Drawable.java revision b8cbb806fc70573def954f7ba84dd7b53b3be1bd
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 com.android.internal.R; 20 21import org.xmlpull.v1.XmlPullParser; 22import org.xmlpull.v1.XmlPullParserException; 23 24import android.annotation.AttrRes; 25import android.annotation.ColorInt; 26import android.annotation.IntRange; 27import android.annotation.NonNull; 28import android.annotation.Nullable; 29import android.content.pm.ActivityInfo.Config; 30import android.content.res.ColorStateList; 31import android.content.res.Resources; 32import android.content.res.Resources.Theme; 33import android.content.res.TypedArray; 34import android.graphics.Bitmap; 35import android.graphics.BitmapFactory; 36import android.graphics.Canvas; 37import android.graphics.Color; 38import android.graphics.ColorFilter; 39import android.graphics.Insets; 40import android.graphics.NinePatch; 41import android.graphics.Outline; 42import android.graphics.PixelFormat; 43import android.graphics.PorterDuff; 44import android.graphics.PorterDuff.Mode; 45import android.graphics.PorterDuffColorFilter; 46import android.graphics.Rect; 47import android.graphics.Region; 48import android.graphics.Xfermode; 49import android.os.Trace; 50import android.util.AttributeSet; 51import android.util.DisplayMetrics; 52import android.util.StateSet; 53import android.util.TypedValue; 54import android.util.Xml; 55import android.view.View; 56 57import java.io.IOException; 58import java.io.InputStream; 59import java.lang.ref.WeakReference; 60import java.util.Arrays; 61import java.util.Collection; 62 63/** 64 * A Drawable is a general abstraction for "something that can be drawn." Most 65 * often you will deal with Drawable as the type of resource retrieved for 66 * drawing things to the screen; the Drawable class provides a generic API for 67 * dealing with an underlying visual resource that may take a variety of forms. 68 * Unlike a {@link android.view.View}, a Drawable does not have any facility to 69 * receive events or otherwise interact with the user. 70 * 71 * <p>In addition to simple drawing, Drawable provides a number of generic 72 * mechanisms for its client to interact with what is being drawn: 73 * 74 * <ul> 75 * <li> The {@link #setBounds} method <var>must</var> be called to tell the 76 * Drawable where it is drawn and how large it should be. All Drawables 77 * should respect the requested size, often simply by scaling their 78 * imagery. A client can find the preferred size for some Drawables with 79 * the {@link #getIntrinsicHeight} and {@link #getIntrinsicWidth} methods. 80 * 81 * <li> The {@link #getPadding} method can return from some Drawables 82 * information about how to frame content that is placed inside of them. 83 * For example, a Drawable that is intended to be the frame for a button 84 * widget would need to return padding that correctly places the label 85 * inside of itself. 86 * 87 * <li> The {@link #setState} method allows the client to tell the Drawable 88 * in which state it is to be drawn, such as "focused", "selected", etc. 89 * Some drawables may modify their imagery based on the selected state. 90 * 91 * <li> The {@link #setLevel} method allows the client to supply a single 92 * continuous controller that can modify the Drawable is displayed, such as 93 * a battery level or progress level. Some drawables may modify their 94 * imagery based on the current level. 95 * 96 * <li> A Drawable can perform animations by calling back to its client 97 * through the {@link Callback} interface. All clients should support this 98 * interface (via {@link #setCallback}) so that animations will work. A 99 * simple way to do this is through the system facilities such as 100 * {@link android.view.View#setBackground(Drawable)} and 101 * {@link android.widget.ImageView}. 102 * </ul> 103 * 104 * Though usually not visible to the application, Drawables may take a variety 105 * of forms: 106 * 107 * <ul> 108 * <li> <b>Bitmap</b>: the simplest Drawable, a PNG or JPEG image. 109 * <li> <b>Nine Patch</b>: an extension to the PNG format allows it to 110 * specify information about how to stretch it and place things inside of 111 * it. 112 * <li> <b>Shape</b>: contains simple drawing commands instead of a raw 113 * bitmap, allowing it to resize better in some cases. 114 * <li> <b>Layers</b>: a compound drawable, which draws multiple underlying 115 * drawables on top of each other. 116 * <li> <b>States</b>: a compound drawable that selects one of a set of 117 * drawables based on its state. 118 * <li> <b>Levels</b>: a compound drawable that selects one of a set of 119 * drawables based on its level. 120 * <li> <b>Scale</b>: a compound drawable with a single child drawable, 121 * whose overall size is modified based on the current level. 