Drawable.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.drawable;
18
19import java.io.InputStream;
20import java.io.IOException;
21import java.util.Arrays;
22
23import org.xmlpull.v1.XmlPullParser;
24import org.xmlpull.v1.XmlPullParserException;
25
26import android.content.res.Resources;
27import android.content.res.TypedArray;
28import android.graphics.*;
29import android.util.AttributeSet;
30import android.util.StateSet;
31import android.util.Xml;
32
33/**
34 * A Drawable is a general abstraction for "something that can be drawn."  Most
35 * often you will deal with Drawable as the type of resource retrieved for
36 * drawing things to the screen; the Drawable class provides a generic API for
37 * dealing with an underlying visual resource that may take a variety of forms.
38 * Unlike a {@link android.view.View}, a Drawable does not have any facility to
39 * receive events or otherwise interact with the user.
40 *
41 * <p>In addition to simple drawing, Drawable provides a number of generic
42 * mechanisms for its client to interact with what is being drawn:
43 *
44 * <ul>
45 *     <li> The {@link #setBounds} method <var>must</var> be called to tell the
46 *     Drawable where it is drawn and how large it should be.  All Drawables
47 *     should respect the requested size, often simply by scaling their
48 *     imagery.  A client can find the preferred size for some Drawables with
49 *     the {@link #getIntrinsicHeight} and {@link #getIntrinsicWidth} methods.
50 *
51 *     <li> The {@link #getPadding} method can return from some Drawables
52 *     information about how to frame content that is placed inside of them.
53 *     For example, a Drawable that is intended to be the frame for a button
54 *     widget would need to return padding that correctly places the label
55 *     inside of itself.
56 *
57 *     <li> The {@link #setState} method allows the client to tell the Drawable
58 *     in which state it is to be drawn, such as "focused", "selected", etc.
59 *     Some drawables may modify their imagery based on the selected state.
60 *
61 *     <li> The {@link #setLevel} method allows the client to supply a single
62 *     continuous controller that can modify the Drawable is displayed, such as
63 *     a battery level or progress level.  Some drawables may modify their
64 *     imagery based on the current level.
65 *
66 *     <li> A Drawable can perform animations by calling back to its client
67 *     through the {@link Callback} interface.  All clients should support this
68 *     interface (via {@link #setCallback}) so that animations will work.  A
69 *     simple way to do this is through the system facilities such as
70 *     {@link android.view.View#setBackgroundDrawable(Drawable)} and
71 *     {@link android.widget.ImageView}.
72 * </ul>
73 *
74 * Though usually not visible to the application, Drawables may take a variety
75 * of forms:
76 *
77 * <ul>
78 *     <li> <b>Bitmap</b>: the simplest Drawable, a PNG or JPEG image.
79 *     <li> <b>Nine Patch</b>: an extension to the PNG format allows it to
80 *     specify information about how to stretch it and place things inside of
81 *     it.
82 *     <li> <b>Shape</b>: contains simple drawing commands instead of a raw
83 *     bitmap, allowing it to resize better in some cases.
84 *     <li> <b>Layers</b>: a compound drawable, which draws multiple underlying
85 *     drawables on top of each other.
86 *     <li> <b>States</b>: a compound drawable that selects one of a set of
87 *     drawables based on its state.
88 *     <li> <b>Levels</b>: a compound drawable that selects one of a set of
89 *     drawables based on its level.
90 *     <li> <b>Scale</b>: a compound drawable with a single child drawable,
91 *     whose overall size is modified based on the current level.
92 * </ul>
93 * <p>For information and examples of creating drawable resources (XML or bitmap files that
94 * can be loaded in code), see <a href="{@docRoot}devel/resources-i18n.html">Resources
95 * and Internationalization</a>.
