ksnapshot/regiongrabber.cpp

   1 /*
   2  *   Copyright (C) 2007 Luca Gugelmann <lucag@student.ethz.ch>
   3  *
   4  *   This program is free software; you can redistribute it and/or modify it
   5  *   under the terms of the GNU Library General Public License version 2 as
   6  *   published by the Free Software Foundation
   7  *
   8  *   This program is distributed in the hope that it will be useful,
   9  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  *   GNU General Public License for more details
  12  *
  13  *   You should have received a copy of the GNU Library General Public
  14  *   License along with this program; if not, write to the
  15  *   Free Software Foundation, Inc.,
  16  *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  17  */
  18
  19 #include "regiongrabber.h"
  20
  21 #include <QPainter>
  22 #include <QMouseEvent>
  23 #include <QApplication>
  24 #include <QDesktopWidget>
  25 #include <QToolTip>
  26
  27 #include <klocale.h>
  28 #include <KWindowSystem>
  29
  30 RegionGrabber::RegionGrabber( ) :
  31     QWidget( 0 ), selection(), mouseDown( false ), newSelection( false ),
  32     handleSize( 10 ), mouseOverHandle( 0 ), idleTimer(),
  33     showHelp( true ), grabbing( false ),
  34     TLHandle(0,0,handleSize,handleSize), TRHandle(0,0,handleSize,handleSize),
  35     BLHandle(0,0,handleSize,handleSize), BRHandle(0,0,handleSize,handleSize),
  36     LHandle(0,0,handleSize,handleSize), THandle(0,0,handleSize,handleSize),
  37     RHandle(0,0,handleSize,handleSize), BHandle(0,0,handleSize,handleSize)
  38 {
  39     handles << &TLHandle << &TRHandle << &BLHandle << &BRHandle
  40             << &LHandle << &THandle << &RHandle << &BHandle;
  41     setMouseTracking( true );
  42     setWindowFlags( Qt::WindowStaysOnTopHint | Qt::FramelessWindowHint | Qt::X11BypassWindowManagerHint);
  43     int timeout = KWindowSystem::compositingActive() ? 200 : 50;
  44     QTimer::singleShot( timeout, this, SLOT(init()) );
  45     connect( &idleTimer, SIGNAL( timeout() ), this, SLOT( displayHelp() ) );
  46     idleTimer.start( 3000 );
  47 }
  48
  49 RegionGrabber::~RegionGrabber()
  50 {
  51 }
  52
  53 void RegionGrabber::init()
  54 {
  55     pixmap = QPixmap::grabWindow( QApplication::desktop()->winId() );
  56     showFullScreen();
  57     resize( pixmap.size() );
  58     move(0, 0);
  59     setCursor( Qt::CrossCursor );
  60 }
  61
  62 void RegionGrabber::displayHelp()
  63 {
  64     showHelp = true;
  65     update();
  66 }
  67
  68 void RegionGrabber::paintEvent( QPaintEvent* e )
  69 {
  70     Q_UNUSED( e );
  71     if ( grabbing ) // grabWindow() should just get the background
  72         return;
  73
  74     QPainter painter( this );
  75
  76     QPalette pal(QToolTip::palette());
  77     QFont font = QToolTip::font();
  78
  79     QColor handleColor = pal.color( QPalette::Active, QPalette::Highlight );
  80     handleColor.setAlpha( 160 );
  81     QColor overlayColor( 0, 0, 0, 160 );
  82     QColor textColor = pal.color( QPalette::Active, QPalette::Text );
  83     QColor textBackgroundColor = pal.color( QPalette::Active, QPalette::Base );
  84     painter.drawPixmap(0, 0, pixmap);
  85     painter.setFont(font);
  86
  87     QRect r = selection.normalized().adjusted( 0, 0, -1, -1 );
  88     if ( !selection.isNull() )
  89     {
  90         QRegion grey( rect() );
  91         grey = grey.subtracted( r );
  92         painter.setPen( handleColor );
  93         painter.setBrush( overlayColor );
  94         painter.setClipRegion( grey );
  95         painter.drawRect( -1, -1, rect().width() + 1, rect().height() + 1 );
  96         painter.setClipRect( rect() );
  97         painter.setBrush( Qt::NoBrush );
  98         painter.drawRect( r );