122 * </ul> 123 * 124 * <div class="special reference"> 125 * <h3>Developer Guides</h3> 126 * <p>For more information about how to use drawables, read the 127 * <a href="{@docRoot}guide/topics/graphics/2d-graphics.html">Canvas and Drawables</a> developer 128 * guide. For information and examples of creating drawable resources (XML or bitmap files that 129 * can be loaded in code), read the 130 * <a href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable Resources</a> 131 * document.</p></div> 132 */ 133public abstract class Drawable { 134 private static final Rect ZERO_BOUNDS_RECT = new Rect(); 135 136 static final PorterDuff.Mode DEFAULT_TINT_MODE = PorterDuff.Mode.SRC_IN; 137 138 private int[] mStateSet = StateSet.WILD_CARD; 139 private int mLevel = 0; 140 private @Config int mChangingConfigurations = 0; 141 private Rect mBounds = ZERO_BOUNDS_RECT; // lazily becomes a new Rect() 142 private WeakReference<Callback> mCallback = null; 143 private boolean mVisible = true; 144 145 private int mLayoutDirection; 146 147 /** 148 * Draw in its bounds (set via setBounds) respecting optional effects such 149 * as alpha (set via setAlpha) and color filter (set via setColorFilter). 150 * 151 * @param canvas The canvas to draw into 152 */ 153 public abstract void draw(@NonNull Canvas canvas); 154 155 /** 156 * Specify a bounding rectangle for the Drawable. This is where the drawable 157 * will draw when its draw() method is called. 158 */ 159 public void setBounds(int left, int top, int right, int bottom) { 160 Rect oldBounds = mBounds; 161 162 if (oldBounds == ZERO_BOUNDS_RECT) { 163 oldBounds = mBounds = new Rect(); 164 } 165 166 if (oldBounds.left != left || oldBounds.top != top || 167 oldBounds.right != right || oldBounds.bottom != bottom) { 168 if (!oldBounds.isEmpty()) { 169 // first invalidate the previous bounds 170 invalidateSelf(); 171 } 172 mBounds.set(left, top, right, bottom); 173 onBoundsChange(mBounds); 174 } 175 } 176 177 /** 178 * Specify a bounding rectangle for the Drawable. This is where the drawable 179 * will draw when its draw() method is called. 180 */ 181 public void setBounds(@NonNull Rect bounds) { 182 setBounds(bounds.left, bounds.top, bounds.right, bounds.bottom); 183 } 184 185 /** 186 * Return a copy of the drawable's bounds in the specified Rect (allocated 187 * by the caller). The bounds specify where this will draw when its draw() 188 * method is called. 189 * 190 * @param bounds Rect to receive the drawable's bounds (allocated by the 191 * caller). 192 */ 193 public final void copyBounds(@NonNull Rect bounds) { 194 bounds.set(mBounds); 195 } 196 197 /** 198 * Return a copy of the drawable's bounds in a new Rect. This returns the 199 * same values as getBounds(), but the returned object is guaranteed to not 200 * be changed later by the drawable (i.e. it retains no reference to this 201 * rect). If the caller already has a Rect allocated, call copyBounds(rect). 202 * 203 * @return A copy of the drawable's bounds 204 */ 205 @NonNull 206 public final Rect copyBounds() { 207 return new Rect(mBounds); 208 } 209 210 /** 211 * Return the drawable's bounds Rect. Note: for efficiency, the returned 212 * object may be the same object stored in the drawable (though this is not 213 * guaranteed), so if a persistent copy of the bounds is needed, call 214 * copyBounds(rect) instead. 215 * You should also not change the object returned by this method as it may 216 * be the same object stored in the drawable. 217 * 218 * @return The bounds of the drawable (which may change later, so caller 219 * beware). DO NOT ALTER the returned object as it may change the 220 * stored bounds of this drawable. 221 * 222 * @see #copyBounds() 223 * @see #copyBounds(android.graphics.Rect) 224 */ 225 @NonNull 226 public final Rect getBounds() { 227 if (mBounds == ZERO_BOUNDS_RECT) { 228 mBounds = new Rect(); 229 } 230 231 return mBounds; 232 } 233 234 /** 235 * Return the drawable's dirty bounds Rect. Note: for efficiency, the 236 * returned object may be the same object stored in the drawable (though 237 * this is not guaranteed). 238 * <p> 239 * By default, this returns the full drawable bounds. Custom drawables may 240 * override this method to perform more precise invalidation. 241 * 242 * @return The dirty bounds of this drawable 243 */ 244 @NonNull 245 public Rect getDirtyBounds() { 246 return getBounds(); 247 } 248 249 /** 250 * Set a mask of the configuration parameters for which this drawable 251 * may change, requiring that it be re-created. 252 * 253 * @param configs A mask of the changing configuration parameters, as 254 * defined by {@link android.content.pm.ActivityInfo}. 