New screenshot effect.

Saves an image of the active window into the home directory when triggered.
It uses an OpenGL FBO and by that can include the alpha channel and the decoration shadows.

svn path=/trunk/KDE/kdebase/workspace/; revision=1157682

effects/CMakeLists.txt

@@ -92,6 +92,7 @@ if( KWIN_HAVE_OPENGL_COMPOSITING )
     include( lookingglass/CMakeLists.txt )
     include( magnifier/CMakeLists.txt )
     include( mousemark/CMakeLists.txt )
+    include( screenshot/CMakeLists.txt )
     include( sharpen/CMakeLists.txt )
     include( sheet/CMakeLists.txt )
     include( snaphelper/CMakeLists.txt )

effects/screenshot/CMakeLists.txt

@@ -0,0 +1,12 @@
+#######################################
+# Effect
+
+# Source files
+set( kwin4_effect_builtins_sources ${kwin4_effect_builtins_sources}
+    screenshot/screenshot.cpp
+    )
+
+# .desktop files
+install( FILES
+    screenshot/screenshot.desktop
+    DESTINATION ${SERVICES_INSTALL_DIR}/kwin )

effects/screenshot/screenshot.cpp

@@ -0,0 +1,162 @@
+/********************************************************************
+ KWin - the KDE window manager
+ This file is part of the KDE project.
+
+ Copyright (C) 2010 Martin Gräßlin <kde@martin-graesslin.com>
+ Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
+
+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; either version 2 of the License, or
+(at your option) any later version.
+
+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, see <http://www.gnu.org/licenses/>.
+*********************************************************************/
+#include "screenshot.h"
+#include <kwinglutils.h>
+#include <QDir>
+#include <KDE/KAction>
+#include <KDE/KActionCollection>
+
+namespace KWin
+{
+
+KWIN_EFFECT( screenshot, ScreenShotEffect )
+KWIN_EFFECT_SUPPORTED( screenshot, ScreenShotEffect::supported() )
+
+bool ScreenShotEffect::supported()
+    {
+    return effects->compositingType() == KWin::OpenGLCompositing && GLRenderTarget::supported();
+    }
+
+ScreenShotEffect::ScreenShotEffect()
+    : m_scheduledScreenshot( 0 )
+    {
+    KActionCollection* actionCollection = new KActionCollection( this );
+    KAction* cubeAction = static_cast< KAction* >( actionCollection->addAction( "Screenshot Effect" ));
+    cubeAction->setText( i18n("Save screenshot of active window" ));
+    cubeAction->setGlobalShortcut( KShortcut(), KAction::ActiveShortcut);
+    connect( cubeAction, SIGNAL(triggered(bool)), SLOT(screenshot()) );
+    }
+
+ScreenShotEffect::~ScreenShotEffect()
+    {
+    }
+void ScreenShotEffect::postPaintScreen()
+    {
+    effects->postPaintScreen();
+    if( m_scheduledScreenshot )
+        {
+        int w = displayWidth();
+        int h = displayHeight();
+        if( !GLTexture::NPOTTextureSupported() )
+            {
+            w = nearestPowerOfTwo( w );
+            h = nearestPowerOfTwo( h );
+            }
+        GLTexture* offscreenTexture = new GLTexture( w, h );
+        offscreenTexture->setFilter( GL_LINEAR );
+        offscreenTexture->setWrapMode( GL_CLAMP_TO_EDGE );
+        GLRenderTarget* target = new GLRenderTarget( offscreenTexture );
+        if( target->valid() )
+            {
+            WindowPaintData d( m_scheduledScreenshot );
+            double left = 0;
+            double top = 0;
+            double right = m_scheduledScreenshot->width();
+            double bottom = m_scheduledScreenshot->height();
+            foreach( const WindowQuad& quad, d.quads )
+                {
+                // we need this loop to include the decoration padding
+                left   = qMin(left, quad.left());
+                top    = qMin(top, quad.top());
+                right  = qMax(right, quad.right());
+                bottom = qMax(bottom, quad.bottom());
+                }
+            int width = right - left;
+            int height = bottom - top;
+            d.xTranslate = -m_scheduledScreenshot->x() - left;
+            d.yTranslate = -m_scheduledScreenshot->y() - top;
+            // render window into offscreen texture
+            int mask = PAINT_WINDOW_TRANSFORMED | PAINT_WINDOW_TRANSLUCENT;
+            effects->pushRenderTarget( target );
+            glClear( GL_COLOR_BUFFER_BIT );
+            effects->drawWindow( m_scheduledScreenshot, mask, QRegion( 0, 0, width, height ), d );
+            // Create a scratch texture and copy the rendered window into it
+            GLTexture* tex = new GLTexture( width, height );
+            tex->setFilter( GL_LINEAR );
+            tex->setWrapMode( GL_CLAMP_TO_EDGE );
+            tex->bind();
+
+            glCopyTexSubImage2D( GL_TEXTURE_2D, 0, 0, 0, 0, offscreenTexture->height() - height, width, height );
+            effects->popRenderTarget();
+            // copy content from GL texture into image
+            QImage img( QSize( width, height ), QImage::Format_ARGB32 );
+            tex->bind();
+            glGetTexImage( GL_TEXTURE_2D, 0, GL_RGBA, GL_UNSIGNED_BYTE, img.bits() );
+            tex->unbind();
+            delete tex;
+            ScreenShotEffect::convertFromGLImage( img, width, height );
+
+            // save screenshot in home directory
+            QString filePart( QDir::homePath() + '/' + m_scheduledScreenshot->caption() );
+            QString file( filePart + ".png" );
+            int counter = 1;
+            while( QFile::exists( file ) )
+                {
+                file = QString( filePart + '_' + QString::number( counter ) + ".png" );
+                counter++;
+                }
+            img.save( file );
+            }
+        delete offscreenTexture;
+        delete target;
+        m_scheduledScreenshot = NULL;
+        }
+    }
+
+void ScreenShotEffect::screenshot()
+    {
+    EffectWindow* w = effects->activeWindow();
+    m_scheduledScreenshot = w;
+    w->addRepaintFull();
+    }
+
+void ScreenShotEffect::convertFromGLImage(QImage &img, int w, int h)
+{
+    // from QtOpenGL/qgl.cpp
+    // Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
+    // see http://qt.gitorious.org/qt/qt/blobs/master/src/opengl/qgl.cpp
+    if (QSysInfo::ByteOrder == QSysInfo::BigEndian) {
+        // OpenGL gives RGBA; Qt wants ARGB
+        uint *p = (uint*)img.bits();
+        uint *end = p + w*h;
+        while (p < end) {
+            uint a = *p << 24;
+            *p = (*p >> 8) | a;
+            p++;
+        }
+    } else {
+        // OpenGL gives ABGR (i.e. RGBA backwards); Qt wants ARGB
+        for (int y = 0; y < h; y++) {
+            uint *q = (uint*)img.scanLine(y);
+            for (int x=0; x < w; ++x) {
+                const uint pixel = *q;
+                *q = ((pixel << 16) & 0xff0000) | ((pixel >> 16) & 0xff)
+                        | (pixel & 0xff00ff00);
+
+                q++;
+            }
+        }
+
+    }
+    img = img.mirrored();
+}
+
+} // namespace