  99     }
 100
 101     if ( showHelp )
 102     {
 103         painter.setPen( textColor );
 104         painter.setBrush( textBackgroundColor );
 105         QString helpText = i18n( "Select a region using the mouse. To take the snapshot, press the Enter key. Press Esc to quit." );
 106         QRect textRect = painter.boundingRect( rect().adjusted( 2, 2, -2, -2 ), Qt::TextWordWrap, helpText );
 107         textRect.adjust( -2, -2, 4, 2 );
 108         painter.drawRect( textRect );
 109         textRect.moveTopLeft( QPoint( 3, 3 ) );
 110         painter.drawText( textRect, helpText );
 111     }
 112
 113     if ( selection.isNull() )
 114     {
 115         return;
 116     }
 117
 118     // The grabbed region is everything which is covered by the drawn
 119     // rectangles (border included). This means that there is no 0px
 120     // selection, since a 0px wide rectangle will always be drawn as a line.
 121     QString txt = QString( "%1x%2" ).arg( selection.width() == 0 ? 2 : selection.width() )
 122                   .arg( selection.height() == 0 ? 2 : selection.height() );
 123     QRect textRect = painter.boundingRect( rect(), Qt::AlignLeft, txt );
 124     QRect boundingRect = textRect.adjusted( -4, 0, 0, 0);
 125
 126     if ( textRect.width() < r.width() - 2*handleSize &&
 127          textRect.height() < r.height() - 2*handleSize &&
 128          ( r.width() > 100 && r.height() > 100 ) ) // center, unsuitable for small selections
 129     {
 130         boundingRect.moveCenter( r.center() );
 131         textRect.moveCenter( r.center() );
 132     }
 133     else if ( r.y() - 3 > textRect.height() &&
 134               r.x() + textRect.width() < rect().right() ) // on top, left aligned
 135     {
 136         boundingRect.moveBottomLeft( QPoint( r.x(), r.y() - 3 ) );
 137         textRect.moveBottomLeft( QPoint( r.x() + 2, r.y() - 3 ) );
 138     }
 139     else if ( r.x() - 3 > textRect.width() ) // left, top aligned
 140     {
 141         boundingRect.moveTopRight( QPoint( r.x() - 3, r.y() ) );
 142         textRect.moveTopRight( QPoint( r.x() - 5, r.y() ) );
 143     }
 144     else if ( r.bottom() + 3 + textRect.height() < rect().bottom() &&
 145               r.right() > textRect.width() ) // at bottom, right aligned
 146     {
 147         boundingRect.moveTopRight( QPoint( r.right(), r.bottom() + 3 ) );
 148         textRect.moveTopRight( QPoint( r.right() - 2, r.bottom() + 3 ) );
 149     }
 150     else if ( r.right() + textRect.width() + 3 < rect().width() ) // right, bottom aligned
 151     {
 152         boundingRect.moveBottomLeft( QPoint( r.right() + 3, r.bottom() ) );
 153         textRect.moveBottomLeft( QPoint( r.right() + 5, r.bottom() ) );
 154     }
 155     // if the above didn't catch it, you are running on a very tiny screen...
 156     painter.setPen( textColor );
 157     painter.setBrush( textBackgroundColor );
 158     painter.drawRect( boundingRect );
 159     painter.drawText( textRect, txt );
 160
 161     if ( ( r.height() > handleSize*2 && r.width() > handleSize*2 )
 162          || !mouseDown )
 163     {
 164         updateHandles();
 165         painter.setPen( handleColor );
 166         handleColor.setAlpha( 60 );
 167         painter.setBrush( handleColor );
 168         painter.drawRects( handleMask().rects() );
 169     }
 170 }
 171
 172 void RegionGrabber::resizeEvent( QResizeEvent* e )
 173 {
 174     Q_UNUSED( e );
 175     if ( selection.isNull() )
 176         return;
 177     QRect r = selection;
 178     r.setTopLeft( limitPointToRect( r.topLeft(), rect() ) );
 179     r.setBottomRight( limitPointToRect( r.bottomRight(), rect() ) );
 180     if ( r.width() <= 1 || r.height() <= 1 ) //this just results in ugly drawing...