96 */
97public abstract class Drawable {
98
99    private int[] mStateSet = StateSet.WILD_CARD;
100    private int mLevel = 0;
101    private int mChangingConfigurations = 0;
102    private Rect mBounds = new Rect();
103    /*package*/ Callback mCallback = null;
104    private boolean mVisible = true;
105
106    /**
107     * Draw in its bounds (set via setBounds) respecting optional effects such
108     * as alpha (set via setAlpha) and color filter (set via setColorFilter).
109     *
110     * @param canvas The canvas to draw into
111     */
112    public abstract void draw(Canvas canvas);
113
114    /**
115     * Specify a bounding rectangle for the Drawable. This is where the drawable
116     * will draw when its draw() method is called.
117     */
118    public void setBounds(int left, int top, int right, int bottom) {
119        Rect oldBounds = mBounds;
120
121        if (oldBounds.left != left || oldBounds.top != top ||
122                oldBounds.right != right || oldBounds.bottom != bottom) {
123            mBounds.set(left, top, right, bottom);
124            onBoundsChange(mBounds);
125        }
126    }
127
128    /**
129     * Specify a bounding rectangle for the Drawable. This is where the drawable
130     * will draw when its draw() method is called.
131     */
132    public void setBounds(Rect bounds) {
133        setBounds(bounds.left, bounds.top, bounds.right, bounds.bottom);
134    }
135
136    /**
137     * Return a copy of the drawable's bounds in the specified Rect (allocated
138     * by the caller). The bounds specify where this will draw when its draw()
139     * method is called.
140     *
141     * @param bounds Rect to receive the drawable's bounds (allocated by the
142     *               caller).
143     */
144    public final void copyBounds(Rect bounds) {
145        bounds.set(mBounds);
146    }
147
148    /**
149     * Return a copy of the drawable's bounds in a new Rect. This returns the
150     * same values as getBounds(), but the returned object is guaranteed to not
151     * be changed later by the drawable (i.e. it retains no reference to this
152     * rect). If the caller already has a Rect allocated, call copyBounds(rect)
153     *
154     * @return A copy of the drawable's bounds
155     */
156    public final Rect copyBounds() {
157        return new Rect(mBounds);
158    }
159
160    /**
161     * Return the drawable's bounds Rect. Note: for efficiency, the returned
162     * object may be the same object stored in the drawable (though this is not
163     * guaranteed), so if a persistent copy of the bounds is needed, call
164     * copyBounds(rect) instead.
165     *
166     * @return The bounds of the drawable (which may change later, so caller
167     *         beware).
168     */
169    public final Rect getBounds() {
170        return mBounds;
171    }
172
173    /**
174     * Set a mask of the configuration parameters for which this drawable
175     * may change, requiring that it be re-created.
176     *
177     * @param configs A mask of the changing configuration parameters, as
178     * defined by {@link android.content.res.Configuration}.
179     *
180     * @see android.content.res.Configuration
181     */
182    public void setChangingConfigurations(int configs) {
183        mChangingConfigurations = configs;
184    }
185
186    /**
187     * Return a mask of the configuration parameters for which this drawable
188     * mau change, requiring that it be re-created.  The default implementation
189     * returns whatever was provided through
190     * {@link #setChangingConfigurations(int)} or 0 by default.  Subclasses
191     * may extend this to or in the changing configurations of any other
192     * drawables they hold.
193     *
194     * @return Returns a mask of the changing configuration parameters, as
195     * defined by {@link android.content.res.Configuration}.
196     *
197     * @see android.content.res.Configuration
198     */
199    public int getChangingConfigurations() {
200        return mChangingConfigurations;
201    }
202
203    /**
204     * Set to true to have the drawable dither its colors when drawn to a device
205     * with fewer than 8-bits per color component. This can improve the look on
206     * those devices, but can also slow down the drawing a little.
207     */
208    public void setDither(boolean dither) {}
209
210    /**
211     * Set to true to have the drawable filter its bitmap when scaled or rotated
212     * (for drawables that use bitmaps). If the drawable does not use bitmaps,
213     * this call is ignored. This can improve the look when scaled or rotated,
214     * but also slows down the drawing.
