Add base to the repository.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@8 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 135 insertions, 0 deletions

diff --git a/base/gfx/bitmap_platform_device.h b/base/gfx/bitmap_platform_device.h
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+++ b/base/gfx/bitmap_platform_device.h
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+// Copyright 2008, Google 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:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * 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.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
+// OWNER OR 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.
+
+#ifndef BASE_GFX_BITMAP_PLATFORM_DEVICE_H__
+#define BASE_GFX_BITMAP_PLATFORM_DEVICE_H__
+
+#include "base/gfx/platform_device.h"
+#include "base/ref_counted.h"
+
+namespace gfx {
+
+// A device is basically a wrapper around SkBitmap that provides a surface for
+// SkCanvas to draw into. Our device provides a surface Windows can also write
+// to. BitmapPlatformDevice creates a bitmap using CreateDIBSection() in a
+// format that Skia supports and can then use this to draw ClearType into, etc.
+// This pixel data is provided to the bitmap that the device contains so that it
+// can be shared.
+//
+// The device owns the pixel data, when the device goes away, the pixel data
+// also becomes invalid. THIS IS DIFFERENT THAN NORMAL SKIA which uses
+// reference counting for the pixel data. In normal Skia, you could assign
+// another bitmap to this device's bitmap and everything will work properly.
+// For us, that other bitmap will become invalid as soon as the device becomes
+// invalid, which may lead to subtle bugs. Therefore, DO NOT ASSIGN THE
+// DEVICE'S PIXEL DATA TO ANOTHER BITMAP, make sure you copy instead.
+class BitmapPlatformDevice : public PlatformDevice {
+ public:
+  // Factory function. The screen DC is used to create the bitmap, and will not
+  // be stored beyond this function. is_opaque should be set if the caller
+  // knows the bitmap will be completely opaque and allows some optimizations.
+  //
+  // The shared_section parameter is optional (pass NULL for default behavior).
+  // If shared_section is non-null, then it must be a handle to a file-mapping
+  // object returned by CreateFileMapping.  See CreateDIBSection for details.
+  static BitmapPlatformDevice* create(HDC screen_dc,
+                                int width,
+                                int height,
+                                bool is_opaque,
+                                HANDLE shared_section);
+
+  // Copy constructor. When copied, devices duplicate their internal data, so
+  // stay linked. This is because their implementation is very heavyweight
+  // (lots of memory and some GDI objects). If a device has been copied, both
+  // clip rects and other state will stay in sync.
+  //
+  // This means it will NOT work to duplicate a device and assign it to a
+  // canvas, because the two canvases will each set their own clip rects, and
+  // the resulting GDI clip rect will be random.
+  //
+  // Copy constucting and "=" is designed for saving the device or passing it
+  // around to another routine willing to deal with the bitmap data directly.
+  BitmapPlatformDevice(const BitmapPlatformDevice& other);
+  virtual ~BitmapPlatformDevice();
+
+  // See warning for copy constructor above.
+  BitmapPlatformDevice& operator=(const BitmapPlatformDevice& other);
+
+  // Retrieves the bitmap DC, which is the memory DC for our bitmap data. The
+  // bitmap DC is lazy created.
+  virtual HDC getBitmapDC();
+  virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region);
+  virtual void setDeviceOffset(int x, int y);
+
+  virtual void drawToHDC(HDC dc, int x, int y, const RECT* src_rect);
+  virtual void prepareForGDI(int x, int y, int width, int height);
+  virtual void postProcessGDI(int x, int y, int width, int height);
+  virtual void makeOpaque(int x, int y, int width, int height);
+  virtual void fixupAlphaBeforeCompositing();
+  virtual bool IsVectorial() { return false; }
+
+  // Returns the color value at the specified location. This does not
+  // consider any transforms that may be set on the device.
+  SkColor getColorAt(int x, int y);
+
+ protected:
+  // Flushes the Windows device context so that the pixel data can be accessed
+  // directly by Skia. Overridden from SkDevice, this is called when Skia
+  // starts accessing pixel data.
+  virtual void onAccessBitmap(SkBitmap* bitmap);
+
+ private:
+  // Function pointer used by the processPixels method for setting the alpha
+  // value of a particular pixel.
+  typedef void (*adjustAlpha)(uint32_t* pixel);
+
+  // Reference counted data that can be shared between multiple devices. This
+  // allows copy constructors and operator= for devices to work properly. The
+  // bitmaps used by the base device class are already refcounted and copyable.
+  class BitmapPlatformDeviceData;
+
+  // Private constructor.
+  BitmapPlatformDevice(BitmapPlatformDeviceData* data, const SkBitmap& bitmap);
+
+  // Loops through each of the pixels in the specified range, invoking
+  // adjustor for the alpha value of each pixel. If |width| or |height| are -1,
+  // the available width/height is used.
+  template<adjustAlpha adjustor>
+  void processPixels(int x,
+                     int y,
+                     int width,
+                     int height);
+
+  // Data associated with this device, guaranteed non-null.
+  scoped_refptr<BitmapPlatformDeviceData> data_;
+};
+
+}  // namespace gfx
+
+#endif  // BASE_GFX_BITMAP_PLATFORM_DEVICE_H__