Canvas.java revision 54b6cfa9a9e5b861a9930af873580d6dc20f773c
1/*
2 * Copyright (C) 2006 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
17package android.graphics;
18
19import android.text.TextUtils;
20import android.text.SpannedString;
21import android.text.SpannableString;
22import android.text.GraphicsOperations;
23
24import javax.microedition.khronos.opengles.GL;
25
26/**
27 * The Canvas class holds the "draw" calls. To draw something, you need
28 * 4 basic components: A Bitmap to hold the pixels, a Canvas to host
29 * the draw calls (writing into the bitmap), a drawing primitive (e.g. Rect,
30 * Path, text, Bitmap), and a paint (to describe the colors and styles for the
31 * drawing).
32 */
33public class Canvas {
34    // assigned in constructors, freed in finalizer
35    final int mNativeCanvas;
36
37    /*  Our native canvas can be either a raster, gl, or picture canvas.
38        If we are raster, then mGL will be null, and mBitmap may or may not be
39        present (our default constructor creates a raster canvas but no
40        java-bitmap is). If we are a gl-based, then mBitmap will be null, and
41        mGL will not be null. Thus both cannot be non-null, but its possible
42        for both to be null.
43    */
44    private Bitmap  mBitmap;    // if not null, mGL must be null
45    private GL      mGL;        // if not null, mBitmap must be null
46
47    // optional field set by the caller
48    private DrawFilter  mDrawFilter;
49
50    // Used by native code
51    @SuppressWarnings({"UnusedDeclaration"})
52    private int         mSurfaceFormat;
53
54    /**
55     * Construct an empty raster canvas. Use setBitmap() to specify a bitmap to
56     * draw into.
57     */
58    public Canvas() {
59        // 0 means no native bitmap
60        mNativeCanvas = initRaster(0);
61    }
62
63    /**
64     * Construct a canvas with the specified bitmap to draw into. The bitmap
65     * must be mutable.
66     *
67     * @param bitmap Specifies a mutable bitmap for the canvas to draw into.
68     */
69    public Canvas(Bitmap bitmap) {
70        if (!bitmap.isMutable()) {
71            throw new IllegalStateException(
72                            "Immutable bitmap passed to Canvas constructor");
73        }
74        throwIfRecycled(bitmap);
75        mNativeCanvas = initRaster(bitmap.ni());
76        mBitmap = bitmap;
77    }
78
79    /*package*/ Canvas(int nativeCanvas) {
80        if (nativeCanvas == 0) {
81            throw new IllegalStateException();
82        }
83        mNativeCanvas = nativeCanvas;
84    }
85
86    /**
87     * Construct a canvas with the specified gl context. All drawing through
88     * this canvas will be redirected to OpenGL. Note: some features may not
89     * be supported in this mode (e.g. some GL implementations may not support
90     * antialiasing or certain effects like ColorMatrix or certain Xfermodes).
91     * However, no exception will be thrown in those cases.
92     */
93    public Canvas(GL gl) {
94        mNativeCanvas = initGL();
95        mGL = gl;
96    }
97
98    /**
99     * Return the GL object associated with this canvas, or null if it is not
100     * backed by GL.
101     */
102    public GL getGL() {
103        return mGL;
104    }
105
106    /**
107     * Call this to free up OpenGL resources that may be cached or allocated
108     * on behalf of the Canvas. Any subsequent drawing with a GL-backed Canvas
109     * will have to recreate those resources.
110     */
111    public static native void freeGlCaches();
112
113    /**
114     * Specify a bitmap for the canvas to draw into.
115     *
116     * @param bitmap Specifies a mutable bitmap for the canvas to draw into.
117     */
118    public void setBitmap(Bitmap bitmap) {
119        if (!bitmap.isMutable()) {
120            throw new IllegalStateException();
121        }
122        if (mGL != null) {
123            throw new RuntimeException("Can't set a bitmap device on a GL canvas");
124        }
125        throwIfRecycled(bitmap);
126
127        native_setBitmap(mNativeCanvas, bitmap.ni());
128        mBitmap = bitmap;
129    }
130
131    /**
132     * Set the viewport dimensions if this canvas is GL based. If it is not,
133     * this method is ignored and no exception is thrown.
134     *
135     *  @param width    The width of the viewport
136     *  @param height   The height of the viewport
137     */
138    public void setViewport(int width, int height) {
139        if (mGL != null) {
140            nativeSetViewport(mNativeCanvas, width, height);
141        }
142    }
143
144    /**
145     * Return true if the device that the current layer draws into is opaque
146     * (i.e. does not support per-pixel alpha).
147     *
148     * @return true if the device that the current layer draws into is opaque
149     */
150    public native boolean isOpaque();
151
152    /**
153     * Returns the width of the current drawing layer
154     *
155     * @return the width of the current drawing layer
156     */
157    public native int getWidth();
158
159    /**
160     * Returns the height of the current drawing layer
161     *
162     * @return the height of the current drawing layer
163     */
164    public native int getHeight();
165
166    // the SAVE_FLAG constants must match their native equivalents
167
168    /** restore the current matrix when restore() is called */
169    public static final int MATRIX_SAVE_FLAG = 0x01;
170    /** restore the current clip when restore() is called */
171    public static final int CLIP_SAVE_FLAG = 0x02;
172    /** the layer needs to per-pixel alpha */
173    public static final int HAS_ALPHA_LAYER_SAVE_FLAG = 0x04;
174    /** the layer needs to 8-bits per color component */
175    public static final int FULL_COLOR_LAYER_SAVE_FLAG = 0x08;
176    /** clip against the layer's bounds */
177    public static final int CLIP_TO_LAYER_SAVE_FLAG = 0x10;
178    /** restore everything when restore() is called */
179    public static final int ALL_SAVE_FLAG = 0x1F;
180
181    /**
182     * Saves the current matrix and clip onto a private stack. Subsequent
183     * calls to translate,scale,rotate,skew,concat or clipRect,clipPath
184     * will all operate as usual, but when the balancing call to restore()
185     * is made, those calls will be forgotten, and the settings that existed
186     * before the save() will be reinstated.
187     *
188     * @return The value to pass to restoreToCount() to balance this save()
189     */
190    public native int save();
191
192    /**
193     * Based on saveFlags, can save the current matrix and clip onto a private
194     * stack. Subsequent calls to translate,scale,rotate,skew,concat or
195     * clipRect,clipPath will all operate as usual, but when the balancing
196     * call to restore() is made, those calls will be forgotten, and the
197     * settings that existed before the save() will be reinstated.
198     *
199     * @param saveFlags flag bits that specify which parts of the Canvas state
200     *                  to save/restore
201     * @return The value to pass to restoreToCount() to balance this save()
202     */
203    public native int save(int saveFlags);
204
205    /**
206     * This behaves the same as save(), but in addition it allocates an
207     * offscreen bitmap. All drawing calls are directed there, and only when
208     * the balancing call to restore() is made is that offscreen transfered to
209     * the canvas (or the previous layer). Subsequent calls to translate,
210     * scale, rotate, skew, concat or clipRect, clipPath all operate on this
211     * copy. When the balancing call to restore() is made, this copy is
212     * deleted and the previous matrix/clip state is restored.
