  39     public void setRotateTransformGroup(TransformGroup group) {
  40         zoom.setRotateTransformGroup(group);
  41     }
  42
  43     /**
  44      * Creates a pick/zoom behavior that waits for user mouse events for
  45      * the scene graph.
  46      * @param root   Root of your scene graph.
  47      * @param canvas Java 3D drawing canvas.
  48      * @param bounds Bounds of your scene.
  49      **/
  50     public SmartPickZoomBehavior(BranchGroup root, Canvas3D canvas, Bounds bounds) {
  51         super(canvas, root, bounds);
  52         zoom = new SmartMouseZoom(MouseBehavior.MANUAL_WAKEUP);
  53         zoom.setTransformGroup(currGrp);
  54         currGrp.addChild(zoom);
  55         zoom.setSchedulingBounds(bounds);
  56         this.setSchedulingBounds(bounds);
  57     }
  58
  59     /**
  60      * Update the scene to manipulate any nodes. This is not meant to be
  61      * called by users. Behavior automatically calls this. You can call
  62      * this only if you know what you are doing.
  63      *
  64      * @param xpos Current mouse X pos.
  65      * @param ypos Current mouse Y pos.
  66      **/
  67     public void updateScene(int xpos, int ypos) {
  68         TransformGroup tg = null;
  69
  70         if (mevent.isAltDown() && !mevent.isMetaDown()) {
  71
  72             pickCanvas.setShapeLocation(xpos, ypos);
  73             PickResult pr = pickCanvas.pickClosest();
  74             if ((pr != null) &&
  75                     ((tg = (TransformGroup) pr.getNode(PickResult.TRANSFORM_GROUP)) != null) &&
  76                     (tg.getCapability(TransformGroup.ALLOW_TRANSFORM_READ)) &&
  77                     (tg.getCapability(TransformGroup.ALLOW_TRANSFORM_WRITE))) {
  78                 zoom.setTransformGroup(tg);
  79                 zoom.wakeup();
  80                 currentTG = tg;
  81             // Need to clean up Issue 123 --- Chien
  82             // freePickResult(pr);
  83             } else if (callback != null) {
  84                 callback.transformChanged(PickingCallback.NO_PICK, null);
  85             }
  86         }
  87     }
  88
  89     /**
  90      * Callback method from MouseZoom
  91      * This is used when the Picking callback is enabled
  92      */
  93     public void transformChanged(int type, Transform3D transform) {
  94         callback.transformChanged(PickingCallback.ZOOM, currentTG);
  95     }
  96
  97     /**
  98      * Register the class @param callback to be called each
  99      * time the picked object moves
 100      */
 101     public void setupCallback(PickingCallback callback) {
 102         this.callback = callback;
 103         if (callback == null) {
 104             zoom.setupCallback(null);
 105         } else {
 106             zoom.setupCallback(this);
 107         }
 108     }
 109 }