Qt: added caching of TQtWidgetSet.WindowFromPoint() to avoid unnecesarry calls of very slow QApplication_widgetAt() function. Now TQtWidgetSet.WindowFromPoint() returns same as Win32 WindowFromPoint(), especially in case if mouse isn't moved but widget under it has been disabled or hidden, or new widget is shown above it.

git-svn-id: trunk@27309 -

lcl/interfaces/qt/qtint.pp

@@ -57,6 +57,11 @@ type
   TQtWidgetSet = Class(TWidgetSet)
   private
     App: QApplicationH;
+
+    // cache for WindowFromPoint
+    FLastWFPMousePos: TPoint;
+    FLastWFPResult: HWND;
+
     FEatNextDeactivate: Boolean;
     FOverrideCursor: TObject;
     SavedDCList: TFPList;
@@ -135,6 +140,11 @@ type
     procedure RemoveHandle(AHandle: TObject);
     function IsValidHandle(AHandle: HWND): Boolean;
 
+    // cache for WindowFromPoint to reduce very expensive calls
+    // of QApplication_widgetAt() inside WindowFromPoint().
+    function IsWidgetAtCache(AHandle: HWND): Boolean;
+    procedure InvalidateWidgetAtCache;
+
     // drag image list
     function DragImageList_BeginDrag(AImage: QImageH; AHotSpot: TPoint): Boolean;
     procedure DragImageList_EndDrag;

lcl/interfaces/qt/qtobject.inc

@@ -52,6 +52,9 @@ end;
  ------------------------------------------------------------------------------}
 constructor TQtWidgetSet.Create;
 begin
+  FLastWFPMousePos := Point(MaxInt, MaxInt);
+  FLastWFPResult := 0;
+
   inherited Create;
 
   App := QApplication_Create(@argc, argv);
@@ -455,6 +458,9 @@ function TQtWidgetSet.EventFilter(Sender: QObjectH; Event: QEventH): Boolean; cd
 var
   AObject: TQtObject;
   W: TQtMainWindow;
+  R: TRect;
+  P: TPoint;
+  Pt: TQtPoint;
 begin
   Result := False;
   case QEvent_type(Event) of
@@ -491,6 +497,21 @@ begin
           FreeSysColorBrushes(True);
         end;
       end;
+    QEventShow,
+    QEventHide:
+      begin
+        // invalidate widgetAt cache if needed
+        if QObject_isWidgetType(Sender) and IsValidHandle(FLastWFPResult) then
+        begin
+          QWidget_geometry(QWidgetH(Sender), @R);
+          Pt.x := 0;
+          Pt.y := 0;
+          QWidget_mapToGlobal(QWidgetH(Sender), @Pt, @Pt);
+          R := Rect(Pt.X, Pt.Y, Pt.X + (R.Right - R.Left), Pt.Y + (R.Bottom - R.Top));
+          if PtInRect(R, FLastWFPMousePos) then
+            InvalidateWidgetAtCache;
+        end;
+      end;
     LCLQt_Destroy:
       begin
         AObject := TQtObject(Pointer(QLCLMessageEvent_getWParam(QLCLMessageEventH(Event))));
@@ -701,6 +722,24 @@ begin
   System.LeaveCriticalsection(CriticalSection);
 end;
 
+{Params: HWND
+ This function is needed by cache used in TQtWidgetSet.WindowFromPoint().
+ Returns: True if we are cached (FLastWFPResult).
+}
+function TQtWidgetSet.IsWidgetAtCache(AHandle: HWND): Boolean;
+begin
+  Result := AHandle = FLastWFPResult;
+end;
+
+{Params: none
+ Invalidates TQtWidgetSet.WindowFromPoint() cache (FLastWFPResult).
+ Returns: nothing
+}
+procedure TQtWidgetSet.InvalidateWidgetAtCache;
+begin
+  FLastWFPResult := 0;
+end;
+
 function TQtWidgetSet.DragImageList_BeginDrag(AImage: QImageH;
   AHotSpot: TPoint): Boolean;
 var