213     *
214     * @param bounds May be null. The maximum size the offscreen bitmap
215     *               needs to be (in local coordinates)
216     * @param paint  This is copied, and is applied to the offscreen when
217     *               restore() is called.
218     * @param saveFlags  see _SAVE_FLAG constants
219     * @return       value to pass to restoreToCount() to balance this save()
220     */
221    public int saveLayer(RectF bounds, Paint paint, int saveFlags) {
222        return native_saveLayer(mNativeCanvas, bounds,
223                                paint != null ? paint.mNativePaint : 0,
224                                saveFlags);
225    }
226
227    /**
228     * Helper version of saveLayer() that takes 4 values rather than a RectF.
229     */
230    public int saveLayer(float left, float top, float right, float bottom,
231                         Paint paint, int saveFlags) {
232        return native_saveLayer(mNativeCanvas, left, top, right, bottom,
233                                paint != null ? paint.mNativePaint : 0,
234                                saveFlags);
235    }
236
237    /**
238     * This behaves the same as save(), but in addition it allocates an
239     * offscreen bitmap. All drawing calls are directed there, and only when
240     * the balancing call to restore() is made is that offscreen transfered to
241     * the canvas (or the previous layer). Subsequent calls to translate,
242     * scale, rotate, skew, concat or clipRect, clipPath all operate on this
243     * copy. When the balancing call to restore() is made, this copy is
244     * deleted and the previous matrix/clip state is restored.
245     *
246     * @param bounds    The maximum size the offscreen bitmap needs to be
247     *                  (in local coordinates)
248     * @param alpha     The alpha to apply to the offscreen when when it is
249                        drawn during restore()
250     * @param saveFlags see _SAVE_FLAG constants
251     * @return          value to pass to restoreToCount() to balance this call
252     */
253    public int saveLayerAlpha(RectF bounds, int alpha, int saveFlags) {
254        alpha = Math.min(255, Math.max(0, alpha));
255        return native_saveLayerAlpha(mNativeCanvas, bounds, alpha, saveFlags);
256    }
257
258    /**
259     * Helper for saveLayerAlpha() that takes 4 values instead of a RectF.
260     */
261    public int saveLayerAlpha(float left, float top, float right, float bottom,
262                              int alpha, int saveFlags) {
263        return native_saveLayerAlpha(mNativeCanvas, left, top, right, bottom,
264                                     alpha, saveFlags);
265    }
266
267    /**
268     * This call balances a previous call to save(), and is used to remove all
269     * modifications to the matrix/clip state since the last save call. It is
270     * an error to call restore() more times than save() was called.
271     */
272    public native void restore();
273
274    /**
275     * Returns the number of matrix/clip states on the Canvas' private stack.
276     * This will equal # save() calls - # restore() calls.
277     */
278    public native int getSaveCount();
279
280    /**
281     * Efficient way to pop any calls to save() that happened after the save
282     * count reached saveCount. It is an error for saveCount to be less than 1.
283     *
284     * Example:
285     *    int count = canvas.save();
286     *    ... // more calls potentially to save()
287     *    canvas.restoreToCount(count);
288     *    // now the canvas is back in the same state it was before the initial
289     *    // call to save().
290     *
291     * @param saveCount The save level to restore to.
292     */
293    public native void restoreToCount(int saveCount);
294
295    /**
296     * Preconcat the current matrix with the specified translation
297     *
298     * @param dx The distance to translate in X
299     * @param dy The distance to translate in Y
300    */
301    public native void translate(float dx, float dy);
302
303    /**
304     * Preconcat the current matrix with the specified scale.
305     *
306     * @param sx The amount to scale in X
307     * @param sy The amount to scale in Y
308     */
309    public native void scale(float sx, float sy);
310
311    /**
312     * Preconcat the current matrix with the specified scale.
313     *
314     * @param sx The amount to scale in X
315     * @param sy The amount to scale in Y
316     * @param px The x-coord for the pivot point (unchanged by the rotation)
317     * @param py The y-coord for the pivot point (unchanged by the rotation)
318     */
319    public final void scale(float sx, float sy, float px, float py) {
320        translate(px, py);
321        scale(sx, sy);
322        translate(-px, -py);
323    }
324
325    /**
326     * Preconcat the current matrix with the specified rotation.
327     *
328     * @param degrees The amount to rotate, in degrees
329     */
330    public native void rotate(float degrees);
331
332    /**
333     * Preconcat the current matrix with the specified rotation.
334     *
335     * @param degrees The amount to rotate, in degrees
336     * @param px The x-coord for the pivot point (unchanged by the rotation)
337     * @param py The y-coord for the pivot point (unchanged by the rotation)
338     */
339    public final void rotate(float degrees, float px, float py) {
340        translate(px, py);
341        rotate(degrees);
342        translate(-px, -py);
343    }
344
345    /**
346     * Preconcat the current matrix with the specified skew.
347     *
348     * @param sx The amount to skew in X
349     * @param sy The amount to skew in Y
350     */
351    public native void skew(float sx, float sy);
352
353    /**
354     * Preconcat the current matrix with the specified matrix.
355     *
356     * @param matrix The matrix to preconcatenate with the current matrix
357     */
358    public void concat(Matrix matrix) {
359        native_concat(mNativeCanvas, matrix.native_instance);
360    }
361
362    /**
363     * Completely replace the current matrix with the specified matrix. If the
364     * matrix parameter is null, then the current matrix is reset to identity.
365     *
366     * @param matrix The matrix to replace the current matrix with. If it is
367     *               null, set the current matrix to identity.
368     */
369    public void setMatrix(Matrix matrix) {
370        native_setMatrix(mNativeCanvas,
371                         matrix == null ? 0 : matrix.native_instance);
372    }
373
374    /**
375     * Return, in ctm, the current transformation matrix. This does not alter
376     * the matrix in the canvas, but just returns a copy of it.
377     */
378    public void getMatrix(Matrix ctm) {
379        native_getCTM(mNativeCanvas, ctm.native_instance);
380    }
381
382    /**
383     * Return a new matrix with a copy of the canvas' current transformation
384     * matrix.
385     */
386    public final Matrix getMatrix() {
387        Matrix m = new Matrix();
388        getMatrix(m);
389        return m;
390    }
391
392    /**
393     * Modify the current clip with the specified rectangle.
394     *
395     * @param rect The rect to intersect with the current clip
396     * @param op How the clip is modified
397     * @return true if the resulting clip is non-empty
398     */
399    public boolean clipRect(RectF rect, Region.Op op) {
400        return native_clipRect(mNativeCanvas,
401                               rect.left, rect.top, rect.right, rect.bottom,
402                               op.nativeInt);
403    }
404
405    /**
406     * Modify the current clip with the specified rectangle, which is
407     * expressed in local coordinates.
408     *
409     * @param rect The rectangle to intersect with the current clip.
410     * @param op How the clip is modified
411     * @return true if the resulting clip is non-empty
412     */
413    public boolean clipRect(Rect rect, Region.Op op) {
414        return native_clipRect(mNativeCanvas,
415                               rect.left, rect.top, rect.right, rect.bottom,
416                               op.nativeInt);
417    }
418
419    /**
420     * Intersect the current clip with the specified rectangle, which is
421     * expressed in local coordinates.
422     *
423     * @param rect The rectangle to intersect with the current clip.
