1
2/*
3 * Copyright 2010 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#ifndef SkLayer_DEFINED
11#define SkLayer_DEFINED
12
13#include "SkRefCnt.h"
14#include "SkTDArray.h"
15#include "SkColor.h"
16#include "SkMatrix.h"
17#include "SkPoint.h"
18#include "SkRect.h"
19#include "SkSize.h"
20
21class SkCanvas;
22
23class SkLayer : public SkRefCnt {
24
25public:
26    SkLayer();
27    SkLayer(const SkLayer&);
28    virtual ~SkLayer();
29
30    bool isInheritFromRootTransform() const;
31    SkScalar getOpacity() const { return m_opacity; }
32    const SkSize& getSize() const { return m_size; }
33    const SkPoint& getPosition() const { return m_position; }
34    const SkPoint& getAnchorPoint() const { return m_anchorPoint; }
35    const SkMatrix& getMatrix() const { return fMatrix; }
36    const SkMatrix& getChildrenMatrix() const { return fChildrenMatrix; }
37
38    SkScalar getWidth() const { return m_size.width(); }
39    SkScalar getHeight() const { return m_size.height(); }
40
41    void setInheritFromRootTransform(bool);
42    void setOpacity(SkScalar opacity) { m_opacity = opacity; }
43    void setSize(SkScalar w, SkScalar h) { m_size.set(w, h); }
44    void setPosition(SkScalar x, SkScalar y) { m_position.set(x, y); }
45    void setAnchorPoint(SkScalar x, SkScalar y) { m_anchorPoint.set(x, y); }
46    void setMatrix(const SkMatrix&);
47    void setChildrenMatrix(const SkMatrix&);
48
49    // children
50
51    /** Return the number of layers in our child list.
52     */
53    int countChildren() const;
54
55    /** Return the child at the specified index (starting at 0). This does not
56        affect the reference count of the child.
57     */
58    SkLayer* getChild(int index) const;
59
60    /** Add this layer to our child list at the end (top-most), and ref() it.
61        If it was already in another hierarchy, remove it from that list.
62        Return the new child.
63     */
64    SkLayer* addChild(SkLayer* child);
65
66    /** Remove this layer from its parent's list (or do nothing if it has no
67        parent.) If it had a parent, then unref() is called.
68     */
69    void detachFromParent();
70
71    /** Remove, and unref(), all of the layers in our child list.
72     */
73    void removeChildren();
74
75    /** Return our parent layer, or NULL if we have none.
76     */
77    SkLayer* getParent() const { return fParent; }
78
79    /** Return the root layer in this hiearchy. If this layer is the root
80        (i.e. has no parent), then this returns itself.
81     */
82    SkLayer* getRootLayer() const;
83
84    // coordinate system transformations
85
86    /** Return, in matrix, the matix transfomations that are applied locally
87        when this layer draws (i.e. its position and matrix/anchorPoint).
88        This does not include the childrenMatrix, since that is only applied
89        after this layer draws (but before its children draw).
90     */
91    void getLocalTransform(SkMatrix* matrix) const;
92
93    /** Return, in matrix, the concatenation of transforms that are applied
94        from this layer's root parent to the layer itself.
95        This is the matrix that is applied to the layer during drawing.
96     */
97    void localToGlobal(SkMatrix* matrix) const;
98
99    // paint method
100
101    void draw(SkCanvas*, SkScalar opacity);
102    void draw(SkCanvas* canvas) {
103        this->draw(canvas, SK_Scalar1);
104    }
105
106protected:
107    virtual void onDraw(SkCanvas*, SkScalar opacity);
108
109private:
110    enum Flags {
111        kInheritFromRootTransform_Flag = 0x01
112    };
113
114    SkLayer*    fParent;
115    SkScalar    m_opacity;
116    SkSize      m_size;
117    SkPoint     m_position;
118    SkPoint     m_anchorPoint;
119    SkMatrix    fMatrix;
120    SkMatrix    fChildrenMatrix;
121    uint32_t    fFlags;
122
123    SkTDArray<SkLayer*> m_children;
124
125    typedef SkRefCnt INHERITED;
126};
127
128#endif
129