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      1 /*
      2  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #include "config.h"
     27 #include "DragImage.h"
     28 
     29 #include "BitmapInfo.h"
     30 #include "CachedImage.h"
     31 #include "GraphicsContextCG.h"
     32 #include "Image.h"
     33 #include "RetainPtr.h"
     34 
     35 #include <CoreGraphics/CoreGraphics.h>
     36 
     37 #include <windows.h>
     38 
     39 namespace WebCore {
     40 
     41 void deallocContext(CGContextRef target)
     42 {
     43     CGContextRelease(target);
     44 }
     45 
     46 HBITMAP allocImage(HDC dc, IntSize size, CGContextRef *targetRef)
     47 {
     48     BitmapInfo bmpInfo = BitmapInfo::create(size);
     49 
     50     LPVOID bits;
     51     HBITMAP hbmp = CreateDIBSection(dc, &bmpInfo, DIB_RGB_COLORS, &bits, 0, 0);
     52 
     53     if (!targetRef)
     54         return hbmp;
     55 
     56     CGContextRef bitmapContext = CGBitmapContextCreate(bits, bmpInfo.bmiHeader.biWidth, bmpInfo.bmiHeader.biHeight, 8,
     57                                                        bmpInfo.bmiHeader.biWidth * 4, deviceRGBColorSpaceRef(),
     58                                                        kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst);
     59     if (!bitmapContext) {
     60         DeleteObject(hbmp);
     61         return 0;
     62     }
     63 
     64     *targetRef = bitmapContext;
     65     return hbmp;
     66 }
     67 
     68 static CGContextRef createCgContextFromBitmap(HBITMAP bitmap)
     69 {
     70     BITMAP info;
     71     GetObject(bitmap, sizeof(info), &info);
     72     ASSERT(info.bmBitsPixel == 32);
     73 
     74     CGContextRef bitmapContext = CGBitmapContextCreate(info.bmBits, info.bmWidth, info.bmHeight, 8,
     75                                                        info.bmWidthBytes, deviceRGBColorSpaceRef(), kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst);
     76     return bitmapContext;
     77 }
     78 
     79 DragImageRef scaleDragImage(DragImageRef image, FloatSize scale)
     80 {
     81     // FIXME: due to the way drag images are done on windows we need
     82     // to preprocess the alpha channel <rdar://problem/5015946>
     83 
     84     if (!image)
     85         return 0;
     86     CGContextRef targetContext;
     87     CGContextRef srcContext;
     88     CGImageRef srcImage;
     89     IntSize srcSize = dragImageSize(image);
     90     IntSize dstSize(static_cast<int>(srcSize.width() * scale.width()), static_cast<int>(srcSize.height() * scale.height()));
     91     HBITMAP hbmp = 0;
     92     HDC dc = GetDC(0);
     93     HDC dstDC = CreateCompatibleDC(dc);
     94     if (!dstDC)
     95         goto exit;
     96 
     97     hbmp = allocImage(dstDC, dstSize, &targetContext);
     98     if (!hbmp)
     99         goto exit;
    100 
    101     srcContext = createCgContextFromBitmap(image);
    102     srcImage = CGBitmapContextCreateImage(srcContext);
    103     CGRect rect;
    104     rect.origin.x = 0;
    105     rect.origin.y = 0;
    106     rect.size = dstSize;
    107     CGContextDrawImage(targetContext, rect, srcImage);
    108     CGImageRelease(srcImage);
    109     CGContextRelease(srcContext);
    110     CGContextRelease(targetContext);
    111     ::DeleteObject(image);
    112     image = 0;
    113 
    114 exit:
    115     if (!hbmp)
    116         hbmp = image;
    117     if (dstDC)
    118         DeleteDC(dstDC);
    119     ReleaseDC(0, dc);
    120     return hbmp;
    121 }
    122 
    123 DragImageRef createDragImageFromImage(Image* img)
    124 {
    125     HBITMAP hbmp = 0;
    126     HDC dc = GetDC(0);
    127     HDC workingDC = CreateCompatibleDC(dc);
    128     CGContextRef drawContext = 0;
    129     if (!workingDC)
    130         goto exit;
    131 
    132     hbmp = allocImage(workingDC, img->size(), &drawContext);
    133 
    134     if (!hbmp)
    135         goto exit;
    136 
    137     if (!drawContext) {
    138         ::DeleteObject(hbmp);
    139         hbmp = 0;
    140     }
    141 
    142     CGImageRef srcImage = img->getCGImageRef();
    143     CGRect rect;
    144     rect.size = img->size();
    145     rect.origin.x = 0;
    146     rect.origin.y = -rect.size.height;
    147     static const CGFloat white [] = {1.0, 1.0, 1.0, 1.0};
    148     CGContextScaleCTM(drawContext, 1, -1);
    149     CGContextSetFillColor(drawContext, white);
    150     CGContextFillRect(drawContext, rect);
    151     CGContextSetBlendMode(drawContext, kCGBlendModeNormal);
    152     CGContextDrawImage(drawContext, rect, srcImage);
    153     CGContextRelease(drawContext);
    154 
    155 exit:
    156     if (workingDC)
    157         DeleteDC(workingDC);
    158     ReleaseDC(0, dc);
    159     return hbmp;
    160 }
    161 
    162 }
    163