add support for clip region to Ripple

lib/rippleoverlay.cpp

@@ -4,7 +4,8 @@
 #include "ripple.h"
 
 RippleOverlay::RippleOverlay(QWidget *parent)
-    : QWidget(parent)
+    : QWidget(parent),
+      useClip(false)
 {
     setAttribute(Qt::WA_TransparentForMouseEvents);
     setAttribute(Qt::WA_NoSystemBackground);
@@ -44,6 +45,10 @@ void RippleOverlay::paintEvent(QPaintEvent *event)
     painter.setRenderHint(QPainter::Antialiasing);
     painter.setPen(Qt::NoPen);
 
+    if (useClip) {
+        painter.setClipRegion(clipRegion);
+    }
+
     QList<Ripple *>::const_iterator i;
     for (i = ripples.begin(); i != ripples.end(); ++i)
     {

lib/rippleoverlay.h

@@ -18,6 +18,11 @@ public:
 
     void setColor(const QColor &color);
 
+    inline void setClipping(bool enabled) { useClip = enabled; update(); }
+    inline bool hasClipping() const { return useClip; }
+
+    inline void setClipRegion(const QRegion &region) { clipRegion = region; update(); }
+
 protected:
     void paintEvent(QPaintEvent *event) Q_DECL_OVERRIDE;
 
@@ -26,6 +31,8 @@ protected slots:
 
 private:
     QList<Ripple *> ripples;
+    QRegion clipRegion;
+    bool    useClip;
 };
 
 #endif // RIPPLEOVERLAY_H