424     * @return true if the resulting clip is non-empty
425     */
426    public native boolean clipRect(RectF rect);
427
428    /**
429     * Intersect the current clip with the specified rectangle, which is
430     * expressed in local coordinates.
431     *
432     * @param rect The rectangle to intersect with the current clip.
433     * @return true if the resulting clip is non-empty
434     */
435    public native boolean clipRect(Rect rect);
436
437    /**
438     * Modify the current clip with the specified rectangle, which is
439     * expressed in local coordinates.
440     *
441     * @param left   The left side of the rectangle to intersect with the
442     *               current clip
443     * @param top    The top of the rectangle to intersect with the current
444     *               clip
445     * @param right  The right side of the rectangle to intersect with the
446     *               current clip
447     * @param bottom The bottom of the rectangle to intersect with the current
448     *               clip
449     * @param op     How the clip is modified
450     * @return       true if the resulting clip is non-empty
451     */
452    public boolean clipRect(float left, float top, float right, float bottom,
453                            Region.Op op) {
454        return native_clipRect(mNativeCanvas, left, top, right, bottom,
455                               op.nativeInt);
456    }
457
458    /**
459     * Intersect the current clip with the specified rectangle, which is
460     * expressed in local coordinates.
461     *
462     * @param left   The left side of the rectangle to intersect with the
463     *               current clip
464     * @param top    The top of the rectangle to intersect with the current clip
465     * @param right  The right side of the rectangle to intersect with the
466     *               current clip
467     * @param bottom The bottom of the rectangle to intersect with the current
468     *               clip
469     * @return       true if the resulting clip is non-empty
470     */
471    public native boolean clipRect(float left, float top,
472                                   float right, float bottom);
473
474    /**
475     * Intersect the current clip with the specified rectangle, which is
476     * expressed in local coordinates.
477     *
478     * @param left   The left side of the rectangle to intersect with the
479     *               current clip
480     * @param top    The top of the rectangle to intersect with the current clip
481     * @param right  The right side of the rectangle to intersect with the
482     *               current clip
483     * @param bottom The bottom of the rectangle to intersect with the current
484     *               clip
485     * @return       true if the resulting clip is non-empty
486     */
487    public native boolean clipRect(int left, int top,
488                                   int right, int bottom);
489
490    /**
491        * Modify the current clip with the specified path.
492     *
493     * @param path The path to operate on the current clip
494     * @param op   How the clip is modified
495     * @return     true if the resulting is non-empty
496     */
497    public boolean clipPath(Path path, Region.Op op) {
498        return native_clipPath(mNativeCanvas, path.ni(), op.nativeInt);
499    }
500
501    /**
502     * Intersect the current clip with the specified path.
503     *
504     * @param path The path to intersect with the current clip
505     * @return     true if the resulting is non-empty
506     */
507    public boolean clipPath(Path path) {
508        return clipPath(path, Region.Op.INTERSECT);
509    }
510
511    /**
512     * Modify the current clip with the specified region. Note that unlike
513     * clipRect() and clipPath() which transform their arguments by the
514     * current matrix, clipRegion() assumes its argument is already in the
515     * coordinate system of the current layer's bitmap, and so not
516     * transformation is performed.
517     *
518     * @param region The region to operate on the current clip, based on op
519     * @param op How the clip is modified
520     * @return true if the resulting is non-empty
521     */
522    public boolean clipRegion(Region region, Region.Op op) {
523        return native_clipRegion(mNativeCanvas, region.ni(), op.nativeInt);
524    }
525
526    /**
527     * Intersect the current clip with the specified region. Note that unlike
528     * clipRect() and clipPath() which transform their arguments by the
529     * current matrix, clipRegion() assumes its argument is already in the
530     * coordinate system of the current layer's bitmap, and so not
531     * transformation is performed.
532     *
533     * @param region The region to operate on the current clip, based on op
534     * @return true if the resulting is non-empty
535     */
536    public boolean clipRegion(Region region) {
537        return clipRegion(region, Region.Op.INTERSECT);
538    }
539
540    public DrawFilter getDrawFilter() {
541        return mDrawFilter;
542    }
543
544    public void setDrawFilter(DrawFilter filter) {
545        int nativeFilter = 0;
546        if (filter != null) {
547            nativeFilter = filter.mNativeInt;
548        }
549        mDrawFilter = filter;
550        nativeSetDrawFilter(mNativeCanvas, nativeFilter);
551    }
552
553    public enum EdgeType {
554        BW(0),  //!< treat edges by just rounding to nearest pixel boundary
555        AA(1);  //!< treat edges by rounding-out, since they may be antialiased
556
557        EdgeType(int nativeInt) {
558            this.nativeInt = nativeInt;
559        }
560        final int nativeInt;
561    }
562
563    /**
564     * Return true if the specified rectangle, after being transformed by the
565     * current matrix, would lie completely outside of the current clip. Call
566     * this to check if an area you intend to draw into is clipped out (and
567     * therefore you can skip making the draw calls).
568     *
569     * @param rect  the rect to compare with the current clip
570     * @param type  specifies how to treat the edges (BW or antialiased)
571     * @return      true if the rect (transformed by the canvas' matrix)
572     *              does not intersect with the canvas' clip
573     */
574    public boolean quickReject(RectF rect, EdgeType type) {
575        return native_quickReject(mNativeCanvas, rect, type.nativeInt);
576    }
577
578    /**
579     * Return true if the specified path, after being transformed by the
580     * current matrix, would lie completely outside of the current clip. Call
581     * this to check if an area you intend to draw into is clipped out (and
582     * therefore you can skip making the draw calls). Note: for speed it may
583     * return false even if the path itself might not intersect the clip
584     * (i.e. the bounds of the path intersects, but the path does not).
585     *
586     * @param path        The path to compare with the current clip
587     * @param type        true if the path should be considered antialiased,
588     *                    since that means it may
589     *                    affect a larger area (more pixels) than
590     *                    non-antialiased.
591     * @return            true if the path (transformed by the canvas' matrix)
592     *                    does not intersect with the canvas' clip
593     */
594    public boolean quickReject(Path path, EdgeType type) {
595        return native_quickReject(mNativeCanvas, path.ni(), type.nativeInt);
596    }
597
598    /**
599     * Return true if the specified rectangle, after being transformed by the
600     * current matrix, would lie completely outside of the current clip. Call
601     * this to check if an area you intend to draw into is clipped out (and
602     * therefore you can skip making the draw calls).
603     *
604     * @param left        The left side of the rectangle to compare with the
605     *                    current clip
606     * @param top         The top of the rectangle to compare with the current
607     *                    clip
608     * @param right       The right side of the rectangle to compare with the
609     *                    current clip
610     * @param bottom      The bottom of the rectangle to compare with the
611     *                    current clip
612     * @param type        true if the rect should be considered antialiased,
613     *                    since that means it may affect a larger area (more
614     *                    pixels) than non-antialiased.
615     * @return            true if the rect (transformed by the canvas' matrix)
616     *                    does not intersect with the canvas' clip
617     */
618    public boolean quickReject(float left, float top, float right, float bottom,
619                               EdgeType type) {
620        return native_quickReject(mNativeCanvas, left, top, right, bottom,
621                                  type.nativeInt);
622    }
623
624    /**
625     * Retrieve the clip bounds, returning true if they are non-empty.
