Check that getting compositing pixmap of a window succeeded.

It may fail (or "fail") if the window is not mapped or if the geometry
doesn't match, both of which may happen due to the asynchronous
nature of X.


svn path=/branches/work/kwin_composite/; revision=637741

client.cpp

@@ -458,8 +458,8 @@ void Client::updateShape()
     else
         XShapeCombineMask( display(), frameId(), ShapeBounding, 0, 0,
                            None, ShapeSet);
-    if( compositing() )
-        discardWindowPixmap();
+    if( compositing())
+        addDamageFull();
     if( scene != NULL )
         scene->windowGeometryShapeChanged( this );
     // workaround for #19644 - shaped windows shouldn't have decoration
@@ -496,8 +496,8 @@ void Client::setMask( const QRegion& reg, int mode )
             xrects, rects.count(), ShapeSet, mode );
         delete[] xrects;
         }
-    if( compositing() )
-        discardWindowPixmap();
+    if( compositing())
+        addDamageFull();
     if( scene != NULL )
         scene->windowGeometryShapeChanged( this );
     }

composite.cpp

@@ -39,6 +39,7 @@ License. See the file "COPYING" for the exact licensing terms.
 #include <stdio.h>
 
 #include <QMenu>
+#include <kxerrorhandler.h>
 
 #include <X11/extensions/shape.h>
 
@@ -367,11 +368,26 @@ void Toplevel::discardWindowPixmap()
     window_pix = None;
     }
 
-Pixmap Toplevel::createWindowPixmap() const
+Pixmap Toplevel::createWindowPixmap()
     {
 #ifdef HAVE_XCOMPOSITE
     assert( compositing());
-    return XCompositeNameWindowPixmap( display(), frameId());
+    grabXServer();
+    KXErrorHandler err;
+    window_pix = XCompositeNameWindowPixmap( display(), frameId());
+    // check that the received pixmap is valid and actually matches what we
+    // know about the window (i.e. size)
+    XWindowAttributes attrs;
+    if( !XGetWindowAttributes( display(), frameId(), &attrs ))
+        window_pix = None;
+    if( err.error( false ))
+        window_pix = None;
+    if( attrs.width != width() || attrs.height != height() || attrs.map_state != IsViewable )
+        window_pix = None;
+    ungrabXServer();
+    if( window_pix == None )
+        kDebug( 1212 ) << "Creating window pixmap failed: " << this << endl;
+    return window_pix;
 #else
     return None;
 #endif

events.cpp

@@ -1633,8 +1633,7 @@ bool Unmanaged::windowEvent( XEvent* e )
             if( e->type == Extensions::shapeNotifyEvent() )
                 {
                 detectShape( window());
-                if( compositing() )
-                    discardWindowPixmap();
+                addDamageFull();
                 if( scene != NULL )
                     scene->windowGeometryShapeChanged( this );
                 }
@@ -1666,9 +1665,9 @@ void Unmanaged::configureNotifyEvent( XConfigureEvent* e )
         return;
     workspace()->addRepaint( geometry()); // damage old area
     geom = newgeom;
+    discardWindowPixmap();
     if( scene != NULL )
         scene->windowGeometryShapeChanged( this );
-    discardWindowPixmap();
     }
 
 // ****************************************

scene_basic.cpp

@@ -48,6 +48,8 @@ void SceneBasic::paint( QRegion, ToplevelList windows )
         if( !r.isEmpty())
             {
             Pixmap pix = (*it)->windowPixmap();
+            if( pix == None )
+                continue;
             XCopyArea( display(), pix, composite_pixmap, gc,
                 qMax( 0, -(*it)->x()), qMax( 0, -(*it)->y()), r.width(), r.height(), r.x(), r.y());
             }

scene_opengl.cpp

@@ -851,14 +851,14 @@ void SceneOpenGL::Window::findTextureTarget()
     }
 
 // Bind the window pixmap to an OpenGL texture.
-void SceneOpenGL::Window::bindTexture()
+bool SceneOpenGL::Window::bindTexture()
     {
     if( texture != 0 && toplevel->damage().isEmpty()
         && !options->glAlwaysRebind ) // interestingly with some gfx cards always rebinding is faster
         {
         // texture doesn't need updating, just bind it
         glBindTexture( texture_target, texture );
-        return;
+        return true;
         }
     if( !toplevel->damage().isEmpty())
         texture_has_valid_mipmaps = false;
@@ -868,11 +868,13 @@ void SceneOpenGL::Window::bindTexture()
             {
             kDebug( 1212 ) << "No framebuffer configuration for depth " << toplevel->depth()
                            << "; not binding window" << endl;
-            return;
+            return false;
             }
         }
     // Get the pixmap with the window contents
     Pixmap pix = toplevel->windowPixmap();
+    if( pix == None )
+        return false;
     // HACK
     // When a window uses ARGB visual and has a decoration, the decoration
     // does use ARGB visual. When converting such window to a texture
@@ -1029,9 +1031,9 @@ void SceneOpenGL::Window::bindTexture()
     // by GLXPixmap in the tfp case or not needed at all in non-tfp cases)
     if( copy_buffer )
         XFreePixmap( display(), pix );
+    return true;
     }
 
-
 QRegion SceneOpenGL::Window::optimizeBindDamage( const QRegion& reg, int limit )
     {
     if( reg.rects().count() <= 1 )
@@ -1141,7 +1143,8 @@ void SceneOpenGL::Window::performPaint( int mask, QRegion region, WindowPaintDat
     region &= shape();
     if( region.isEmpty())
         return;
-    bindTexture();
+    if( !bindTexture())
+        return;
     glPushMatrix();
     // set texture filter
     if( options->smoothScale != 0 ) // default to yes

scene_opengl.h

@@ -94,7 +94,7 @@ class SceneOpenGL::Window
         virtual void performPaint( int mask, QRegion region, WindowPaintData data );
         virtual void prepareForPainting();
         void findTextureTarget();
-        void bindTexture();
+        bool bindTexture();
         void enableTexture();
         void disableTexture();
         void discardTexture();

scene_xrender.cpp

@@ -325,6 +325,8 @@ Picture SceneXrender::Window::picture()
         {
         // Get the pixmap with the window contents.
         Pixmap pix = toplevel->windowPixmap();
+        if( pix == None )
+            return None;
         // HACK the same alpha clear hack like with opengl, see there
         Client* c = dynamic_cast< Client* >( toplevel );
         bool alpha_clear = c != NULL && c->hasAlpha() && !c->noBorder();

toplevel.h

@@ -78,7 +78,7 @@ class Toplevel
         pid_t pid() const;
         static bool resourceMatch( const Toplevel* c1, const Toplevel* c2 );
 
-        Pixmap windowPixmap( bool allow_create = true ); // for use with compositing
+        Pixmap windowPixmap( bool allow_create = true ); // may return None (e.g. at a bad moment while resizing)
         Visual* visual() const;
         bool shape() const;
         void setOpacity( double opacity );
@@ -102,7 +102,7 @@ class Toplevel
         void detectShape( Window id );
         virtual void propertyNotifyEvent( XPropertyEvent* e );
         void damageNotifyEvent( XDamageNotifyEvent* e );
-        Pixmap createWindowPixmap() const;
+        Pixmap createWindowPixmap();
         void discardWindowPixmap();
         void addDamage( const QRect& r );
         void addDamage( int x, int y, int w, int h );