Improved event firing of OnDoubleClick and OnClick

* Single click produces one OnClick event
* On a Double Click in produces a OnClick, then a OnDoubleClick
  event. Old behaviour used to procuder yet another OnClick at
  the end. This is not needed.
* OnMouseDown and OnMouseUp events behaviour has not changed.

The reason we introduce the FOnClickPending instead of fully
handling the events in TfpgWidget.MsgMouseUp is because a TfpgButton
has slightly different behavior (eg: When clicking on a button, keep
mouse down, and move mouse out of button rectangle, then an
OnClick must not fire.) The extra FOnClickPending allows us to
toggle this behaviour of HandleLButtonUp (which normally fires
the OnClick event)

2 files changed, 12 insertions, 6 deletions

diff --git a/src/corelib/fpg_widget.pas b/src/corelib/fpg_widget.pas
index f0c7f514..2afb667a 100644
--- a/src/corelib/fpg_widget.pas
+++ b/src/corelib/fpg_widget.pas
@@ -99,6 +99,7 @@ type
     FBackgroundColor: TfpgColor;
     FTextColor: TfpgColor;
     FIsContainer: Boolean;
+    FOnClickPending: Boolean;
     procedure   SetAcceptDrops(const AValue: boolean); virtual;
     function    GetOnShowHint: THintEvent; virtual;
     procedure   SetOnShowHint(const AValue: THintEvent); virtual;
@@ -470,6 +471,7 @@ begin
   FTextColor      := clText1;
   FAcceptDrops    := False;
   FDragActive     := False;
+  FOnClickPending := False;
 
   inherited Create(AOwner);
 
@@ -670,6 +672,7 @@ begin
   case msg.Params.mouse.Buttons of
     MOUSE_LEFT:
       begin
+        FOnClickPending := True;
         mb := mbLeft;
         if uLastClickWidget = self then
           IsDblClick := ((fpgGetTickCount - uLastClickTime) <= DOUBLECLICK_MS)
@@ -683,7 +686,7 @@ begin
         uLastClickTime := fpgGetTickCount;
         if IsDblClick then
         begin
-
+          FOnClickPending := False; { When Double Click occurs we don't want single click }
           HandleDoubleClick(msg.Params.mouse.x, msg.Params.mouse.y, msg.Params.mouse.Buttons, msg.Params.mouse.shiftstate);
           if Assigned(FOnDoubleClick) then
             FOnDoubleClick(self, mb, msg.Params.mouse.shiftstate,
@@ -1032,7 +1035,7 @@ end;
 
 procedure TfpgWidget.HandleLMouseUp(x, y: integer; shiftstate: TShiftState);
 begin
-  if Assigned(FOnClick) then
+  if FOnClickPending and Assigned(FOnClick) then
     FOnClick(self);
 end;
 
diff --git a/src/gui/fpg_button.pas b/src/gui/fpg_button.pas
index fbca006f..cc9866c3 100644
--- a/src/gui/fpg_button.pas
+++ b/src/gui/fpg_button.pas
@@ -664,7 +664,7 @@ begin
       FDown := False;
       RePaint;
       fpgApplication.ProcessMessages;
-      if PtInRect(r, Point(x, y)) then
+      if PtInRect(r, Point(x, y)) and FOnClickPending then
         Click;
     end;
   end
@@ -675,7 +675,7 @@ begin
       FDown := False;
       RePaint;
       fpgApplication.ProcessMessages;
-      if PtInRect(r, Point(x, y)) then
+      if PtInRect(r, Point(x, y)) and FOnClickPending then
         Click;
     end;
   end;
@@ -785,8 +785,11 @@ begin
 
   if Assigned(FCommand) then    // ICommand takes preference to OnClick
     FCommand.Execute
-  else if Assigned(OnClick) then
-    OnClick(self);
+  else
+  begin
+    if Assigned(OnClick) then
+      OnClick(self);
+  end;
 end;
 
 function TfpgBaseButton.GetCommand: ICommand;