626     *
627     * @param bounds Return the clip bounds here. If it is null, ignore it but
628     *               still return true if the current clip is non-empty.
629     * @return true if the current clip is non-empty.
630     */
631    public boolean getClipBounds(Rect bounds) {
632        return native_getClipBounds(mNativeCanvas, bounds);
633    }
634
635    /**
636     * Retrieve the clip bounds.
637     *
638     * @return the clip bounds, or [0, 0, 0, 0] if the clip is empty.
639     */
640    public final Rect getClipBounds() {
641        Rect r = new Rect();
642        getClipBounds(r);
643        return r;
644    }
645
646    /**
647     * Fill the entire canvas' bitmap (restricted to the current clip) with the
648     * specified RGB color, using srcover porterduff mode.
649     *
650     * @param r red component (0..255) of the color to draw onto the canvas
651     * @param g green component (0..255) of the color to draw onto the canvas
652     * @param b blue component (0..255) of the color to draw onto the canvas
653     */
654    public void drawRGB(int r, int g, int b) {
655        native_drawRGB(mNativeCanvas, r, g, b);
656    }
657
658    /**
659     * Fill the entire canvas' bitmap (restricted to the current clip) with the
660     * specified ARGB color, using srcover porterduff mode.
661     *
662     * @param a alpha component (0..255) of the color to draw onto the canvas
663     * @param r red component (0..255) of the color to draw onto the canvas
664     * @param g green component (0..255) of the color to draw onto the canvas
665     * @param b blue component (0..255) of the color to draw onto the canvas
666     */
667    public void drawARGB(int a, int r, int g, int b) {
668        native_drawARGB(mNativeCanvas, a, r, g, b);
669    }
670
671    /**
672     * Fill the entire canvas' bitmap (restricted to the current clip) with the
673     * specified color, using srcover porterduff mode.
674     *
675     * @param color the color to draw onto the canvas
676     */
677    public void drawColor(int color) {
678        native_drawColor(mNativeCanvas, color);
679    }
680
681    /**
682     * Fill the entire canvas' bitmap (restricted to the current clip) with the
683     * specified color and porter-duff xfermode.
684     *
685     * @param color the color to draw with
686     * @param mode  the porter-duff mode to apply to the color
687     */
688    public void drawColor(int color, PorterDuff.Mode mode) {
689        native_drawColor(mNativeCanvas, color, mode.nativeInt);
690    }
691
692    /**
693     * Fill the entire canvas' bitmap (restricted to the current clip) with
694     * the specified paint. This is equivalent (but faster) to drawing an
695     * infinitely large rectangle with the specified paint.
696     *
697     * @param paint The paint used to draw onto the canvas
698     */
699    public void drawPaint(Paint paint) {
700        native_drawPaint(mNativeCanvas, paint.mNativePaint);
701    }
702
703    /**
704     * Draw a series of points. Each point is centered at the coordinate
705     * specified by pts[], and its diameter is specified by the paint's stroke
706     * width (as transformed by the canvas' CTM), with special treatment for
707     * a stroke width of 0, which always draws exactly 1 pixel (or at most 4
708     * if antialiasing is enabled). The shape of the point is controlled by
709     * the paint's Cap type. The shape is a square, unless the cap type is
710     * Round, in which case the shape is a circle.
711     *
712     * @param pts      Array of points to draw [x0 y0 x1 y1 x2 y2 ...]
713     * @param offset   Number of values to skip before starting to draw.
714     * @param count    The number of values to process, after skipping offset
715     *                 of them. Since one point uses two values, the number of
716     *                 "points" that are drawn is really (count >> 1).
717     * @param paint    The paint used to draw the points
718     */
719    public native void drawPoints(float[] pts, int offset, int count,
720                                  Paint paint);
721
722    /**
723     * Helper for drawPoints() that assumes you want to draw the entire array
724     */
725    public void drawPoints(float[] pts, Paint paint) {
726        drawPoints(pts, 0, pts.length, paint);
727    }
728
729    /**
730     * Helper for drawPoints() for drawing a single point.
731     */
732    public native void drawPoint(float x, float y, Paint paint);
733
734    /**
735     * Draw a line segment with the specified start and stop x,y coordinates,
736     * using the specified paint. NOTE: since a line is always "framed", the
737     * Style is ignored in the paint.
738     *
739     * @param startX The x-coordinate of the start point of the line
740     * @param startY The y-coordinate of the start point of the line
741     * @param paint  The paint used to draw the line
742     */
743    public void drawLine(float startX, float startY, float stopX, float stopY,
744                         Paint paint) {
745        native_drawLine(mNativeCanvas, startX, startY, stopX, stopY,
746                        paint.mNativePaint);
747    }
748
749    /**
750     * Draw a series of lines. Each line is taken from 4 consecutive values
751     * in the pts array. Thus to draw 1 line, the array must contain at least 4
752     * values. This is logically the same as drawing the array as follows:
753     * drawLine(pts[0], pts[1], pts[2], pts[3]) followed by
754     * drawLine(pts[4], pts[5], pts[6], pts[7]) and so on.
755     *
756     * @param pts      Array of points to draw [x0 y0 x1 y1 x2 y2 ...]
757     * @param offset   Number of values in the array to skip before drawing.
758     * @param count    The number of values in the array to process, after
759     *                 skipping "offset" of them. Since each line uses 4 values,
760     *                 the number of "lines" that are drawn is really
761     *                 (count >> 2).
762     * @param paint    The paint used to draw the points
763     */
764    public native void drawLines(float[] pts, int offset, int count,
765                                 Paint paint);
766
767    public void drawLines(float[] pts, Paint paint) {
768        drawLines(pts, 0, pts.length, paint);
769    }
770
771    /**
772     * Draw the specified Rect using the specified paint. The rectangle will
773     * be filled or framed based on the Style in the paint.
774     *
775     * @param rect  The rect to be drawn
776     * @param paint The paint used to draw the rect
777     */
778    public void drawRect(RectF rect, Paint paint) {
779        native_drawRect(mNativeCanvas, rect, paint.mNativePaint);
780    }
781
782    /**
783     * Draw the specified Rect using the specified Paint. The rectangle
784     * will be filled or framed based on the Style in the paint.
785     *
786     * @param r        The rectangle to be drawn.
787     * @param paint    The paint used to draw the rectangle
788     */
789    public void drawRect(Rect r, Paint paint) {
790        drawRect(r.left, r.top, r.right, r.bottom, paint);
791    }
792
793
794    /**
795     * Draw the specified Rect using the specified paint. The rectangle will
796     * be filled or framed based on the Style in the paint.
797     *
798     * @param left   The left side of the rectangle to be drawn
799     * @param top    The top side of the rectangle to be drawn
800     * @param right  The right side of the rectangle to be drawn
801     * @param bottom The bottom side of the rectangle to be drawn
802     * @param paint  The paint used to draw the rect
803     */
804    public void drawRect(float left, float top, float right, float bottom,
805                         Paint paint) {
806        native_drawRect(mNativeCanvas, left, top, right, bottom,
807                        paint.mNativePaint);
808    }
809
810    /**
811     * Draw the specified oval using the specified paint. The oval will be
812     * filled or framed based on the Style in the paint.
