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#ifndef SkDrawLooper_DEFINED
#define SkDrawLooper_DEFINED
#include "SkFlattenable.h"
////////////////// EXPERIMENTAL <reed> //////////////////////////
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 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.
<reed> is this required, since the subclass knows when it is done???
<reed> 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() {}
};
#endif
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