lcl/interfaces/qt/qtwidgets.pas

@@ -209,6 +209,7 @@ type
     function getLayoutDirection: QtLayoutDirection;
     function getVisible: Boolean; virtual;
     function getVisibleTo(AWidget: QWidgetH): Boolean; virtual;
+    function getOwner: TQtWidget;
     function getParent: QWidgetH;
     function getPos: TQtPoint;
     function getFrameSize: TSize;
@@ -2046,6 +2047,11 @@ begin
   if LCLObject <> nil then
   begin
     case QEvent_type(Event) of
+      QEventEnabledChange:
+        begin
+          if QtWidgetSet.IsWidgetAtCache(HWND(Self)) then
+            QtWidgetSet.InvalidateWidgetAtCache;
+        end;
       QEventShow: SlotShow(True);
       QEventHide: SlotShow(False);
       QEventClose:
@@ -2950,6 +2956,8 @@ begin
     WriteLn('TQtWidget.SlotMove');
   {$endif}
 
+  if QtWidgetSet.IsWidgetAtCache(HWND(Self)) then
+    QtWidgetSet.InvalidateWidgetAtCache;
   // do not loop with LCL
   if InUpdate then
     exit;
@@ -3094,7 +3102,10 @@ begin
   {$ifdef VerboseQt}
     WriteLn('TQtWidget.SlotResize');
   {$endif}
-  
+
+  if QtWidgetSet.IsWidgetAtCache(HWND(Self)) then
+    QtWidgetSet.InvalidateWidgetAtCache;
+
   // return size w/o frame
   NewSize := QResizeEvent_size(QResizeEventH(Event))^;
 {
@@ -3379,6 +3390,8 @@ end;
 
 function TQtWidget.getEnabled: Boolean;
 begin
+  if Widget = nil then
+    exit(False);
   Result := QWidget_isEnabled(Widget);
 end;
 
@@ -3409,14 +3422,23 @@ end;
 
 function TQtWidget.getVisible: boolean;
 begin
+  if Widget = nil then
+    exit(False);
   Result := QWidget_isVisible(Widget);
 end;
 
 function TQtWidget.getVisibleTo(AWidget: QWidgetH): Boolean;
 begin
+  if Widget = nil then
+    exit(False);
   Result := QWidget_isVisibleTo(Widget, AWidget);
 end;
 
+function TQtWidget.getOwner: TQtWidget;
+begin
+  Result := FOwner;
+end;
+
 function TQtWidget.getParent: QWidgetH;
 begin
   Result := QWidget_parentWidget(Widget);
@@ -10539,6 +10561,8 @@ end;
 
 function TQtMenu.getVisible: Boolean;
 begin
+  if ActionHandle = nil then
+    exit(False);
   Result := QAction_isVisible(ActionHandle);
 end;
 

lcl/interfaces/qt/qtwinapi.inc

@@ -5677,21 +5677,53 @@ end;
   If the point is over a static text control,
   the return value is a handle to the window under the static text control.
  ------------------------------------------------------------------------------}
-function TQtWidgetSet.WindowFromPoint(Point: TPoint): HWND;
+function TQtWidgetSet.WindowFromPoint(APoint: TPoint): HWND;
 var
   Widget: QWidgetH;
   AForm: TCustomForm;
 begin
-  {$note QApplication_widgetAt() is very expensive operation,
-    we must do some kind of caching here like gtk2 does.}
+  // we use cachedresults instead of calling very expensive widgetAt
+  if (FLastWFPResult <> 0) then
+  begin
+    if not IsValidHandle(FLastWFPResult) then
+      FLastWFPResult := 0
+    else
+    if (APoint.X = FLastWFPMousePos.X) and (APoint.Y = FLastWFPMousePos.Y) and
+      TQtWidget(FLastWFPResult).getVisible and
+      TQtWidget(FLastWFPResult).getEnabled then
+    begin
+      // return from cache
+      exit(FLastWFPResult);
+    end;
+  end;
+
   Result := 0;
-  Widget := QApplication_widgetAt(Point.x, Point.y);
+  Widget := QApplication_widgetAt(APoint.x, APoint.y);
+
   if (Widget = nil) then
+  begin
+    if (APoint.X = FLastWFPMousePos.X) and (APoint.Y = FLastWFPMousePos.Y) then
+    begin
+      FLastWFPMousePos := Point(MaxInt, MaxInt);
+      FLastWFPResult := 0;
+    end;
     exit;
+  end;
 