813     *
814     * @param oval The rectangle bounds of the oval to be drawn
815     */
816    public void drawOval(RectF oval, Paint paint) {
817        if (oval == null) {
818            throw new NullPointerException();
819        }
820        native_drawOval(mNativeCanvas, oval, paint.mNativePaint);
821    }
822
823    /**
824     * Draw the specified circle using the specified paint. If radius is <= 0,
825     * then nothing will be drawn. The circle will be filled or framed based
826     * on the Style in the paint.
827     *
828     * @param cx     The x-coordinate of the center of the cirle to be drawn
829     * @param cy     The y-coordinate of the center of the cirle to be drawn
830     * @param radius The radius of the cirle to be drawn
831     * @param paint  The paint used to draw the circle
832     */
833    public void drawCircle(float cx, float cy, float radius, Paint paint) {
834        native_drawCircle(mNativeCanvas, cx, cy, radius,
835                          paint.mNativePaint);
836    }
837
838    /**
839     * Draw the specified arc, which will be scaled to fit inside the
840     * specified oval. If the sweep angle is >= 360, then the oval is drawn
841     * completely. Note that this differs slightly from SkPath::arcTo, which
842     * treats the sweep angle mod 360.
843     *
844     * @param oval       The bounds of oval used to define the shape and size
845     *                   of the arc
846     * @param startAngle Starting angle (in degrees) where the arc begins
847     * @param sweepAngle Sweep angle (in degrees) measured clockwise
848     * @param useCenter If true, include the center of the oval in the arc, and
849                        close it if it is being stroked. This will draw a wedge
850     * @param paint      The paint used to draw the arc
851     */
852    public void drawArc(RectF oval, float startAngle, float sweepAngle,
853                        boolean useCenter, Paint paint) {
854        if (oval == null) {
855            throw new NullPointerException();
856        }
857        native_drawArc(mNativeCanvas, oval, startAngle, sweepAngle,
858                       useCenter, paint.mNativePaint);
859    }
860
861    /**
862     * Draw the specified round-rect using the specified paint. The roundrect
863     * will be filled or framed based on the Style in the paint.
864     *
865     * @param rect  The rectangular bounds of the roundRect to be drawn
866     * @param rx    The x-radius of the oval used to round the corners
867     * @param ry    The y-radius of the oval used to round the corners
868     * @param paint The paint used to draw the roundRect
869     */
870    public void drawRoundRect(RectF rect, float rx, float ry, Paint paint) {
871        if (rect == null) {
872            throw new NullPointerException();
873        }
874        native_drawRoundRect(mNativeCanvas, rect, rx, ry,
875                             paint.mNativePaint);
876    }
877
878    /**
879     * Draw the specified path using the specified paint. The path will be
880     * filled or framed based on the Style in the paint.
881     *
882     * @param path  The path to be drawn
883     * @param paint The paint used to draw the path
884     */
885    public void drawPath(Path path, Paint paint) {
886        native_drawPath(mNativeCanvas, path.ni(), paint.mNativePaint);
887    }
888
889    private static void throwIfRecycled(Bitmap bitmap) {
890        if (bitmap.isRecycled()) {
891            throw new RuntimeException(
892                        "Canvas: trying to use a recycled bitmap " + bitmap);
893        }
894    }
895
896    /**
897     * Draw the specified bitmap, with its top/left corner at (x,y), using
898     * the specified paint, transformed by the current matrix.
899     * Note: if the paint contains a maskfilter that generates a mask which
900     * extends beyond the bitmap's original width/height (e.g. BlurMaskFilter),
901     * then the bitmap will be drawn as if it were in a Shader with CLAMP mode.
902     * Thus the color outside of the original width/height will be the edge
903     * color replicated.
904     *
905     * @param bitmap The bitmap to be drawn
906     * @param left   The position of the left side of the bitmap being drawn
907     * @param top    The position of the top side of the bitmap being drawn
908     * @param paint  The paint used to draw the bitmap (may be null)
909     */
910    public void drawBitmap(Bitmap bitmap, float left, float top, Paint paint) {
911        throwIfRecycled(bitmap);
912        native_drawBitmap(mNativeCanvas, bitmap.ni(), left, top,
913                          paint != null ? paint.mNativePaint : 0);
914    }
915
916    /**
917     * Draw the specified bitmap, scaling/translating automatically to fill
918     * the destination rectangle. If the source rectangle is not null, it
919     * specifies the subset of the bitmap to draw.
920     * Note: if the paint contains a maskfilter that generates a mask which
921     * extends beyond the bitmap's original width/height (e.g. BlurMaskFilter),
922     * then the bitmap will be drawn as if it were in a Shader with CLAMP mode.
923     * Thus the color outside of the original width/height will be the edge
924     * color replicated.
925     *
926     * @param bitmap The bitmap to be drawn
927     * @param src    May be null. The subset of the bitmap to be drawn
928     * @param dst    The rectangle that the bitmap will be scaled/translated
929     *               to fit into
930     * @param paint  May be null. The paint used to draw the bitmap
931     */
932    public void drawBitmap(Bitmap bitmap, Rect src, RectF dst, Paint paint) {
933        if (dst == null) {
934            throw new NullPointerException();
935        }
936        throwIfRecycled(bitmap);
937        native_drawBitmap(mNativeCanvas, bitmap.ni(), src, dst,
938                          paint != null ? paint.mNativePaint : 0);
939    }
940
941    /**
942     * Draw the specified bitmap, scaling/translating automatically to fill
943     * the destination rectangle. If the source rectangle is not null, it
944     * specifies the subset of the bitmap to draw.
945     * Note: if the paint contains a maskfilter that generates a mask which
946     * extends beyond the bitmap's original width/height (e.g. BlurMaskFilter),
947     * then the bitmap will be drawn as if it were in a Shader with CLAMP mode.
948     * Thus the color outside of the original width/height will be the edge
949     * color replicated.
950     *
951     * @param bitmap The bitmap to be drawn
952     * @param src    May be null. The subset of the bitmap to be drawn
953     * @param dst    The rectangle that the bitmap will be scaled/translated
954     *               to fit into
955     * @param paint  May be null. The paint used to draw the bitmap
956     */
957    public void drawBitmap(Bitmap bitmap, Rect src, Rect dst, Paint paint) {
958        if (dst == null) {
959            throw new NullPointerException();
960        }
961        throwIfRecycled(bitmap);
962        native_drawBitmap(mNativeCanvas, bitmap.ni(), src, dst,
963                          paint != null ? paint.mNativePaint : 0);
964    }
965
966    /**
967     * Treat the specified array of colors as a bitmap, and draw it. This gives
968     * the same result as first creating a bitmap from the array, and then
969     * drawing it, but this method avoids explicitly creating a bitmap object
970     * which can be more efficient if the colors are changing often.
971     *
972     * @param colors Array of colors representing the pixels of the bitmap
973     * @param offset Offset into the array of colors for the first pixel
974     * @param stride The number of of colors in the array between rows (must be
975     *               >= width or <= -width).
976     * @param x The X coordinate for where to draw the bitmap
977     * @param y The Y coordinate for where to draw the bitmap
978     * @param width The width of the bitmap
979     * @param height The height of the bitmap
980     * @param hasAlpha True if the alpha channel of the colors contains valid
981     *                 values. If false, the alpha byte is ignored (assumed to
982     *                 be 0xFF for every pixel).
