Update cached Shadow information on size changes

In order to notice when the geometry changes a new signal is
added to toplevel and both Unmanaged and Client connect all their
signals which are emitted whenever the geometry changes in some way
to this new signal.

Shadow connects to the signal and updates the quads and region
whenever the size changes.

client.cpp

@@ -194,6 +194,10 @@ Client::Client(Workspace* ws)
     ready_for_painting = false; // wait for first damage or sync reply
 #endif
 
+    connect(this, SIGNAL(clientGeometryShapeChanged(KWin::Client*,QRect)), SIGNAL(geometryChanged()));
+    connect(this, SIGNAL(clientMaximizedStateChanged(KWin::Client*,KDecorationDefines::MaximizeMode)), SIGNAL(geometryChanged()));
+    connect(this, SIGNAL(clientStepUserMovedResized(KWin::Client*,QRect)), SIGNAL(geometryChanged()));
+
     // SELI TODO: Initialize xsizehints??
 }
 

shadow.cpp

@@ -31,7 +31,9 @@ namespace KWin
 
 Shadow::Shadow(Toplevel *toplevel)
     : m_topLevel(toplevel)
+    , m_cachedSize(toplevel->geometry().size())
 {
+    connect(m_topLevel, SIGNAL(geometryChanged()), SLOT(geometryChanged()));
 }
 
 Shadow::~Shadow()
@@ -99,14 +101,18 @@ bool Shadow::init(const QVector< long > &data)
     m_rightOffset = data[ShadowElementsCount+1];
     m_bottomOffset = data[ShadowElementsCount+2];
     m_leftOffset = data[ShadowElementsCount+3];
-    // prepare shadow region
+    updateShadowRegion();
+    buildQuads();
+    return true;
+}
+
+void Shadow::updateShadowRegion()
+{
     const QRect topRect(0, - m_topOffset, m_topLevel->width(), m_topOffset);
     const QRect rightRect(m_topLevel->width(), - m_topOffset, m_rightOffset, m_topLevel->height() + m_topOffset + m_bottomOffset);
     const QRect bottomRect(0, m_topLevel->height(), m_topLevel->width(), m_bottomOffset);
     const QRect leftRect(- m_leftOffset, - m_topOffset, m_leftOffset, m_topLevel->height() + m_topOffset + m_bottomOffset);
     m_shadowRegion = QRegion(topRect).united(rightRect).united(bottomRect).united(leftRect);
-    buildQuads();
-    return true;
 }
 
 void Shadow::buildQuads()
@@ -184,6 +190,16 @@ bool Shadow::updateShadow()
 void Shadow::setToplevel(Toplevel *topLevel)
 {
     m_topLevel = topLevel;
+    connect(m_topLevel, SIGNAL(geometryChanged()), SLOT(geometryChanged()));
+}
+void Shadow::geometryChanged()
+{
+    if (m_cachedSize == m_topLevel->geometry().size()) {
+        return;
+    }
+    m_cachedSize = m_topLevel->geometry().size();
+    updateShadowRegion();
+    buildQuads();
 }
 
 } // namespace

shadow.h

@@ -92,6 +92,9 @@ public:
      **/
     void setToplevel(Toplevel *toplevel);
 
+public Q_SLOTS:
+    void geometryChanged();
+
 protected:
     Shadow(Toplevel *toplevel);
     enum ShadowElements {
@@ -121,6 +124,7 @@ protected:
         return m_leftOffset;
     };
     virtual void buildQuads();
+    void updateShadowRegion();
 
 private:
     static QVector<long> readX11ShadowProperty(WId id);
@@ -136,6 +140,7 @@ private:
     // caches
     QRegion m_shadowRegion;
     WindowQuadList m_shadowQuads;
+    QSize m_cachedSize;
 };
 
 }

toplevel.h

@@ -162,6 +162,7 @@ signals:
     void opacityChanged(KWin::Toplevel* toplevel, qreal oldOpacity);
     void damaged(KWin::Toplevel* toplevel, const QRect& damage);
     void propertyNotify(KWin::Toplevel* toplevel, long a);
+    void geometryChanged();
 
 protected:
     virtual ~Toplevel();

unmanaged.cpp

@@ -32,6 +32,7 @@ namespace KWin
 Unmanaged::Unmanaged(Workspace* ws)
     : Toplevel(ws)
 {
+    connect(this, SIGNAL(unmanagedGeometryShapeChanged(KWin::Unmanaged*,QRect)), SIGNAL(geometryChanged()));
 }
 
 Unmanaged::~Unmanaged()