7ffb1b21ab
- Export/import skia APIs if SKIA_DLL is defined. - This change has no effect on skia. Review URL: http://codereview.appspot.com/4282042 git-svn-id: http://skia.googlecode.com/svn/trunk@944 2bbb7eff-a529-9590-31e7-b0007b416f81
65 lines
2.4 KiB
C++
65 lines
2.4 KiB
C++
/*
|
|
* Copyright (C) 2008 The Android Open Source Project
|
|
*
|
|
* 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 SkDrawLooper_DEFINED
|
|
#define SkDrawLooper_DEFINED
|
|
|
|
#include "SkFlattenable.h"
|
|
|
|
////////////////// EXPERIMENTAL //////////////////////////
|
|
|
|
class SkCanvas;
|
|
class SkPaint;
|
|
|
|
/** \class SkDrawLooper
|
|
Subclasses of SkDrawLooper can be attached to a SkPaint. Where they are,
|
|
and something is drawn to a canvas with that paint, the looper subclass will
|
|
be called, allowing it to modify the canvas and/or paint for that draw call.
|
|
More than that, via the next() method, the looper can modify the draw to be
|
|
invoked multiple times (hence the name loop-er), allow it to perform effects
|
|
like shadows or frame/fills, that require more than one pass.
|
|
*/
|
|
class SK_API SkDrawLooper : public SkFlattenable {
|
|
public:
|
|
/** Called right before something is being drawn to the specified canvas
|
|
with the specified paint. Subclass that want to modify either parameter
|
|
can do so now.
|
|
*/
|
|
virtual void init(SkCanvas*, SkPaint*) {}
|
|
/** Called in a loop (after init()). Each time true is returned, the object
|
|
is drawn (possibly with a modified canvas and/or paint). When false is
|
|
finally returned, drawing for the object stops.
|
|
*/
|
|
virtual bool next() { return false; }
|
|
/** Called after the looper has finally returned false from next(), allowing
|
|
the looper to restore the canvas/paint to their original states.
|
|
is this required, since the subclass knows when it is done???
|
|
should we pass the canvas/paint here, and/or to the next call
|
|
so that subclasses don't need to retain pointers to them during the
|
|
loop?
|
|
*/
|
|
virtual void restore() {}
|
|
|
|
protected:
|
|
SkDrawLooper() {}
|
|
SkDrawLooper(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {}
|
|
|
|
private:
|
|
typedef SkFlattenable INHERITED;
|
|
};
|
|
|
|
#endif
|