215     */
216    public void setFilterBitmap(boolean filter) {}
217
218    /**
219     * Implement this interface if you want to create an animated drawable that
220     * extends {@link android.graphics.drawable.Drawable Drawable}.
221     * Upon retrieving a drawable, use
222     * {@link Drawable#setCallback(android.graphics.drawable.Drawable.Callback)}
223     * to supply your implementation of the interface to the drawable; it uses
224     * this interface to schedule and execute animation changes.
225     */
226    public static interface Callback {
227        /**
228         * Called when the drawable needs to be redrawn.  A view at this point
229         * should invalidate itself (or at least the part of itself where the
230         * drawable appears).
231         *
232         * @param who The drawable that is requesting the update.
233         */
234        public void invalidateDrawable(Drawable who);
235
236        /**
237         * A Drawable can call this to schedule the next frame of its
238         * animation.  An implementation can generally simply call
239         * {@link android.os.Handler#postAtTime(Runnable, Object, long)} with
240         * the parameters <var>(what, who, when)</var> to perform the
241         * scheduling.
242         *
243         * @param who The drawable being scheduled.
244         * @param what The action to execute.
245         * @param when The time (in milliseconds) to run.  The timebase is
246         *             {@link android.os.SystemClock#uptimeMillis}
247         */
248        public void scheduleDrawable(Drawable who, Runnable what, long when);
249
250        /**
251         * A Drawable can call this to unschedule an action previously
252         * scheduled with {@link #scheduleDrawable}.  An implementation can
253         * generally simply call
254         * {@link android.os.Handler#removeCallbacks(Runnable, Object)} with
255         * the parameters <var>(what, who)</var> to unschedule the drawable.
256         *
257         * @param who The drawable being unscheduled.
258         * @param what The action being unscheduled.
259         */
260        public void unscheduleDrawable(Drawable who, Runnable what);
261    }
262
263    /**
264     * Bind a {@link Callback} object to this Drawable.  Required for clients
265     * that want to support animated drawables.
266     *
267     * @param cb The client's Callback implementation.
268     */
269    public final void setCallback(Callback cb) {
270        mCallback = cb;
271    }
272
273    /**
274     * Use the current {@link Callback} implementation to have this Drawable
275     * redrawn.  Does nothing if there is no Callback attached to the
276     * Drawable.
277     *
278     * @see Callback#invalidateDrawable
279     */
280    public void invalidateSelf()
281    {
282        if (mCallback != null) {
283            mCallback.invalidateDrawable(this);
284        }
285    }
286
287    /**
288     * Use the current {@link Callback} implementation to have this Drawable
289     * scheduled.  Does nothing if there is no Callback attached to the
290     * Drawable.
291     *
292     * @param what The action being scheduled.
293     * @param when The time (in milliseconds) to run.
294     *
295     * @see Callback#scheduleDrawable
296     */
297    public void scheduleSelf(Runnable what, long when)
298    {
299        if (mCallback != null) {
300            mCallback.scheduleDrawable(this, what, when);
301        }
302    }
303
304    /**
305     * Use the current {@link Callback} implementation to have this Drawable
306     * unscheduled.  Does nothing if there is no Callback attached to the
307     * Drawable.
308     *
309     * @param what The runnable that you no longer want called.
310     *
311     * @see Callback#unscheduleDrawable
312     */
313    public void unscheduleSelf(Runnable what)
314    {
315        if (mCallback != null) {
316            mCallback.unscheduleDrawable(this, what);
317        }
318    }
319
320    /**
321     * Specify an alpha value for the drawable. 0 means fully transparent, and
322     * 255 means fully opaque.
323     */
324    public abstract void setAlpha(int alpha);
325
326    /**
327     * Specify an optional colorFilter for the drawable. Pass null to remove
328     * any filters.