255 * 256 * @see android.content.pm.ActivityInfo 257 */ 258 public void setChangingConfigurations(@Config int configs) { 259 mChangingConfigurations = configs; 260 } 261 262 /** 263 * Return a mask of the configuration parameters for which this drawable 264 * may change, requiring that it be re-created. The default implementation 265 * returns whatever was provided through 266 * {@link #setChangingConfigurations(int)} or 0 by default. Subclasses 267 * may extend this to or in the changing configurations of any other 268 * drawables they hold. 269 * 270 * @return Returns a mask of the changing configuration parameters, as 271 * defined by {@link android.content.pm.ActivityInfo}. 272 * 273 * @see android.content.pm.ActivityInfo 274 */ 275 public @Config int getChangingConfigurations() { 276 return mChangingConfigurations; 277 } 278 279 /** 280 * Set to true to have the drawable dither its colors when drawn to a 281 * device with fewer than 8-bits per color component. 282 * 283 * @see android.graphics.Paint#setDither(boolean); 284 * @deprecated This property is ignored. 285 */ 286 @Deprecated 287 public void setDither(boolean dither) {} 288 289 /** 290 * Set to true to have the drawable filter its bitmaps with bilinear 291 * sampling when they are scaled or rotated. 292 * 293 * <p>This can improve appearance when bitmaps are rotated. If the drawable 294 * does not use bitmaps, this call is ignored.</p> 295 * 296 * @see #isFilterBitmap() 297 * @see android.graphics.Paint#setFilterBitmap(boolean); 298 */ 299 public void setFilterBitmap(boolean filter) {} 300 301 /** 302 * @return whether this drawable filters its bitmaps 303 * @see #setFilterBitmap(boolean) 304 */ 305 public boolean isFilterBitmap() { 306 return false; 307 } 308 309 /** 310 * Implement this interface if you want to create an animated drawable that 311 * extends {@link android.graphics.drawable.Drawable Drawable}. 312 * Upon retrieving a drawable, use 313 * {@link Drawable#setCallback(android.graphics.drawable.Drawable.Callback)} 314 * to supply your implementation of the interface to the drawable; it uses 315 * this interface to schedule and execute animation changes. 316 */ 317 public interface Callback { 318 /** 319 * Called when the drawable needs to be redrawn. A view at this point 320 * should invalidate itself (or at least the part of itself where the 321 * drawable appears). 322 * 323 * @param who The drawable that is requesting the update. 324 */ 325 void invalidateDrawable(@NonNull Drawable who); 326 327 /** 328 * A Drawable can call this to schedule the next frame of its 329 * animation. An implementation can generally simply call 330 * {@link android.os.Handler#postAtTime(Runnable, Object, long)} with 331 * the parameters <var>(what, who, when)</var> to perform the 332 * scheduling. 333 * 334 * @param who The drawable being scheduled. 335 * @param what The action to execute. 336 * @param when The time (in milliseconds) to run. The timebase is 337 * {@link android.os.SystemClock#uptimeMillis} 338 */ 339 void scheduleDrawable(@NonNull Drawable who, @NonNull Runnable what, long when); 340 341 /** 342 * A Drawable can call this to unschedule an action previously 343 * scheduled with {@link #scheduleDrawable}. An implementation can 344 * generally simply call 345 * {@link android.os.Handler#removeCallbacks(Runnable, Object)} with 346 * the parameters <var>(what, who)</var> to unschedule the drawable. 347 * 348 * @param who The drawable being unscheduled. 349 * @param what The action being unscheduled. 350 */ 351 void unscheduleDrawable(@NonNull Drawable who, @NonNull Runnable what); 352 } 353 354 /** 355 * Bind a {@link Callback} object to this Drawable. Required for clients 356 * that want to support animated drawables. 357 * 358 * @param cb The client's Callback implementation. 359 * 360 * @see #getCallback() 361 */ 362 public final void setCallback(@Nullable Callback cb) { 363 mCallback = cb != null ? new WeakReference<>(cb) : null; 364 } 365 366 /** 367 * Return the current {@link Callback} implementation attached to this 368 * Drawable. 369 * 370 * @return A {@link Callback} instance or null if no callback was set. 371 * 372 * @see #setCallback(android.graphics.drawable.Drawable.Callback) 373 */ 374 @Nullable 375 public Callback getCallback() { 376 return mCallback != null ? mCallback.get() : null; 377 } 378 379 /** 380 * Use the current {@link Callback} implementation to have this Drawable 381 * redrawn. Does nothing if there is no Callback attached to the 382 * Drawable. 383 * 384 * @see Callback#invalidateDrawable 385 * @see #getCallback() 386 * @see #setCallback(android.graphics.drawable.Drawable.Callback) 387 */ 388 public void invalidateSelf() { 389 final Callback callback = getCallback(); 390 if (callback != null) { 391 callback.invalidateDrawable(this); 392 } 393 } 394 395 /** 396 * Use the current {@link Callback} implementation to have this Drawable 397 * scheduled. Does nothing if there is no Callback attached to the 398 * Drawable. 