I think I got persuaded that having a direct access to the decorated

window might be useful in very very very rare cases.

svn path=/trunk/kdebase/kwin/; revision=368911

bridge.cpp

@@ -103,6 +103,11 @@ QWidget* Bridge::workspaceWidget() const
     return c->workspace()->desktopWidget();
     }
 
+WId Bridge::windowId() const
+    {
+    return c->window();
+    }
+
 void Bridge::titlebarDblClickOperation()
     {
     c->workspace()->performWindowOperation( c, options->operationTitlebarDblClick());

bridge.h

@@ -50,6 +50,7 @@ class Bridge : public KDecorationBridge
         virtual QRect iconGeometry() const;
         virtual QRegion unobscuredRegion( const QRegion& r ) const;
         virtual QWidget* workspaceWidget() const;
+        virtual WId windowId() const;
         virtual void closeWindow();
         virtual void maximize( MaximizeMode mode );
         virtual void minimize();

kcmkwin/kwindecoration/preview.cpp

@@ -375,6 +375,11 @@ QWidget* KDecorationPreviewBridge::workspaceWidget() const
     return preview;
     }
         
+WId KDecorationPreviewBridge::windowId() const
+    {
+    return 0; // no decorated window
+    }
+
 void KDecorationPreviewBridge::closeWindow()
     {
     }

kcmkwin/kwindecoration/preview.h

@@ -93,6 +93,7 @@ class KDecorationPreviewBridge
         virtual QRect iconGeometry() const;
         virtual QRegion unobscuredRegion( const QRegion& r ) const;
         virtual QWidget* workspaceWidget() const;
+        virtual WId windowId() const;
 	virtual void closeWindow();
 	virtual void maximize( MaximizeMode mode );
 	virtual void minimize();

lib/kdecoration.cpp

@@ -226,6 +226,11 @@ QWidget* KDecoration::workspaceWidget() const
     return bridge_->workspaceWidget();
     }
         
+WId KDecoration::windowId() const
+    {
+    return bridge_->windowId();
+    }
+        
 void KDecoration::closeWindow()
     {
     bridge_->closeWindow();

lib/kdecoration.h

@@ -519,6 +519,20 @@ class KWIN_EXPORT KDecoration
 	 * allow painting the minimize animation or the transparent move bound on it.
 	 */
         QWidget* workspaceWidget() const;
+        /**
+         * Returns the handle of the window that is being decorated. It is possible
+         * the returned value will be 0.
+         * IMPORTANT: This function is meant for special purposes, and it
+         * usually should not be used. The main purpose is finding out additional
+         * information about the window's state. Also note that different kinds
+         * of windows are decorated: Toplevel windows managed by the window manager,
+         * test window in the window manager decoration module, and possibly also
+         * other cases.
+         * Careless abuse of this function will usually sooner or later lead
+         * to problems.
+         * @since 3.4
+         */
+        WId windowId() const;
 	/**
 	 * Convenience function that returns the width of the decoration.
 	 */

lib/kdecoration_p.h

@@ -89,6 +89,7 @@ class KDecorationBridge : public KDecorationDefines
         virtual QRect iconGeometry() const = 0;
         virtual QRegion unobscuredRegion( const QRegion& r ) const = 0;
         virtual QWidget* workspaceWidget() const = 0;
+        virtual WId windowId() const = 0;
 	virtual void closeWindow() = 0;
 	virtual void maximize( MaximizeMode mode ) = 0;
 	virtual void minimize() = 0;