329    */
330    public abstract void setColorFilter(ColorFilter cf);
331
332    /**
333     * Specify a color and porterduff mode to be the colorfilter for this
334     * drawable.
335     */
336    public void setColorFilter(int color, PorterDuff.Mode mode) {
337        setColorFilter(new PorterDuffColorFilter(color, mode));
338    }
339
340    public void clearColorFilter() {
341        setColorFilter(null);
342    }
343
344    /**
345     * Indicates whether this view will change its appearance based on state.
346     * Clients can use this to determine whether it is necessary to calculate
347     * their state and call setState.
348     *
349     * @return True if this view changes its appearance based on state, false
350     *         otherwise.
351     *
352     * @see #setState(int[])
353     */
354    public boolean isStateful() {
355        return false;
356    }
357
358    /**
359     * Specify a set of states for the drawable. These are use-case specific,
360     * so see the relevant documentation. As an example, the background for
361     * widgets like Button understand the following states:
362     * [{@link android.R.attr#state_focused},
363     *  {@link android.R.attr#state_pressed}].
364     *
365     * <p>If the new state you are supplying causes the appearance of the
366     * Drawable to change, then it is responsible for calling
367     * {@link #invalidateSelf} in order to have itself redrawn, <em>and</em>
368     * true will be returned from this function.
369     *
370     * <p>Note: The Drawable holds a reference on to <var>stateSet</var>
371     * until a new state array is given to it, so you must not modify this
372     * array during that time.</p>
373     *
374     * @param stateSet The new set of states to be displayed.
375     *
376     * @return Returns true if this change in state has caused the appearance
377     * of the Drawable to change (hence requiring an invalidate), otherwise
378     * returns false.
379     */
380    public boolean setState(final int[] stateSet) {
381        if (!Arrays.equals(mStateSet, stateSet)) {
382            mStateSet = stateSet;
383            return onStateChange(stateSet);
384        }
385        return false;
386    }
387
388    /**
389     * Describes the current state, as a union of primitve states, such as
390     * {@link android.R.attr#state_focused},
391     * {@link android.R.attr#state_selected}, etc.
392     * Some drawables may modify their imagery based on the selected state.
393     * @return An array of resource Ids describing the current state.
394     */
395    public int[] getState() {
396        return mStateSet;
397    }
398
399    /**
400     * @return The current drawable that will be used by this drawable. For simple drawables, this
401     *         is just the drawable itself. For drawables that change state like
402     *         {@link StateListDrawable} and {@link LevelListDrawable} this will be the child drawable
403     *         currently in use.
404     */
405    public Drawable getCurrent() {
406        return this;
407    }
408
409    /**
410     * Specify the level for the drawable.  This allows a drawable to vary its
411     * imagery based on a continuous controller, for example to show progress
412     * or volume level.
413     *
414     * <p>If the new level you are supplying causes the appearance of the
415     * Drawable to change, then it is responsible for calling
416     * {@link #invalidateSelf} in order to have itself redrawn, <em>and</em>
417     * true will be returned from this function.
418     *
419     * @param level The new level, from 0 (minimum) to 10000 (maximum).
420     *
421     * @return Returns true if this change in level has caused the appearance
422     * of the Drawable to change (hence requiring an invalidate), otherwise
423     * returns false.
424     */
425    public final boolean setLevel(int level) {
426        if (mLevel != level) {
427            mLevel = level;
428            return onLevelChange(level);
429        }
430        return false;
431    }
432
433    /**
434     * Retrieve the current level.
435     *
436     * @return int Current level, from 0 (minimum) to 10000 (maximum).
437     */
438    public final int getLevel() {
439        return mLevel;
440    }
441
442    /**
443     * Set whether this Drawable is visible.  This generally does not impact
444     * the Drawable's behavior, but is a hint that can be used by some
445     * Drawables, for example, to decide whether run animations.
