Source/WebKit2/UIProcess/mac/BackingStoreMac.mm - external/Webkit - Git at Google

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */

 #import "config.h"
 #import "BackingStore.h"

 #import "CGUtilities.h"
 #import "ShareableBitmap.h"
 #import "UpdateInfo.h"
 #import "WebPageProxy.h"
 #import <WebCore/GraphicsContext.h>
 #import <WebCore/Region.h>

 using namespace WebCore;

 namespace WebKit {

 void BackingStore::performWithScrolledRectTransform(const IntRect& rect, void (^block)(const IntRect&, const IntSize&))
 {
     if (m_scrolledRect.isEmpty() || m_scrolledRectOffset.isZero() || !m_scrolledRect.intersects(rect)) {
         block(rect, IntSize());
         return;
     }

     // The part of rect that's outside the scrolled rect is not translated.
     Region untranslatedRegion = rect;
     untranslatedRegion.subtract(m_scrolledRect);
     Vector<IntRect> untranslatedRects = untranslatedRegion.rects();
     for (size_t i = 0; i < untranslatedRects.size(); ++i)
         block(untranslatedRects[i], IntSize());

     // The part of rect that intersects the scrolled rect comprises up to four parts, each subject
     // to a different translation (all translations are equivalent modulo the dimensions of the
     // scrolled rect to the scroll offset).
     IntRect intersection = rect;
     intersection.intersect(m_scrolledRect);

     IntRect scrolledRect = m_scrolledRect;
     IntSize offset = m_scrolledRectOffset;
     scrolledRect.move(-offset);

     IntRect part = intersection;
     part.intersect(scrolledRect);
     if (!part.isEmpty())
         block(part, offset);

     part = intersection;
     offset += IntSize(0, -m_scrolledRect.height());
     scrolledRect.move(IntSize(0, m_scrolledRect.height()));
     part.intersect(scrolledRect);
     if (!part.isEmpty())
         block(part, offset);

     part = intersection;
     offset += IntSize(-m_scrolledRect.width(), 0);
     scrolledRect.move(IntSize(m_scrolledRect.width(), 0));
     part.intersect(scrolledRect);
     if (!part.isEmpty())
         block(part, offset);

     part = intersection;
     offset += IntSize(0, m_scrolledRect.height());
     scrolledRect.move(IntSize(0, -m_scrolledRect.height()));
     part.intersect(scrolledRect);
     if (!part.isEmpty())
         block(part, offset);
 }

 void BackingStore::resetScrolledRect()
 {
     ASSERT(!m_scrolledRect.isEmpty());

     if (m_scrolledRectOffset.isZero()) {
         m_scrolledRect = IntRect();
         return;
     }

     IntSize scaledSize = m_scrolledRect.size();
     scaledSize.scale(m_deviceScaleFactor);

     RetainPtr<CGColorSpaceRef> colorSpace = adoptCF(CGColorSpaceCreateDeviceRGB());
     RetainPtr<CGContextRef> context = adoptCF(CGBitmapContextCreate(0, scaledSize.width(), scaledSize.height(), 8, scaledSize.width() * 4, colorSpace.get(), kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host));

     CGContextScaleCTM(context.get(), m_deviceScaleFactor, m_deviceScaleFactor);

     CGContextScaleCTM(context.get(), 1, -1);
     CGContextTranslateCTM(context.get(), -m_scrolledRect.x(), -m_scrolledRect.maxY());
     paint(context.get(), m_scrolledRect);

     IntRect sourceRect(IntPoint(), m_scrolledRect.size());
     paintBitmapContext(backingStoreContext(), context.get(), m_deviceScaleFactor, m_scrolledRect.location(), sourceRect);

     m_scrolledRect = IntRect();
     m_scrolledRectOffset = IntSize();
 }

 void BackingStore::paint(PlatformGraphicsContext context, const IntRect& rect)
 {
     // FIXME: This is defined outside the block to work around bugs in llvm-gcc 4.2.
     __block CGRect source;
     performWithScrolledRectTransform(rect, ^(const IntRect& part, const IntSize& offset) {
         if (m_cgLayer) {
             CGContextSaveGState(context);
             CGContextClipToRect(context, part);

             CGContextScaleCTM(context, 1, -1);
             CGContextDrawLayerAtPoint(context, CGPointMake(-offset.width(), offset.height() - m_size.height()), m_cgLayer.get());

