From fa6f15ad9a8247e64dfeb003f62e60d66fbb2394 Mon Sep 17 00:00:00 2001
From: micha <micha@lazarus-ide.org>
Date: Mon, 3 Jul 2006 12:58:28 +0000
Subject: [PATCH] preserve content when resizing bitmap (issue #1245)

git-svn-id: trunk@9545 -
---
 lcl/include/bitmap.inc | 7 +++++--
 lcl/intfgraphics.pas   | 8 ++++++--
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/lcl/include/bitmap.inc b/lcl/include/bitmap.inc
index 6344c20e52..3bc9a48769 100644
--- a/lcl/include/bitmap.inc
+++ b/lcl/include/bitmap.inc
@@ -507,7 +507,7 @@ begin
         // copy content
         IntfImage:=TLazIntfImage.Create(0,0);
         try
-          IntfImage.LoadFromBitmap(FImage.FHandle,FImage.FMaskHandle);
+          IntfImage.LoadFromBitmap(FImage.FHandle,FImage.FMaskHandle,Width,Height);
           IntfImage.CreateBitmap(NewImage.FHandle,NewImage.FMaskHandle,false);
           FillChar(NewImage.FDIB, SizeOf(NewImage.FDIB), 0);
           if NewImage.HandleAllocated then
@@ -643,7 +643,10 @@ begin
   if (FImage.FDIB.dsbm.bmHeight <> NewHeight)
   or (FImage.FDIB.dsbm.bmWidth <> NewWidth) then
   begin
-    FreeImage;
+    if (Width <> 0) and (Height <> 0) and (NewWidth <> 0) and (NewHeight <> 0) then
+      UnshareImage(true)
+    else
+      FreeImage;
     FImage.FDIB.dsbm.bmWidth := NewWidth;
     FImage.FDIB.dsbm.bmHeight := NewHeight;
     Changed(Self);
diff --git a/lcl/intfgraphics.pas b/lcl/intfgraphics.pas
index 78be3b4bc9..9a846077bd 100644
--- a/lcl/intfgraphics.pas
+++ b/lcl/intfgraphics.pas
@@ -182,7 +182,7 @@ type
     procedure GetDescriptionFromDevice(DC: HDC); virtual;
     procedure GetDescriptionFromBitmap(Bitmap: HBitmap); virtual;
     procedure LoadFromDevice(DC: HDC); virtual;
-    procedure LoadFromBitmap(Bitmap, MaskBitmap: HBitmap); virtual;
+    procedure LoadFromBitmap(Bitmap, MaskBitmap: HBitmap; AWidth: integer = -1; AHeight: integer = -1); virtual;
     procedure CreateBitmap(var Bitmap, MaskBitmap: HBitmap;
                            AlwaysCreateMask: boolean); virtual;
     procedure SetRawImage(const RawImage: TRawImage); virtual;
@@ -1678,7 +1678,7 @@ begin
   SetRawImage(ARawImage);
 end;
 
-procedure TLazIntfImage.LoadFromBitmap(Bitmap, MaskBitmap: HBitmap);
+procedure TLazIntfImage.LoadFromBitmap(Bitmap, MaskBitmap: HBitmap; AWidth, AHeight: integer);
 var
   ARect: TRect;
   ARawImage: TRawImage;
@@ -1687,6 +1687,10 @@ begin
   if not GetBitmapRawImageDescription(Bitmap,@NewDataDescription) then
     raise FPImageException.Create('Failed to get raw image description from bitmap');
   ARect:=Rect(0,0,NewDataDescription.Width,NewDataDescription.Height);
+  if (AWidth >= 0) and (dword(AWidth) < NewDataDescription.Width) then
+    ARect.Right := AWidth;
+  if (AHeight >= 0) and (dword(AHeight) > NewDataDescription.Height) then
+    ARect.Bottom := AHeight;
   if not GetRawImageFromBitmap(Bitmap,MaskBitmap,ARect,ARawImage) then
     raise FPImageException.Create('Failed to get raw image from bitmap');
   SetRawImage(ARawImage);