Drawable.java revision 2f8ba8f7fad2b608102a9282219aaea2223e94f5
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 android.graphics.Insets; 20import android.graphics.Xfermode; 21import android.os.Trace; 22 23import org.xmlpull.v1.XmlPullParser; 24import org.xmlpull.v1.XmlPullParserException; 25 26import android.content.res.Resources; 27import android.content.res.Resources.Theme; 28import android.content.res.TypedArray; 29import android.graphics.Bitmap; 30import android.graphics.BitmapFactory; 31import android.graphics.Canvas; 32import android.graphics.ColorFilter; 33import android.graphics.NinePatch; 34import android.graphics.Outline; 35import android.graphics.PixelFormat; 36import android.graphics.PorterDuff; 37import android.graphics.PorterDuffColorFilter; 38import android.graphics.Rect; 39import android.graphics.Region; 40import android.graphics.PorterDuff.Mode; 41import android.util.AttributeSet; 42import android.util.DisplayMetrics; 43import android.util.StateSet; 44import android.util.TypedValue; 45import android.util.Xml; 46import android.view.View; 47 48import java.io.IOException; 49import java.io.InputStream; 50import java.lang.ref.WeakReference; 51import java.util.Arrays; 52 53/** 54 * A Drawable is a general abstraction for "something that can be drawn." Most 55 * often you will deal with Drawable as the type of resource retrieved for 56 * drawing things to the screen; the Drawable class provides a generic API for 57 * dealing with an underlying visual resource that may take a variety of forms. 58 * Unlike a {@link android.view.View}, a Drawable does not have any facility to 59 * receive events or otherwise interact with the user. 60 * 61 * <p>In addition to simple drawing, Drawable provides a number of generic 62 * mechanisms for its client to interact with what is being drawn: 63 * 64 * <ul> 65 * <li> The {@link #setBounds} method <var>must</var> be called to tell the 66 * Drawable where it is drawn and how large it should be. All Drawables 67 * should respect the requested size, often simply by scaling their 68 * imagery. A client can find the preferred size for some Drawables with 69 * the {@link #getIntrinsicHeight} and {@link #getIntrinsicWidth} methods. 70 * 71 * <li> The {@link #getPadding} method can return from some Drawables 72 * information about how to frame content that is placed inside of them. 73 * For example, a Drawable that is intended to be the frame for a button 74 * widget would need to return padding that correctly places the label 75 * inside of itself. 76 * 77 * <li> The {@link #setState} method allows the client to tell the Drawable 78 * in which state it is to be drawn, such as "focused", "selected", etc. 79 * Some drawables may modify their imagery based on the selected state. 80 * 81 * <li> The {@link #setLevel} method allows the client to supply a single 82 * continuous controller that can modify the Drawable is displayed, such as 83 * a battery level or progress level. Some drawables may modify their 84 * imagery based on the current level. 85 * 86 * <li> A Drawable can perform animations by calling back to its client 87 * through the {@link Callback} interface. All clients should support this 88 * interface (via {@link #setCallback}) so that animations will work. A 89 * simple way to do this is through the system facilities such as 90 * {@link android.view.View#setBackground(Drawable)} and 91 * {@link android.widget.ImageView}. 92 * </ul> 93 * 94 * Though usually not visible to the application, Drawables may take a variety 95 * of forms: 96 * 97 * <ul> 98 * <li> <b>Bitmap</b>: the simplest Drawable, a PNG or JPEG image. 99 * <li> <b>Nine Patch</b>: an extension to the PNG format allows it to 100 * specify information about how to stretch it and place things inside of 101 * it. 102 * <li> <b>Shape</b>: contains simple drawing commands instead of a raw 103 * bitmap, allowing it to resize better in some cases. 104 * <li> <b>Layers</b>: a compound drawable, which draws multiple underlying 105 * drawables on top of each other. 106 * <li> <b>States</b>: a compound drawable that selects one of a set of 107 * drawables based on its state. 108 * <li> <b>Levels</b>: a compound drawable that selects one of a set of 109 * drawables based on its level. 110 * <li> <b>Scale</b>: a compound drawable with a single child drawable, 111 * whose overall size is modified based on the current level. 112 * </ul> 113 * 114 * <div class="special reference"> 115 * <h3>Developer Guides</h3> 116 * <p>For more information about how to use drawables, read the 117 * <a href="{@docRoot}guide/topics/graphics/2d-graphics.html">Canvas and Drawables</a> developer 118 * guide. For information and examples of creating drawable resources (XML or bitmap files that 119 * can be loaded in code), read the 120 * <a href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable Resources</a> 121 * document.</p></div> 122 */ 123public abstract class Drawable { 124 private static final Rect ZERO_BOUNDS_RECT = new Rect(); 125 126 private int[] mStateSet = StateSet.WILD_CARD; 127 private int mLevel = 0; 128 private int mChangingConfigurations = 0; 129 private Rect mBounds = ZERO_BOUNDS_RECT; // lazily becomes a new Rect() 130 private WeakReference<Callback> mCallback = null; 131 private boolean mVisible = true; 132 133 private int mLayoutDirection; 134 135 /** 136 * Draw in its bounds (set via setBounds) respecting optional effects such 137 * as alpha (set via setAlpha) and color filter (set via setColorFilter). 