             CGContextRestoreGState(context);
             return;
         }

         ASSERT(m_bitmapContext);
         source = part;
         source.origin.x += offset.width();
         source.origin.y += offset.height();
         paintBitmapContext(context, m_bitmapContext.get(), m_deviceScaleFactor, part.location(), source);
     });
 }

 CGContextRef BackingStore::backingStoreContext()
 {
     if (m_cgLayer)
         return CGLayerGetContext(m_cgLayer.get());

     // Try to create a layer.
     if (CGContextRef containingWindowContext = m_webPageProxy->containingWindowGraphicsContext()) {
         m_cgLayer = adoptCF(CGLayerCreateWithContext(containingWindowContext, m_size, 0));
         CGContextRef layerContext = CGLayerGetContext(m_cgLayer.get());

         CGContextSetBlendMode(layerContext, kCGBlendModeCopy);

         // We want the origin to be in the top left corner so flip the backing store context.
         CGContextTranslateCTM(layerContext, 0, m_size.height());
         CGContextScaleCTM(layerContext, 1, -1);

         if (m_bitmapContext) {
             // Paint the contents of the bitmap into the layer context.
             paintBitmapContext(layerContext, m_bitmapContext.get(), m_deviceScaleFactor, CGPointZero, CGRectMake(0, 0, m_size.width(), m_size.height()));
             m_bitmapContext = nullptr;
         }

         return layerContext;
     }

     if (!m_bitmapContext) {
         RetainPtr<CGColorSpaceRef> colorSpace = adoptCF(CGColorSpaceCreateDeviceRGB());

         IntSize scaledSize(m_size);
         scaledSize.scale(m_deviceScaleFactor);
         m_bitmapContext = adoptCF(CGBitmapContextCreate(0, scaledSize.width(), scaledSize.height(), 8, scaledSize.width() * 4, colorSpace.get(), kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host));

         CGContextSetBlendMode(m_bitmapContext.get(), kCGBlendModeCopy);

         CGContextScaleCTM(m_bitmapContext.get(), m_deviceScaleFactor, m_deviceScaleFactor);

         // We want the origin to be in the top left corner so flip the backing store context.
         CGContextTranslateCTM(m_bitmapContext.get(), 0, m_size.height());
         CGContextScaleCTM(m_bitmapContext.get(), 1, -1);
     }

     return m_bitmapContext.get();
 }

 void BackingStore::incorporateUpdate(ShareableBitmap* bitmap, const UpdateInfo& updateInfo)
 {
     CGContextRef context = backingStoreContext();

     scroll(updateInfo.scrollRect, updateInfo.scrollOffset);

     IntPoint updateRectLocation = updateInfo.updateRectBounds.location();

     GraphicsContext ctx(context);
     __block GraphicsContext* graphicsContext = &ctx;

     // Paint all update rects.
     for (size_t i = 0; i < updateInfo.updateRects.size(); ++i) {
         IntRect updateRect = updateInfo.updateRects[i];
         IntRect srcRect = updateRect;
         // FIXME: This is defined outside the block to work around bugs in llvm-gcc 4.2.
         __block IntRect srcPart;
         performWithScrolledRectTransform(srcRect, ^(const IntRect& part, const IntSize& offset) {
             srcPart = part;
             srcPart.move(-updateRectLocation.x(), -updateRectLocation.y());
             bitmap->paint(*graphicsContext, updateInfo.deviceScaleFactor, part.location() + offset, srcPart);
         });
     }
 }

 void BackingStore::scroll(const IntRect& scrollRect, const IntSize& scrollOffset)
 {
     if (scrollOffset.isZero())
         return;

     ASSERT(!scrollRect.isEmpty());

     if (!m_scrolledRect.isEmpty() && m_scrolledRect != scrollRect)
         resetScrolledRect();

     m_scrolledRect = scrollRect;

     int width = (m_scrolledRectOffset.width() - scrollOffset.width()) % m_scrolledRect.width();
     if (width < 0)
         width += m_scrolledRect.width();
     m_scrolledRectOffset.setWidth(width);

     int height = (m_scrolledRectOffset.height() - scrollOffset.height()) % m_scrolledRect.height();
     if (height < 0)
         height += m_scrolledRect.height();
     m_scrolledRectOffset.setHeight(height);
 }

 } // namespace WebKit
	/*
	* Copyright (C) 2011 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#import "config.h"
	#import "BackingStore.h"

