SkBlurDrawLooper.h revision 8a1c16ff38322f0210116fa7293eb8817c7e477e 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef SkBlurDrawLooper_DEFINED
18#define SkBlurDrawLooper_DEFINED
19
20#include "SkDrawLooper.h"
21#include "SkColor.h"
22
23class SkMaskFilter;
24
25/** \class SkBlurDrawLooper
26    This class draws a shadow of the object (possibly offset), and then draws
27    the original object in its original position.
28    should there be an option to just draw the shadow/blur layer? webkit?
29*/
30class SkBlurDrawLooper : public SkDrawLooper {
31public:
32    SkBlurDrawLooper(SkScalar radius, SkScalar dx, SkScalar dy, SkColor color);
33    virtual ~SkBlurDrawLooper();
34
35    // overrides from SkDrawLooper
36    virtual void init(SkCanvas*, SkPaint*);
37    virtual bool next();
38    virtual void restore();
39
40    static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer) {
41        return SkNEW_ARGS(SkBlurDrawLooper, (buffer));
42    }
43
44protected:
45    SkBlurDrawLooper(SkFlattenableReadBuffer&);
46    // overrides from SkFlattenable
47    virtual void flatten(SkFlattenableWriteBuffer& );
48    virtual Factory getFactory() { return CreateProc; }
49
50private:
51    SkCanvas*       fCanvas;
52    SkPaint*        fPaint;
53    SkMaskFilter*   fBlur;
54    SkScalar        fDx, fDy;
55    SkColor         fBlurColor;
56    SkColor         fSavedColor;    // remember the original
57    int             fSaveCount;
58
59    enum State {
60        kBeforeEdge,
61        kAfterEdge,
62        kDone
63    };
64    State   fState;
65
66    typedef SkDrawLooper INHERITED;
67};
68
69#endif
70