60 lines
1.7 KiB
C
60 lines
1.7 KiB
C
|
/*
|
||
|
|
* Copyright 2014 Google Inc.
|
||
|
|
*
|
||
|
|
* Use of this source code is governed by a BSD-style license that can be
|
||
|
|
* found in the LICENSE file.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef SkCanvasDrawable_DEFINED
|
||
|
|
#define SkCanvasDrawable_DEFINED
|
||
|
|
|
||
|
|
#include "SkRefCnt.h"
|
||
|
|
|
||
|
|
class SkCanvas;
|
||
|
|
struct SkRect;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Base-class to capture a set of drawing commands (sent to SkCanvas). Instances of this class
|
||
|
|
* need not be thread-safe, but they must be able to be used in a thread different from where
|
||
|
|
* they were created.
|
||
|
|
*/
|
||
|
|
class SkCanvasDrawable : public SkRefCnt {
|
||
|
|
public:
|
||
|
|
SkCanvasDrawable();
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Draws into the specified content. The drawing sequence will be balanced upon return
|
||
|
|
* (i.e. the saveLevel() on the canvas will match what it was when draw() was called,
|
||
|
|
* and the current matrix and clip settings will not be changed.
|
||
|
|
*/
|
||
|
|
void draw(SkCanvas*);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Return a unique value for this instance. If two calls to this return the same value,
|
||
|
|
* it is presumed that calling the draw() method will render the same thing as well.
|
||
|
|
*
|
||
|
|
* Subclasses that change their state should call notifyDrawingChanged() to ensure that
|
||
|
|
* a new value will be returned the next time it is called.
|
||
|
|
*/
|
||
|
|
uint32_t getGenerationID();
|
||
|
|
|
||
|
|
/**
|
||
|
|
* If the drawable knows a bounds that will contains all of its drawing, return true and
|
||
|
|
* set the parameter to that rectangle. If one is not known, ignore the parameter and
|
||
|
|
* return false.
|
||
|
|
*/
|
||
|
|
bool getBounds(SkRect*);
|
||
|
|
|
||
|
|
void notifyDrawingChanged();
|
||
|
|
|
||
|
|
protected:
|
||
|
|
virtual void onDraw(SkCanvas*) = 0;
|
||
|
|
|
||
|
|
virtual bool onGetBounds(SkRect*) { return false; }
|
||
|
|
|
||
|
|
private:
|
||
|
|
int32_t fGenerationID;
|
||
|
|
};
|
||
|
|
|
||
|
|
#endif
|