446     *
447     * @param visible Set to true if visible, false if not.
448     * @param restart You can supply true here to force the drawable to behave
449     *                as if it has just become visible, even if it had last
450     *                been set visible.  Used for example to force animations
451     *                to restart.
452     *
453     * @return boolean Returns true if the new visibility is different than
454     *         its previous state.
455     */
456    public boolean setVisible(boolean visible, boolean restart) {
457        boolean changed = mVisible != visible;
458        mVisible = visible;
459        return changed;
460    }
461
462    public final boolean isVisible() {
463        return mVisible;
464    }
465
466    /**
467     * Return the opacity/transparency of this Drawable.  The returned value is
468     * one of the abstract format constants in
469     * {@link android.graphics.PixelFormat}:
470     * {@link android.graphics.PixelFormat#UNKNOWN},
471     * {@link android.graphics.PixelFormat#TRANSLUCENT},
472     * {@link android.graphics.PixelFormat#TRANSPARENT}, or
473     * {@link android.graphics.PixelFormat#OPAQUE}.
474     *
475     * <p>Generally a Drawable should be as conservative as possible with the
476     * value it returns.  For example, if it contains multiple child drawables
477     * and only shows one of them at a time, if only one of the children is
478     * TRANSLUCENT and the others are OPAQUE then TRANSLUCENT should be
479     * returned.  You can use the method {@link #resolveOpacity} to perform a
480     * standard reduction of two opacities to the appropriate single output.
481     *
482     * <p>Note that the returned value does <em>not</em> take into account a
483     * custom alpha or color filter that has been applied by the client through
484     * the {@link #setAlpha} or {@link #setColorFilter} methods.
485     *
486     * @return int The opacity class of the Drawable.
487     *
488     * @see android.graphics.PixelFormat
489     */
490    public abstract int getOpacity();
491
492    /**
493     * Return the appropriate opacity value for two source opacities.  If
494     * either is UNKNOWN, that is returned; else, if either is TRANSLUCENT,
495     * that is returned; else, if either is TRANSPARENT, that is returned;
496     * else, OPAQUE is returned.
497     *
498     * <p>This is to help in implementing {@link #getOpacity}.
499     *
500     * @param op1 One opacity value.
501     * @param op2 Another opacity value.
502     *
503     * @return int The combined opacity value.
504     *
505     * @see #getOpacity
506     */
507    public static int resolveOpacity(int op1, int op2) {
508        if (op1 == op2) {
509            return op1;
510        }
511        if (op1 == PixelFormat.UNKNOWN || op2 == PixelFormat.UNKNOWN) {
512            return PixelFormat.UNKNOWN;
513        }
514        if (op1 == PixelFormat.TRANSLUCENT || op2 == PixelFormat.TRANSLUCENT) {
515            return PixelFormat.TRANSLUCENT;
516        }
517        if (op1 == PixelFormat.TRANSPARENT || op2 == PixelFormat.TRANSPARENT) {
518            return PixelFormat.TRANSPARENT;
519        }
520        return PixelFormat.OPAQUE;
521    }
522
523    /**
524     * Returns a Region representing the part of the Drawable that is completely
525     * transparent.  This can be used to perform drawing operations, identifying
526     * which parts of the target will not change when rendering the Drawable.
527     * The default implementation returns null, indicating no transparent
528     * region; subclasses can optionally override this to return an actual
529     * Region if they want to supply this optimization information, but it is
530     * not required that they do so.
531     *
532     * @return Returns null if the Drawables has no transparent region to
533     * report, else a Region holding the parts of the Drawable's bounds that
534     * are transparent.
535     */
536    public Region getTransparentRegion() {
537        return null;
538    }
539
540    /**
541     * Override this in your subclass to change appearance if you recognize the
542     * specified state.
543     *
544     * @return Returns true if the state change has caused the appearance of
545     * the Drawable to change (that is, it needs to be drawn), else false
546     * if it looks the same and there is no need to redraw it since its
547     * last state.