138 * 139 * @param canvas The canvas to draw into 140 */ 141 public abstract void draw(Canvas canvas); 142 143 /** 144 * Specify a bounding rectangle for the Drawable. This is where the drawable 145 * will draw when its draw() method is called. 146 */ 147 public void setBounds(int left, int top, int right, int bottom) { 148 Rect oldBounds = mBounds; 149 150 if (oldBounds == ZERO_BOUNDS_RECT) { 151 oldBounds = mBounds = new Rect(); 152 } 153 154 if (oldBounds.left != left || oldBounds.top != top || 155 oldBounds.right != right || oldBounds.bottom != bottom) { 156 if (!oldBounds.isEmpty()) { 157 // first invalidate the previous bounds 158 invalidateSelf(); 159 } 160 mBounds.set(left, top, right, bottom); 161 onBoundsChange(mBounds); 162 } 163 } 164 165 /** 166 * Specify a bounding rectangle for the Drawable. This is where the drawable 167 * will draw when its draw() method is called. 168 */ 169 public void setBounds(Rect bounds) { 170 setBounds(bounds.left, bounds.top, bounds.right, bounds.bottom); 171 } 172 173 /** 174 * Return a copy of the drawable's bounds in the specified Rect (allocated 175 * by the caller). The bounds specify where this will draw when its draw() 176 * method is called. 177 * 178 * @param bounds Rect to receive the drawable's bounds (allocated by the 179 * caller). 180 */ 181 public final void copyBounds(Rect bounds) { 182 bounds.set(mBounds); 183 } 184 185 /** 186 * Return a copy of the drawable's bounds in a new Rect. This returns the 187 * same values as getBounds(), but the returned object is guaranteed to not 188 * be changed later by the drawable (i.e. it retains no reference to this 189 * rect). If the caller already has a Rect allocated, call copyBounds(rect). 190 * 191 * @return A copy of the drawable's bounds 192 */ 193 public final Rect copyBounds() { 194 return new Rect(mBounds); 195 } 196 197 /** 198 * Return the drawable's bounds Rect. Note: for efficiency, the returned 199 * object may be the same object stored in the drawable (though this is not 200 * guaranteed), so if a persistent copy of the bounds is needed, call 201 * copyBounds(rect) instead. 202 * You should also not change the object returned by this method as it may 203 * be the same object stored in the drawable. 204 * 205 * @return The bounds of the drawable (which may change later, so caller 206 * beware). DO NOT ALTER the returned object as it may change the 207 * stored bounds of this drawable. 208 * 209 * @see #copyBounds() 210 * @see #copyBounds(android.graphics.Rect) 211 */ 212 public final Rect getBounds() { 213 if (mBounds == ZERO_BOUNDS_RECT) { 214 mBounds = new Rect(); 215 } 216 217 return mBounds; 218 } 219 220 /** 221 * Return the drawable's dirty bounds Rect. Note: for efficiency, the 222 * returned object may be the same object stored in the drawable (though 223 * this is not guaranteed). 224 * <p> 225 * By default, this returns the full drawable bounds. Custom drawables may 226 * override this method to perform more precise invalidation. 227 * 228 * @hide 229 */ 230 public Rect getDirtyBounds() { 231 return getBounds(); 232 } 233 234 /** 235 * Set a mask of the configuration parameters for which this drawable 236 * may change, requiring that it be re-created. 237 * 238 * @param configs A mask of the changing configuration parameters, as 239 * defined by {@link android.content.res.Configuration}. 240 * 241 * @see android.content.res.Configuration 242 */ 243 public void setChangingConfigurations(int configs) { 244 mChangingConfigurations = configs; 245 } 246 247 /** 248 * Return a mask of the configuration parameters for which this drawable 249 * may change, requiring that it be re-created. The default implementation 250 * returns whatever was provided through 251 * {@link #setChangingConfigurations(int)} or 0 by default. Subclasses 252 * may extend this to or in the changing configurations of any other 253 * drawables they hold. 254 * 255 * @return Returns a mask of the changing configuration parameters, as 256 * defined by {@link android.content.res.Configuration}. 257 * 258 * @see android.content.res.Configuration 259 */ 260 public int getChangingConfigurations() { 261 return mChangingConfigurations; 262 } 263 264 /** 265 * Set to true to have the drawable dither its colors when drawn to a device 266 * with fewer than 8-bits per color component. This can improve the look on 267 * those devices, but can also slow down the drawing a little. 268 */ 269 public void setDither(boolean dither) {} 270 271 /** 272 * Set to true to have the drawable filter its bitmap when scaled or rotated 273 * (for drawables that use bitmaps). If the drawable does not use bitmaps, 274 * this call is ignored. This can improve the look when scaled or rotated, 275 * but also slows down the drawing. 276 */ 277 public void setFilterBitmap(boolean filter) {} 278 279 /** 280 * Implement this interface if you want to create an animated drawable that 281 * extends {@link android.graphics.drawable.Drawable Drawable}. 282 * Upon retrieving a drawable, use 283 * {@link Drawable#setCallback(android.graphics.drawable.Drawable.Callback)} 284 * to supply your implementation of the interface to the drawable; it uses 285 * this interface to schedule and execute animation changes. 286 */ 287 public static interface Callback { 288 /** 289 * Called when the drawable needs to be redrawn. A view at this point 290 * should invalidate itself (or at least the part of itself where the 291 * drawable appears). 292 * 293 * @param who The drawable that is requesting the update. 