399 * 400 * @param what The action being scheduled. 401 * @param when The time (in milliseconds) to run. 402 * 403 * @see Callback#scheduleDrawable 404 */ 405 public void scheduleSelf(@NonNull Runnable what, long when) { 406 final Callback callback = getCallback(); 407 if (callback != null) { 408 callback.scheduleDrawable(this, what, when); 409 } 410 } 411 412 /** 413 * Use the current {@link Callback} implementation to have this Drawable 414 * unscheduled. Does nothing if there is no Callback attached to the 415 * Drawable. 416 * 417 * @param what The runnable that you no longer want called. 418 * 419 * @see Callback#unscheduleDrawable 420 */ 421 public void unscheduleSelf(@NonNull Runnable what) { 422 final Callback callback = getCallback(); 423 if (callback != null) { 424 callback.unscheduleDrawable(this, what); 425 } 426 } 427 428 /** 429 * Returns the resolved layout direction for this Drawable. 430 * 431 * @return One of {@link android.view.View#LAYOUT_DIRECTION_LTR}, 432 * {@link android.view.View#LAYOUT_DIRECTION_RTL} 433 * @see #setLayoutDirection(int) 434 */ 435 public @View.ResolvedLayoutDir int getLayoutDirection() { 436 return mLayoutDirection; 437 } 438 439 /** 440 * Set the layout direction for this drawable. Should be a resolved 441 * layout direction, as the Drawable has no capacity to do the resolution on 442 * its own. 443 * 444 * @param layoutDirection the resolved layout direction for the drawable, 445 * either {@link android.view.View#LAYOUT_DIRECTION_LTR} 446 * or {@link android.view.View#LAYOUT_DIRECTION_RTL} 447 * @see #getLayoutDirection() 448 */ 449 public final boolean setLayoutDirection(@View.ResolvedLayoutDir int layoutDirection) { 450 if (mLayoutDirection != layoutDirection) { 451 mLayoutDirection = layoutDirection; 452 return onLayoutDirectionChanged(layoutDirection); 453 } 454 return false; 455 } 456 457 /** 458 * Called when the drawable's resolved layout direction changes. 459 * 460 * @param layoutDirection the new resolved layout direction 461 * @return true if the layout direction change has caused the appearance of 462 * the drawable to change and it needs to be re-drawn 463 * @see #setLayoutDirection(int) 464 */ 465 public boolean onLayoutDirectionChanged(@View.ResolvedLayoutDir int layoutDirection) { 466 return false; 467 } 468 469 /** 470 * Specify an alpha value for the drawable. 0 means fully transparent, and 471 * 255 means fully opaque. 472 */ 473 public abstract void setAlpha(@IntRange(from=0,to=255) int alpha); 474 475 /** 476 * Gets the current alpha value for the drawable. 0 means fully transparent, 477 * 255 means fully opaque. This method is implemented by 478 * Drawable subclasses and the value returned is specific to how that class treats alpha. 479 * The default return value is 255 if the class does not override this method to return a value 480 * specific to its use of alpha. 481 */ 482 @IntRange(from=0,to=255) 483 public int getAlpha() { 484 return 0xFF; 485 } 486 487 /** 488 * @hide 489 * 490 * Internal-only method for setting xfermode on certain supported drawables. 491 * 492 * Should not be made public since the layers and drawing area with which 493 * Drawables draw is private implementation detail, and not something apps 494 * should rely upon. 495 */ 496 public void setXfermode(@Nullable Xfermode mode) { 497 // Base implementation drops it on the floor for compatibility. Whee! 498 } 499 500 /** 501 * Specify an optional color filter for the drawable. 502 * <p> 503 * If a Drawable has a ColorFilter, each output pixel of the Drawable's 504 * drawing contents will be modified by the color filter before it is 505 * blended onto the render target of a Canvas. 506 * </p> 507 * <p> 508 * Pass {@code null} to remove any existing color filter. 509 * </p> 510 * <p class="note"><strong>Note:</strong> Setting a non-{@code null} color 511 * filter disables {@link #setTintList(ColorStateList) tint}. 512 * </p> 513 * 514 * @param colorFilter The color filter to apply, or {@code null} to remove the 515 * existing color filter 516 */ 517 public abstract void setColorFilter(@Nullable ColorFilter colorFilter); 518 519 /** 520 * Specify a color and Porter-Duff mode to be the color filter for this 521 * drawable. 522 * <p> 523 * Convenience for {@link #setColorFilter(ColorFilter)} which constructs a 524 * {@link PorterDuffColorFilter}. 525 * </p> 526 * <p class="note"><strong>Note:</strong> Setting a color filter disables 527 * {@link #setTintList(ColorStateList) tint}. 528 * </p> 529 */ 530 public void setColorFilter(@ColorInt int color, @NonNull PorterDuff.Mode mode) { 531 setColorFilter(new PorterDuffColorFilter(color, mode)); 532 } 533 534 /** 535 * Specifies tint color for this drawable. 