[jgardou] 57574: [SHELL32] - cope with alpha channel when shortcut-overlaying an icon. CORE-6099 #comment Fixed by rev 57574 #resolve

Author: jgardou
Date: Thu Oct 18 18:37:37 2012
New Revision: 57574

URL: http://svn.reactos.org/svn/reactos?rev=57574&view=rev
Log:
[SHELL32]
 - cope with alpha channel when shortcut-overlaying an icon.
CORE-6099 #comment Fixed by rev 57574 #resolve

Modified:
    trunk/reactos/dll/win32/shell32/iconcache.cpp

Modified: trunk/reactos/dll/win32/shell32/iconcache.cpp
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/shell32/iconcach…
==============================================================================
--- trunk/reactos/dll/win32/shell32/iconcache.cpp [iso-8859-1] (original)
+++ trunk/reactos/dll/win32/shell32/iconcache.cpp [iso-8859-1] Thu Oct 18 18:37:37 2012
@@ -83,26 +83,38 @@
  * NOTES
  *  Creates a new icon as a copy of the passed-in icon, overlayed with a
  *  shortcut image.
+ * FIXME: This should go to the ImageList implementation!
  */
 static HICON SIC_OverlayShortcutImage(HICON SourceIcon, BOOL large)
-{    ICONINFO SourceIconInfo, ShortcutIconInfo, TargetIconInfo;
-    HICON ShortcutIcon, TargetIcon;
-    BITMAP SourceBitmapInfo, ShortcutBitmapInfo;
-    HDC SourceDC = NULL,
-      ShortcutDC = NULL,
-      TargetDC = NULL,
-      ScreenDC = NULL;
-    HBITMAP OldSourceBitmap = NULL,
-      OldShortcutBitmap = NULL,
+{    
+    ICONINFO ShortcutIconInfo, TargetIconInfo;
+    HICON ShortcutIcon = NULL, TargetIcon;
+    BITMAP TargetBitmapInfo, ShortcutBitmapInfo;
+    HDC ShortcutDC = NULL,
+      TargetDC = NULL;
+    HBITMAP OldShortcutBitmap = NULL,
       OldTargetBitmap = NULL;
 
     static int s_imgListIdx = -1;
-
-    /* Get information about the source icon and shortcut overlay */
-    if (! GetIconInfo(SourceIcon, &SourceIconInfo)
-        || 0 == GetObjectW(SourceIconInfo.hbmColor, sizeof(BITMAP),
&SourceBitmapInfo))
-    {
-      return NULL;
+    ZeroMemory(&ShortcutIconInfo, sizeof(ShortcutIconInfo));
+    ZeroMemory(&TargetIconInfo, sizeof(TargetIconInfo));
+
+    /* Get information about the source icon and shortcut overlay.
+     * We will write over the source bitmaps to get the final ones */
+    if (! GetIconInfo(SourceIcon, &TargetIconInfo))
+        return NULL;
+    
+    /* Is it possible with the ImageList implementation? */
+    if(!TargetIconInfo.hbmColor)
+    {
+        /* Maybe we'll support this at some point */
+        FIXME("1bpp icon wants its overlay!\n");
+        goto fail;
+    }
+        
+    if(!GetObjectW(TargetIconInfo.hbmColor, sizeof(BITMAP), &TargetBitmapInfo))
+    {
+        goto fail;
     }
 
     /* search for the shortcut icon only once */
@@ -121,23 +133,25 @@
     } else
         ShortcutIcon = NULL;
 