effects/screenshot/screenshot.desktop

@@ -0,0 +1,17 @@
+[Desktop Entry]
+Name=Screenshot
+Icon=preferences-system-windows-effect-screenshot
+Comment=Saves screenshot of active window into the home directory
+
+Type=Service
+X-KDE-ServiceTypes=KWin/Effect
+X-KDE-PluginInfo-Author=Martin Gräßlin
+X-KDE-PluginInfo-Email=kde@martin-graesslin.com
+X-KDE-PluginInfo-Name=kwin4_effect_screenshot
+X-KDE-PluginInfo-Version=0.1.0
+X-KDE-PluginInfo-Category=Appearance
+X-KDE-PluginInfo-Depends=
+X-KDE-PluginInfo-License=GPL
+X-KDE-PluginInfo-EnabledByDefault=true
+X-KDE-Library=kwin4_effect_builtins
+X-KDE-Ordering=50

effects/screenshot/screenshot.h

@@ -0,0 +1,49 @@
+/********************************************************************
+ KWin - the KDE window manager
+ This file is part of the KDE project.
+
+ Copyright (C) 2010 Martin Gräßlin <kde@martin-graesslin.com>
+
+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; either version 2 of the License, or
+(at your option) any later version.
+
+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, see <http://www.gnu.org/licenses/>.
+*********************************************************************/
+
+#ifndef KWIN_SCREENSHOT_H
+#define KWIN_SCREENSHOT_H
+
+#include <kwineffects.h>
+#include <QObject>
+
+namespace KWin
+{
+
+class ScreenShotEffect : public QObject, public Effect
+    {
+    Q_OBJECT
+    public:
+        ScreenShotEffect();
+        virtual ~ScreenShotEffect();
+        virtual void postPaintScreen();
+
+        static bool supported();
+        static void convertFromGLImage(QImage &img, int w, int h);
+    public Q_SLOTS:
+        void screenshot();
+
+    private:
+        EffectWindow *m_scheduledScreenshot;
+    };
+
+} // namespace
+
+#endif // KWIN_SCREENSHOT_H