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// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_RENDERER_HOST_BACKING_STORE_H_
#define CHROME_BROWSER_RENDERER_HOST_BACKING_STORE_H_
#include "base/basictypes.h"
#include "base/gfx/rect.h"
#include "base/gfx/size.h"
#include "base/process.h"
#include "build/build_config.h"
#include "chrome/common/mru_cache.h"
#if defined(OS_WIN)
#include <windows.h>
#endif
class RenderWidgetHost;
// BackingStore ----------------------------------------------------------------
// Represents a backing store for the pixels in a RenderWidgetHost.
class BackingStore {
public:
BackingStore(const gfx::Size& size);
~BackingStore();
const gfx::Size& size() { return size_; }
#if defined(OS_WIN)
HDC hdc() { return hdc_; }
#endif
// Paints the bitmap from the renderer onto the backing store.
// TODO(port): The HANDLE is a shared section on Windows. Abstract this.
bool PaintRect(base::ProcessHandle process,
HANDLE bitmap_section,
const gfx::Rect& bitmap_rect);
// Scrolls the given rect in the backing store, replacing the given region
// identified by |bitmap_rect| by the bitmap in the file identified by the
// given file handle.
// TODO(port): The HANDLE is a shared section on Windows. Abstract this.
void ScrollRect(base::ProcessHandle process,
HANDLE bitmap, const gfx::Rect& bitmap_rect,
int dx, int dy,
const gfx::Rect& clip_rect,
const gfx::Size& view_size);
private:
// The size of the backing store.
gfx::Size size_;
#if defined(OS_WIN)
// Creates a dib conforming to the height/width/section parameters passed
// in. The use_os_color_depth parameter controls whether we use the color
// depth to create an appropriate dib or not.
HANDLE CreateDIB(HDC dc,
int width, int height,
bool use_os_color_depth,
HANDLE section);
// The backing store dc.
HDC hdc_;
// Handle to the backing store dib.
HANDLE backing_store_dib_;
// Handle to the original bitmap in the dc.
HANDLE original_bitmap_;
#endif
DISALLOW_COPY_AND_ASSIGN(BackingStore);
};
// BackingStoreManager ---------------------------------------------------------
// This class manages backing stores in the browsr. Every RenderWidgetHost is
// associated with a backing store which it requests from this class. The
// hosts don't maintain any references to the backing stores. These backing
// stores are maintained in a cache which can be trimmed as needed.
class BackingStoreManager {
public:
// Returns a backing store which matches the desired dimensions.
//
// backing_store_rect
// The desired backing store dimensions.
// Returns a pointer to the backing store on success, NULL on failure.
static BackingStore* GetBackingStore(RenderWidgetHost* host,
const gfx::Size& desired_size);
// Returns a backing store which is fully ready for consumption, i.e. the
// bitmap from the renderer has been copied into the backing store dc, or the
// bitmap in the backing store dc references the renderer bitmap.
//
// backing_store_rect
// The desired backing store dimensions.
// process_handle
// The renderer process handle.
// bitmap_section
// The bitmap section from the renderer.
// bitmap_rect
// The rect to be painted into the backing store
// needs_full_paint
// Set if we need to send out a request to paint the view
// to the renderer.
// TODO(port): The HANDLE is a shared section on Windows. Abstract this.
static BackingStore* PrepareBackingStore(RenderWidgetHost* host,
const gfx::Rect& backing_store_rect,
base::ProcessHandle process_handle,
HANDLE bitmap_section,
const gfx::Rect& bitmap_rect,
bool* needs_full_paint);
// Returns a matching backing store for the host.
// Returns NULL if we fail to find one.
static BackingStore* Lookup(RenderWidgetHost* host);
// Removes the backing store for the host.
static void RemoveBackingStore(RenderWidgetHost* host);
private:
// Not intended for instantiation.
BackingStoreManager() {}
DISALLOW_COPY_AND_ASSIGN(BackingStoreManager);
};
#endif // CHROME_BROWSER_RENDERER_HOST_BACKING_STORE_H_
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