1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef SKIA_EXT_BITMAP_PLATFORM_DEVICE_WIN_H_
6 #define SKIA_EXT_BITMAP_PLATFORM_DEVICE_WIN_H_
8 #include "base/basictypes.h"
9 #include "base/compiler_specific.h"
10 #include "skia/ext/platform_device.h"
11 #include "skia/ext/refptr.h"
15 // A device is basically a wrapper around SkBitmap that provides a surface for
16 // SkCanvas to draw into. Our device provides a surface Windows can also write
17 // to. BitmapPlatformDevice creates a bitmap using CreateDIBSection() in a
18 // format that Skia supports and can then use this to draw ClearType into, etc.
19 // This pixel data is provided to the bitmap that the device contains so that it
22 // The device owns the pixel data, when the device goes away, the pixel data
23 // also becomes invalid. THIS IS DIFFERENT THAN NORMAL SKIA which uses
24 // reference counting for the pixel data. In normal Skia, you could assign
25 // another bitmap to this device's bitmap and everything will work properly.
26 // For us, that other bitmap will become invalid as soon as the device becomes
27 // invalid, which may lead to subtle bugs. Therefore, DO NOT ASSIGN THE
28 // DEVICE'S PIXEL DATA TO ANOTHER BITMAP, make sure you copy instead.
29 class SK_API BitmapPlatformDevice : public SkBitmapDevice, public PlatformDevice {
31 // Factory function. is_opaque should be set if the caller knows the bitmap
32 // will be completely opaque and allows some optimizations.
34 // The |shared_section| parameter is optional (pass NULL for default
35 // behavior). If |shared_section| is non-null, then it must be a handle to a
36 // file-mapping object returned by CreateFileMapping. See CreateDIBSection
37 // for details. If |shared_section| is null, the bitmap backing store is not
39 static BitmapPlatformDevice* Create(int width, int height,
40 bool is_opaque, HANDLE shared_section);
42 // Create a BitmapPlatformDevice with no shared section. The bitmap is not
44 static BitmapPlatformDevice* Create(int width, int height, bool is_opaque);
46 // Creates a BitmapPlatformDevice instance respecting the parameters as above.
47 // If |is_opaque| is false, then the bitmap is initialzed to 0.
48 static BitmapPlatformDevice* CreateAndClear(int width, int height,
51 virtual ~BitmapPlatformDevice();
53 // PlatformDevice overrides
54 // Retrieves the bitmap DC, which is the memory DC for our bitmap data. The
55 // bitmap DC is lazy created.
56 virtual PlatformSurface BeginPlatformPaint() OVERRIDE;
57 virtual void EndPlatformPaint() OVERRIDE;
59 virtual void DrawToNativeContext(HDC dc, int x, int y,
60 const RECT* src_rect) OVERRIDE;
62 // Loads the given transform and clipping region into the HDC. This is
63 // overridden from SkBaseDevice.
64 virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
65 const SkClipStack&) OVERRIDE;
68 // Flushes the Windows device context so that the pixel data can be accessed
69 // directly by Skia. Overridden from SkBaseDevice, this is called when Skia
70 // starts accessing pixel data.
71 virtual const SkBitmap& onAccessBitmap() OVERRIDE;
73 virtual SkBaseDevice* onCreateCompatibleDevice(SkBitmap::Config, int width,
74 int height, bool isOpaque,
75 Usage usage) OVERRIDE;
78 // Reference counted data that can be shared between multiple devices. This
79 // allows copy constructors and operator= for devices to work properly. The
80 // bitmaps used by the base device class are already refcounted and copyable.
81 class BitmapPlatformDeviceData;
83 // Private constructor.
84 BitmapPlatformDevice(const skia::RefPtr<BitmapPlatformDeviceData>& data,
85 const SkBitmap& bitmap);
87 // Data associated with this device, guaranteed non-null.
88 skia::RefPtr<BitmapPlatformDeviceData> data_;
91 int begin_paint_count_;
94 DISALLOW_COPY_AND_ASSIGN(BitmapPlatformDevice);
99 #endif // SKIA_EXT_BITMAP_PLATFORM_DEVICE_WIN_H_