Magnifier glass - like Zoom, but only for a small part of the screen.

svn path=/branches/work/kwin_composite/; revision=653542

effects/CMakeLists.txt

@@ -19,6 +19,7 @@ SET(kwin4_effect_builtins_sources
     fade.cpp
     fallapart.cpp
     flame.cpp
+    magnifier.cpp
     maketransparent.cpp
     minimizeanimation.cpp
     presentwindows.cpp
@@ -78,6 +79,7 @@ install( FILES
     fallapart.desktop
     flame.desktop
     howto.desktop
+    magnifier.desktop
     maketransparent.desktop
     minimizeanimation.desktop
     presentwindows.desktop

effects/magnifier.cpp

@@ -0,0 +1,145 @@
+/*****************************************************************
+ KWin - the KDE window manager
+ This file is part of the KDE project.
+
+Copyright (C) 2006 Lubos Lunak <l.lunak@kde.org>
+
+You can Freely distribute this program under the GNU General Public
+License. See the file "COPYING" for the exact licensing terms.
+******************************************************************/
+
+#include <config.h>
+
+#include "magnifier.h"
+
+#include <kaction.h>
+#include <kactioncollection.h>
+#include <kstandardaction.h>
+
+#ifdef HAVE_OPENGL
+#include <GL/gl.h>
+#endif
+
+namespace KWin
+{
+
+KWIN_EFFECT( Magnifier, MagnifierEffect )
+
+MagnifierEffect::MagnifierEffect()
+    : zoom( 1 )
+    , target_zoom( 1 )
+    {
+    KActionCollection* actionCollection = new KActionCollection( this );
+    KAction* a;
+    a = static_cast< KAction* >( actionCollection->addAction( KStandardAction::ZoomIn, this, SLOT( zoomIn())));
+    a->setGlobalShortcut(KShortcut(Qt::META + Qt::Key_Equal));
+    a = static_cast< KAction* >( actionCollection->addAction( KStandardAction::ZoomOut, this, SLOT( zoomOut())));
+    a->setGlobalShortcut(KShortcut(Qt::META + Qt::Key_Minus));
+    a = static_cast< KAction* >( actionCollection->addAction( KStandardAction::ActualSize, this, SLOT( toggle())));
+    a->setGlobalShortcut(KShortcut(Qt::META + Qt::Key_0));
+    magnifier_size = QSize( 200, 200 ); // TODO config option
+    }
+
+void MagnifierEffect::prePaintScreen( int* mask, QRegion* region, int time )
+    {
+    if( zoom != target_zoom )
+        {
+        double diff = time / 500.0;
+        if( target_zoom > zoom )
+            zoom = qMin( zoom * qMax( 1 + diff, 1.2 ), target_zoom );
+        else
+            zoom = qMax( zoom * qMin( 1 - diff, 0.8 ), target_zoom );
+        }
+    effects->prePaintScreen( mask, region, time );
+    }
+
+void MagnifierEffect::paintScreen( int mask, QRegion region, ScreenPaintData& data )
+    {
+    ScreenPaintData data2 = data;
+    effects->paintScreen( mask, region, data ); // paint normal screen
+    if( zoom != 1.0 )
+        { // paint magnifier
+        glPushAttrib( GL_ENABLE_BIT );
+        QRect area = magnifierArea();
+        glEnable( GL_SCISSOR_TEST );
+        int dh = displayHeight();
+        // Scissor rect has to be given in OpenGL coords
+        glScissor( area.x(), dh - area.y() - area.height(), area.width(), area.height());
+        mask |= PAINT_SCREEN_TRANSFORMED;
+        data2.xScale *= zoom;
+        data2.yScale *= zoom;
+        QPoint cursor = cursorPos();
+        // set the position so that the cursor is in the same position in the scaled view
+        data2.xTranslate = - int( cursor.x() * ( zoom - 1 ));
+        data2.yTranslate = - int( cursor.y() * ( zoom - 1 ));
+        effects->paintScreen( mask, region, data2 );
+        glPopAttrib();
+        glPushAttrib( GL_CURRENT_BIT );
+        glColor4f( 0, 0, 0, 1 ); // black
+        glBegin( GL_QUADS );
+        glVertex2i( area.left() - 5, area.top() - 5 ); // top frame
+        glVertex2i( area.right() + 5, area.top() - 5 );
+        glVertex2i( area.right() + 5, area.top() - 1 );
+        glVertex2i( area.left() - 5, area.top() - 1 );
+        glVertex2i( area.left() - 5, area.top() - 5 ); // left frame
+        glVertex2i( area.left() - 1, area.top() - 5 );
+        glVertex2i( area.left() - 1, area.bottom() + 5 );
+        glVertex2i( area.left() - 5, area.bottom() + 5 );
+        glVertex2i( area.right() + 1, area.top() - 5 ); // right frame
+        glVertex2i( area.right() + 5, area.top() - 5 );
+        glVertex2i( area.right() + 5, area.bottom() + 5 );
+        glVertex2i( area.right() + 1, area.bottom() + 5 );
+        glVertex2i( area.left() - 5, area.bottom() + 1 ); // bottom frame
+        glVertex2i( area.right() + 5, area.bottom() + 1 );
+        glVertex2i( area.right() + 5, area.bottom() + 5 );
+        glVertex2i( area.left() - 5, area.bottom() + 5 );
+        glEnd();
+        glPopAttrib();
+        }
+    }
+
+void MagnifierEffect::postPaintScreen()
+    {
+    if( zoom != target_zoom )
+        effects->addRepaintFull();
+    if( zoom != 1.0 )
+        { // TODO repaint only what's need and when needed
+//        effects->addRepaint( magnifierArea());
+        effects->addRepaintFull();
+        }
+    effects->postPaintScreen();
+    }
+
+QRect MagnifierEffect::magnifierArea() const
+    {
+    QPoint cursor = cursorPos();
+    return QRect( cursor.x() - magnifier_size.width() / 2, cursor.y() - magnifier_size.height() / 2,
+        magnifier_size.width(), magnifier_size.height());
+    }
+
+void MagnifierEffect::zoomIn()
+    {
+    target_zoom *= 1.2;
+    effects->addRepaintFull();
+    }
+
+void MagnifierEffect::zoomOut()
+    {
+    target_zoom /= 1.2;
+    if( target_zoom < 1 )
+        target_zoom = 1;
+    effects->addRepaintFull();
+    }
+
+void MagnifierEffect::toggle()
+    {
+    if( target_zoom == 1.0 )
+        target_zoom = 2;
+    else
+        target_zoom = 1;
+    effects->addRepaintFull();
+    }
+
+} // namespace
+
+#include "magnifier.moc"