983     * @param paint  May be null. The paint used to draw the bitmap
984     */
985    public void drawBitmap(int[] colors, int offset, int stride, int x, int y,
986                           int width, int height, boolean hasAlpha,
987                           Paint paint) {
988        // check for valid input
989        if (width < 0) {
990            throw new IllegalArgumentException("width must be >= 0");
991        }
992        if (height < 0) {
993            throw new IllegalArgumentException("height must be >= 0");
994        }
995        if (Math.abs(stride) < width) {
996            throw new IllegalArgumentException("abs(stride) must be >= width");
997        }
998        int lastScanline = offset + (height - 1) * stride;
999        int length = colors.length;
1000        if (offset < 0 || (offset + width > length) || lastScanline < 0
1001                || (lastScanline + width > length)) {
1002            throw new ArrayIndexOutOfBoundsException();
1003        }
1004        // quick escape if there's nothing to draw
1005        if (width == 0 || height == 0) {
1006            return;
1007        }
1008        // punch down to native for the actual draw
1009        native_drawBitmap(mNativeCanvas, colors, offset, stride, x, y,
1010                          width, height, hasAlpha,
1011                          paint != null ? paint.mNativePaint : 0);
1012    }
1013
1014    /**
1015     * Draw the bitmap using the specified matrix.
1016     *
1017     * @param bitmap The bitmap to draw
1018     * @param matrix The matrix used to transform the bitmap when it is drawn
1019     * @param paint  May be null. The paint used to draw the bitmap
1020     */
1021    public void drawBitmap(Bitmap bitmap, Matrix matrix, Paint paint) {
1022        nativeDrawBitmapMatrix(mNativeCanvas, bitmap.ni(), matrix.ni(),
1023                               paint != null ? paint.mNativePaint : 0);
1024    }
1025
1026    private static void checkRange(int length, int offset, int count) {
1027        if ((offset | count) < 0 || offset + count > length) {
1028            throw new ArrayIndexOutOfBoundsException();
1029        }
1030    }
1031
1032    /**
1033     * Draw the bitmap through the mesh, where mesh vertices are evenly
1034     * distributed across the bitmap. There are meshWidth+1 vertices across, and
1035     * meshHeight+1 vertices down. The verts array is accessed in row-major
1036     * order, so that the first meshWidth+1 vertices are distributed across the
1037     * top of the bitmap from left to right. A more general version of this
1038     * methid is drawVertices().
1039     *
1040     * @param bitmap The bitmap to draw using the mesh
1041     * @param meshWidth The number of columns in the mesh. Nothing is drawn if
1042     *                  this is 0
1043     * @param meshHeight The number of rows in the mesh. Nothing is drawn if
1044     *                   this is 0
1045     * @param verts Array of x,y pairs, specifying where the mesh should be
1046     *              drawn. There must be at least
1047     *              (meshWidth+1) * (meshHeight+1) * 2 + meshOffset values
1048     *              in the array
1049     * @param vertOffset Number of verts elements to skip before drawing
1050     * @param colors May be null. Specifies a color at each vertex, which is
1051     *               interpolated across the cell, and whose values are
1052     *               multiplied by the corresponding bitmap colors. If not null,
1053     *               there must be at least (meshWidth+1) * (meshHeight+1) +
1054     *               colorOffset values in the array.
1055     * @param colorOffset Number of color elements to skip before drawing
1056     * @param paint  May be null. The paint used to draw the bitmap
1057     */
1058    public void drawBitmapMesh(Bitmap bitmap, int meshWidth, int meshHeight,
1059                               float[] verts, int vertOffset,
1060                               int[] colors, int colorOffset, Paint paint) {
1061        if ((meshWidth | meshHeight | vertOffset | colorOffset) < 0) {
1062            throw new ArrayIndexOutOfBoundsException();
1063        }
1064        if (meshWidth == 0 || meshHeight == 0) {
1065            return;
1066        }
1067        int count = (meshWidth + 1) * (meshHeight + 1);
1068        // we mul by 2 since we need two floats per vertex
1069        checkRange(verts.length, vertOffset, count * 2);
1070        if (colors != null) {
1071            // no mul by 2, since we need only 1 color per vertex
1072            checkRange(colors.length, colorOffset, count);
1073        }
1074        nativeDrawBitmapMesh(mNativeCanvas, bitmap.ni(), meshWidth, meshHeight,
1075                             verts, vertOffset, colors, colorOffset,
1076                             paint != null ? paint.mNativePaint : 0);
1077    }
1078
1079    public enum VertexMode {
1080        TRIANGLES(0),
1081        TRIANGLE_STRIP(1),
1082        TRIANGLE_FAN(2);
1083
1084        VertexMode(int nativeInt) {
1085            this.nativeInt = nativeInt;
1086        }
1087        final int nativeInt;
1088    }
1089
1090    /**
1091     * Draw the array of vertices, interpreted as triangles (based on mode). The
1092     * verts array is required, and specifies the x,y pairs for each vertex. If
1093     * texs is non-null, then it is used to specify the coordinate in shader
1094     * coordinates to use at each vertex (the paint must have a shader in this
1095     * case). If there is no texs array, but there is a color array, then each
1096     * color is interpolated across its corresponding triangle in a gradient. If
1097     * both texs and colors arrays are present, then they behave as before, but
1098     * the resulting color at each pixels is the result of multiplying the
1099     * colors from the shader and the color-gradient together. The indices array
1100     * is optional, but if it is present, then it is used to specify the index
1101     * of each triangle, rather than just walking through the arrays in order.
1102     *
1103     * @param mode How to interpret the array of vertices
1104     * @param vertexCount The number of values in the vertices array (and
1105     *      corresponding texs and colors arrays if non-null). Each logical
1106     *      vertex is two values (x, y), vertexCount must be a multiple of 2.
1107     * @param verts Array of vertices for the mesh
1108     * @param vertOffset Number of values in the verts to skip before drawing.
1109     * @param texs May be null. If not null, specifies the coordinates to sample
1110     *      into the current shader (e.g. bitmap tile or gradient)
1111     * @param texOffset Number of values in texs to skip before drawing.
1112     * @param colors May be null. If not null, specifies a color for each
1113     *      vertex, to be interpolated across the triangle.
1114     * @param colorOffset Number of values in colors to skip before drawing.
1115     * @param indices If not null, array of indices to reference into the
1116     *      vertex (texs, colors) array.
1117     * @param indexCount number of entries in the indices array (if not null).
1118     * @param paint Specifies the shader to use if the texs array is non-null.
1119     */
1120    public void drawVertices(VertexMode mode, int vertexCount,
1121                             float[] verts, int vertOffset,
1122                             float[] texs, int texOffset,
1123                             int[] colors, int colorOffset,
1124                             short[] indices, int indexOffset,
1125                             int indexCount, Paint paint) {
1126        checkRange(verts.length, vertOffset, vertexCount);
1127        if (texs != null) {
1128            checkRange(texs.length, texOffset, vertexCount);
1129        }
1130        if (colors != null) {
1131            checkRange(colors.length, colorOffset, vertexCount);
1132        }
1133        if (indices != null) {
1134            checkRange(indices.length, indexOffset, indexCount);
1135        }
1136        nativeDrawVertices(mNativeCanvas, mode.nativeInt, vertexCount, verts,
1137                           vertOffset, texs, texOffset, colors, colorOffset,
1138                          indices, indexOffset, indexCount, paint.mNativePaint);
1139    }
1140
1141    /**
1142     * Draw the text, with origin at (x,y), using the specified paint. The
1143     * origin is interpreted based on the Align setting in the paint.