294 */ 295 public void invalidateDrawable(Drawable who); 296 297 /** 298 * A Drawable can call this to schedule the next frame of its 299 * animation. An implementation can generally simply call 300 * {@link android.os.Handler#postAtTime(Runnable, Object, long)} with 301 * the parameters <var>(what, who, when)</var> to perform the 302 * scheduling. 303 * 304 * @param who The drawable being scheduled. 305 * @param what The action to execute. 306 * @param when The time (in milliseconds) to run. The timebase is 307 * {@link android.os.SystemClock#uptimeMillis} 308 */ 309 public void scheduleDrawable(Drawable who, Runnable what, long when); 310 311 /** 312 * A Drawable can call this to unschedule an action previously 313 * scheduled with {@link #scheduleDrawable}. An implementation can 314 * generally simply call 315 * {@link android.os.Handler#removeCallbacks(Runnable, Object)} with 316 * the parameters <var>(what, who)</var> to unschedule the drawable. 317 * 318 * @param who The drawable being unscheduled. 319 * @param what The action being unscheduled. 320 */ 321 public void unscheduleDrawable(Drawable who, Runnable what); 322 } 323 324 /** 325 * Bind a {@link Callback} object to this Drawable. Required for clients 326 * that want to support animated drawables. 327 * 328 * @param cb The client's Callback implementation. 329 * 330 * @see #getCallback() 331 */ 332 public final void setCallback(Callback cb) { 333 mCallback = new WeakReference<Callback>(cb); 334 } 335 336 /** 337 * Return the current {@link Callback} implementation attached to this 338 * Drawable. 339 * 340 * @return A {@link Callback} instance or null if no callback was set. 341 * 342 * @see #setCallback(android.graphics.drawable.Drawable.Callback) 343 */ 344 public Callback getCallback() { 345 if (mCallback != null) { 346 return mCallback.get(); 347 } 348 return null; 349 } 350 351 /** 352 * Use the current {@link Callback} implementation to have this Drawable 353 * redrawn. Does nothing if there is no Callback attached to the 354 * Drawable. 355 * 356 * @see Callback#invalidateDrawable 357 * @see #getCallback() 358 * @see #setCallback(android.graphics.drawable.Drawable.Callback) 359 */ 360 public void invalidateSelf() { 361 final Callback callback = getCallback(); 362 if (callback != null) { 363 callback.invalidateDrawable(this); 364 } 365 } 366 367 /** 368 * Use the current {@link Callback} implementation to have this Drawable 369 * scheduled. Does nothing if there is no Callback attached to the 370 * Drawable. 371 * 372 * @param what The action being scheduled. 373 * @param when The time (in milliseconds) to run. 374 * 375 * @see Callback#scheduleDrawable 376 */ 377 public void scheduleSelf(Runnable what, long when) { 378 final Callback callback = getCallback(); 379 if (callback != null) { 380 callback.scheduleDrawable(this, what, when); 381 } 382 } 383 384 /** 385 * Use the current {@link Callback} implementation to have this Drawable 386 * unscheduled. Does nothing if there is no Callback attached to the 387 * Drawable. 388 * 389 * @param what The runnable that you no longer want called. 390 * 391 * @see Callback#unscheduleDrawable 392 */ 393 public void unscheduleSelf(Runnable what) { 394 final Callback callback = getCallback(); 395 if (callback != null) { 396 callback.unscheduleDrawable(this, what); 397 } 398 } 399 400 /** 401 * Returns the resolved layout direction for this Drawable. 402 * 403 * @return One of {@link android.view.View#LAYOUT_DIRECTION_LTR}, 404 * {@link android.view.View#LAYOUT_DIRECTION_RTL} 405 * 406 * @hide 407 */ 408 public int getLayoutDirection() { 409 return mLayoutDirection; 410 } 411 412 /** 413 * Set the layout direction for this drawable. Should be a resolved direction as the 414 * Drawable as no capacity to do the resolution on his own. 415 * 416 * @param layoutDirection One of {@link android.view.View#LAYOUT_DIRECTION_LTR}, 417 * {@link android.view.View#LAYOUT_DIRECTION_RTL} 418 * 419 * @hide 420 */ 421 public void setLayoutDirection(@View.ResolvedLayoutDir int layoutDirection) { 422 if (getLayoutDirection() != layoutDirection) { 423 mLayoutDirection = layoutDirection; 424 } 425 } 426 427 /** 428 * Specify an alpha value for the drawable. 0 means fully transparent, and 429 * 255 means fully opaque. 430 */ 431 public abstract void setAlpha(int alpha); 432 433 /** 434 * Gets the current alpha value for the drawable. 0 means fully transparent, 435 * 255 means fully opaque. This method is implemented by 436 * Drawable subclasses and the value returned is specific to how that class treats alpha. 437 * The default return value is 255 if the class does not override this method to return a value 438 * specific to its use of alpha. 439 */ 440 public int getAlpha() { 441 return 0xFF; 442 } 443 444 /** 445 * @hide Consider for future API inclusion 446 */ 447 public void setXfermode(Xfermode mode) { 448 // Base implementation drops it on the floor for compatibility. Whee! 449 // TODO: For this to be included in the API proper, all framework drawables need impls. 450 // For right now only BitmapDrawable has it. 451 } 452 453 /** 454 * Specify an optional color filter for the drawable. Pass {@code null} to 455 * remove any existing color filter. 456 * 457 * @param cf the color filter to apply, or {@code null} to remove the 458 * existing color filter 459 */ 460 public abstract void setColorFilter(ColorFilter cf); 461 462 /** 463 * Specify a color and Porter-Duff mode to be the color filter for this 464 * drawable. 465 */ 466 public void setColorFilter(int color, PorterDuff.Mode mode) { 467 setColorFilter(new PorterDuffColorFilter(color, mode)); 468 } 469 470 /** 471 * Returns the current color filter, or {@code null} if none set. 472 * 473 * @return the current color filter, or {@code null} if none set 474 */ 475 public ColorFilter getColorFilter() { 476 return null; 477 } 478 479 /** 480 * Removes the color filter for this drawable. 