1/*
2 * Copyright (C) 2011 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 INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#import "config.h"
27#import "BackingStore.h"
28
29#import "CGUtilities.h"
30#import "ShareableBitmap.h"
31#import "UpdateInfo.h"
32#import "WebPageProxy.h"
33#import <WebCore/GraphicsContext.h>
34
35using namespace WebCore;
36
37namespace WebKit {
38
39void BackingStore::paint(PlatformGraphicsContext context, const IntRect& rect)
40{
41    if (m_cgLayer) {
42        CGContextSaveGState(context);
43        CGContextClipToRect(context, rect);
44
45        CGContextScaleCTM(context, 1, -1);
46        CGContextDrawLayerAtPoint(context, CGPointMake(0, -m_size.height()), m_cgLayer.get());
47
48        CGContextRestoreGState(context);
49        return;
50    }
51
52    ASSERT(m_bitmapContext);
53    paintBitmapContext(context, m_bitmapContext.get(), rect.location(), rect);
54}
55
56CGContextRef BackingStore::backingStoreContext()
57{
58    if (m_cgLayer)
59        return CGLayerGetContext(m_cgLayer.get());
60
61    // Try to create a layer.
62    if (CGContextRef containingWindowContext = m_webPageProxy->containingWindowGraphicsContext()) {
63        m_cgLayer.adoptCF(CGLayerCreateWithContext(containingWindowContext, NSSizeToCGSize(m_size), 0));
64        CGContextRef layerContext = CGLayerGetContext(m_cgLayer.get());
65
66        CGContextSetBlendMode(layerContext, kCGBlendModeCopy);
67
68        // We want the origin to be in the top left corner so flip the backing store context.
69        CGContextTranslateCTM(layerContext, 0, m_size.height());
70        CGContextScaleCTM(layerContext, 1, -1);
71
72        if (m_bitmapContext) {
73            // Paint the contents of the bitmap into the layer context.
74            paintBitmapContext(layerContext, m_bitmapContext.get(), CGPointZero, CGRectMake(0, 0, m_size.width(), m_size.height()));
75            m_bitmapContext = nullptr;
76        }
77
78        return layerContext;
79    }
80
81    if (!m_bitmapContext) {
82        RetainPtr<CGColorSpaceRef> colorSpace(AdoptCF, CGColorSpaceCreateDeviceRGB());
83
84        m_bitmapContext.adoptCF(CGBitmapContextCreate(0, m_size.width(), m_size.height(), 8, m_size.width() * 4, colorSpace.get(), kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host));
85
86        CGContextSetBlendMode(m_bitmapContext.get(), kCGBlendModeCopy);
87
88        // We want the origin to be in the top left corner so flip the backing store context.
89        CGContextTranslateCTM(m_bitmapContext.get(), 0, m_size.height());
90        CGContextScaleCTM(m_bitmapContext.get(), 1, -1);
91    }
92
93    return m_bitmapContext.get();
94}
95
96void BackingStore::incorporateUpdate(ShareableBitmap* bitmap, const UpdateInfo& updateInfo)
97{
98    CGContextRef context = backingStoreContext();
99
100    scroll(updateInfo.scrollRect, updateInfo.scrollOffset);
101
102    IntPoint updateRectLocation = updateInfo.updateRectBounds.location();
103
104    GraphicsContext graphicsContext(context);
105
106    // Paint all update rects.
107    for (size_t i = 0; i < updateInfo.updateRects.size(); ++i) {
108        IntRect updateRect = updateInfo.updateRects[i];
109        IntRect srcRect = updateRect;
110        srcRect.move(-updateRectLocation.x(), -updateRectLocation.y());
111
112        bitmap->paint(graphicsContext, updateRect.location(), srcRect);
113    }
114}
115
116void BackingStore::scroll(const IntRect& scrollRect, const IntSize& scrollOffset)
117{
118    if (scrollOffset.isZero())
119        return;
120
121    if (m_cgLayer) {
122        CGContextRef layerContext = CGLayerGetContext(m_cgLayer.get());
123
124        // Scroll the layer by painting it into itself with the given offset.
125        CGContextSaveGState(layerContext);
126        CGContextClipToRect(layerContext, scrollRect);
127        CGContextScaleCTM(layerContext, 1, -1);
128        CGContextDrawLayerAtPoint(layerContext, CGPointMake(scrollOffset.width(), -m_size.height() - scrollOffset.height()), m_cgLayer.get());
129        CGContextRestoreGState(layerContext);
130
131        return;
132    }
133
134    ASSERT(m_bitmapContext);
135
136    CGContextSaveGState(m_bitmapContext.get());
137    CGContextClipToRect(m_bitmapContext.get(), scrollRect);
138    CGPoint destination = CGPointMake(scrollRect.x() + scrollOffset.width(), scrollRect.y() + scrollOffset.height());
139    paintBitmapContext(m_bitmapContext.get(), m_bitmapContext.get(), destination, scrollRect);
140    CGContextRestoreGState(m_bitmapContext.get());
141}
142
143} // namespace WebKit
144