	#import "CGUtilities.h"
	#import "ShareableBitmap.h"
	#import "UpdateInfo.h"
	#import "WebPageProxy.h"
	#import <WebCore/GraphicsContext.h>
	#import <WebCore/Region.h>

	using namespace WebCore;

	namespace WebKit {

	void BackingStore::performWithScrolledRectTransform(const IntRect& rect, void (^block)(const IntRect&, const IntSize&))
	{
	if (m_scrolledRect.isEmpty() \|\| m_scrolledRectOffset.isZero() \|\| !m_scrolledRect.intersects(rect)) {
	block(rect, IntSize());
	return;
	}

	// The part of rect that's outside the scrolled rect is not translated.
	Region untranslatedRegion = rect;
	untranslatedRegion.subtract(m_scrolledRect);
	Vector<IntRect> untranslatedRects = untranslatedRegion.rects();
	for (size_t i = 0; i < untranslatedRects.size(); ++i)
	block(untranslatedRects[i], IntSize());

	// The part of rect that intersects the scrolled rect comprises up to four parts, each subject
	// to a different translation (all translations are equivalent modulo the dimensions of the
	// scrolled rect to the scroll offset).
	IntRect intersection = rect;
	intersection.intersect(m_scrolledRect);

	IntRect scrolledRect = m_scrolledRect;
	IntSize offset = m_scrolledRectOffset;
	scrolledRect.move(-offset);

	IntRect part = intersection;
	part.intersect(scrolledRect);
	if (!part.isEmpty())
	block(part, offset);

	part = intersection;
	offset += IntSize(0, -m_scrolledRect.height());
	scrolledRect.move(IntSize(0, m_scrolledRect.height()));
	part.intersect(scrolledRect);
	if (!part.isEmpty())
	block(part, offset);

	part = intersection;
	offset += IntSize(-m_scrolledRect.width(), 0);
	scrolledRect.move(IntSize(m_scrolledRect.width(), 0));
	part.intersect(scrolledRect);
	if (!part.isEmpty())
	block(part, offset);

	part = intersection;
	offset += IntSize(0, m_scrolledRect.height());
	scrolledRect.move(IntSize(0, -m_scrolledRect.height()));
	part.intersect(scrolledRect);
	if (!part.isEmpty())
	block(part, offset);
	}

	void BackingStore::resetScrolledRect()
	{
	ASSERT(!m_scrolledRect.isEmpty());

	if (m_scrolledRectOffset.isZero()) {
	m_scrolledRect = IntRect();
	return;
	}

	IntSize scaledSize = m_scrolledRect.size();
	scaledSize.scale(m_deviceScaleFactor);

	RetainPtr<CGColorSpaceRef> colorSpace = adoptCF(CGColorSpaceCreateDeviceRGB());
	RetainPtr<CGContextRef> context = adoptCF(CGBitmapContextCreate(0, scaledSize.width(), scaledSize.height(), 8, scaledSize.width() * 4, colorSpace.get(), kCGImageAlphaPremultipliedFirst \| kCGBitmapByteOrder32Host));

	CGContextScaleCTM(context.get(), m_deviceScaleFactor, m_deviceScaleFactor);

	CGContextScaleCTM(context.get(), 1, -1);
	CGContextTranslateCTM(context.get(), -m_scrolledRect.x(), -m_scrolledRect.maxY());
	paint(context.get(), m_scrolledRect);

	IntRect sourceRect(IntPoint(), m_scrolledRect.size());
	paintBitmapContext(backingStoreContext(), context.get(), m_deviceScaleFactor, m_scrolledRect.location(), sourceRect);

	m_scrolledRect = IntRect();
	m_scrolledRectOffset = IntSize();
	}

	void BackingStore::paint(PlatformGraphicsContext context, const IntRect& rect)
	{
	// FIXME: This is defined outside the block to work around bugs in llvm-gcc 4.2.
	__block CGRect source;
	performWithScrolledRectTransform(rect, ^(const IntRect& part, const IntSize& offset) {
	if (m_cgLayer) {
	CGContextSaveGState(context);
	CGContextClipToRect(context, part);

	CGContextScaleCTM(context, 1, -1);
	CGContextDrawLayerAtPoint(context, CGPointMake(-offset.width(), offset.height() - m_size.height()), m_cgLayer.get());

