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1 /*
2  * Copyright (C) 2014 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 #pragma once
18 
19 #include <cutils/compiler.h>
20 #include <utils/Functor.h>
21 
22 #include <androidfw/ResourceTypes.h>
23 #include "GlFunctorLifecycleListener.h"
24 #include "Properties.h"
25 #include "utils/Macros.h"
26 
27 #include <SkBitmap.h>
28 #include <SkCanvas.h>
29 #include <SkMatrix.h>
30 
31 class SkAnimatedImage;
32 class SkCanvasState;
33 class SkVertices;
34 
35 namespace minikin {
36 class Layout;
37 class MeasuredText;
38 enum class Bidi : uint8_t;
39 }
40 
41 namespace android {
42 
43 namespace uirenderer {
44 class CanvasPropertyPaint;
45 class CanvasPropertyPrimitive;
46 class DeferredLayerUpdater;
47 class DisplayList;
48 class RenderNode;
49 }
50 
51 namespace SaveFlags {
52 
53 // These must match the corresponding Canvas API constants.
54 enum {
55     Matrix = 0x01,
56     Clip = 0x02,
57     HasAlphaLayer = 0x04,
58     ClipToLayer = 0x10,
59 
60     // Helper constant
61     MatrixClip = Matrix | Clip,
62 };
63 typedef uint32_t Flags;
64 
65 }  // namespace SaveFlags
66 
67 namespace uirenderer {
68 class SkiaCanvasProxy;
69 namespace VectorDrawable {
70 class Tree;
71 };
72 };
73 typedef uirenderer::VectorDrawable::Tree VectorDrawableRoot;
74 
75 typedef std::function<void(uint16_t* text, float* positions)> ReadGlyphFunc;
76 
77 class AnimatedImageDrawable;
78 class Bitmap;
79 class Paint;
80 struct Typeface;
81 
82 class ANDROID_API Canvas {
83 public:
~Canvas()84     virtual ~Canvas(){};
85 
86     static Canvas* create_canvas(const SkBitmap& bitmap);
87 
88     /**
89      *  Create a new Canvas object that records view system drawing operations for deferred
90      *  rendering. A canvas returned by this call supports calls to the resetRecording(...) and
91      *  finishRecording() calls.  The latter call returns a DisplayList that is specific to the
92      *  RenderPipeline defined by Properties::getRenderPipelineType().
93      *
94      *  @param width of the requested Canvas.
95      *  @param height of the requested Canvas.
96      *  @param renderNode is an optional parameter that specifies the node that will consume the
97      *      DisplayList produced by the returned Canvas.  This enables the reuse of select C++
98      *      objects as a speed optimization.
99      *  @return new non-null Canvas Object.  The type of DisplayList produced by this canvas is
100             determined based on Properties::getRenderPipelineType().
101      *
102      */
103     static WARN_UNUSED_RESULT Canvas* create_recording_canvas(
104             int width, int height, uirenderer::RenderNode* renderNode = nullptr);
105 
106     /**
107      *  Create a new Canvas object which delegates to an SkCanvas.
108      *
109      *  @param skiaCanvas Must not be NULL. All drawing calls will be
110      *      delegated to this object. This function will call ref() on the
111      *      SkCanvas, and the returned Canvas will unref() it upon
112      *      destruction.
113      *  @return new non-null Canvas Object.  The type of DisplayList produced by this canvas is
114      *      determined based on  Properties::getRenderPipelineType().
115      */
116     static Canvas* create_canvas(SkCanvas* skiaCanvas);
117 
118     /**
119      *  Sets the target SDK version used to build the app.
120      *
121      *  @param apiLevel API level
122      *
123      */
124     static void setCompatibilityVersion(int apiLevel);
125 
126     /**
127      *  Provides a Skia SkCanvas interface that acts as a proxy to this Canvas.
128      *  It is useful for testing and clients (e.g. Picture/Movie) that expect to
129      *  draw their contents into an SkCanvas.
130      *
131      *  The SkCanvas returned is *only* valid until another Canvas call is made
132      *  that would change state (e.g. matrix or clip). Clients of asSkCanvas()
133      *  are responsible for *not* persisting this pointer.
134      *
135      *  Further, the returned SkCanvas should NOT be unref'd and is valid until
136      *  this canvas is destroyed or a new bitmap is set.
