workspace/kwin/effects/taskbarthumbnail.cpp

   1 /********************************************************************
   2  KWin - the KDE window manager
   3  This file is part of the KDE project.
   4
   5 Copyright (C) 2007 Rivo Laks <rivolaks@hot.ee>
   6 Copyright (C) 2007 Lubos Lunak <l.lunak@kde.org>
   7
   8 This program is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2 of the License, or
  11 (at your option) any later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 *********************************************************************/
  21
  22 #include "taskbarthumbnail.h"
  23
  24 #include <kdebug.h>
  25
  26
  27 // This effect shows a preview inside a window that has a special property set
  28 // on it that says which window and where to render. It is used by the taskbar
  29 // to show window previews in tooltips.
  30
  31 namespace KWin
  32 {
  33
  34 KWIN_EFFECT( taskbarthumbnail, TaskbarThumbnailEffect )
  35
  36 TaskbarThumbnailEffect::TaskbarThumbnailEffect()
  37     {
  38     atom = XInternAtom( display(), "_KDE_WINDOW_PREVIEW", False );
  39     effects->registerPropertyType( atom, true );
  40     // TODO hackish way to announce support, make better after 4.0
  41     unsigned char dummy = 0;
  42     XChangeProperty( display(), rootWindow(), atom, atom, 8, PropModeReplace, &dummy, 1 );
  43     }
  44
  45 TaskbarThumbnailEffect::~TaskbarThumbnailEffect()
  46     {
  47     XDeleteProperty( display(), rootWindow(), atom );
  48     effects->registerPropertyType( atom, false );
  49     }
  50
  51 void TaskbarThumbnailEffect::prePaintScreen( ScreenPrePaintData& data, int time )
  52     {
  53 //    if( thumbnails.count() > 0 )
  54 //        // TODO this should not be needed (it causes whole screen repaint)
  55 //        data.mask |= PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS;
  56     effects->prePaintScreen(data, time);
  57     }
  58
  59 void TaskbarThumbnailEffect::prePaintWindow( EffectWindow* w, WindowPrePaintData& data, int time )
  60     {
  61     // TODO what if of the windows is translucent and one not? change data.mask?
  62     effects->prePaintWindow( w, data, time );
  63     }
  64
  65 void TaskbarThumbnailEffect::paintWindow( EffectWindow* w, int mask, QRegion region, WindowPaintData& data )
  66     {
  67     effects->paintWindow( w, mask, region, data ); // paint window first
  68     if( thumbnails.contains( w ))
  69         { // paint thumbnails on it
  70         foreach( const Data &thumb, thumbnails.values( w ))
  71             {
  72             EffectWindow* thumbw = effects->findWindow( thumb.window );
  73             if( thumbw == NULL )
  74                 continue;
  75             WindowPaintData data( thumbw );
  76             QRect r;
  77             setPositionTransformations( data, r,
  78                 thumbw, thumb.rect.translated( w->pos()), Qt::KeepAspectRatio );
  79             effects->drawWindow( thumbw,
  80                 PAINT_WINDOW_OPAQUE | PAINT_WINDOW_TRANSFORMED,
  81                 r, data );
  82             }
  83         }
  84     }
  85
  86 void TaskbarThumbnailEffect::windowAdded( EffectWindow* w )
  87     {
  88     propertyNotify( w, atom ); // read initial value
  89     }
  90
  91 void TaskbarThumbnailEffect::windowRemoved( EffectWindow* w )
  92     {
  93     thumbnails.remove( w );
  94     }
  95
  96 void TaskbarThumbnailEffect::propertyNotify( EffectWindow* w, long a )
  97     {
  98     if( a != atom )
  99         return;
 100     thumbnails.remove( w );
 101     QByteArray data = w->readProperty( atom, atom, 32 );
 102     if( data.length() < 1 )
 103         return;
 104     long* d = reinterpret_cast< long* >( data.data());
 105     int len = data.length() / sizeof( d[ 0 ] );
 106     int pos = 0;
 107     int cnt = d[ 0 ];
 108     ++pos;
 109     for( int i = 0;
 110          i < cnt;
 111          ++i )
 112         {
 113         int size = d[ pos ];
 114         if( len - pos < size )
 115             return; // format error
 116         ++pos;
 117         Data data;
 118         data.window = d[ pos ];
 119         data.rect = QRect( d[ pos + 1 ], d[ pos + 2 ], d[ pos + 3 ], d[ pos + 4 ] );
 120         thumbnails.insert( w, data );
 121         pos += size;
 122         }
 123     }
 124
 125 } // namespace