Make use of resize effect when resizing windows

Fixes a regression. When resize effect is available we can do a
fast resizing by only perform the resizing after the user ended
resizing the window.

REVIEW: 103363

client.cpp

@@ -71,6 +71,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 namespace KWin
 {
 
+bool Client::s_haveResizeEffect = false;
+
 // Creating a client:
 //  - only by calling Workspace::createClient()
 //      - it creates a new client and calls manage() for it

client.h

@@ -587,6 +587,7 @@ private:
     bool move_resize_has_keyboard_grab;
     bool unrestrictedMoveResize;
     int moveResizeStartScreen;
+    static bool s_haveResizeEffect;
 
     Position mode;
     QPoint moveOffset;

composite.cpp

@@ -811,6 +811,8 @@ void Client::finishCompositing()
     Toplevel::finishCompositing();
     updateVisibility();
     updateDecoration(true, true);
+    // for safety in case KWin is just resizing the window
+    s_haveResizeEffect = false;
 }
 
 bool Client::shouldUnredirect() const

geometry.cpp

@@ -2580,6 +2580,7 @@ bool Client::startMoveResize()
     }
 
     moveResizeMode = true;
+    s_haveResizeEffect = effects && static_cast<EffectsHandlerImpl*>(effects)->provides(Effect::Resize);
     moveResizeStartScreen = screen();
     workspace()->setClientIsMoving(this);
     initialMoveResizeGeom = moveResizeGeom = geometry();
@@ -3034,7 +3035,7 @@ void Client::handleMoveResize(int x, int y, int x_root, int y_root)
         return;
 
 #ifdef HAVE_XSYNC
-    if (isResize() && syncRequest.counter != None) {
+    if (isResize() && syncRequest.counter != None && !s_haveResizeEffect) {
         if (!syncRequest.timeout) {
             syncRequest.timeout = new QTimer(this);
             connect(syncRequest.timeout, SIGNAL(timeout()), SLOT(performMoveResize()));
@@ -3062,7 +3063,11 @@ void Client::performMoveResize()
 #ifdef KWIN_BUILD_TILING
     if (!workspace()->tiling()->isEnabled())
 #endif
-        setGeometry(moveResizeGeom);
+    {
+        if (isMove() || (isResize() && !s_haveResizeEffect)) {
+            setGeometry(moveResizeGeom);
+        }
+    }
 #ifdef HAVE_XSYNC
     if (isResize() && syncRequest.counter != None)
         addRepaintFull();