LCL, fix normal row drawing over fixed row (gtk), issue #13404

git-svn-id: trunk@27549 -

lcl/grids.pas

@@ -4133,7 +4133,9 @@ begin
   end else
   if goSmoothScroll in Options then begin
     CacheVisibleGrid;
-    R.TopLeft:=Point(0, FGCache.FixedHeight);
+    with FGCache do
+      R.TopLeft := Point(0,
+        TWSCustomGridClass(WidgetSetClass).InvalidateStartY(FixedHeight, TLRowOff));
     R.BottomRight:=FGCache.MaxClientXY;
     if FGcache.MaxClientXY.Y<FGCache.ClientHeight then
       R.BottomRight.y := FGCache.ClientHeight;

lcl/interfaces/gtk/gtkwsgrids.pp

@@ -35,6 +35,7 @@ type
   TGtkWSCustomGrid = class(TWSCustomGrid)
   published
     class procedure SetFont(const AWinControl: TWinControl; const AFont: TFont); override;
+    class function InvalidateStartY(const FixedHeight, RowOffset: Integer): integer; override;
   end;
 
 
@@ -48,4 +49,13 @@ begin
   //
 end;
 
+class function TGtkWSCustomGrid.InvalidateStartY(const FixedHeight,
+  RowOffset: Integer): integer;
+begin
+  if RowOffset<>0 then
+    result := 0
+  else
+    result := FixedHeight;
+end;
+
 end.

lcl/widgetset/wsgrids.pp

@@ -54,6 +54,7 @@ type
   TWSCustomGrid = class(TWSCustomControl)
   published
     class procedure SendCharToEditor(AEditor:TWinControl; Ch: TUTF8Char); virtual;
+    class function InvalidateStartY(const FixedHeight, RowOffset: Integer): integer; virtual;
   end;
   TWSCustomGridClass = class of TWSCustomgrid;
 
@@ -80,6 +81,11 @@ begin
   AEditor.Dispatch(GMsg);
 end;
 
+class function TWSCustomGrid.InvalidateStartY(const FixedHeight, RowOffset: Integer): Integer;
+begin
+  result := FixedHeight;
+end;
+
 { WidgetSetRegistration }
 
 function RegisterCustomGrid: Boolean;