Delay added signal and other signal bindings for synced windows until the window is actually visually shown

Makes animations of showing windows run completely and thus appear smoother

REVIEW: 103742

client.cpp

@@ -2174,8 +2174,7 @@ void Client::sendSyncRequest()
 void Client::removeSyncSupport()
 {
     if (!ready_for_painting) {
-        ready_for_painting = true;
-        addRepaintFull();
+        setReadyForPainting();
         return;
     }
     syncRequest.isPending = false;

composite.cpp

@@ -663,11 +663,13 @@ void Client::damageNotifyEvent(XDamageNotifyEvent* e)
 #ifdef HAVE_XSYNC
     if (syncRequest.isPending && isResize())
         return;
-    if (syncRequest.counter == None)   // cannot detect complete redraw, consider done now
-        ready_for_painting = true;
+    if (!ready_for_painting) { // avoid "setReadyForPainting()" function calling overhead
+        if (syncRequest.counter == None)   // cannot detect complete redraw, consider done now
+            setReadyForPainting();
 #else
-    ready_for_painting = true;
+        setReadyForPainting();
 #endif
+    }
 
     Toplevel::damageNotifyEvent(e);
 }

effects.cpp

@@ -373,16 +373,25 @@ void EffectsHandlerImpl::slotOpacityChanged(Toplevel *t, qreal oldOpacity)
 
 void EffectsHandlerImpl::slotClientAdded(Client *c)
 {
-    setupClientConnections(c);
-    emit windowAdded(c->effectWindow());
+    if (c->readyForPainting())
+        slotClientShown(c);
+    else
+        connect(c, SIGNAL(windowShown(KWin::Toplevel*)), SLOT(slotClientShown(KWin::Toplevel*)));
 }
 
 void EffectsHandlerImpl::slotUnmanagedAdded(Unmanaged *u)
-{
+{   // regardless, unmanaged windows are -yet?- not synced anyway
     setupUnmanagedConnections(u);
     emit windowAdded(u->effectWindow());
 }
 
+void EffectsHandlerImpl::slotClientShown(KWin::Toplevel *c)
+{
+    Q_ASSERT(dynamic_cast<Client*>(c));
+    setupClientConnections(static_cast<Client*>(c));
+    emit windowAdded(c->effectWindow());
+}
+
 void EffectsHandlerImpl::slotDeletedRemoved(KWin::Deleted *d)
 {
     emit windowDeleted(d->effectWindow());

effects.h

@@ -184,6 +184,7 @@ public Q_SLOTS:
 protected Q_SLOTS:
     void slotDesktopChanged(int old);
     void slotClientAdded(KWin::Client *c);
+    void slotClientShown(KWin::Toplevel*);
     void slotUnmanagedAdded(KWin::Unmanaged *u);
     void slotWindowClosed(KWin::Toplevel *c);
     void slotClientActivated(KWin::Client *c);

events.cpp

@@ -1562,7 +1562,7 @@ void Client::keyPressEvent(uint key_code)
 void Client::syncEvent(XSyncAlarmNotifyEvent* e)
 {
     if (e->alarm == syncRequest.alarm && XSyncValueEqual(e->counter_value, syncRequest.value)) {
-        ready_for_painting = true;
+        setReadyForPainting();
         syncRequest.isPending = false;
         if (syncRequest.failsafeTimeout)
             syncRequest.failsafeTimeout->stop();
@@ -1570,7 +1570,7 @@ void Client::syncEvent(XSyncAlarmNotifyEvent* e)
             if (syncRequest.timeout)
                 syncRequest.timeout->stop();
             performMoveResize();
-        } else
+        } else // setReadyForPainting does as well, but there's a small chance for resize syncs after the resize ended
             addRepaintFull();
     }
 }

toplevel.cpp

@@ -329,6 +329,17 @@ void Toplevel::setOpacity(double new_opacity)
     }
 }
 
+void Toplevel::setReadyForPainting()
+{
+    if (!ready_for_painting) {
+        ready_for_painting = true;
+        if (compositing()) {
+            addRepaintFull();
+            emit windowShown(this);
+        }
+    }
+}
+
 void Toplevel::deleteEffectWindow()
 {
     delete effect_window;

toplevel.h

@@ -266,6 +266,7 @@ signals:
     void geometryChanged();
     void geometryShapeChanged(KWin::Toplevel* toplevel, const QRect& old);
     void windowClosed(KWin::Toplevel* toplevel, KWin::Deleted* deleted);
+    void windowShown(KWin::Toplevel* toplevel);
 
 protected:
     virtual ~Toplevel();
@@ -280,6 +281,7 @@ protected:
     void addDamageFull();
     void getWmClientLeader();
     void getWmClientMachine();
+    void setReadyForPainting();
 
     /**
      * This function fetches the opaque region from this Toplevel.