 181         r = QRect();
 182     selection = r;
 183 }
 184
 185 void RegionGrabber::mousePressEvent( QMouseEvent* e )
 186 {
 187     showHelp = false;
 188     idleTimer.stop();
 189     if ( e->button() == Qt::LeftButton )
 190     {
 191         mouseDown = true;
 192         dragStartPoint = e->pos();
 193         selectionBeforeDrag = selection;
 194         if ( !selection.contains( e->pos() ) )
 195         {
 196             newSelection = true;
 197             selection = QRect();
 198             showHelp = true;
 199         }
 200         else
 201         {
 202             setCursor( Qt::ClosedHandCursor );
 203         }
 204     }
 205     else if ( e->button() == Qt::RightButton )
 206     {
 207         newSelection = false;
 208         selection = QRect();
 209         setCursor( Qt::CrossCursor );
 210     }
 211     update();
 212 }
 213
 214 void RegionGrabber::mouseMoveEvent( QMouseEvent* e )
 215 {
 216     if ( mouseDown )
 217     {
 218         if ( newSelection )
 219         {
 220             QPoint p = e->pos();
 221             QRect r = rect();
 222             selection = QRect( dragStartPoint, limitPointToRect( p, r ) ).normalized();
 223         }
 224         else if ( mouseOverHandle == 0 ) // moving the whole selection
 225         {
 226             QRect r = rect().normalized(), s = selectionBeforeDrag.normalized();
 227             QPoint p = s.topLeft() + e->pos() - dragStartPoint;
 228             r.setBottomRight( r.bottomRight() - QPoint( s.width(), s.height() ) );
 229             if ( !r.isNull() && r.isValid() )
 230                 selection.moveTo( limitPointToRect( p, r ) );
 231         }
 232         else // dragging a handle
 233         {
 234             QRect r = selectionBeforeDrag;
 235             QPoint offset = e->pos() - dragStartPoint;
 236
 237             if ( mouseOverHandle == &TLHandle || mouseOverHandle == &THandle
 238                  || mouseOverHandle == &TRHandle ) // dragging one of the top handles
 239             {
 240                 r.setTop( r.top() + offset.y() );
 241             }
 242
 243             if ( mouseOverHandle == &TLHandle || mouseOverHandle == &LHandle
 244                  || mouseOverHandle == &BLHandle ) // dragging one of the left handles
 245             {
 246                 r.setLeft( r.left() + offset.x() );
 247             }
 248
 249             if ( mouseOverHandle == &BLHandle || mouseOverHandle == &BHandle
 250                  || mouseOverHandle == &BRHandle ) // dragging one of the bottom handles
 251             {
 252                 r.setBottom( r.bottom() + offset.y() );
 253             }
 254
 255             if ( mouseOverHandle == &TRHandle || mouseOverHandle == &RHandle
 256                  || mouseOverHandle == &BRHandle ) // dragging one of the right handles
 257             {
 258                 r.setRight( r.right() + offset.x() );
 259             }
 260             r = r.normalized();
 261             r.setTopLeft( limitPointToRect( r.topLeft(), rect() ) );
 262             r.setBottomRight( limitPointToRect( r.bottomRight(), rect() ) );
 263             selection = r;
 264         }
 265         update();
 266     }
 267     else
 268     {
 269         if ( selection.isNull() )
 270             return;
 271         bool found = false;
 272         foreach( QRect* r, handles )
 273         {