1144     *
1145     * @param text  The text to be drawn
1146     * @param x     The x-coordinate of the origin of the text being drawn
1147     * @param y     The y-coordinate of the origin of the text being drawn
1148     * @param paint The paint used for the text (e.g. color, size, style)
1149     */
1150    public void drawText(char[] text, int index, int count, float x, float y,
1151                         Paint paint) {
1152        if ((index | count | (index + count) |
1153            (text.length - index - count)) < 0) {
1154            throw new IndexOutOfBoundsException();
1155        }
1156        native_drawText(mNativeCanvas, text, index, count, x, y,
1157                        paint.mNativePaint);
1158    }
1159
1160    /**
1161     * Draw the text, with origin at (x,y), using the specified paint. The
1162     * origin is interpreted based on the Align setting in the paint.
1163     *
1164     * @param text  The text to be drawn
1165     * @param x     The x-coordinate of the origin of the text being drawn
1166     * @param y     The y-coordinate of the origin of the text being drawn
1167     * @param paint The paint used for the text (e.g. color, size, style)
1168     */
1169    public native void drawText(String text, float x, float y, Paint paint);
1170
1171    /**
1172     * Draw the text, with origin at (x,y), using the specified paint.
1173     * The origin is interpreted based on the Align setting in the paint.
1174     *
1175     * @param text  The text to be drawn
1176     * @param start The index of the first character in text to draw
1177     * @param end   (end - 1) is the index of the last character in text to draw
1178     * @param x     The x-coordinate of the origin of the text being drawn
1179     * @param y     The y-coordinate of the origin of the text being drawn
1180     * @param paint The paint used for the text (e.g. color, size, style)
1181     */
1182    public void drawText(String text, int start, int end, float x, float y,
1183                         Paint paint) {
1184        if ((start | end | (end - start) | (text.length() - end)) < 0) {
1185            throw new IndexOutOfBoundsException();
1186        }
1187        native_drawText(mNativeCanvas, text, start, end, x, y,
1188                        paint.mNativePaint);
1189    }
1190
1191    /**
1192     * Draw the specified range of text, specified by start/end, with its
1193     * origin at (x,y), in the specified Paint. The origin is interpreted
1194     * based on the Align setting in the Paint.
1195     *
1196     * @param text     The text to be drawn
1197     * @param start    The index of the first character in text to draw
1198     * @param end      (end - 1) is the index of the last character in text
1199     *                 to draw
1200     * @param x        The x-coordinate of origin for where to draw the text
1201     * @param y        The y-coordinate of origin for where to draw the text
1202     * @param paint The paint used for the text (e.g. color, size, style)
1203     */
1204    public void drawText(CharSequence text, int start, int end, float x,
1205                         float y, Paint paint) {
1206        if (text instanceof String || text instanceof SpannedString ||
1207            text instanceof SpannableString) {
1208            native_drawText(mNativeCanvas, text.toString(), start, end, x, y,
1209                            paint.mNativePaint);
1210        }
1211        else if (text instanceof GraphicsOperations) {
1212            ((GraphicsOperations) text).drawText(this, start, end, x, y,
1213                                                     paint);
1214        }
1215        else {
1216            char[] buf = TemporaryBuffer.obtain(end - start);
1217            TextUtils.getChars(text, start, end, buf, 0);
1218            drawText(buf, 0, end - start, x, y, paint);
1219            TemporaryBuffer.recycle(buf);
1220        }
1221    }
1222
1223    /**
1224     * Draw the text in the array, with each character's origin specified by
1225     * the pos array.
1226     *
1227     * @param text     The text to be drawn
1228     * @param index    The index of the first character to draw
1229     * @param count    The number of characters to draw, starting from index.
1230     * @param pos      Array of [x,y] positions, used to position each
1231     *                 character
1232     * @param paint    The paint used for the text (e.g. color, size, style)
1233     */
1234    public void drawPosText(char[] text, int index, int count, float[] pos,
1235                            Paint paint) {
1236        if (index < 0 || index + count > text.length || count*2 > pos.length) {
1237            throw new IndexOutOfBoundsException();
1238        }
1239        native_drawPosText(mNativeCanvas, text, index, count, pos,
1240                           paint.mNativePaint);
1241    }
1242
1243    /**
1244     * Draw the text in the array, with each character's origin specified by
1245     * the pos array.
1246     *
1247     * @param text  The text to be drawn
1248     * @param pos   Array of [x,y] positions, used to position each character
1249     * @param paint The paint used for the text (e.g. color, size, style)
1250     */
1251    public void drawPosText(String text, float[] pos, Paint paint) {
1252        if (text.length()*2 > pos.length) {
1253            throw new ArrayIndexOutOfBoundsException();
1254        }
1255        native_drawPosText(mNativeCanvas, text, pos, paint.mNativePaint);
1256    }
1257
1258    /**
1259     * Draw the text, with origin at (x,y), using the specified paint, along
1260     * the specified path. The paint's Align setting determins where along the
1261     * path to start the text.
1262     *
1263     * @param text     The text to be drawn
1264     * @param path     The path the text should follow for its baseline
1265     * @param hOffset  The distance along the path to add to the text's
1266     *                 starting position
1267     * @param vOffset  The distance above(-) or below(+) the path to position
1268     *                 the text
1269     * @param paint    The paint used for the text (e.g. color, size, style)
1270     */
1271    public void drawTextOnPath(char[] text, int index, int count, Path path,
1272                               float hOffset, float vOffset, Paint paint) {
1273        if (index < 0 || index + count > text.length) {
1274            throw new ArrayIndexOutOfBoundsException();
1275        }
1276        native_drawTextOnPath(mNativeCanvas, text, index, count,
1277                              path.ni(), hOffset, vOffset,
1278                              paint.mNativePaint);
1279    }
1280
1281    /**
1282     * Draw the text, with origin at (x,y), using the specified paint, along
1283     * the specified path. The paint's Align setting determins where along the
1284     * path to start the text.
1285     *
1286     * @param text     The text to be drawn
1287     * @param path     The path the text should follow for its baseline
1288     * @param hOffset  The distance along the path to add to the text's
1289     *                 starting position
1290     * @param vOffset  The distance above(-) or below(+) the path to position
1291     *                 the text
1292     * @param paint    The paint used for the text (e.g. color, size, style)
1293     */
1294    public void drawTextOnPath(String text, Path path, float hOffset,
1295                               float vOffset, Paint paint) {
1296        if (text.length() > 0) {
1297            native_drawTextOnPath(mNativeCanvas, text, path.ni(),
1298                                  hOffset, vOffset, paint.mNativePaint);
1299        }
1300    }
1301
1302    /**
1303     * Save the canvas state, draw the picture, and restore the canvas state.
1304     * This differs from picture.draw(canvas), which does not perform any
1305     * save/restore.
1306     *
1307     * @param picture  The picture to be drawn
1308     */
1309    public void drawPicture(Picture picture) {
1310        picture.endRecording();
1311        native_drawPicture(mNativeCanvas, picture.ni());
1312    }
1313
1314    /**
1315     * Draw the picture, stretched to fit into the dst rectangle.