	CGContextRestoreGState(context);
	return;
	}

	ASSERT(m_bitmapContext);
	source = part;
	source.origin.x += offset.width();
	source.origin.y += offset.height();
	paintBitmapContext(context, m_bitmapContext.get(), m_deviceScaleFactor, part.location(), source);
	});
	}

	CGContextRef BackingStore::backingStoreContext()
	{
	if (m_cgLayer)
	return CGLayerGetContext(m_cgLayer.get());

	// Try to create a layer.
	if (CGContextRef containingWindowContext = m_webPageProxy->containingWindowGraphicsContext()) {
	m_cgLayer = adoptCF(CGLayerCreateWithContext(containingWindowContext, m_size, 0));
	CGContextRef layerContext = CGLayerGetContext(m_cgLayer.get());

	CGContextSetBlendMode(layerContext, kCGBlendModeCopy);

	// We want the origin to be in the top left corner so flip the backing store context.
	CGContextTranslateCTM(layerContext, 0, m_size.height());
	CGContextScaleCTM(layerContext, 1, -1);

	if (m_bitmapContext) {
	// Paint the contents of the bitmap into the layer context.
	paintBitmapContext(layerContext, m_bitmapContext.get(), m_deviceScaleFactor, CGPointZero, CGRectMake(0, 0, m_size.width(), m_size.height()));
	m_bitmapContext = nullptr;
	}

	return layerContext;
	}

	if (!m_bitmapContext) {
	RetainPtr<CGColorSpaceRef> colorSpace = adoptCF(CGColorSpaceCreateDeviceRGB());

	IntSize scaledSize(m_size);
	scaledSize.scale(m_deviceScaleFactor);
	m_bitmapContext = adoptCF(CGBitmapContextCreate(0, scaledSize.width(), scaledSize.height(), 8, scaledSize.width() * 4, colorSpace.get(), kCGImageAlphaPremultipliedFirst \| kCGBitmapByteOrder32Host));

	CGContextSetBlendMode(m_bitmapContext.get(), kCGBlendModeCopy);

	CGContextScaleCTM(m_bitmapContext.get(), m_deviceScaleFactor, m_deviceScaleFactor);

	// We want the origin to be in the top left corner so flip the backing store context.
	CGContextTranslateCTM(m_bitmapContext.get(), 0, m_size.height());
	CGContextScaleCTM(m_bitmapContext.get(), 1, -1);
	}

	return m_bitmapContext.get();
	}

	void BackingStore::incorporateUpdate(ShareableBitmap* bitmap, const UpdateInfo& updateInfo)
	{
	CGContextRef context = backingStoreContext();

	scroll(updateInfo.scrollRect, updateInfo.scrollOffset);

	IntPoint updateRectLocation = updateInfo.updateRectBounds.location();

	GraphicsContext ctx(context);
	__block GraphicsContext* graphicsContext = &ctx;

	// Paint all update rects.
	for (size_t i = 0; i < updateInfo.updateRects.size(); ++i) {
	IntRect updateRect = updateInfo.updateRects[i];
	IntRect srcRect = updateRect;
	// FIXME: This is defined outside the block to work around bugs in llvm-gcc 4.2.
	__block IntRect srcPart;
	performWithScrolledRectTransform(srcRect, ^(const IntRect& part, const IntSize& offset) {
	srcPart = part;
	srcPart.move(-updateRectLocation.x(), -updateRectLocation.y());
	bitmap->paint(*graphicsContext, updateInfo.deviceScaleFactor, part.location() + offset, srcPart);
	});
	}
	}

	void BackingStore::scroll(const IntRect& scrollRect, const IntSize& scrollOffset)
	{
	if (scrollOffset.isZero())
	return;

	ASSERT(!scrollRect.isEmpty());

	if (!m_scrolledRect.isEmpty() && m_scrolledRect != scrollRect)
	resetScrolledRect();

	m_scrolledRect = scrollRect;

	int width = (m_scrolledRectOffset.width() - scrollOffset.width()) % m_scrolledRect.width();
	if (width < 0)
	width += m_scrolledRect.width();
	m_scrolledRectOffset.setWidth(width);

	int height = (m_scrolledRectOffset.height() - scrollOffset.height()) % m_scrolledRect.height();
	if (height < 0)
	height += m_scrolledRect.height();
	m_scrolledRectOffset.setHeight(height);
	}

	} // namespace WebKit