536 * <p> 537 * A Drawable's drawing content will be blended together with its tint 538 * before it is drawn to the screen. This functions similarly to 539 * {@link #setColorFilter(int, PorterDuff.Mode)}. 540 * </p> 541 * <p> 542 * To clear the tint, pass {@code null} to 543 * {@link #setTintList(ColorStateList)}. 544 * </p> 545 * <p class="note"><strong>Note:</strong> Setting a color filter via 546 * {@link #setColorFilter(ColorFilter)} or 547 * {@link #setColorFilter(int, PorterDuff.Mode)} overrides tint. 548 * </p> 549 * 550 * @param tintColor Color to use for tinting this drawable 551 * @see #setTintList(ColorStateList) 552 * @see #setTintMode(PorterDuff.Mode) 553 */ 554 public void setTint(@ColorInt int tintColor) { 555 setTintList(ColorStateList.valueOf(tintColor)); 556 } 557 558 /** 559 * Specifies tint color for this drawable as a color state list. 560 * <p> 561 * A Drawable's drawing content will be blended together with its tint 562 * before it is drawn to the screen. This functions similarly to 563 * {@link #setColorFilter(int, PorterDuff.Mode)}. 564 * </p> 565 * <p class="note"><strong>Note:</strong> Setting a color filter via 566 * {@link #setColorFilter(ColorFilter)} or 567 * {@link #setColorFilter(int, PorterDuff.Mode)} overrides tint. 568 * </p> 569 * 570 * @param tint Color state list to use for tinting this drawable, or 571 * {@code null} to clear the tint 572 * @see #setTint(int) 573 * @see #setTintMode(PorterDuff.Mode) 574 */ 575 public void setTintList(@Nullable ColorStateList tint) {} 576 577 /** 578 * Specifies a tint blending mode for this drawable. 579 * <p> 580 * Defines how this drawable's tint color should be blended into the drawable 581 * before it is drawn to screen. Default tint mode is {@link PorterDuff.Mode#SRC_IN}. 582 * </p> 583 * <p class="note"><strong>Note:</strong> Setting a color filter via 584 * {@link #setColorFilter(ColorFilter)} or 585 * {@link #setColorFilter(int, PorterDuff.Mode)} overrides tint. 586 * </p> 587 * 588 * @param tintMode A Porter-Duff blending mode 589 * @see #setTint(int) 590 * @see #setTintList(ColorStateList) 591 */ 592 public void setTintMode(@NonNull PorterDuff.Mode tintMode) {} 593 594 /** 595 * Returns the current color filter, or {@code null} if none set. 596 * 597 * @return the current color filter, or {@code null} if none set 598 */ 599 public @Nullable ColorFilter getColorFilter() { 600 return null; 601 } 602 603 /** 604 * Removes the color filter for this drawable. 605 */ 606 public void clearColorFilter() { 607 setColorFilter(null); 608 } 609 610 /** 611 * Specifies the hotspot's location within the drawable. 612 * 613 * @param x The X coordinate of the center of the hotspot 614 * @param y The Y coordinate of the center of the hotspot 615 */ 616 public void setHotspot(float x, float y) {} 617 618 /** 619 * Sets the bounds to which the hotspot is constrained, if they should be 620 * different from the drawable bounds. 621 * 622 * @param left position in pixels of the left bound 623 * @param top position in pixels of the top bound 624 * @param right position in pixels of the right bound 625 * @param bottom position in pixels of the bottom bound 626 * @see #getHotspotBounds(android.graphics.Rect) 627 */ 628 public void setHotspotBounds(int left, int top, int right, int bottom) {} 629 630 /** 631 * Populates {@code outRect} with the hotspot bounds. 632 * 633 * @param outRect the rect to populate with the hotspot bounds 634 * @see #setHotspotBounds(int, int, int, int) 635 */ 636 public void getHotspotBounds(@NonNull Rect outRect) { 637 outRect.set(getBounds()); 638 } 639 640 /** 641 * Whether this drawable requests projection. 642 * 643 * @hide magic! 644 */ 645 public boolean isProjected() { 646 return false; 647 } 648 649 /** 650 * Indicates whether this drawable will change its appearance based on 651 * state. Clients can use this to determine whether it is necessary to 652 * calculate their state and call setState. 653 * 654 * @return True if this drawable changes its appearance based on state, 655 * false otherwise. 656 * @see #setState(int[]) 657 */ 658 public boolean isStateful() { 659 return false; 660 } 661 662 /** 663 * Specify a set of states for the drawable. These are use-case specific, 664 * so see the relevant documentation. As an example, the background for 665 * widgets like Button understand the following states: 666 * [{@link android.R.attr#state_focused}, 667 * {@link android.R.attr#state_pressed}]. 668 * 669 * <p>If the new state you are supplying causes the appearance of the 670 * Drawable to change, then it is responsible for calling 671 * {@link #invalidateSelf} in order to have itself redrawn, <em>and</em> 672 * true will be returned from this function. 