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1 /*
2  * Copyright (C) 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 "GraphicsContext.h"
28 
29 #include "AffineTransform.h"
30 #include "Path.h"
31 
32 #include <cairo-win32.h>
33 #include "GraphicsContextPlatformPrivateCairo.h"
34 
35 using namespace std;
36 
37 namespace WebCore {
38 
createCairoContextWithHDC(HDC hdc,bool hasAlpha)39 static cairo_t* createCairoContextWithHDC(HDC hdc, bool hasAlpha)
40 {
41     // Put the HDC In advanced mode so it will honor affine transforms.
42     SetGraphicsMode(hdc, GM_ADVANCED);
43 
44     cairo_surface_t* surface = 0;
45 
46     HBITMAP bitmap = static_cast<HBITMAP>(GetCurrentObject(hdc, OBJ_BITMAP));
47 
48     BITMAP info;
49     if (!GetObject(bitmap, sizeof(info), &info))
50         surface = cairo_win32_surface_create(hdc);
51     else {
52         ASSERT(info.bmBitsPixel == 32);
53 
54         surface = cairo_image_surface_create_for_data((unsigned char*)info.bmBits,
55                                                CAIRO_FORMAT_ARGB32,
56                                                info.bmWidth,
57                                                info.bmHeight,
58                                                info.bmWidthBytes);
59     }
60 
61     cairo_t* context = cairo_create(surface);
62     cairo_surface_destroy(surface);
63 
64     return context;
65 }
66 
GraphicsContext(HDC dc,bool hasAlpha)67 GraphicsContext::GraphicsContext(HDC dc, bool hasAlpha)
68     : m_updatingControlTints(false)
69 {
70     platformInit(dc, hasAlpha);
71 }
72 
platformInit(HDC dc,bool hasAlpha)73 void GraphicsContext::platformInit(HDC dc, bool hasAlpha)
74 {
75     cairo_t* cr = 0;
76     if (dc)
77         cr = createCairoContextWithHDC(dc, hasAlpha);
78     else
79         setPaintingDisabled(true);
80 
81     m_data = new GraphicsContextPlatformPrivateToplevel(new PlatformContextCairo(cr));
82     m_data->m_hdc = dc;
83     if (platformContext()->cr()) {
84         // Make sure the context starts in sync with our state.
85         setPlatformFillColor(fillColor(), fillColorSpace());
86         setPlatformStrokeColor(strokeColor(), strokeColorSpace());
87     }
88 }
89 
setRGBABitmapAlpha(unsigned char * bytes,size_t length,unsigned char level)90 static void setRGBABitmapAlpha(unsigned char* bytes, size_t length, unsigned char level)
91 {
92     for (size_t i = 0; i < length; i += 4)
93         bytes[i + 3] = level;
94 }
95 
drawBitmapToContext(GraphicsContextPlatformPrivate * context,cairo_t * cr,const DIBPixelData & pixelData,const IntSize & translate)96 static void drawBitmapToContext(GraphicsContextPlatformPrivate* context, cairo_t* cr, const DIBPixelData& pixelData, const IntSize& translate)
97 {
98     // Need to make a cairo_surface_t out of the bitmap's pixel buffer and then draw
99     // it into our context.
100     cairo_surface_t* surface = cairo_image_surface_create_for_data(pixelData.buffer(),
101                                                                    CAIRO_FORMAT_ARGB32,
102                                                                    pixelData.size().width(),
103                                                                    pixelData.size().height(),
104                                                                    pixelData.bytesPerRow());
105 
106     // Flip the target surface so that when we set the srcImage as
107     // the surface it will draw right-side-up.
108     cairo_save(cr);
109     cairo_translate(cr, static_cast<double>(translate.width()), static_cast<double>(translate.height()));
110     cairo_scale(cr, 1, -1);
111     cairo_set_source_surface(cr, surface, 0, 0);
112 
113     if (context->layers.size())
114         cairo_paint_with_alpha(cr, context->layers.last());
115     else
116         cairo_paint(cr);
117 
118     // Delete all our junk.
119     cairo_surface_destroy(surface);
120     cairo_restore(cr);
121 }
122 
releaseWindowsContext(HDC hdc,const IntRect & dstRect,bool supportAlphaBlend,bool mayCreateBitmap)123 void GraphicsContext::releaseWindowsContext(HDC hdc, const IntRect& dstRect, bool supportAlphaBlend, bool mayCreateBitmap)
124 {
125     bool createdBitmap = mayCreateBitmap && (!m_data->m_hdc || inTransparencyLayer());
126     if (!hdc || !createdBitmap) {
127         m_data->restore();
128         return;
129     }
130 
131     if (dstRect.isEmpty())
132         return;
133 
134     OwnPtr<HBITMAP> bitmap = adoptPtr(static_cast<HBITMAP>(GetCurrentObject(hdc, OBJ_BITMAP)));
135 
136     DIBPixelData pixelData(bitmap.get());
137     ASSERT(pixelData.bitsPerPixel() == 32);
138 
139     // If this context does not support alpha blending, then it may have
140     // been drawn with GDI functions which always set the alpha channel
141     // to zero. We need to manually set the bitmap to be fully opaque.
142     unsigned char* bytes = reinterpret_cast<unsigned char*>(pixelData.buffer());
143     if (!supportAlphaBlend)
144         setRGBABitmapAlpha(bytes, pixelData.size().height() * pixelData.bytesPerRow(), 255);
145 
146     drawBitmapToContext(m_data, platformContext()->cr(), pixelData, IntSize(dstRect.x(), dstRect.height() + dstRect.y()));
147 
148     ::DeleteDC(hdc);
149 }
150 
drawWindowsBitmap(WindowsBitmap * bitmap,const IntPoint & point)151 void GraphicsContext::drawWindowsBitmap(WindowsBitmap* bitmap, const IntPoint& point)
152 {
153     drawBitmapToContext(m_data, platformContext()->cr(), bitmap->windowsDIB(), IntSize(point.x(), bitmap->size().height() + point.y()));
154 }
155 
syncContext(cairo_t * cr)156 void GraphicsContextPlatformPrivate::syncContext(cairo_t* cr)
157 {
158     if (!cr)
159        return;
160 
161     cairo_surface_t* surface = cairo_get_target(cr);
162     m_hdc = cairo_win32_surface_get_dc(surface);
163 
164     SetGraphicsMode(m_hdc, GM_ADVANCED); // We need this call for themes to honor world transforms.
165 }
166 
flush()167 void GraphicsContextPlatformPrivate::flush()
168 {
169     cairo_surface_t* surface = cairo_win32_surface_create(m_hdc);
170     cairo_surface_flush(surface);
171     cairo_surface_destroy(surface);
172 }
173 
174 }
175