481 */ 482 public void clearColorFilter() { 483 setColorFilter(null); 484 } 485 486 /** 487 * Indicates whether the drawable supports hotspots. Hotspots are uniquely 488 * identifiable coordinates the may be added, updated and removed within a 489 * drawable. 490 * 491 * @return true if hotspots are supported 492 * @see #setHotspot(int, float, float) 493 * @see #removeHotspot(int) 494 * @see #clearHotspots() 495 */ 496 public boolean supportsHotspots() { 497 return false; 498 } 499 500 /** 501 * Specifies a hotspot's location within the drawable. 502 * <p> 503 * The specified key should be an id declared in the resources of the 504 * application to ensure it is unique (see the <a 505 * href={@docRoot}guide/topics/resources/more-resources.html#Id">ID resource type</a>). 506 * 507 * @param key The key identifying the hotspot 508 * @param x The X coordinate of the center of the hotspot 509 * @param y The Y coordinate of the center of the hotspot 510 */ 511 public void setHotspot(int key, float x, float y) {} 512 513 /** 514 * Removes the hotspot with the specified key from the drawable. 515 * 516 * @param key The key identifying the hotspot 517 */ 518 public void removeHotspot(int key) {} 519 520 /** 521 * Removes all hotspots from the drawable. 522 */ 523 public void clearHotspots() {} 524 525 /** 526 * Whether this drawable requests projection. 527 * 528 * @hide until we finalize these APIs 529 */ 530 public boolean isProjected() { 531 return false; 532 } 533 534 /** 535 * Indicates whether this view will change its appearance based on state. 536 * Clients can use this to determine whether it is necessary to calculate 537 * their state and call setState. 538 * 539 * @return True if this view changes its appearance based on state, false 540 * otherwise. 541 * 542 * @see #setState(int[]) 543 */ 544 public boolean isStateful() { 545 return false; 546 } 547 548 /** 549 * Specify a set of states for the drawable. These are use-case specific, 550 * so see the relevant documentation. As an example, the background for 551 * widgets like Button understand the following states: 552 * [{@link android.R.attr#state_focused}, 553 * {@link android.R.attr#state_pressed}]. 554 * 555 * <p>If the new state you are supplying causes the appearance of the 556 * Drawable to change, then it is responsible for calling 557 * {@link #invalidateSelf} in order to have itself redrawn, <em>and</em> 558 * true will be returned from this function. 559 * 560 * <p>Note: The Drawable holds a reference on to <var>stateSet</var> 561 * until a new state array is given to it, so you must not modify this 562 * array during that time.</p> 563 * 564 * @param stateSet The new set of states to be displayed. 565 * 566 * @return Returns true if this change in state has caused the appearance 567 * of the Drawable to change (hence requiring an invalidate), otherwise 568 * returns false. 569 */ 570 public boolean setState(final int[] stateSet) { 571 if (!Arrays.equals(mStateSet, stateSet)) { 572 mStateSet = stateSet; 573 return onStateChange(stateSet); 574 } 575 return false; 576 } 577 578 /** 579 * Describes the current state, as a union of primitve states, such as 580 * {@link android.R.attr#state_focused}, 581 * {@link android.R.attr#state_selected}, etc. 582 * Some drawables may modify their imagery based on the selected state. 583 * @return An array of resource Ids describing the current state. 584 */ 585 public int[] getState() { 586 return mStateSet; 587 } 588 589 /** 590 * If this Drawable does transition animations between states, ask that 591 * it immediately jump to the current state and skip any active animations. 592 */ 593 public void jumpToCurrentState() { 594 } 595 596 /** 597 * @return The current drawable that will be used by this drawable. For simple drawables, this 598 * is just the drawable itself. For drawables that change state like 599 * {@link StateListDrawable} and {@link LevelListDrawable} this will be the child drawable 600 * currently in use. 601 */ 602 public Drawable getCurrent() { 603 return this; 604 } 605 606 /** 607 * Specify the level for the drawable. This allows a drawable to vary its 608 * imagery based on a continuous controller, for example to show progress 609 * or volume level. 610 * 611 * <p>If the new level you are supplying causes the appearance of the 612 * Drawable to change, then it is responsible for calling 613 * {@link #invalidateSelf} in order to have itself redrawn, <em>and</em> 614 * true will be returned from this function. 615 * 616 * @param level The new level, from 0 (minimum) to 10000 (maximum). 617 * 618 * @return Returns true if this change in level has caused the appearance 619 * of the Drawable to change (hence requiring an invalidate), otherwise 620 * returns false. 621 */ 622 public final boolean setLevel(int level) { 623 if (mLevel != level) { 624 mLevel = level; 625 return onLevelChange(level); 626 } 627 return false; 628 } 629 630 /** 631 * Retrieve the current level. 632 * 633 * @return int Current level, from 0 (minimum) to 10000 (maximum). 634 */ 635 public final int getLevel() { 636 return mLevel; 637 } 638 639 /** 640 * Set whether this Drawable is visible. This generally does not impact 641 * the Drawable's behavior, but is a hint that can be used by some 642 * Drawables, for example, to decide whether run animations. 