// Copyright (c) 2010 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 GFX_CANVAS_SKIA_H_
#define GFX_CANVAS_SKIA_H_
#pragma once
#include "base/basictypes.h"
#include "gfx/canvas.h"
#include "skia/ext/platform_canvas.h"
#if defined(OS_POSIX) && !defined(OS_MACOSX)
typedef struct _GdkPixbuf GdkPixbuf;
#endif
namespace gfx {
class Canvas;
// CanvasSkia is a SkCanvas subclass that provides a number of methods for
// common operations used throughout an application built using base/gfx and
// app/gfx.
//
// All methods that take integer arguments (as is used throughout views)
// end with Int. If you need to use methods provided by the superclass
// you'll need to do a conversion. In particular you'll need to use
// macro SkIntToScalar(xxx), or if converting from a scalar to an integer
// SkScalarRound.
//
// A handful of methods in this class are overloaded providing an additional
// argument of type SkXfermode::Mode. SkXfermode::Mode specifies how the
// source and destination colors are combined. Unless otherwise specified,
// the variant that does not take a SkXfermode::Mode uses a transfer mode
// of kSrcOver_Mode.
class CanvasSkia : public skia::PlatformCanvas,
public Canvas {
public:
// Creates an empty Canvas. Callers must use initialize before using the
// canvas.
CanvasSkia();
CanvasSkia(int width, int height, bool is_opaque);
virtual ~CanvasSkia();
// Compute the size required to draw some text with the provided font.
// Attempts to fit the text with the provided width and height. Increases
// height and then width as needed to make the text fit. This method
// supports multiple lines.
static void SizeStringInt(const std::wstring& text,
const gfx::Font& font,
int* width, int* height,
int flags);
// Returns the default text alignment to be used when drawing text on a
// gfx::CanvasSkia based on the directionality of the system locale language.
// This function is used by gfx::Canvas::DrawStringInt when the text alignment
// is not specified.
//
// This function returns either gfx::Canvas::TEXT_ALIGN_LEFT or
// gfx::Canvas::TEXT_ALIGN_RIGHT.
static int DefaultCanvasTextAlignment();
#if defined(OS_POSIX) && !defined(OS_MACOSX)
// Draw the pixbuf in its natural size at (x, y).
void DrawGdkPixbuf(GdkPixbuf* pixbuf, int x, int y);
#endif
#ifdef OS_WIN // Only implemented on Windows for now.
// Draws text with a 1-pixel halo around it of the given color. It allows
// ClearType to be drawn to an otherwise transparenct bitmap for drag images.
// Drag images have only 1-bit of transparency, so we don't do any fancy
// blurring.
void DrawStringWithHalo(const std::wstring& text,
const gfx::Font& font,
const SkColor& text_color,
const SkColor& halo_color,
int x, int y, int w, int h,
int flags);
#endif
// Extracts a bitmap from the contents of this canvas.
SkBitmap ExtractBitmap() const;
// Overridden from Canvas:
virtual void Save();
virtual void SaveLayerAlpha(uint8 alpha);
virtual void SaveLayerAlpha(uint8 alpha, const gfx::Rect& layer_bounds);
virtual void Restore();
virtual bool ClipRectInt(int x, int y, int w, int h);
virtual void TranslateInt(int x, int y);
virtual void ScaleInt(int x, int y);
virtual void FillRectInt(const SkColor& color, int x, int y, int w, int h);
virtual void FillRectInt(const gfx::Brush* brush, int x, int y, int w, int h);
virtual void DrawRectInt(const SkColor& color, int x, int y, int w, int h);
virtual void DrawRectInt(const SkColor& color,
int x, int y, int w, int h,
SkXfermode::Mode mode);
virtual void DrawRectInt(int x, int y, int w, int h, const SkPaint& paint);
virtual void DrawLineInt(const SkColor& color,
int x1, int y1,
int x2, int y2);
virtual void DrawBitmapInt(const SkBitmap& bitmap, int x, int y);
virtual void DrawBitmapInt(const SkBitmap& bitmap,
int x, int y,
const SkPaint& paint);
virtual void DrawBitmapInt(const SkBitmap& bitmap,
int src_x, int src_y, int src_w, int src_h,
int dest_x, int dest_y, int dest_w, int dest_h,
bool filter);
virtual void DrawBitmapInt(const SkBitmap& bitmap,
int src_x, int src_y, int src_w, int src_h,
int dest_x, int dest_y, int dest_w, int dest_h,
bool filter,
const SkPaint& paint);
virtual void DrawStringInt(const std::wstring& text,
const gfx::Font& font,
const SkColor& color,
int x, int y, int w, int h);
virtual void DrawStringInt(const std::wstring& text,
const gfx::Font& font,
const SkColor& color,
const gfx::Rect& display_rect);
virtual void DrawStringInt(const std::wstring& text,
const gfx::Font& font,
const SkColor& color,
int x, int y, int w, int h,
int flags);
virtual void DrawFocusRect(int x, int y, int width, int height);
virtual void TileImageInt(const SkBitmap& bitmap, int x, int y, int w, int h);
virtual void TileImageInt(const SkBitmap& bitmap,
int src_x, int src_y,
int dest_x, int dest_y, int w, int h);
virtual gfx::NativeDrawingContext BeginPlatformPaint();
virtual void EndPlatformPaint();
virtual CanvasSkia* AsCanvasSkia();
virtual const CanvasSkia* AsCanvasSkia() const;
private:
// Test whether the provided rectangle intersects the current clip rect.
bool IntersectsClipRectInt(int x, int y, int w, int h);
#if defined(OS_WIN)
// Draws text with the specified color, font and location. The text is
// aligned to the left, vertically centered, clipped to the region. If the
// text is too big, it is truncated and '...' is added to the end.
void DrawStringInt(const std::wstring& text,
HFONT font,
const SkColor& color,
int x, int y, int w, int h,
int flags);
#endif
DISALLOW_COPY_AND_ASSIGN(CanvasSkia);
};
} // namespace gfx;
#endif // GFX_CANVAS_SKIA_H_