   // according to MSDN disabled widget shouldn't be in result
+  // but win32 returns first enabled and visible parent !
   if not QWidget_isEnabled(Widget) or not QWidget_isVisible(Widget) then
-    exit;
+  begin
+    while Widget <> nil do
+    begin
+      Widget := QWidget_parentWidget(Widget);
+      if (Widget <> nil) and QWidget_IsVisible(Widget) and
+        QWidget_isEnabled(Widget) then
+          break;
+    end;
+    if Widget = nil then
+      exit;
+  end;
 
   Result := HWND(QtObjectFromWidgetH(Widget));
 
@@ -5700,44 +5732,34 @@ begin
   begin
     if QWidget_parentWidget(Widget) <> nil then
     begin
-      Widget := QWidget_parentWidget(Widget);
-      Result := HWND(QtObjectFromWidgetH(Widget));
+      while (Widget <> nil) do
+      begin
+        Widget := QWidget_parentWidget(Widget);
+        if Widget <> nil then
+          Result := HWND(QtObjectFromWidgetH(Widget));
+        if Result <> 0 then
+          break;
+      end;
     end;
   end;
 
   if (Result <> 0) and
     not (TQtWidget(Result) is TQtMainWindow) then
   begin
-    // just in case we are an orphan
-    if TQtWidget(Result).LCLObject = nil then
-    begin
-      while Widget <> nil do
-      begin
-        Widget := QWidget_parentWidget(Widget);
-        if Widget <> nil then
-        begin
-          Result := HWND(QtObjectFromWidgetH(Widget));
-          if (Result <> 0) and (TQtWidget(Result).LCLObject <> nil) then
-            break;
-        end;
-      end;
-    end;
-
-    //if we are TQtViewPort -> return correct handle -> TQtCustomControl !
-    if (Result <> 0) and (TQtWidget(Result) is TQtViewPort) then
-    begin
-      Widget := QWidget_parentWidget(TQtWidget(Result).Widget);
-      Result := HWND(QtObjectFromWidgetH(Widget));
-    end;
-
+    if TQtWidget(Result).getOwner <> nil then
+      Result := HWND(TQtWidget(Result).getOwner);
   end else
   begin
-    Widget := QApplication_topLevelAt(Point.x, Point.y);
+    Widget := QApplication_topLevelAt(APoint.x, APoint.y);
     if (Widget <> nil) and QWidget_isEnabled(Widget) then
       Result := HWND(QtObjectFromWidgetH(Widget))
     else
       Result := 0;
   end;
+
+  // add to cache
+  FLastWFPResult := Result;
+  FLastWFPMousePos := APoint;
 end;
 
 //##apiwiz##eps##   // Do not remove, no wizard declaration after this line

lcl/interfaces/qt/qtwinapih.inc

@@ -215,7 +215,7 @@ function SystemParametersInfo(uiAction: DWord; uiParam: DWord; pvParam: Pointer;
 
 function TextOut(DC: HDC; X,Y : Integer; Str : Pchar; Count: Integer) : Boolean; override;
 function UpdateWindow(Handle: HWND): Boolean; override;
-function WindowFromPoint(Point: TPoint): HWND; override;
+function WindowFromPoint(APoint: TPoint): HWND; override;
 
 //##apiwiz##eps##   // Do not remove, no wizard declaration after this line