From: Mark Harmstone <hellas@burntcomma.com>
Subject: [PATCH] uxtheme: Support images in GetThemeBackgroundRegion. (try 2)
Message-Id: <54EF9F64.9070200@burntcomma.com>
Date: Thu, 26 Feb 2015 22:34:12 +0000

Resubmission using a DIB instead of a DDB.

---
 dlls/uxtheme/draw.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 110 insertions(+), 2 deletions(-)

diff --git a/dlls/uxtheme/draw.c b/dlls/uxtheme/draw.c
index 1e15d3b..acb6d28 100644
--- a/dlls/uxtheme/draw.c
+++ b/dlls/uxtheme/draw.c
@@ -1763,6 +1763,115 @@ HRESULT WINAPI GetThemeBackgroundExtent(HTHEME hTheme, HDC hdc, int iPartId,
     return S_OK;
 }
 
+static HRESULT create_image_bg_region(HTHEME theme, int part, int state, const RECT *rect, HRGN *rgn)
+{
+    RECT r;
+    HDC dc;
+    HBITMAP bmp;
+    HRGN hrgn, rgntemp;
+    BOOL istrans;
+    COLORREF transcolour;
+    HBRUSH transbrush;
+    unsigned int x, y;
+    BITMAPINFO bitmapinfo;
+    unsigned char *bits, *ptr;
+
+    r = *rect;
+    OffsetRect(&r, -r.left, -r.top);
+
+    hrgn = CreateRectRgn(r.left, r.top, r.right, r.bottom);
+
+    if (FAILED(GetThemeBool(theme, part, state, TMT_TRANSPARENT, &istrans)) || !istrans) {
+        OffsetRgn(hrgn, rect->left, rect->top);
+        *rgn = hrgn;
+        return S_OK;
+    }
+
+    if (FAILED(GetThemeColor(theme, part, state, TMT_TRANSPARENTCOLOR, &transcolour)))
+        transcolour = RGB(255, 0, 255); /* defaults to magenta */
+
+    dc = CreateCompatibleDC(NULL);
+    if (!dc) {
+        WARN("CreateCompatibleDC failed\n");
+        DeleteObject(hrgn);
+        return E_FAIL;
+    }
+
+    bitmapinfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
+    bitmapinfo.bmiHeader.biWidth = r.right - r.left;
+    bitmapinfo.bmiHeader.biHeight = -(r.bottom - r.top);
+    bitmapinfo.bmiHeader.biPlanes = 1;
+    bitmapinfo.bmiHeader.biBitCount = 32;
+    bitmapinfo.bmiHeader.biCompression = BI_RGB;
+    bitmapinfo.bmiHeader.biSizeImage = bitmapinfo.bmiHeader.biWidth * bitmapinfo.bmiHeader.biHeight * 4;
+    bitmapinfo.bmiHeader.biXPelsPerMeter = 0;
+    bitmapinfo.bmiHeader.biYPelsPerMeter = 0;
+    bitmapinfo.bmiHeader.biClrUsed = 0;
+    bitmapinfo.bmiHeader.biClrImportant = 0;
+
+    bmp = CreateDIBSection(dc, &bitmapinfo, DIB_RGB_COLORS, (void**)&bits, NULL, 0);
+    if (!bmp) {
+        WARN("CreateDIBSection failed\n");
+        DeleteDC(dc);
+        DeleteObject(hrgn);
+        return E_FAIL;
+    }
+
+    SelectObject(dc, bmp);
+
+    transbrush = CreateSolidBrush(transcolour);
+    FillRect(dc, &r, transbrush);
+    DeleteObject(transbrush);
+
+    if (FAILED(DrawThemeBackground(theme, dc, part, state, &r, NULL))) {
+        WARN("DrawThemeBackground failed\n");
+        DeleteObject(bmp);
+        DeleteDC(dc);
+        DeleteObject(hrgn);
+        return E_FAIL;
+    }
+
+    /* loop through the image looking for transparent pixels,
+     * grouping together horizontal runs into one rect */
+    ptr = bits;
+    for (y = 0; y < r.bottom; y++) {
+        BOOL trans = FALSE;
+        int transstart;
+
+        for (x = 0; x < r.right; x++) {
+            COLORREF colour = ptr[2] << 16 | ptr[1] << 8 | ptr[0];
+            ptr += 4;
+
+            if (colour == transcolour) {
+                if (!trans) {
+                    transstart = x;
+                    trans = TRUE;
+                }
+            } else if (trans) {
+                rgntemp = CreateRectRgn(transstart, y, x, y+1);
+                CombineRgn(hrgn, hrgn, rgntemp, RGN_DIFF);
+                DeleteObject(rgntemp);
+                trans = FALSE;
+            }
+        }
+
+        if (trans) {
+            rgntemp = CreateRectRgn(transstart, y, r.right, y+1);
+            CombineRgn(hrgn, hrgn, rgntemp, RGN_DIFF);
+            DeleteObject(rgntemp);
+        }
+    }
+
+    OffsetRgn(hrgn, rect->left, rect->top);
+    *rgn = hrgn;
+
+    DeleteObject(bmp);
+
+    DeleteDC(dc);
+
+    return S_OK;
+}
+
 /***********************************************************************
  *      GetThemeBackgroundRegion                            (UXTHEME.@)
  *
@@ -1784,8 +1893,7 @@ HRESULT WINAPI GetThemeBackgroundRegion(HTHEME hTheme, HDC hdc, int iPartId,
 
     GetThemeEnumValue(hTheme, iPartId, iStateId, TMT_BGTYPE, &bgtype);
     if(bgtype == BT_IMAGEFILE) {
-        FIXME("Images not handled yet\n");
-        hr = ERROR_CALL_NOT_IMPLEMENTED;
+        hr = create_image_bg_region(hTheme, iPartId, iStateId, pRect, pRegion);
     }
     else if(bgtype == BT_BORDERFILL) {
         *pRegion = CreateRectRgn(pRect->left, pRect->top, pRect->right, pRect->bottom);