-    if (NULL == ShortcutIcon
-        || ! GetIconInfo(ShortcutIcon, &ShortcutIconInfo)
-        || 0 == GetObjectW(ShortcutIconInfo.hbmColor, sizeof(BITMAP),
&ShortcutBitmapInfo))
-    {
-      return NULL;
-    }
-
-    TargetIconInfo = SourceIconInfo;
-    TargetIconInfo.hbmMask = NULL;
-    TargetIconInfo.hbmColor = NULL;
-
-    /* Setup the source, shortcut and target masks */
-    SourceDC = CreateCompatibleDC(NULL);
-    if (NULL == SourceDC) goto fail;
-    OldSourceBitmap = (HBITMAP)SelectObject(SourceDC, SourceIconInfo.hbmMask);
-    if (NULL == OldSourceBitmap) goto fail;
-
+    if (!ShortcutIcon || !GetIconInfo(ShortcutIcon, &ShortcutIconInfo))
+    {
+        goto fail;
+    }
+    
+    /* Is it possible with the ImageLists ? */
+    if(!ShortcutIconInfo.hbmColor)
+    {
+        /* Maybe we'll support this at some point */
+        FIXME("Should draw 1bpp overlay!\n");
+        goto fail;
+    }
+    
+    if(!GetObjectW(ShortcutIconInfo.hbmColor, sizeof(BITMAP), &ShortcutBitmapInfo))
+    {
+        goto fail;
+    }
+
+    /* Setup the masks */
     ShortcutDC = CreateCompatibleDC(NULL);
     if (NULL == ShortcutDC) goto fail;
     OldShortcutBitmap = (HBITMAP)SelectObject(ShortcutDC, ShortcutIconInfo.hbmMask);
@@ -145,44 +159,120 @@
 
     TargetDC = CreateCompatibleDC(NULL);
     if (NULL == TargetDC) goto fail;
-    TargetIconInfo.hbmMask = CreateCompatibleBitmap(TargetDC, SourceBitmapInfo.bmWidth,
-                                                    SourceBitmapInfo.bmHeight);
-    if (NULL == TargetIconInfo.hbmMask) goto fail;
-    ScreenDC = GetDC(NULL);
-    if (NULL == ScreenDC) goto fail;
-    TargetIconInfo.hbmColor = CreateCompatibleBitmap(ScreenDC, SourceBitmapInfo.bmWidth,
-                                                     SourceBitmapInfo.bmHeight);
-    ReleaseDC(NULL, ScreenDC);
-    if (NULL == TargetIconInfo.hbmColor) goto fail;
     OldTargetBitmap = (HBITMAP)SelectObject(TargetDC, TargetIconInfo.hbmMask);
     if (NULL == OldTargetBitmap) goto fail;
 
-    /* Create the target mask by ANDing the source and shortcut masks */
-    if (! BitBlt(TargetDC, 0, 0, SourceBitmapInfo.bmWidth, SourceBitmapInfo.bmHeight,
-                 SourceDC, 0, 0, SRCCOPY) ||
-        ! BitBlt(TargetDC, 0, SourceBitmapInfo.bmHeight - ShortcutBitmapInfo.bmHeight,
-                 ShortcutBitmapInfo.bmWidth, ShortcutBitmapInfo.bmHeight,
-                 ShortcutDC, 0, 0, SRCAND))
+    /* Create the complete mask by ANDing the source and shortcut masks.
+     * NOTE: in an ImageList, all icons have the same dimensions */
+    if (!BitBlt(TargetDC, 0, 0, ShortcutBitmapInfo.bmWidth, ShortcutBitmapInfo.bmHeight,
+                ShortcutDC, 0, 0, SRCAND))
     {
       goto fail;
     }
 
