* Added a property to TfpgCanvasImpl(x11) FastDoubleBuffer

* Fixed painting of ListView Column
* Misc Listview painting changes
* Added OnColumnPaint to ListView

The new property FastDoubleBuffer will probably be moved to TfpgCanvaseBase also perhaps this can be set with an application 
property since it doesn't free the backbuffer until the Canvas is freed which will result in some increase in memory usage.

The listview can have double buffering disabled now and it won't flicker sonce the painting is done with no overlapping rects.

1 files changed, 28 insertions, 6 deletions

diff --git a/src/corelib/x11/gfx_x11.pas b/src/corelib/x11/gfx_x11.pas
index 55362421..e26550c3 100644
--- a/src/corelib/x11/gfx_x11.pas
+++ b/src/corelib/x11/gfx_x11.pas
@@ -80,12 +80,15 @@ type
   end;
 
 
+  { TfpgCanvasImpl }
+
   TfpgCanvasImpl = class(TfpgCanvasBase)
   private
     FDrawing: boolean;
     FDrawWindow: TfpgWindowImpl;
     FBufferPixmap: TPixmap;
     FDrawHandle: TXID;
+    FFastDoubleBuffer: Boolean;
     Fgc: TfpgGContext;
     FCurFontRes: TfpgFontResourceImpl;
     FClipRect: TfpgRect;
@@ -94,6 +97,9 @@ type
     FXftDrawBuffer: PXftDraw;
     FColorTextXft: TXftColor;
     FClipRegion: TRegion;
+    FPixHeight,
+    FPixWidth: Integer;
+    procedure   TryFreePixmap;
   protected
     procedure   DoSetFontRes(fntres: TfpgFontResourceBase); override;
     procedure   DoSetTextColor(cl: TfpgColor); override;
@@ -121,6 +127,7 @@ type
   public
     constructor Create; override;
     destructor  Destroy; override;
+    property    FastDoubleBuffer: Boolean read FFastDoubleBuffer write FFastDoubleBuffer;
   end;
 
 
@@ -1243,12 +1250,14 @@ begin
   Fgc           := nil;
   FXftDraw      := nil;
   FClipRegion   := nil;
+  FFastDoubleBuffer := True;
 end;
 
 destructor TfpgCanvasImpl.Destroy;
 begin
   if FDrawing then
     DoEndDraw;
+  TryFreePixmap;
   inherited Destroy;
 end;
 
@@ -1282,15 +1291,21 @@ begin
 
     if buffered then
     begin
-      FBufferPixmap := XCreatePixmap(xapplication.display, FDrawWindow.FWinHandle, w, h, xapplication.DisplayDepth);
+      if (FastDoubleBuffer = False) or (FBufferPixmap = 0) or (w <> FPixWidth) or (h <> FPixHeight) then
+      begin
+        TryFreePixmap;
+        FBufferPixmap := XCreatePixmap(xapplication.display, FDrawWindow.FWinHandle, w, h, xapplication.DisplayDepth);
+      end;
+      FPixHeight := h;
+      FPixWidth := w;
       FDrawHandle   := FBufferPixmap;
     end
     else
     begin
-      FBufferPixmap := 0;
+      TryFreePixmap;
       FDrawHandle   := FDrawWindow.FWinHandle;
     end;
-
+    
     Fgc := XCreateGc(xapplication.display, FDrawHandle, 0, @GcValues);
     // CapNotLast is so we get the same behavior as Windows. See documentation for more details.
     XSetLineAttributes(xapplication.display, Fgc, 0, LineSolid, CapNotLast, JoinMiter);
@@ -1300,6 +1315,7 @@ begin
       XDefaultColormap(xapplication.display, xapplication.DefaultScreen));
 
     FClipRegion := XCreateRegion;
+    
   end;
 
   FDrawing := True;
@@ -1326,9 +1342,8 @@ begin
     XftDrawDestroy(FXftDraw);
     XFreeGc(xapplication.display, Fgc);
 
-    if FBufferPixmap > 0 then
-      XFreePixmap(xapplication.Display, FBufferPixmap);
-    FBufferPixmap := 0;
+    if FastDoubleBuffer = False then
+      TryFreePixmap;
 
     FDrawing    := False;
     FDrawWindow := nil;
@@ -1382,6 +1397,13 @@ begin
       Trunc(64 * a1), Trunc(64 * a2));
 end;
 
+procedure TfpgCanvasImpl.TryFreePixmap;
+begin
+  if FBufferPixmap > 0 then
+    XFreePixmap(xapplication.Display, FBufferPixmap);
+  FBufferPixmap := 0;
+end;
+
 procedure TfpgCanvasImpl.DoSetFontRes(fntres: TfpgFontResourceBase);
 begin
   if fntres = nil then