137      */
138     virtual SkCanvas* asSkCanvas() = 0;
139 
140     virtual void setBitmap(const SkBitmap& bitmap) = 0;
141 
142     virtual bool isOpaque() = 0;
143     virtual int width() = 0;
144     virtual int height() = 0;
145 
146     // ----------------------------------------------------------------------------
147     // View System operations (not exposed in public Canvas API)
148     // ----------------------------------------------------------------------------
149 
150     virtual void resetRecording(int width, int height,
151                                 uirenderer::RenderNode* renderNode = nullptr) = 0;
152     virtual uirenderer::DisplayList* finishRecording() = 0;
153     virtual void insertReorderBarrier(bool enableReorder) = 0;
154 
isHighContrastText()155     bool isHighContrastText() const { return uirenderer::Properties::enableHighContrastText; }
156 
157     virtual void drawRoundRect(uirenderer::CanvasPropertyPrimitive* left,
158                                uirenderer::CanvasPropertyPrimitive* top,
159                                uirenderer::CanvasPropertyPrimitive* right,
160                                uirenderer::CanvasPropertyPrimitive* bottom,
161                                uirenderer::CanvasPropertyPrimitive* rx,
162                                uirenderer::CanvasPropertyPrimitive* ry,
163                                uirenderer::CanvasPropertyPaint* paint) = 0;
164     virtual void drawCircle(uirenderer::CanvasPropertyPrimitive* x,
165                             uirenderer::CanvasPropertyPrimitive* y,
166                             uirenderer::CanvasPropertyPrimitive* radius,
167                             uirenderer::CanvasPropertyPaint* paint) = 0;
168 
169     virtual void drawLayer(uirenderer::DeferredLayerUpdater* layerHandle) = 0;
170     virtual void drawRenderNode(uirenderer::RenderNode* renderNode) = 0;
171     virtual void callDrawGLFunction(Functor* functor,
172                                     uirenderer::GlFunctorLifecycleListener* listener) = 0;
173 
174     // ----------------------------------------------------------------------------
175     // Canvas state operations
176     // ----------------------------------------------------------------------------
177 
178     // Save (layer)
179     virtual int getSaveCount() const = 0;
180     virtual int save(SaveFlags::Flags flags) = 0;
181     virtual void restore() = 0;
182     virtual void restoreToCount(int saveCount) = 0;
183 
184     virtual int saveLayer(float left, float top, float right, float bottom, const SkPaint* paint,
185                           SaveFlags::Flags flags) = 0;
186     virtual int saveLayerAlpha(float left, float top, float right, float bottom, int alpha,
187                                SaveFlags::Flags flags) = 0;
188 
189     // Matrix
190     virtual void getMatrix(SkMatrix* outMatrix) const = 0;
191     virtual void setMatrix(const SkMatrix& matrix) = 0;
192 
193     virtual void concat(const SkMatrix& matrix) = 0;
194     virtual void rotate(float degrees) = 0;
195     virtual void scale(float sx, float sy) = 0;
196     virtual void skew(float sx, float sy) = 0;
197     virtual void translate(float dx, float dy) = 0;
198 
199     // clip
200     virtual bool getClipBounds(SkRect* outRect) const = 0;
201     virtual bool quickRejectRect(float left, float top, float right, float bottom) const = 0;
202     virtual bool quickRejectPath(const SkPath& path) const = 0;
203 
204     virtual bool clipRect(float left, float top, float right, float bottom, SkClipOp op) = 0;
205     virtual bool clipPath(const SkPath* path, SkClipOp op) = 0;
206 
207     // filters
208     virtual SkDrawFilter* getDrawFilter() = 0;
209     virtual void setDrawFilter(SkDrawFilter* drawFilter) = 0;
210 
211     // WebView only
captureCanvasState()212     virtual SkCanvasState* captureCanvasState() const { return nullptr; }
213 
214     // ----------------------------------------------------------------------------
215     // Canvas draw operations
216     // ----------------------------------------------------------------------------
217     virtual void drawColor(int color, SkBlendMode mode) = 0;
218     virtual void drawPaint(const SkPaint& paint) = 0;
219 
220     // Geometry
221     virtual void drawPoint(float x, float y, const SkPaint& paint) = 0;
222     virtual void drawPoints(const float* points, int floatCount, const SkPaint& paint) = 0;
223     virtual void drawLine(float startX, float startY, float stopX, float stopY,
