Add a method for setting the blur region for a window.

svn path=/trunk/KDE/kdelibs/; revision=1100073

windoweffects.cpp

@@ -25,6 +25,7 @@
 
 #ifdef Q_WS_X11
 #include <X11/Xlib.h>
+#include <X11/Xatom.h>
 #include <QX11Info>
 #endif
 
@@ -61,6 +62,10 @@ bool isEffectAvailable(Effect effect)
         break;
     case OverrideShadow:
         effectName = "_KDE_SHADOW_OVERRIDE";
+        break;
+    case BlurBehind:
+        effectName = "_KDE_NET_WM_BLUR_REGION";
+        break;
     default:
         return false;
     }
@@ -296,6 +301,28 @@ void overrideShadow(WId window, bool override)
 #endif
 }
 
+void enableBlurBehind(WId window, bool enable, const QRegion &region)
+{
+#ifdef Q_WS_X11
+    Display *dpy = QX11Info::display();
+    Atom atom = XInternAtom(dpy, "_KDE_NET_WM_BLUR_REGION", False);
+
+    if (enable) {
+        QVector<QRect> rects = region.rects();
+        QVector<quint32> data;
+        for (int i = 0; i < rects.count(); i++) {
+            const QRect r = rects[i];
+            data << r.x() << r.y() << r.width() << r.height();
+        }
+
+        XChangeProperty(dpy, window, atom, XA_CARDINAL, 32, PropModeReplace,
+                        reinterpret_cast<const unsigned char *>(data.constData()), data.size());
+    } else {
+        XDeleteProperty(dpy, window, atom);
+    }
+#endif
+}
+
 }
 
 }

windoweffects.h

@@ -41,7 +41,8 @@ namespace WindowEffects
         PresentWindows = 3,
         PresentWindowsGroup = 4,
         HighlightWindows = 5,
-        OverrideShadow = 6
+        OverrideShadow = 6,
+        BlurBehind = 7
     };
 
     /**
@@ -133,6 +134,22 @@ namespace WindowEffects
      * @since 4.4
      */
     PLASMA_EXPORT void overrideShadow(WId window, bool override);
+
+    /**
+     * Instructs the window manager to blur the background in the specified region
+     * behind the given window. Passing a null region will enable the blur effect
+     * for the whole window. The region is relative to the top-left corner of the
+     * client area.
+     *
+     * Note that you will usually want to set the region to the shape of the window,
+     * excluding any shadow or halo.
+     *
+     * @param window The window for which to enable the blur effect
+     * @param enable Enable the effect if @a true, disable it if @false 
+     * @param region The region within the window where the background will be blurred
+     * @since 4.5
+     */
+    PLASMA_EXPORT void enableBlurBehind(WId window, bool enable = true, const QRegion &region = QRegion());
 }
 
 } // namespace Plasma