 274             if ( r->contains( e->pos() ) )
 275             {
 276                 mouseOverHandle = r;
 277                 found = true;
 278                 break;
 279             }
 280         }
 281         if ( !found )
 282         {
 283             mouseOverHandle = 0;
 284             if ( selection.contains( e->pos() ) )
 285                 setCursor( Qt::OpenHandCursor );
 286             else
 287                 setCursor( Qt::CrossCursor );
 288         }
 289         else
 290         {
 291             if ( mouseOverHandle == &TLHandle || mouseOverHandle == &BRHandle )
 292                 setCursor( Qt::SizeFDiagCursor );
 293             if ( mouseOverHandle == &TRHandle || mouseOverHandle == &BLHandle )
 294                 setCursor( Qt::SizeBDiagCursor );
 295             if ( mouseOverHandle == &LHandle || mouseOverHandle == &RHandle )
 296                 setCursor( Qt::SizeHorCursor );
 297             if ( mouseOverHandle == &THandle || mouseOverHandle == &BHandle )
 298                 setCursor( Qt::SizeVerCursor );
 299         }
 300     }
 301 }
 302
 303 void RegionGrabber::mouseReleaseEvent( QMouseEvent* e )
 304 {
 305     mouseDown = false;
 306     newSelection = false;
 307     idleTimer.start();
 308     if ( mouseOverHandle == 0 && selection.contains( e->pos() ) )
 309         setCursor( Qt::OpenHandCursor );
 310     update();
 311 }
 312
 313 void RegionGrabber::mouseDoubleClickEvent( QMouseEvent* )
 314 {
 315     grabRect();
 316 }
 317
 318 void RegionGrabber::keyPressEvent( QKeyEvent* e )
 319 {
 320     if ( e->key() == Qt::Key_Escape )
 321     {
 322         emit regionGrabbed( QPixmap() );
 323     }
 324     else if ( e->key() == Qt::Key_Enter || e->key() == Qt::Key_Return )
 325     {
 326         grabRect();
 327     }
 328     else
 329     {
 330         e->ignore();
 331     }
 332 }
 333
 334 void RegionGrabber::grabRect()
 335 {
 336     QRect r = selection.normalized();
 337     if ( !r.isNull() && r.isValid() )
 338     {
 339         grabbing = true;
 340         emit regionGrabbed( pixmap.copy(r) );
 341     }
 342 }
 343
 344 void RegionGrabber::updateHandles()
 345 {
 346     QRect r = selection.normalized().adjusted( 0, 0, -1, -1 );
 347     int s2 = handleSize / 2;
 348
 349     TLHandle.moveTopLeft( r.topLeft() );
 350     TRHandle.moveTopRight( r.topRight() );
 351     BLHandle.moveBottomLeft( r.bottomLeft() );
 352     BRHandle.moveBottomRight( r.bottomRight() );
 353
 354     LHandle.moveTopLeft( QPoint( r.x(), r.y() + r.height() / 2 - s2) );
 355     THandle.moveTopLeft( QPoint( r.x() + r.width() / 2 - s2, r.y() ) );
 356     RHandle.moveTopRight( QPoint( r.right(), r.y() + r.height() / 2 - s2 ) );
 357     BHandle.moveBottomLeft( QPoint( r.x() + r.width() / 2 - s2, r.bottom() ) );
 358 }
 359
 360 QRegion RegionGrabber::handleMask() const
 361 {
 362     // note: not normalized QRects are bad here, since they will not be drawn
 363     QRegion mask;
 364     foreach( QRect* rect, handles ) mask += QRegion( *rect );
 365     return mask;
 366 }
 367
 368 QPoint RegionGrabber::limitPointToRect( const QPoint &p, const QRect &r ) const
 369 {
 370     QPoint q;
 371     q.setX( p.x() < r.x() ? r.x() : p.x() < r.right() ? p.x() : r.right() );
 372     q.setY( p.y() < r.y() ? r.y() : p.y() < r.bottom() ? p.y() : r.bottom() );
 373     return q;
 374 }
 375
 376 #include "regiongrabber.moc"