Add Xorg composition support to kdm

KDM composition can be enabled in the control center
When enabled, it provides seamless composited logins to Trinity sessions
It also gets rid of the remaining artifacts in the themed kdm login screen


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdebase@1246834 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 29 insertions, 1 deletions

diff --git a/kdm/kfrontend/themer/kdmitem.cpp b/kdm/kfrontend/themer/kdmitem.cpp
index 88e5a7489..eb5283cd9 100644
--- a/kdm/kfrontend/themer/kdmitem.cpp
+++ b/kdm/kfrontend/themer/kdmitem.cpp
@@ -38,6 +38,8 @@
 #include <tqimage.h>
 #include <tqpainter.h>
 
+extern bool argb_visual_available;
+
 KdmItem::KdmItem( KdmItem *parent, const TQDomNode &node, const char *name )
     : TQObject( parent, name )
     , boxManager( 0 )
@@ -289,11 +291,13 @@ KdmItem::paint( TQPainter *p, const TQRect &rect )
 
 	if (myWidget || (myLayoutItem && myLayoutItem->widget())) {
             // KListView because it's missing a Q_OBJECT'
-            // FIXME: This is a nice idea intheory, but in practice it is
+            // FIXME: This is a nice idea in theory, but in practice it is
             // very confusing for the user not to see the empty list box
             // delineated from the rest of the greeter.
             // Maybe set a darker version of the background instead of an exact copy?
             if ( myWidget && myWidget->isA( "KListView" ) ) {
+              if ((_compositor.isEmpty()) || (!argb_visual_available)) {
+                // Software blend only (no compositing support)
                 TQPixmap copy( myWidget->size() );
                 kdDebug() <<  myWidget->tqgeometry() << " " << area << " " << myWidget->size() << endl;
                 bitBlt( &copy, TQPoint( 0, 0), p->device(), myWidget->geometry(), TQt::CopyROP );
@@ -327,6 +331,30 @@ KdmItem::paint( TQPainter *p, const TQRect &rect )
                 copy = lightVersion;
                 // Set it
                 myWidget->setPaletteBackgroundPixmap( copy );
+              }
+              else {
+		// We have compositing support!
+		TQRgb blend_color = tqRgba(m_backgroundModifier, m_backgroundModifier, m_backgroundModifier, 0);   // RGBA overlay
+		float alpha = tqAlpha(blend_color) / 255.;
+		int pixel = tqAlpha(blend_color) << 24 |
+				int(tqRed(blend_color) * alpha) << 16 |
+				int(tqGreen(blend_color) * alpha) << 8  |
+				int(tqBlue(blend_color) * alpha);
+
+		TQImage img( myWidget->size(), 32 );
+		img = img.convertDepth(32);
+		img.setAlphaBuffer(true);
+		register uchar * rd = img.bits();
+		for( int y = 0; y < img.height(); ++y )
+		{
+			for( short int x = 0; x < img.width(); ++x )
+			{
+				*reinterpret_cast<TQRgb*>(rd) = blend_color;
+				rd += 4;
+			}
+		}
+		myWidget->setPaletteBackgroundPixmap( img );
+              }
             }
             return;
         }