673 * 674 * <p>Note: The Drawable holds a reference on to <var>stateSet</var> 675 * until a new state array is given to it, so you must not modify this 676 * array during that time.</p> 677 * 678 * @param stateSet The new set of states to be displayed. 679 * 680 * @return Returns true if this change in state has caused the appearance 681 * of the Drawable to change (hence requiring an invalidate), otherwise 682 * returns false. 683 */ 684 public boolean setState(@NonNull final int[] stateSet) { 685 if (!Arrays.equals(mStateSet, stateSet)) { 686 mStateSet = stateSet; 687 return onStateChange(stateSet); 688 } 689 return false; 690 } 691 692 /** 693 * Describes the current state, as a union of primitve states, such as 694 * {@link android.R.attr#state_focused}, 695 * {@link android.R.attr#state_selected}, etc. 696 * Some drawables may modify their imagery based on the selected state. 697 * @return An array of resource Ids describing the current state. 698 */ 699 public @NonNull int[] getState() { 700 return mStateSet; 701 } 702 703 /** 704 * If this Drawable does transition animations between states, ask that 705 * it immediately jump to the current state and skip any active animations. 706 */ 707 public void jumpToCurrentState() { 708 } 709 710 /** 711 * @return The current drawable that will be used by this drawable. For simple drawables, this 712 * is just the drawable itself. For drawables that change state like 713 * {@link StateListDrawable} and {@link LevelListDrawable} this will be the child drawable 714 * currently in use. 715 */ 716 public @NonNull Drawable getCurrent() { 717 return this; 718 } 719 720 /** 721 * Specify the level for the drawable. This allows a drawable to vary its 722 * imagery based on a continuous controller, for example to show progress 723 * or volume level. 724 * 725 * <p>If the new level you are supplying causes the appearance of the 726 * Drawable to change, then it is responsible for calling 727 * {@link #invalidateSelf} in order to have itself redrawn, <em>and</em> 728 * true will be returned from this function. 729 * 730 * @param level The new level, from 0 (minimum) to 10000 (maximum). 731 * 732 * @return Returns true if this change in level has caused the appearance 733 * of the Drawable to change (hence requiring an invalidate), otherwise 734 * returns false. 735 */ 736 public final boolean setLevel(@IntRange(from=0,to=10000) int level) { 737 if (mLevel != level) { 738 mLevel = level; 739 return onLevelChange(level); 740 } 741 return false; 742 } 743 744 /** 745 * Retrieve the current level. 746 * 747 * @return int Current level, from 0 (minimum) to 10000 (maximum). 748 */ 749 public final @IntRange(from=0,to=10000) int getLevel() { 750 return mLevel; 751 } 752 753 /** 754 * Set whether this Drawable is visible. This generally does not impact 755 * the Drawable's behavior, but is a hint that can be used by some 756 * Drawables, for example, to decide whether run animations. 757 * 758 * @param visible Set to true if visible, false if not. 759 * @param restart You can supply true here to force the drawable to behave 760 * as if it has just become visible, even if it had last 761 * been set visible. Used for example to force animations 762 * to restart. 763 * 764 * @return boolean Returns true if the new visibility is different than 765 * its previous state. 766 */ 767 public boolean setVisible(boolean visible, boolean restart) { 768 boolean changed = mVisible != visible; 769 if (changed) { 770 mVisible = visible; 771 invalidateSelf(); 772 } 773 return changed; 774 } 775 776 public final boolean isVisible() { 777 return mVisible; 778 } 779 780 /** 781 * Set whether this Drawable is automatically mirrored when its layout direction is RTL 782 * (right-to left). See {@link android.util.LayoutDirection}. 783 * 784 * @param mirrored Set to true if the Drawable should be mirrored, false if not. 785 */ 786 public void setAutoMirrored(boolean mirrored) { 787 } 788 789 /** 790 * Tells if this Drawable will be automatically mirrored when its layout direction is RTL 791 * right-to-left. See {@link android.util.LayoutDirection}. 792 * 793 * @return boolean Returns true if this Drawable will be automatically mirrored. 794 */ 795 public boolean isAutoMirrored() { 796 return false; 797 } 798 799 /** 800 * Applies the specified theme to this Drawable and its children. 801 * 802 * @param t the theme to apply 803 */ 804 public void applyTheme(@NonNull @SuppressWarnings("unused") Theme t) { 805 } 806 807 public boolean canApplyTheme() { 808 return false; 809 } 810 811 /** 812 * Return the opacity/transparency of this Drawable. The returned value is 813 * one of the abstract format constants in 814 * {@link android.graphics.PixelFormat}: 815 * {@link android.graphics.PixelFormat#UNKNOWN}, 816 * {@link android.graphics.PixelFormat#TRANSLUCENT}, 817 * {@link android.graphics.PixelFormat#TRANSPARENT}, or 818 * {@link android.graphics.PixelFormat#OPAQUE}. 