-    /* Setup the source and target xor bitmap */
-    if (NULL == SelectObject(SourceDC, SourceIconInfo.hbmColor) ||
+    /*
+     * We must remove or add the alpha component to the shortcut overlay:
+     * If we don't, SRCCOPY will copy it to our resulting icon, resulting in a
+     * partially transparent icons where it shouldn't be, and to an invisible icon
+     * if the underlying icon don't have any alpha channel information. (16bpp only
icon for instance).
+     * But if the underlying icon has alpha channel information, then we must mark the
overlay information
+     * as opaque.
+     * NOTE: This code sucks(tm) and should belong to the ImageList implementation.
+     * NOTE2: there are better ways to do this.
+     */
+    if(ShortcutBitmapInfo.bmBitsPixel == 32)
+    {
+        BOOL add_alpha;
+        BYTE buffer[FIELD_OFFSET(BITMAPINFO, bmiColors[256])];
+        BITMAPINFO* lpbmi = (BITMAPINFO*)buffer;
+        PVOID bits;
+        PULONG pixel;
+        INT i, j;
+        
+        /* Find if the source bitmap has an alpha channel */
+        if(TargetBitmapInfo.bmBitsPixel != 32) add_alpha = FALSE;
+        else
+        {
+            ZeroMemory(buffer, sizeof(buffer));
+            lpbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
+            lpbmi->bmiHeader.biWidth = TargetBitmapInfo.bmWidth;
+            lpbmi->bmiHeader.biHeight = TargetBitmapInfo.bmHeight;
+            lpbmi->bmiHeader.biPlanes = 1;
+            lpbmi->bmiHeader.biBitCount = 32;
+            
+            bits = HeapAlloc(GetProcessHeap(), 0, TargetBitmapInfo.bmHeight *
TargetBitmapInfo.bmWidthBytes);
+            
+            if(!bits) goto fail;
+            
+            if(!GetDIBits(TargetDC, TargetIconInfo.hbmColor, 0,
TargetBitmapInfo.bmHeight, bits, lpbmi, DIB_RGB_COLORS))
+            {
+                ERR("GetBIBits failed!\n");
+                HeapFree(GetProcessHeap(), 0, bits);
+                goto fail;
+            }
+            
+            i = j = 0;
+            pixel = (PULONG)bits;
+            
+            for(i=0; i<TargetBitmapInfo.bmHeight; i++)
+            {
+                for(j=0; j<TargetBitmapInfo.bmWidth; j++)
+                {
+                    add_alpha = (*pixel++ & 0xFF000000) != 0;
+                    if(add_alpha) break;
+                }
+                if(add_alpha) break;
+            }
+            HeapFree(GetProcessHeap(), 0, bits);
+        }
+        
+        /* Allocate the bits */
+        bits = HeapAlloc(GetProcessHeap(), 0,
ShortcutBitmapInfo.bmHeight*ShortcutBitmapInfo.bmWidthBytes);
+        if(!bits) goto fail;
+        
+        ZeroMemory(buffer, sizeof(buffer));
+        lpbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
+        lpbmi->bmiHeader.biWidth = ShortcutBitmapInfo.bmWidth;
+        lpbmi->bmiHeader.biHeight = ShortcutBitmapInfo.bmHeight;
+        lpbmi->bmiHeader.biPlanes = 1;
+        lpbmi->bmiHeader.biBitCount = 32;
+        
+        if(!GetDIBits(TargetDC, ShortcutIconInfo.hbmColor, 0,
ShortcutBitmapInfo.bmHeight, bits, lpbmi, DIB_RGB_COLORS))
+        {
+            ERR("GetBIBits failed!\n");
+            HeapFree(GetProcessHeap(), 0, bits);
+            goto fail;
+        }
+        
+        pixel = (PULONG)bits;
+        /* Remove alpha channel component or make it totally opaque */
+        for(i=0; i<ShortcutBitmapInfo.bmHeight; i++)
+        {
+            for(j=0; j<ShortcutBitmapInfo.bmWidth; j++)
+            {
+                if(add_alpha) *pixel++ |= 0xFF000000;
+                else *pixel++ &= 0x00FFFFFF;
+            }
+        }
+        
+        /* GetDIBits return BI_BITFIELDS with masks set to 0, and SetDIBits fails when
masks are 0. The irony... */
+        lpbmi->bmiHeader.biCompression = BI_RGB;
+        
+        /* Set the bits again */
+        if(!SetDIBits(TargetDC, ShortcutIconInfo.hbmColor, 0,
ShortcutBitmapInfo.bmHeight, bits, lpbmi, DIB_RGB_COLORS))
+        {
+            ERR("SetBIBits failed!, %lu\n", GetLastError());
+            HeapFree(GetProcessHeap(), 0, bits);
+            goto fail;
+        }
+        HeapFree(GetProcessHeap(), 0, bits);
+    }
+
+    /* Now do the copy. We overwrite the original icon data */
+    if (NULL == SelectObject(ShortcutDC, ShortcutIconInfo.hbmColor) ||
         NULL == SelectObject(TargetDC, TargetIconInfo.hbmColor))
-    {
-      goto fail;
-    }
-
-    /* Copy the source color bitmap to the target */
-    if (! BitBlt(TargetDC, 0, 0, SourceBitmapInfo.bmWidth, SourceBitmapInfo.bmHeight,
-                 SourceDC, 0, 0, SRCCOPY)) goto fail;
-
-    /* Copy the source xor bitmap to the target and clear out part of it by using
-       the shortcut mask */
-    if (NULL == SelectObject(ShortcutDC, ShortcutIconInfo.hbmColor)) goto fail;
-    if (!MaskBlt(TargetDC, 0, SourceBitmapInfo.bmHeight - ShortcutBitmapInfo.bmHeight,
-                 ShortcutBitmapInfo.bmWidth, ShortcutBitmapInfo.bmHeight,
+        goto fail;
+    if (!MaskBlt(TargetDC, 0, 0, ShortcutBitmapInfo.bmWidth,
ShortcutBitmapInfo.bmHeight,
                  ShortcutDC, 0, 0, ShortcutIconInfo.hbmMask, 0, 0,
                  MAKEROP4(0xAA0000, SRCCOPY)))
     {
@@ -192,11 +282,9 @@
     /* Clean up, we're not goto'ing to 'fail' after this so we can be
lazy and not set
        handles to NULL */
     SelectObject(TargetDC, OldTargetBitmap);
-    DeleteObject(TargetDC);
+    DeleteDC(TargetDC);
     SelectObject(ShortcutDC, OldShortcutBitmap);
-    DeleteObject(ShortcutDC);
-    SelectObject(SourceDC, OldSourceBitmap);
-    DeleteObject(SourceDC);
+    DeleteDC(ShortcutDC);
 