effects/magnifier.desktop

@@ -0,0 +1,4 @@
+[Desktop Entry]
+Encoding=UTF-8
+Name=Magnifier
+X-KDE-Library=kwin4_effect_builtins

effects/magnifier.h

@@ -0,0 +1,41 @@
+/*****************************************************************
+ KWin - the KDE window manager
+ This file is part of the KDE project.
+
+Copyright (C) 2007 Lubos Lunak <l.lunak@kde.org>
+
+You can Freely distribute this program under the GNU General Public
+License. See the file "COPYING" for the exact licensing terms.
+******************************************************************/
+
+#ifndef KWIN_MAGNIFIER_H
+#define KWIN_MAGNIFIER_H
+
+#include <kwineffects.h>
+
+namespace KWin
+{
+
+class MagnifierEffect
+    : public QObject, public Effect
+    {
+    Q_OBJECT
+    public:
+        MagnifierEffect();
+        virtual void prePaintScreen( int* mask, QRegion* region, int time );
+        virtual void paintScreen( int mask, QRegion region, ScreenPaintData& data );
+        virtual void postPaintScreen();
+    private slots:
+        void zoomIn();
+        void zoomOut();
+        void toggle();
+    private:
+        QRect magnifierArea() const;
+        double zoom;
+        double target_zoom;
+        QSize magnifier_size;
+    };
+
+} // namespace
+
+#endif