643 * 644 * @param visible Set to true if visible, false if not. 645 * @param restart You can supply true here to force the drawable to behave 646 * as if it has just become visible, even if it had last 647 * been set visible. Used for example to force animations 648 * to restart. 649 * 650 * @return boolean Returns true if the new visibility is different than 651 * its previous state. 652 */ 653 public boolean setVisible(boolean visible, boolean restart) { 654 boolean changed = mVisible != visible; 655 if (changed) { 656 mVisible = visible; 657 invalidateSelf(); 658 } 659 return changed; 660 } 661 662 public final boolean isVisible() { 663 return mVisible; 664 } 665 666 /** 667 * Set whether this Drawable is automatically mirrored when its layout direction is RTL 668 * (right-to left). See {@link android.util.LayoutDirection}. 669 * 670 * @param mirrored Set to true if the Drawable should be mirrored, false if not. 671 */ 672 public void setAutoMirrored(boolean mirrored) { 673 } 674 675 /** 676 * Tells if this Drawable will be automatically mirrored when its layout direction is RTL 677 * right-to-left. See {@link android.util.LayoutDirection}. 678 * 679 * @return boolean Returns true if this Drawable will be automatically mirrored. 680 */ 681 public boolean isAutoMirrored() { 682 return false; 683 } 684 685 /** 686 * Applies the specified theme to this Drawable and its children. 687 */ 688 public void applyTheme(@SuppressWarnings("unused") Theme t) { 689 } 690 691 public boolean canApplyTheme() { 692 return false; 693 } 694 695 /** 696 * Return the opacity/transparency of this Drawable. The returned value is 697 * one of the abstract format constants in 698 * {@link android.graphics.PixelFormat}: 699 * {@link android.graphics.PixelFormat#UNKNOWN}, 700 * {@link android.graphics.PixelFormat#TRANSLUCENT}, 701 * {@link android.graphics.PixelFormat#TRANSPARENT}, or 702 * {@link android.graphics.PixelFormat#OPAQUE}. 703 * 704 * <p>Generally a Drawable should be as conservative as possible with the 705 * value it returns. For example, if it contains multiple child drawables 706 * and only shows one of them at a time, if only one of the children is 707 * TRANSLUCENT and the others are OPAQUE then TRANSLUCENT should be 708 * returned. You can use the method {@link #resolveOpacity} to perform a 709 * standard reduction of two opacities to the appropriate single output. 710 * 711 * <p>Note that the returned value does <em>not</em> take into account a 712 * custom alpha or color filter that has been applied by the client through 713 * the {@link #setAlpha} or {@link #setColorFilter} methods. 714 * 715 * @return int The opacity class of the Drawable. 716 * 717 * @see android.graphics.PixelFormat 718 */ 719 public abstract int getOpacity(); 720 721 /** 722 * Return the appropriate opacity value for two source opacities. If 723 * either is UNKNOWN, that is returned; else, if either is TRANSLUCENT, 724 * that is returned; else, if either is TRANSPARENT, that is returned; 725 * else, OPAQUE is returned. 726 * 727 * <p>This is to help in implementing {@link #getOpacity}. 728 * 729 * @param op1 One opacity value. 730 * @param op2 Another opacity value. 731 * 732 * @return int The combined opacity value. 733 * 734 * @see #getOpacity 735 */ 736 public static int resolveOpacity(int op1, int op2) { 737 if (op1 == op2) { 738 return op1; 739 } 740 if (op1 == PixelFormat.UNKNOWN || op2 == PixelFormat.UNKNOWN) { 741 return PixelFormat.UNKNOWN; 742 } 743 if (op1 == PixelFormat.TRANSLUCENT || op2 == PixelFormat.TRANSLUCENT) { 744 return PixelFormat.TRANSLUCENT; 745 } 746 if (op1 == PixelFormat.TRANSPARENT || op2 == PixelFormat.TRANSPARENT) { 747 return PixelFormat.TRANSPARENT; 748 } 749 return PixelFormat.OPAQUE; 750 } 751 752 /** 753 * Returns a Region representing the part of the Drawable that is completely 754 * transparent. This can be used to perform drawing operations, identifying 755 * which parts of the target will not change when rendering the Drawable. 756 * The default implementation returns null, indicating no transparent 757 * region; subclasses can optionally override this to return an actual 758 * Region if they want to supply this optimization information, but it is 759 * not required that they do so. 760 * 761 * @return Returns null if the Drawables has no transparent region to 762 * report, else a Region holding the parts of the Drawable's bounds that 763 * are transparent. 764 */ 765 public Region getTransparentRegion() { 766 return null; 767 } 768 769 /** 770 * Override this in your subclass to change appearance if you recognize the 771 * specified state. 772 * 773 * @return Returns true if the state change has caused the appearance of 774 * the Drawable to change (that is, it needs to be drawn), else false 775 * if it looks the same and there is no need to redraw it since its 776 * last state. 777 */ 778 protected boolean onStateChange(int[] state) { return false; } 779 /** Override this in your subclass to change appearance if you vary based 780 * on level. 781 * @return Returns true if the level change has caused the appearance of 782 * the Drawable to change (that is, it needs to be drawn), else false 783 * if it looks the same and there is no need to redraw it since its 784 * last level. 785 */ 786 protected boolean onLevelChange(int level) { return false; } 787 /** 788 * Override this in your subclass to change appearance if you vary based on 789 * the bounds. 790 */ 791 protected void onBoundsChange(Rect bounds) {} 792 793 /** 794 * Return the intrinsic width of the underlying drawable object. Returns 795 * -1 if it has no intrinsic width, such as with a solid color. 