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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 "GraphicsContext.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     CGColorSpaceRef deviceRGB = CGColorSpaceCreateDeviceRGB();
     57     CGContextRef bitmapContext = CGBitmapContextCreate(bits, bmpInfo.bmiHeader.biWidth, bmpInfo.bmiHeader.biHeight, 8,
     58                                                        bmpInfo.bmiHeader.biWidth * 4, deviceRGB,
     59                                                        kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst);
     60     CGColorSpaceRelease(deviceRGB);
     61     if (!bitmapContext) {
     62         DeleteObject(hbmp);
     63         return 0;
     64     }
     65 
     66     *targetRef = bitmapContext;
     67     return hbmp;
     68 }
     69 
     70 static CGContextRef createCgContextFromBitmap(HBITMAP bitmap)
     71 {
     72     BITMAP info;
     73     GetObject(bitmap, sizeof(info), &info);
     74     ASSERT(info.bmBitsPixel == 32);
     75 
     76     CGColorSpaceRef deviceRGB = CGColorSpaceCreateDeviceRGB();
     77     CGContextRef bitmapContext = CGBitmapContextCreate(info.bmBits, info.bmWidth, info.bmHeight, 8,
     78                                                        info.bmWidthBytes, deviceRGB, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst);
     79     CGColorSpaceRelease(deviceRGB);
     80     return bitmapContext;
     81 }
     82 
     83 DragImageRef scaleDragImage(DragImageRef image, FloatSize scale)
     84 {
     85     // FIXME: due to the way drag images are done on windows we need
     86     // to preprocess the alpha channel <rdar://problem/5015946>
     87 
     88     if (!image)
     89         return 0;
     90     CGContextRef targetContext;
     91     CGContextRef srcContext;
     92     CGImageRef srcImage;
     93     IntSize srcSize = dragImageSize(image);
     94     IntSize dstSize(static_cast<int>(srcSize.width() * scale.width()), static_cast<int>(srcSize.height() * scale.height()));
     95     HBITMAP hbmp = 0;
     96     HDC dc = GetDC(0);
     97     HDC dstDC = CreateCompatibleDC(dc);
     98     if (!dstDC)
     99         goto exit;
    100 
    101     hbmp = allocImage(dstDC, dstSize, &targetContext);
    102     if (!hbmp)
    103         goto exit;
    104 
    105     srcContext = createCgContextFromBitmap(image);
    106     srcImage = CGBitmapContextCreateImage(srcContext);
    107     CGRect rect;
    108     rect.origin.x = 0;
    109     rect.origin.y = 0;
    110     rect.size = dstSize;
    111     CGContextDrawImage(targetContext, rect, srcImage);
    112     CGImageRelease(srcImage);
    113     CGContextRelease(srcContext);
    114     CGContextRelease(targetContext);
    115     ::DeleteObject(image);
    116     image = 0;
    117 
    118 exit:
    119     if (!hbmp)
    120         hbmp = image;
    121     if (dstDC)
    122         DeleteDC(dstDC);
    123     ReleaseDC(0, dc);
    124     return hbmp;
    125 }
    126 
    127 DragImageRef createDragImageFromImage(Image* img)
    128 {
    129     HBITMAP hbmp = 0;
    130     HDC dc = GetDC(0);
    131     HDC workingDC = CreateCompatibleDC(dc);
    132     CGContextRef drawContext = 0;
    133     if (!workingDC)
    134         goto exit;
    135 
    136     hbmp = allocImage(workingDC, img->size(), &drawContext);
    137 
    138     if (!hbmp)
    139         goto exit;
    140 
    141     if (!drawContext) {
    142         ::DeleteObject(hbmp);
    143         hbmp = 0;
    144     }
    145 
    146     CGImageRef srcImage = img->getCGImageRef();
    147     CGRect rect;
    148     rect.size = img->size();
    149     rect.origin.x = 0;
    150     rect.origin.y = -rect.size.height;
    151     static const CGFloat white [] = {1.0, 1.0, 1.0, 1.0};
    152     CGContextScaleCTM(drawContext, 1, -1);
    153     CGContextSetFillColor(drawContext, white);
    154     CGContextFillRect(drawContext, rect);
    155     CGContextSetBlendMode(drawContext, kCGBlendModeNormal);
    156     CGContextDrawImage(drawContext, rect, srcImage);
    157     CGContextRelease(drawContext);
    158 
    159 exit:
    160     if (workingDC)
    161         DeleteDC(workingDC);
    162     ReleaseDC(0, dc);
    163     return hbmp;
    164 }
    165 
    166 }
    167