548     */
549    protected boolean onStateChange(int[] state) { return false; }
550    /** Override this in your subclass to change appearance if you vary based
551     *  on level.
552     * @return Returns true if the level change has caused the appearance of
553     * the Drawable to change (that is, it needs to be drawn), else false
554     * if it looks the same and there is no need to redraw it since its
555     * last level.
556     */
557    protected boolean onLevelChange(int level) { return false; }
558    /**
559     * Override this in your subclass to change appearance if you recognize the
560     * specified state.
561     */
562    protected void onBoundsChange(Rect bounds) {}
563
564    /**
565     * Return the intrinsic width of the underlying drawable object.  Returns
566     * -1 if it has no intrinsic width, such as with a solid color.
567     */
568    public int getIntrinsicWidth() {
569        return -1;
570    }
571
572    /**
573     * Return the intrinsic height of the underlying drawable object. Returns
574     * -1 if it has no intrinsic height, such as with a solid color.
575     */
576    public int getIntrinsicHeight() {
577        return -1;
578    }
579
580    /**
581     * Returns the minimum width suggested by this Drawable. If a View uses this
582     * Drawable as a background, it is suggested that the View use at least this
583     * value for its width. (There will be some scenarios where this will not be
584     * possible.) This value should INCLUDE any padding.
585     *
586     * @return The minimum width suggested by this Drawable. If this Drawable
587     *         doesn't have a suggested minimum width, 0 is returned.
588     */
589    public int getMinimumWidth() {
590        final int intrinsicWidth = getIntrinsicWidth();
591        return intrinsicWidth > 0 ? intrinsicWidth : 0;
592    }
593
594    /**
595     * Returns the minimum height suggested by this Drawable. If a View uses this
596     * Drawable as a background, it is suggested that the View use at least this
597     * value for its height. (There will be some scenarios where this will not be
598     * possible.) This value should INCLUDE any padding.
599     *
600     * @return The minimum height suggested by this Drawable. If this Drawable
601     *         doesn't have a suggested minimum height, 0 is returned.
602     */
603    public int getMinimumHeight() {
604        final int intrinsicHeight = getIntrinsicHeight();
605        return intrinsicHeight > 0 ? intrinsicHeight : 0;
606    }
607
608    /**
609     * Return in padding the insets suggested by this Drawable for placing
610     * content inside the drawable's bounds. Positive values move toward the
611     * center of the Drawable (set Rect.inset). Returns true if this drawable
612     * actually has a padding, else false. When false is returned, the padding
613     * is always set to 0.
614     */
615    public boolean getPadding(Rect padding) {
616        padding.set(0, 0, 0, 0);
617        return false;
618    }
619
620    /**
621     * Create a drawable from an inputstream
622     */
623    public static Drawable createFromStream(InputStream is, String srcName) {
624        if (is == null) {
625            return null;
626        }
627
628        /*  ugh. The decodeStream contract is that we have already allocated
629            the pad rect, but if the bitmap does not had a ninepatch chunk,
630            then the pad will be ignored. If we could change this to lazily
631            alloc/assign the rect, we could avoid the GC churn of making new
632            Rects only to drop them on the floor.
633        */
634        Rect pad = new Rect();
635        Bitmap  bm = BitmapFactory.decodeStream(is, pad, null);
636        if (bm != null) {
637            byte[] np = bm.getNinePatchChunk();
638            if (np == null || !NinePatch.isNinePatchChunk(np)) {
639                np = null;
640                pad = null;
641            }
642            return drawableFromBitmap(bm, np, pad, srcName);
643        }
644        return null;
645    }
646
647    /**
648     * Create a drawable from an XML document. For more information on how to
649     * create resources in XML, see
650     * <a href="{@docRoot}devel/resources-i18n.html">Resources and
651     * Internationalization</a>.