     /* Create the icon using the bitmaps prepared earlier */
     TargetIcon = CreateIconIndirect(&TargetIconInfo);
@@ -204,19 +292,24 @@
     /* CreateIconIndirect copies the bitmaps, so we can release our bitmaps now */
     DeleteObject(TargetIconInfo.hbmColor);
     DeleteObject(TargetIconInfo.hbmMask);
+    /* Delete what GetIconInfo gave us */
+    DeleteObject(ShortcutIconInfo.hbmColor);
+    DeleteObject(ShortcutIconInfo.hbmMask);
+    DestroyIcon(ShortcutIcon);
 
     return TargetIcon;
 
 fail:
     /* Clean up scratch resources we created */
     if (NULL != OldTargetBitmap) SelectObject(TargetDC, OldTargetBitmap);
+    if (NULL != TargetDC) DeleteDC(TargetDC);
+    if (NULL != OldShortcutBitmap) SelectObject(ShortcutDC, OldShortcutBitmap);
+    if (NULL != ShortcutDC) DeleteDC(ShortcutDC);
     if (NULL != TargetIconInfo.hbmColor) DeleteObject(TargetIconInfo.hbmColor);
     if (NULL != TargetIconInfo.hbmMask) DeleteObject(TargetIconInfo.hbmMask);
-    if (NULL != TargetDC) DeleteObject(TargetDC);
-    if (NULL != OldShortcutBitmap) SelectObject(ShortcutDC, OldShortcutBitmap);
-    if (NULL != ShortcutDC) DeleteObject(ShortcutDC);
-    if (NULL != OldSourceBitmap) SelectObject(SourceDC, OldSourceBitmap);
-    if (NULL != SourceDC) DeleteObject(SourceDC);
+    if (NULL != ShortcutIconInfo.hbmColor) DeleteObject(ShortcutIconInfo.hbmColor);
+    if (NULL != ShortcutIconInfo.hbmMask) DeleteObject(ShortcutIconInfo.hbmColor);
+    if (NULL != ShortcutIcon) DestroyIcon(ShortcutIcon);
 
     return NULL;
 }