1316     */
1317    public void drawPicture(Picture picture, RectF dst) {
1318        save();
1319        translate(dst.left, dst.top);
1320        if (picture.getWidth() > 0 && picture.getHeight() > 0) {
1321            scale(dst.width() / picture.getWidth(),
1322                  dst.height() / picture.getHeight());
1323        }
1324        drawPicture(picture);
1325        restore();
1326    }
1327
1328    /**
1329     * Draw the picture, stretched to fit into the dst rectangle.
1330     */
1331    public void drawPicture(Picture picture, Rect dst) {
1332        save();
1333        translate(dst.left, dst.top);
1334        if (picture.getWidth() > 0 && picture.getHeight() > 0) {
1335            scale((float)dst.width() / picture.getWidth(),
1336                  (float)dst.height() / picture.getHeight());
1337        }
1338        drawPicture(picture);
1339        restore();
1340    }
1341
1342    protected void finalize() throws Throwable {
1343        super.finalize();
1344        finalizer(mNativeCanvas);
1345    }
1346
1347    private static native int initRaster(int nativeBitmapOrZero);
1348    private static native int initGL();
1349    private static native void native_setBitmap(int nativeCanvas, int bitmap);
1350    private static native void nativeSetViewport(int nCanvas, int w, int h);
1351    private static native int native_saveLayer(int nativeCanvas, RectF bounds,
1352                                               int paint, int layerFlags);
1353    private static native int native_saveLayer(int nativeCanvas, float l,
1354                                               float t, float r, float b,
1355                                               int paint, int layerFlags);
1356    private static native int native_saveLayerAlpha(int nativeCanvas,
1357                                                    RectF bounds, int alpha,
1358                                                    int layerFlags);
1359    private static native int native_saveLayerAlpha(int nativeCanvas, float l,
1360                                                    float t, float r, float b,
1361                                                    int alpha, int layerFlags);
1362
1363    private static native void native_concat(int nCanvas, int nMatrix);
1364    private static native void native_setMatrix(int nCanvas, int nMatrix);
1365    private static native boolean native_clipRect(int nCanvas,
1366                                                  float left, float top,
1367                                                  float right, float bottom,
1368                                                  int regionOp);
1369    private static native boolean native_clipPath(int nativeCanvas,
1370                                                  int nativePath,
1371                                                  int regionOp);
1372    private static native boolean native_clipRegion(int nativeCanvas,
1373                                                    int nativeRegion,
1374                                                    int regionOp);
1375    private static native void nativeSetDrawFilter(int nativeCanvas,
1376                                                   int nativeFilter);
1377    private static native boolean native_getClipBounds(int nativeCanvas,
1378                                                       Rect bounds);
1379    private static native void native_getCTM(int canvas, int matrix);
1380    private static native boolean native_quickReject(int nativeCanvas,
1381                                                     RectF rect,
1382                                                     int native_edgeType);
1383    private static native boolean native_quickReject(int nativeCanvas,
1384                                                     int path,
1385                                                     int native_edgeType);
1386    private static native boolean native_quickReject(int nativeCanvas,
1387                                                     float left, float top,
1388                                                     float right, float bottom,
1389                                                     int native_edgeType);
1390    private static native void native_drawRGB(int nativeCanvas, int r, int g,
1391                                              int b);
1392    private static native void native_drawARGB(int nativeCanvas, int a, int r,
1393                                               int g, int b);
1394    private static native void native_drawColor(int nativeCanvas, int color);
1395    private static native void native_drawColor(int nativeCanvas, int color,
1396                                                int mode);
1397    private static native void native_drawPaint(int nativeCanvas, int paint);
1398    private static native void native_drawLine(int nativeCanvas, float startX,
1399                                               float startY, float stopX,
1400                                               float stopY, int paint);
1401    private static native void native_drawRect(int nativeCanvas, RectF rect,
1402                                               int paint);
1403    private static native void native_drawRect(int nativeCanvas, float left,
1404                                               float top, float right,
1405                                               float bottom, int paint);
1406    private static native void native_drawOval(int nativeCanvas, RectF oval,
1407                                               int paint);
1408    private static native void native_drawCircle(int nativeCanvas, float cx,
1409                                                 float cy, float radius,
1410                                                 int paint);
1411    private static native void native_drawArc(int nativeCanvas, RectF oval,
1412                                              float startAngle, float sweep,
1413                                              boolean useCenter, int paint);
1414    private static native void native_drawRoundRect(int nativeCanvas,
1415                                                    RectF rect, float rx,
1416                                                    float ry, int paint);
1417    private static native void native_drawPath(int nativeCanvas, int path,
1418                                               int paint);
1419    private static native void native_drawBitmap(int nativeCanvas, int bitmap,
1420                                                 float left, float top,
1421                                                 int nativePaintOrZero);
1422    private static native void native_drawBitmap(int nativeCanvas, int bitmap,
1423                                                 Rect src, RectF dst,
1424                                                 int nativePaintOrZero);
1425    private static native void native_drawBitmap(int nativeCanvas, int bitmap,
1426                                                 Rect src, Rect dst,
1427                                                 int nativePaintOrZero);
1428    private static native void native_drawBitmap(int nativeCanvas, int[] colors,
1429                                                 int offset, int stride, int x,
1430                                                 int y, int width, int height,
1431                                                 boolean hasAlpha,
1432                                                 int nativePaintOrZero);
1433    private static native void nativeDrawBitmapMatrix(int nCanvas, int nBitmap,
1434                                                      int nMatrix, int nPaint);
1435    private static native void nativeDrawBitmapMesh(int nCanvas, int nBitmap,
1436                int meshWidth, int meshHeight, float[] verts, int vertOffset,
1437                                    int[] colors, int colorOffset, int nPaint);
1438    private static native void nativeDrawVertices(int nCanvas, int mode, int n,
1439                   float[] verts, int vertOffset, float[] texs, int texOffset,
1440                   int[] colors, int colorOffset, short[] indices,
1441                   int indexOffset, int indexCount, int nPaint);
1442
1443    private static native void native_drawText(int nativeCanvas, char[] text,
1444                                               int index, int count, float x,
1445                                               float y, int paint);
1446    private static native void native_drawText(int nativeCanvas, String text,
1447                                               int start, int end, float x,
1448                                               float y, int paint);
1449    private static native void native_drawPosText(int nativeCanvas,
1450                                                  char[] text, int index,
1451                                                  int count, float[] pos,
1452                                                  int paint);
1453    private static native void native_drawPosText(int nativeCanvas,
1454                                                  String text, float[] pos,
1455                                                  int paint);
1456    private static native void native_drawTextOnPath(int nativeCanvas,
1457                                                     char[] text, int index,
1458                                                     int count, int path,
1459                                                     float hOffset,
1460                                                     float vOffset, int paint);
1461    private static native void native_drawTextOnPath(int nativeCanvas,
1462                                                     String text, int path,
1463                                                     float hOffset,
1464                                                     float vOffset, int paint);
1465    private static native void native_drawPicture(int nativeCanvas,
1466                                                  int nativePicture);
1467    private static native void finalizer(int nativeCanvas);
1468}
1469