796 */ 797 public int getIntrinsicWidth() { 798 return -1; 799 } 800 801 /** 802 * Return the intrinsic height of the underlying drawable object. Returns 803 * -1 if it has no intrinsic height, such as with a solid color. 804 */ 805 public int getIntrinsicHeight() { 806 return -1; 807 } 808 809 /** 810 * Returns the minimum width suggested by this Drawable. If a View uses this 811 * Drawable as a background, it is suggested that the View use at least this 812 * value for its width. (There will be some scenarios where this will not be 813 * possible.) This value should INCLUDE any padding. 814 * 815 * @return The minimum width suggested by this Drawable. If this Drawable 816 * doesn't have a suggested minimum width, 0 is returned. 817 */ 818 public int getMinimumWidth() { 819 final int intrinsicWidth = getIntrinsicWidth(); 820 return intrinsicWidth > 0 ? intrinsicWidth : 0; 821 } 822 823 /** 824 * Returns the minimum height suggested by this Drawable. If a View uses this 825 * Drawable as a background, it is suggested that the View use at least this 826 * value for its height. (There will be some scenarios where this will not be 827 * possible.) This value should INCLUDE any padding. 828 * 829 * @return The minimum height suggested by this Drawable. If this Drawable 830 * doesn't have a suggested minimum height, 0 is returned. 831 */ 832 public int getMinimumHeight() { 833 final int intrinsicHeight = getIntrinsicHeight(); 834 return intrinsicHeight > 0 ? intrinsicHeight : 0; 835 } 836 837 /** 838 * Return in padding the insets suggested by this Drawable for placing 839 * content inside the drawable's bounds. Positive values move toward the 840 * center of the Drawable (set Rect.inset). Returns true if this drawable 841 * actually has a padding, else false. When false is returned, the padding 842 * is always set to 0. 843 */ 844 public boolean getPadding(Rect padding) { 845 padding.set(0, 0, 0, 0); 846 return false; 847 } 848 849 /** 850 * Return in insets the layout insets suggested by this Drawable for use with alignment 851 * operations during layout. 852 * 853 * @hide 854 */ 855 public Insets getOpticalInsets() { 856 return Insets.NONE; 857 } 858 859 /** 860 * Returns the outline for this drawable if defined, null if not. 861 * <p> 862 * This method will be called by a View on its background Drawable after 863 * bounds change, if the View's Outline isn't set explicitly. This allows 864 * the background Drawable to provide the shape of the shadow casting 865 * portion of the View. It can also serve to clip the area of the View if 866 * if {@link View#setClipToOutline(boolean)} is set on the View. 867 * <p> 868 * The Outline queried by the View will not be modified, and is treated as 869 * a static shape that only needs to be requeried when the drawable's bounds 870 * change. 871 * 872 * @see View#setOutline(android.view.Outline) 873 * @see View#setClipToOutline(boolean) 874 */ 875 public Outline getOutline() { return null; } 876 877 /** 878 * Make this drawable mutable. This operation cannot be reversed. A mutable 879 * drawable is guaranteed to not share its state with any other drawable. 880 * This is especially useful when you need to modify properties of drawables 881 * loaded from resources. By default, all drawables instances loaded from 882 * the same resource share a common state; if you modify the state of one 883 * instance, all the other instances will receive the same modification. 884 * 885 * Calling this method on a mutable Drawable will have no effect. 886 * 887 * @return This drawable. 888 * @see ConstantState 889 * @see #getConstantState() 890 */ 891 public Drawable mutate() { 892 return this; 893 } 894 895 /** 896 * Create a drawable from an inputstream 897 */ 898 public static Drawable createFromStream(InputStream is, String srcName) { 899 return createFromStreamThemed(is, srcName, null); 900 } 901 902 public static Drawable createFromStreamThemed(InputStream is, String srcName, Theme theme) { 903 Trace.traceBegin(Trace.TRACE_TAG_RESOURCES, srcName != null ? srcName : "Unknown drawable"); 904 try { 905 return createFromResourceStreamThemed(null, null, is, srcName, theme); 906 } finally { 907 Trace.traceEnd(Trace.TRACE_TAG_RESOURCES); 908 } 909 } 910 911 /** 912 * Create a drawable from an inputstream, using the given resources and 913 * value to determine density information. 914 */ 915 public static Drawable createFromResourceStream(Resources res, TypedValue value, 916 InputStream is, String srcName) { 917 return createFromResourceStreamThemed(res, value, is, srcName, null); 918 } 919 920 public static Drawable createFromResourceStreamThemed(Resources res, TypedValue value, 921 InputStream is, String srcName, Theme theme) { 922 Trace.traceBegin(Trace.TRACE_TAG_RESOURCES, srcName != null ? srcName : "Unknown drawable"); 923 try { 924 return createFromResourceStreamThemed(res, value, is, srcName, null, theme); 925 } finally { 926 Trace.traceEnd(Trace.TRACE_TAG_RESOURCES); 927 } 928 } 929 930 /** 931 * Create a drawable from an inputstream, using the given resources and 932 * value to determine density information. 933 */ 934 public static Drawable createFromResourceStream(Resources res, TypedValue value, 935 InputStream is, String srcName, BitmapFactory.Options opts) { 936 return createFromResourceStreamThemed(res, value, is, srcName, opts, null); 937 } 938 939 public static Drawable createFromResourceStreamThemed(Resources res, TypedValue value, 940 InputStream is, String srcName, BitmapFactory.Options opts, Theme theme) { 941 if (is == null) { 942 return null; 943 } 944 945 /* ugh. The decodeStream contract is that we have already allocated 946 the pad rect, but if the bitmap does not had a ninepatch chunk, 947 then the pad will be ignored. If we could change this to lazily 948 alloc/assign the rect, we could avoid the GC churn of making new 949 Rects only to drop them on the floor. 