224                           const SkPaint& paint) = 0;
225     virtual void drawLines(const float* points, int floatCount, const SkPaint& paint) = 0;
226     virtual void drawRect(float left, float top, float right, float bottom,
227                           const SkPaint& paint) = 0;
228     virtual void drawRegion(const SkRegion& region, const SkPaint& paint) = 0;
229     virtual void drawRoundRect(float left, float top, float right, float bottom, float rx, float ry,
230                                const SkPaint& paint) = 0;
231     virtual void drawCircle(float x, float y, float radius, const SkPaint& paint) = 0;
232     virtual void drawOval(float left, float top, float right, float bottom,
233                           const SkPaint& paint) = 0;
234     virtual void drawArc(float left, float top, float right, float bottom, float startAngle,
235                          float sweepAngle, bool useCenter, const SkPaint& paint) = 0;
236     virtual void drawPath(const SkPath& path, const SkPaint& paint) = 0;
237     virtual void drawVertices(const SkVertices*, SkBlendMode, const SkPaint& paint) = 0;
238 
239     // Bitmap-based
240     virtual void drawBitmap(Bitmap& bitmap, float left, float top, const SkPaint* paint) = 0;
241     virtual void drawBitmap(Bitmap& bitmap, const SkMatrix& matrix, const SkPaint* paint) = 0;
242     virtual void drawBitmap(Bitmap& bitmap, float srcLeft, float srcTop, float srcRight,
243                             float srcBottom, float dstLeft, float dstTop, float dstRight,
244                             float dstBottom, const SkPaint* paint) = 0;
245     virtual void drawBitmapMesh(Bitmap& bitmap, int meshWidth, int meshHeight,
246                                 const float* vertices, const int* colors, const SkPaint* paint) = 0;
247     virtual void drawNinePatch(Bitmap& bitmap, const android::Res_png_9patch& chunk, float dstLeft,
248                                float dstTop, float dstRight, float dstBottom,
249                                const SkPaint* paint) = 0;
250 
251     virtual double drawAnimatedImage(AnimatedImageDrawable* imgDrawable) = 0;
252 
253     /**
254      * Specifies if the positions passed to ::drawText are absolute or relative
255      * to the (x,y) value provided.
256      *
257      * If true the (x,y) values are ignored. Otherwise, those (x,y) values need
258      * to be added to each glyph's position to get its absolute position.
259      */
260     virtual bool drawTextAbsolutePos() const = 0;
261 
262     /**
263      * Draws a VectorDrawable onto the canvas.
264      */
265     virtual void drawVectorDrawable(VectorDrawableRoot* tree) = 0;
266 
267     /**
268      * Converts utf16 text to glyphs, calculating position and boundary,
269      * and delegating the final draw to virtual drawGlyphs method.
270      */
271     void drawText(const uint16_t* text, int start, int count, int contextCount, float x, float y,
272                   minikin::Bidi bidiFlags, const Paint& origPaint, const Typeface* typeface,
273                   minikin::MeasuredText* mt);
274 
275     void drawTextOnPath(const uint16_t* text, int count, minikin::Bidi bidiFlags,
276                         const SkPath& path, float hOffset, float vOffset, const Paint& paint,
277                         const Typeface* typeface);
278 
GetApiLevel()279     static int GetApiLevel() { return sApiLevel; }
280 
281 protected:
282     void drawTextDecorations(float x, float y, float length, const SkPaint& paint);
283 
284     /**
285      * glyphFunc: valid only for the duration of the call and should not be cached.
286      * drawText: count is of glyphs
287      * totalAdvance: used to define width of text decorations (underlines, strikethroughs).
288      */
289     virtual void drawGlyphs(ReadGlyphFunc glyphFunc, int count, const SkPaint& paint, float x,
290                             float y, float boundsLeft, float boundsTop, float boundsRight,
291                             float boundsBottom, float totalAdvance) = 0;
292     virtual void drawLayoutOnPath(const minikin::Layout& layout, float hOffset, float vOffset,
293                                   const SkPaint& paint, const SkPath& path, size_t start,
294                                   size_t end) = 0;
295     static int sApiLevel;
296 
297     friend class DrawTextFunctor;
298     friend class DrawTextOnPathFunctor;
299     friend class uirenderer::SkiaCanvasProxy;
300 };
301 
302 };  // namespace android
303