skia/ext/vector_platform_device_emf_win.h

   1 // Copyright (c) 2011 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.
   4
   5 #ifndef SKIA_EXT_VECTOR_PLATFORM_DEVICE_EMF_WIN_H_
   6 #define SKIA_EXT_VECTOR_PLATFORM_DEVICE_EMF_WIN_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/compiler_specific.h"
  10 #include "skia/ext/platform_device.h"
  11 #include "third_party/skia/include/core/SkMatrix.h"
  12 #include "third_party/skia/include/core/SkRegion.h"
  13
  14 namespace skia {
  15
  16 // A device is basically a wrapper around SkBitmap that provides a surface for
  17 // SkCanvas to draw into. This specific device is not not backed by a surface
  18 // and is thus unreadable. This is because the backend is completely vectorial.
  19 // This device is a simple wrapper over a Windows device context (HDC) handle.
  20 // TODO(robertphillips): Once Skia's SkBaseDevice is refactored to remove
  21 // the bitmap-specific entry points, this class should derive from it.
  22 class VectorPlatformDeviceEmf : public SkBitmapDevice, public PlatformDevice {
  23  public:
  24   SK_API static SkBaseDevice* CreateDevice(int width, int height, bool isOpaque,
  25                                            HANDLE shared_section);
  26
  27   // Factory function. The DC is kept as the output context.
  28   static SkBaseDevice* create(HDC dc, int width, int height);
  29
  30   VectorPlatformDeviceEmf(HDC dc, const SkBitmap& bitmap);
  31   virtual ~VectorPlatformDeviceEmf();
  32
  33   // PlatformDevice methods
  34   virtual PlatformSurface BeginPlatformPaint() OVERRIDE;
  35   virtual void DrawToNativeContext(HDC dc, int x, int y,
  36                                    const RECT* src_rect) OVERRIDE;
  37   // SkBaseDevice methods.
  38   virtual void drawPaint(const SkDraw& draw, const SkPaint& paint) OVERRIDE;
  39   virtual void drawPoints(const SkDraw& draw, SkCanvas::PointMode mode,
  40                           size_t count, const SkPoint[],
  41                           const SkPaint& paint) OVERRIDE;
  42   virtual void drawRect(const SkDraw& draw, const SkRect& r,
  43                         const SkPaint& paint) OVERRIDE;
  44   virtual void drawRRect(const SkDraw&, const SkRRect& rr,
  45                          const SkPaint& paint) OVERRIDE;
  46   virtual void drawPath(const SkDraw& draw, const SkPath& path,
  47                         const SkPaint& paint,
  48                         const SkMatrix* prePathMatrix = NULL,
  49                         bool pathIsMutable = false) OVERRIDE;
  50   virtual void drawBitmapRect(const SkDraw& draw, const SkBitmap& bitmap,
  51                               const SkRect* src, const SkRect& dst,
  52                               const SkPaint& paint,
  53                               SkCanvas::DrawBitmapRectFlags flags) SK_OVERRIDE;
  54   virtual void drawBitmap(const SkDraw& draw, const SkBitmap& bitmap,
  55                           const SkMatrix& matrix,
  56                           const SkPaint& paint) OVERRIDE;
  57   virtual void drawSprite(const SkDraw& draw, const SkBitmap& bitmap,
  58                           int x, int y, const SkPaint& paint) OVERRIDE;
  59   virtual void drawText(const SkDraw& draw, const void* text, size_t len,
  60                         SkScalar x, SkScalar y, const SkPaint& paint) OVERRIDE;
  61   virtual void drawPosText(const SkDraw& draw, const void* text, size_t len,
  62                            const SkScalar pos[], SkScalar constY,
  63                            int scalarsPerPos, const SkPaint& paint) OVERRIDE;
  64   virtual void drawTextOnPath(const SkDraw& draw, const void* text, size_t len,
  65                               const SkPath& path, const SkMatrix* matrix,
  66                               const SkPaint& paint) OVERRIDE;
  67   virtual void drawVertices(const SkDraw& draw, SkCanvas::VertexMode,
  68                             int vertexCount,
  69                             const SkPoint verts[], const SkPoint texs[],
  70                             const SkColor colors[], SkXfermode* xmode,
  71                             const uint16_t indices[], int indexCount,
  72                             const SkPaint& paint) OVERRIDE;
  73   virtual void drawDevice(const SkDraw& draw, SkBaseDevice*, int x, int y,
  74                           const SkPaint&) OVERRIDE;
  75
  76   virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
  77                              const SkClipStack&) OVERRIDE;
  78
  79   void LoadClipRegion();
  80
  81  protected:
  82   virtual SkBaseDevice* onCreateDevice(const SkImageInfo& info,
  83                                        Usage usage) OVERRIDE;
  84
  85  private:
  86   // Applies the SkPaint's painting properties in the current GDI context, if
  87   // possible. If GDI can't support all paint's properties, returns false. It
  88   // doesn't execute the "commands" in SkPaint.
  89   bool ApplyPaint(const SkPaint& paint);
  90
  91   // Selects a new object in the device context. It can be a pen, a brush, a
  92   // clipping region, a bitmap or a font. Returns the old selected object.
  93   HGDIOBJ SelectObject(HGDIOBJ object);
  94
  95   // Creates a brush according to SkPaint's properties.
  96   bool CreateBrush(bool use_brush, const SkPaint& paint);
  97
  98   // Creates a pen according to SkPaint's properties.
  99   bool CreatePen(bool use_pen, const SkPaint& paint);
 100
 101   // Restores back the previous objects (pen, brush, etc) after a paint command.
 102   void Cleanup();
 103
 104   // Creates a brush according to SkPaint's properties.
 105   bool CreateBrush(bool use_brush, COLORREF color);
 106
 107   // Creates a pen according to SkPaint's properties.
 108   bool CreatePen(bool use_pen, COLORREF color, int stroke_width,
 109                  float stroke_miter, DWORD pen_style);
 110
 111   // Draws a bitmap in the the device, using the currently loaded matrix.
 112   void InternalDrawBitmap(const SkBitmap& bitmap, int x, int y,
 113                           const SkPaint& paint);
 114
 115   // The Windows Device Context handle. It is the backend used with GDI drawing.
 116   // This backend is write-only and vectorial.
 117   HDC hdc_;
 118
 119   // Translation assigned to the DC: we need to keep track of this separately
 120   // so it can be updated even if the DC isn't created yet.
 121   SkMatrix transform_;
 122
 123   // The current clipping
 124   SkRegion clip_region_;
 125
 126   // Previously selected brush before the current drawing.
 127   HGDIOBJ previous_brush_;
 128
 129   // Previously selected pen before the current drawing.
 130   HGDIOBJ previous_pen_;
 131
 132   DISALLOW_COPY_AND_ASSIGN(VectorPlatformDeviceEmf);
 133 };
 134
 135 typedef void (*SkiaEnsureTypefaceCharactersAccessible)
 136     (const LOGFONT& font, const wchar_t* text, unsigned int text_length);
 137
 138 SK_API void SetSkiaEnsureTypefaceCharactersAccessible(
 139     SkiaEnsureTypefaceCharactersAccessible func);
 140
 141 }  // namespace skia
 142
 143 #endif  // SKIA_EXT_VECTOR_PLATFORM_DEVICE_EMF_WIN_H_