950 */ 951 Rect pad = new Rect(); 952 953 // Special stuff for compatibility mode: if the target density is not 954 // the same as the display density, but the resource -is- the same as 955 // the display density, then don't scale it down to the target density. 956 // This allows us to load the system's density-correct resources into 957 // an application in compatibility mode, without scaling those down 958 // to the compatibility density only to have them scaled back up when 959 // drawn to the screen. 960 if (opts == null) opts = new BitmapFactory.Options(); 961 opts.inScreenDensity = res != null 962 ? res.getDisplayMetrics().noncompatDensityDpi : DisplayMetrics.DENSITY_DEVICE; 963 Bitmap bm = BitmapFactory.decodeResourceStream(res, value, is, pad, opts); 964 if (bm != null) { 965 byte[] np = bm.getNinePatchChunk(); 966 if (np == null || !NinePatch.isNinePatchChunk(np)) { 967 np = null; 968 pad = null; 969 } 970 int[] layoutBounds = bm.getLayoutBounds(); 971 Rect layoutBoundsRect = null; 972 if (layoutBounds != null) { 973 layoutBoundsRect = new Rect(layoutBounds[0], layoutBounds[1], 974 layoutBounds[2], layoutBounds[3]); 975 } 976 return drawableFromBitmap(res, bm, np, pad, layoutBoundsRect, srcName); 977 } 978 return null; 979 } 980 981 /** 982 * Create a drawable from an XML document. For more information on how to 983 * create resources in XML, see 984 * <a href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable Resources</a>. 985 */ 986 public static Drawable createFromXml(Resources r, XmlPullParser parser) 987 throws XmlPullParserException, IOException { 988 return createFromXmlThemed(r, parser, null); 989 } 990 991 /** 992 * Create a themed drawable from an XML document. For more information on 993 * how to create resources in XML, see 994 * <a href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable Resources</a>. 995 */ 996 public static Drawable createFromXmlThemed(Resources r, XmlPullParser parser, Theme theme) 997 throws XmlPullParserException, IOException { 998 AttributeSet attrs = Xml.asAttributeSet(parser); 999 1000 int type; 1001 while ((type=parser.next()) != XmlPullParser.START_TAG && 1002 type != XmlPullParser.END_DOCUMENT) { 1003 // Empty loop 1004 } 1005 1006 if (type != XmlPullParser.START_TAG) { 1007 throw new XmlPullParserException("No start tag found"); 1008 } 1009 1010 Drawable drawable = createFromXmlInnerThemed(r, parser, attrs, theme); 1011 1012 if (drawable == null) { 1013 throw new RuntimeException("Unknown initial tag: " + parser.getName()); 1014 } 1015 1016 return drawable; 1017 } 1018 1019 /** 1020 * Create from inside an XML document. Called on a parser positioned at 1021 * a tag in an XML document, tries to create a Drawable from that tag. 1022 * Returns null if the tag is not a valid drawable. 1023 */ 1024 public static Drawable createFromXmlInner(Resources r, XmlPullParser parser, AttributeSet attrs) 1025 throws XmlPullParserException, IOException { 1026 return createFromXmlInnerThemed(r, parser, attrs, null); 1027 } 1028 1029 public static Drawable createFromXmlInnerThemed(Resources r, XmlPullParser parser, 1030 AttributeSet attrs, Theme theme) throws XmlPullParserException, IOException { 1031 final Drawable drawable; 1032 1033 final String name = parser.getName(); 1034 if (name.equals("selector")) { 1035 drawable = new StateListDrawable(); 1036 } else if (name.equals("level-list")) { 1037 drawable = new LevelListDrawable(); 1038 } else if (name.equals("layer-list")) { 1039 drawable = new LayerDrawable(); 1040 } else if (name.equals("transition")) { 1041 drawable = new TransitionDrawable(); 1042 } else if (name.equals("touch-feedback")) { 1043 drawable = new TouchFeedbackDrawable(); 1044 } else if (name.equals("color")) { 1045 drawable = new ColorDrawable(); 1046 } else if (name.equals("shape")) { 1047 drawable = new GradientDrawable(); 1048 } else if (name.equals("vector")) { 1049 drawable = new VectorDrawable(); 1050 } else if (name.equals("scale")) { 1051 drawable = new ScaleDrawable(); 1052 } else if (name.equals("clip")) { 1053 drawable = new ClipDrawable(); 1054 } else if (name.equals("rotate")) { 1055 drawable = new RotateDrawable(); 1056 } else if (name.equals("animated-rotate")) { 1057 drawable = new AnimatedRotateDrawable(); 1058 } else if (name.equals("animation-list")) { 1059 drawable = new AnimationDrawable(); 1060 } else if (name.equals("inset")) { 1061 drawable = new InsetDrawable(); 1062 } else if (name.equals("bitmap")) { 1063 //noinspection deprecation 1064 drawable = new BitmapDrawable(r); 1065 if (r != null) { 1066 ((BitmapDrawable) drawable).setTargetDensity(r.getDisplayMetrics()); 1067 } 1068 } else if (name.equals("nine-patch")) { 1069 drawable = new NinePatchDrawable(); 1070 if (r != null) { 1071 ((NinePatchDrawable) drawable).setTargetDensity(r.getDisplayMetrics()); 1072 } 1073 } else { 1074 throw new XmlPullParserException(parser.getPositionDescription() + 1075 ": invalid drawable tag " + name); 1076 } 1077 1078 drawable.inflate(r, parser, attrs, theme); 1079 return drawable; 1080 } 1081 1082 1083 /** 1084 * Create a drawable from file path name. 1085 */ 1086 public static Drawable createFromPath(String pathName) { 1087 if (pathName == null) { 1088 return null; 1089 } 1090 1091 Trace.traceBegin(Trace.TRACE_TAG_RESOURCES, pathName); 1092 try { 1093 Bitmap bm = BitmapFactory.decodeFile(pathName); 1094 if (bm != null) { 1095 return drawableFromBitmap(null, bm, null, null, null, pathName); 1096 } 1097 } finally { 1098 Trace.traceEnd(Trace.TRACE_TAG_RESOURCES); 1099 } 1100 1101 return null; 1102 } 1103 1104 /** 1105 * Inflate this Drawable from an XML resource. Does not apply a theme. 