819 * 820 * <p>An OPAQUE drawable is one that draws all all content within its bounds, completely 821 * covering anything behind the drawable. A TRANSPARENT drawable is one that draws nothing 822 * within its bounds, allowing everything behind it to show through. A TRANSLUCENT drawable 823 * is a drawable in any other state, where the drawable will draw some, but not all, 824 * of the content within its bounds and at least some content behind the drawable will 825 * be visible. If the visibility of the drawable's contents cannot be determined, the 826 * safest/best return value is TRANSLUCENT. 827 * 828 * <p>Generally a Drawable should be as conservative as possible with the 829 * value it returns. For example, if it contains multiple child drawables 830 * and only shows one of them at a time, if only one of the children is 831 * TRANSLUCENT and the others are OPAQUE then TRANSLUCENT should be 832 * returned. You can use the method {@link #resolveOpacity} to perform a 833 * standard reduction of two opacities to the appropriate single output. 834 * 835 * <p>Note that the returned value does not necessarily take into account a 836 * custom alpha or color filter that has been applied by the client through 837 * the {@link #setAlpha} or {@link #setColorFilter} methods. Some subclasses, 838 * such as {@link BitmapDrawable}, {@link ColorDrawable}, and {@link GradientDrawable}, 839 * do account for the value of {@link #setAlpha}, but the general behavior is dependent 840 * upon the implementation of the subclass. 841 * 842 * @return int The opacity class of the Drawable. 843 * 844 * @see android.graphics.PixelFormat 845 */ 846 public abstract @PixelFormat.Opacity int getOpacity(); 847 848 /** 849 * Return the appropriate opacity value for two source opacities. If 850 * either is UNKNOWN, that is returned; else, if either is TRANSLUCENT, 851 * that is returned; else, if either is TRANSPARENT, that is returned; 852 * else, OPAQUE is returned. 853 * 854 * <p>This is to help in implementing {@link #getOpacity}. 855 * 856 * @param op1 One opacity value. 857 * @param op2 Another opacity value. 858 * 859 * @return int The combined opacity value. 860 * 861 * @see #getOpacity 862 */ 863 public static @PixelFormat.Opacity int resolveOpacity(@PixelFormat.Opacity int op1, 864 @PixelFormat.Opacity int op2) { 865 if (op1 == op2) { 866 return op1; 867 } 868 if (op1 == PixelFormat.UNKNOWN || op2 == PixelFormat.UNKNOWN) { 869 return PixelFormat.UNKNOWN; 870 } 871 if (op1 == PixelFormat.TRANSLUCENT || op2 == PixelFormat.TRANSLUCENT) { 872 return PixelFormat.TRANSLUCENT; 873 } 874 if (op1 == PixelFormat.TRANSPARENT || op2 == PixelFormat.TRANSPARENT) { 875 return PixelFormat.TRANSPARENT; 876 } 877 return PixelFormat.OPAQUE; 878 } 879 880 /** 881 * Returns a Region representing the part of the Drawable that is completely 882 * transparent. This can be used to perform drawing operations, identifying 883 * which parts of the target will not change when rendering the Drawable. 884 * The default implementation returns null, indicating no transparent 885 * region; subclasses can optionally override this to return an actual 886 * Region if they want to supply this optimization information, but it is 887 * not required that they do so. 888 * 889 * @return Returns null if the Drawables has no transparent region to 890 * report, else a Region holding the parts of the Drawable's bounds that 891 * are transparent. 892 */ 893 public @Nullable Region getTransparentRegion() { 894 return null; 895 } 896 897 /** 898 * Override this in your subclass to change appearance if you recognize the 899 * specified state. 900 * 901 * @return Returns true if the state change has caused the appearance of 902 * the Drawable to change (that is, it needs to be drawn), else false 903 * if it looks the same and there is no need to redraw it since its 904 * last state. 905 */ 906 protected boolean onStateChange(int[] state) { 907 return false; 908 } 909 910 /** Override this in your subclass to change appearance if you vary based 911 * on level. 912 * @return Returns true if the level change has caused the appearance of 913 * the Drawable to change (that is, it needs to be drawn), else false 914 * if it looks the same and there is no need to redraw it since its 915 * last level. 916 */ 917 protected boolean onLevelChange(int level) { 918 return false; 919 } 920 921 /** 922 * Override this in your subclass to change appearance if you vary based on 923 * the bounds. 924 */ 925 protected void onBoundsChange(Rect bounds) { 926 // Stub method. 927 } 928 929 /** 930 * Returns the drawable's intrinsic width. 