652     */
653    public static Drawable createFromXml(Resources r, XmlPullParser parser)
654            throws XmlPullParserException, IOException {
655        AttributeSet attrs = Xml.asAttributeSet(parser);
656
657        int type;
658        while ((type=parser.next()) != XmlPullParser.START_TAG &&
659                type != XmlPullParser.END_DOCUMENT) {
660            // Empty loop
661        }
662
663        if (type != XmlPullParser.START_TAG) {
664            throw new XmlPullParserException("No start tag found");
665        }
666
667        Drawable drawable = createFromXmlInner(r, parser, attrs);
668
669        if (drawable == null) {
670            throw new RuntimeException("Unknown initial tag: " + parser.getName());
671        }
672
673        return drawable;
674    }
675
676    /**
677     * Create from inside an XML document.  Called on a parser positioned at
678     * a tag in an XML document, tries to create a Drawable from that tag.
679     * Returns null if the tag is not a valid drawable.
680     */
681    public static Drawable createFromXmlInner(Resources r, XmlPullParser parser, AttributeSet attrs)
682    throws XmlPullParserException, IOException {
683        Drawable drawable;
684
685        final String name = parser.getName();
686
687        if (name.equals("selector")) {
688            drawable = new StateListDrawable();
689        } else if (name.equals("level-list")) {
690            drawable = new LevelListDrawable();
691        } else if (name.equals("layer-list")) {
692            drawable = new LayerDrawable();
693        } else if (name.equals("transition")) {
694            drawable = new TransitionDrawable();
695        } else if (name.equals("color")) {
696            drawable = new ColorDrawable();
697        } else if (name.equals("shape")) {
698            drawable = new GradientDrawable();
699        } else if (name.equals("scale")) {
700            drawable = new ScaleDrawable();
701        } else if (name.equals("clip")) {
702            drawable = new ClipDrawable();
703        } else if (name.equals("rotate")) {
704            drawable = new RotateDrawable();
705        } else if (name.equals("animation-list")) {
706            drawable = new AnimationDrawable();
707        } else if (name.equals("inset")) {
708            drawable = new InsetDrawable();
709        } else if (name.equals("bitmap")) {
710            drawable = new BitmapDrawable();
711        } else {
712            throw new XmlPullParserException(parser.getPositionDescription() +
713                    ": invalid drawable tag " + name);
714        }
715
716        drawable.inflate(r, parser, attrs);
717        return drawable;
718    }
719
720
721    /**
722     * Create a drawable from file path name.
723     */
724    public static Drawable createFromPath(String pathName) {
725        if (pathName == null) {
726            return null;
727        }
728
729        Bitmap bm = BitmapFactory.decodeFile(pathName);
730        if (bm != null) {
731            return drawableFromBitmap(bm, null, null, pathName);
732        }
733
734        return null;
735    }
736
737    public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs)
738            throws XmlPullParserException, IOException {
739
740        TypedArray a = r.obtainAttributes(attrs, com.android.internal.R.styleable.Drawable);
741        inflateWithAttributes(r, parser, a, com.android.internal.R.styleable.Drawable_visible);
742        a.recycle();
743    }
744
745    void inflateWithAttributes(Resources r, XmlPullParser parser,
746            TypedArray attrs, int visibleAttr)
747            throws XmlPullParserException, IOException {
748
749        mVisible = attrs.getBoolean(visibleAttr, mVisible);
750    }
751
752    public static abstract class ConstantState {
753        public abstract Drawable newDrawable();
754        public abstract int getChangingConfigurations();
755    }
756
757    public ConstantState getConstantState() {
758        return null;
759    }
760
761    private static Drawable drawableFromBitmap(Bitmap bm, byte[] np, Rect pad, String srcName) {
762        if (np != null) {
763            return new NinePatchDrawable(bm, np, pad, srcName);
764        }
765        return new BitmapDrawable(bm);
766    }
767}
768
769