include/graphics/SkBounder.h

/* include/graphics/SkBounder.h
**
** Copyright 2006, Google Inc.
**
** Licensed under the Apache License, Version 2.0 (the "License"); 
** you may not use this file except in compliance with the License. 
** You may obtain a copy of the License at 
**
**     http://www.apache.org/licenses/LICENSE-2.0 
**
** Unless required by applicable law or agreed to in writing, software 
** distributed under the License is distributed on an "AS IS" BASIS, 
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
** See the License for the specific language governing permissions and 
** limitations under the License.
*/

#ifndef SkBounder_DEFINED
#define SkBounder_DEFINED

#include "SkTypes.h"
#include "SkRefCnt.h"

struct SkRect16;
struct SkPoint;
struct SkRect;
class SkPaint;
class SkPath;
class SkRegion;

/** \class SkBounder

    Base class for intercepting the device bounds of shapes before they are drawn.
    Install a subclass of this in your canvas.
*/
class SkBounder : public SkRefCnt {
public:
    bool doIRect(const SkRect16&, const SkRegion&);
    bool doHairline(const SkPoint&, const SkPoint&, const SkPaint&, const SkRegion&);
    bool doRect(const SkRect&, const SkPaint&, const SkRegion&);
    bool doPath(const SkPath&, const SkPaint&, const SkRegion&, bool doFill);

protected:
    /** Override in your subclass. This is called with the device bounds of an
        object (text, geometry, image) just before it is drawn. If your method
        returns false, the drawing for that shape is aborted. If your method
        returns true, drawing continues. The bounds your method receives have already
        been transformed in to device coordinates, and clipped to the current clip.
    */
    virtual bool onIRect(const SkRect16&) = 0;

    /** Called after each shape has been drawn. The default implementation does
        nothing, but your override could use this notification to signal itself
        that the offscreen being rendered into needs to be updated to the screen.
    */
    virtual void commit();

    friend class SkAutoBounderCommit;
};

#endif