From e579957f39fdbaa01dfae624a20479ae9a332dcd Mon Sep 17 00:00:00 2001
From: zeljko <zeljko@lazarus-ide.org>
Date: Tue, 11 Nov 2008 16:41:48 +0000
Subject: [PATCH] Qt: Huge boost to designer painting when "Show grid" enabled
 (on X11 is at least x10)., implemented qtlclintf DrawGrid().

git-svn-id: trunk@17347 -
---
 lcl/interfaces/qt/qtlclintf.inc  | 20 ++++++++++++++++++++
 lcl/interfaces/qt/qtlclintfh.inc |  1 +
 2 files changed, 21 insertions(+)

diff --git a/lcl/interfaces/qt/qtlclintf.inc b/lcl/interfaces/qt/qtlclintf.inc
index a711036169..cb007a1352 100644
--- a/lcl/interfaces/qt/qtlclintf.inc
+++ b/lcl/interfaces/qt/qtlclintf.inc
@@ -147,6 +147,26 @@ begin
   end;
 end;
 
+procedure TQtWidgetSet.DrawGrid(DC: HDC; const R: TRect; DX, DY: Integer);
+var
+  QtDC: TQtDeviceContext absolute DC;
+  X, Y: Integer;
+  W, H: Integer;
+begin
+  if not IsValidDC(DC) then
+    exit;
+  QtDC.save;
+  try
+    W := (R.Right - R.Left - 1) div DX;
+    H := (R.Bottom - R.Top - 1) div DY;
+
+    for X := 0 to W do
+      for Y := 0 to H do
+        QtDC.drawPoint(R.Left + X * DX, R.Top + Y * DY + 1);
+  finally
+    QtDC.restore;
+  end;
+end;
 
 {------------------------------------------------------------------------------
   Function: FontCanUTF8
diff --git a/lcl/interfaces/qt/qtlclintfh.inc b/lcl/interfaces/qt/qtlclintfh.inc
index 1142eef0b0..eeac10dfa6 100644
--- a/lcl/interfaces/qt/qtlclintfh.inc
+++ b/lcl/interfaces/qt/qtlclintfh.inc
@@ -40,6 +40,7 @@ function AddProcessEventHandler(AHandle: THandle;
 function CreateStandardCursor(ACursor: SmallInt): HCURSOR; override;
 procedure DrawArrow(Arrow: TComponent; Canvas: TPersistent); override;
 procedure DrawDefaultDockImage(AOldRect, ANewRect: TRect; AOperation: TDockImageOperation); override;
+procedure DrawGrid(DC: HDC; const R: TRect; DX, DY: Integer); override;
 
 function FontCanUTF8(Font: HFont): boolean; override;
 function FontIsMonoSpace(Font: HFont): boolean; override;