1106 * 1107 * @see #inflate(Resources, XmlPullParser, AttributeSet, Theme) 1108 */ 1109 public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs) 1110 throws XmlPullParserException, IOException { 1111 inflate(r, parser, attrs, null); 1112 } 1113 1114 /** 1115 * Inflate this Drawable from an XML resource optionally styled by a theme. 1116 * 1117 * @param r Resources used to resolve attribute values 1118 * @param parser XML parser from which to inflate this Drawable 1119 * @param attrs Base set of attribute values 1120 * @param theme Theme to apply, may be null 1121 * @throws XmlPullParserException 1122 * @throws IOException 1123 */ 1124 public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs, Theme theme) 1125 throws XmlPullParserException, IOException { 1126 final TypedArray a; 1127 if (theme != null) { 1128 a = theme.obtainStyledAttributes( 1129 attrs, com.android.internal.R.styleable.Drawable, 0, 0); 1130 } else { 1131 a = r.obtainAttributes(attrs, com.android.internal.R.styleable.Drawable); 1132 } 1133 1134 inflateWithAttributes(r, parser, a, com.android.internal.R.styleable.Drawable_visible); 1135 a.recycle(); 1136 } 1137 1138 /** 1139 * Inflate a Drawable from an XML resource. 1140 * 1141 * @throws XmlPullParserException 1142 * @throws IOException 1143 */ 1144 void inflateWithAttributes(Resources r, XmlPullParser parser, TypedArray attrs, int visibleAttr) 1145 throws XmlPullParserException, IOException { 1146 mVisible = attrs.getBoolean(visibleAttr, mVisible); 1147 } 1148 1149 /** 1150 * This abstract class is used by {@link Drawable}s to store shared constant state and data 1151 * between Drawables. {@link BitmapDrawable}s created from the same resource will for instance 1152 * share a unique bitmap stored in their ConstantState. 1153 * 1154 * <p> 1155 * {@link #newDrawable(Resources)} can be used as a factory to create new Drawable instances 1156 * from this ConstantState. 1157 * </p> 1158 * 1159 * Use {@link Drawable#getConstantState()} to retrieve the ConstantState of a Drawable. Calling 1160 * {@link Drawable#mutate()} on a Drawable should typically create a new ConstantState for that 1161 * Drawable. 1162 */ 1163 public static abstract class ConstantState { 1164 /** 1165 * Create a new drawable without supplying resources the caller 1166 * is running in. Note that using this means the density-dependent 1167 * drawables (like bitmaps) will not be able to update their target 1168 * density correctly. One should use {@link #newDrawable(Resources)} 1169 * instead to provide a resource. 1170 */ 1171 public abstract Drawable newDrawable(); 1172 1173 /** 1174 * Create a new Drawable instance from its constant state. This 1175 * must be implemented for drawables that change based on the target 1176 * density of their caller (that is depending on whether it is 1177 * in compatibility mode). 1178 */ 1179 public Drawable newDrawable(Resources res) { 1180 return newDrawable(); 1181 } 1182 1183 /** 1184 * Create a new Drawable instance from its constant state. This must be 1185 * implemented for drawables that can have a theme applied. 1186 */ 1187 public Drawable newDrawable(Resources res, Theme theme) { 1188 return newDrawable(); 1189 } 1190 1191 /** 1192 * Return a bit mask of configuration changes that will impact 1193 * this drawable (and thus require completely reloading it). 1194 */ 1195 public abstract int getChangingConfigurations(); 1196 1197 /** 1198 * @hide 1199 */ 1200 public Bitmap getBitmap() { 1201 return null; 1202 } 1203 1204 /** 1205 * Return whether this constant state can have a theme applied. 1206 */ 1207 public boolean canApplyTheme() { 1208 return false; 1209 } 1210 } 1211 1212 /** 1213 * Return a {@link ConstantState} instance that holds the shared state of this Drawable. 1214 * 1215 * @return The ConstantState associated to that Drawable. 1216 * @see ConstantState 1217 * @see Drawable#mutate() 1218 */ 1219 public ConstantState getConstantState() { 1220 return null; 1221 } 1222 1223 private static Drawable drawableFromBitmap(Resources res, Bitmap bm, byte[] np, 1224 Rect pad, Rect layoutBounds, String srcName) { 1225 1226 if (np != null) { 1227 return new NinePatchDrawable(res, bm, np, pad, layoutBounds, srcName); 1228 } 1229 1230 return new BitmapDrawable(res, bm); 1231 } 1232 1233 /** 1234 * Obtains styled attributes from the theme, if available, or unstyled 1235 * resources if the theme is null. 1236 */ 1237 static TypedArray obtainAttributes( 1238 Resources res, Theme theme, AttributeSet set, int[] attrs) { 1239 if (theme == null) { 1240 return res.obtainAttributes(set, attrs); 1241 } 1242 return theme.obtainStyledAttributes(set, attrs, 0, 0); 1243 } 1244 1245 /** 1246 * Parses a {@link android.graphics.PorterDuff.Mode} from a tintMode 1247 * attribute's enum value. 1248 */ 1249 static PorterDuff.Mode parseTintMode(int value, Mode defaultMode) { 1250 switch (value) { 1251 case 3: return Mode.SRC_OVER; 1252 case 5: return Mode.SRC_IN; 1253 case 9: return Mode.SRC_ATOP; 1254 case 14: return Mode.MULTIPLY; 1255 case 15: return Mode.SCREEN; 1256 case 16: return Mode.ADD; 1257 default: return defaultMode; 1258 } 1259 } 1260} 1261 1262