931 * <p> 932 * Intrinsic width is the width at which the drawable would like to be laid 933 * out, including any inherent padding. If the drawable has no intrinsic 934 * width, such as a solid color, this method returns -1. 935 * 936 * @return the intrinsic width, or -1 if no intrinsic width 937 */ 938 public int getIntrinsicWidth() { 939 return -1; 940 } 941 942 /** 943 * Returns the drawable's intrinsic height. 944 * <p> 945 * Intrinsic height is the height at which the drawable would like to be 946 * laid out, including any inherent padding. If the drawable has no 947 * intrinsic height, such as a solid color, this method returns -1. 948 * 949 * @return the intrinsic height, or -1 if no intrinsic height 950 */ 951 public int getIntrinsicHeight() { 952 return -1; 953 } 954 955 /** 956 * Returns the minimum width suggested by this Drawable. If a View uses this 957 * Drawable as a background, it is suggested that the View use at least this 958 * value for its width. (There will be some scenarios where this will not be 959 * possible.) This value should INCLUDE any padding. 960 * 961 * @return The minimum width suggested by this Drawable. If this Drawable 962 * doesn't have a suggested minimum width, 0 is returned. 963 */ 964 public int getMinimumWidth() { 965 final int intrinsicWidth = getIntrinsicWidth(); 966 return intrinsicWidth > 0 ? intrinsicWidth : 0; 967 } 968 969 /** 970 * Returns the minimum height suggested by this Drawable. If a View uses this 971 * Drawable as a background, it is suggested that the View use at least this 972 * value for its height. (There will be some scenarios where this will not be 973 * possible.) This value should INCLUDE any padding. 974 * 975 * @return The minimum height suggested by this Drawable. If this Drawable 976 * doesn't have a suggested minimum height, 0 is returned. 977 */ 978 public int getMinimumHeight() { 979 final int intrinsicHeight = getIntrinsicHeight(); 980 return intrinsicHeight > 0 ? intrinsicHeight : 0; 981 } 982 983 /** 984 * Return in padding the insets suggested by this Drawable for placing 985 * content inside the drawable's bounds. Positive values move toward the 986 * center of the Drawable (set Rect.inset). 987 * 988 * @return true if this drawable actually has a padding, else false. When false is returned, 989 * the padding is always set to 0. 990 */ 991 public boolean getPadding(@NonNull Rect padding) { 992 padding.set(0, 0, 0, 0); 993 return false; 994 } 995 996 /** 997 * Return in insets the layout insets suggested by this Drawable for use with alignment 998 * operations during layout. 999 * 1000 * @hide 1001 */ 1002 public @NonNull Insets getOpticalInsets() { 1003 return Insets.NONE; 1004 } 1005 1006 /** 1007 * Called to get the drawable to populate the Outline that defines its drawing area. 1008 * <p> 1009 * This method is called by the default {@link android.view.ViewOutlineProvider} to define 1010 * the outline of the View. 1011 * <p> 1012 * The default behavior defines the outline to be the bounding rectangle of 0 alpha. 1013 * Subclasses that wish to convey a different shape or alpha value must override this method. 1014 * 1015 * @see android.view.View#setOutlineProvider(android.view.ViewOutlineProvider) 1016 */ 1017 public void getOutline(@NonNull Outline outline) { 1018 outline.setRect(getBounds()); 1019 outline.setAlpha(0); 1020 } 1021 1022 /** 1023 * Make this drawable mutable. This operation cannot be reversed. A mutable 1024 * drawable is guaranteed to not share its state with any other drawable. 1025 * This is especially useful when you need to modify properties of drawables 1026 * loaded from resources. By default, all drawables instances loaded from 1027 * the same resource share a common state; if you modify the state of one 1028 * instance, all the other instances will receive the same modification. 1029 * 1030 * Calling this method on a mutable Drawable will have no effect. 1031 * 1032 * @return This drawable. 1033 * @see ConstantState 1034 * @see #getConstantState() 1035 */ 1036 public @NonNull Drawable mutate() { 1037 return this; 1038 } 1039 1040 /** 1041 * Clears the mutated state, allowing this drawable to be cached and 1042 * mutated again. 1043 * <p> 1044 * This is hidden because only framework drawables can be cached, so 1045 * custom drawables don't need to support constant state, mutate(), or 1046 * clearMutated(). 1047 * 1048 * @hide 1049 */ 1050 public void clearMutated() { 1051 // Default implementation is no-op. 1052 } 1053 1054 /** 1055 * Create a drawable from an inputstream 1056 */ 1057 public static Drawable createFromStream(InputStream is, String srcName) { 1058 Trace.traceBegin(Trace.TRACE_TAG_RESOURCES, srcName != null ? srcName : "Unknown drawable"); 1059 try { 1060 return createFromResourceStream(null, null, is, srcName); 1061 } finally { 1062 Trace.traceEnd(Trace.TRACE_TAG_RESOURCES); 1063 } 1064 } 1065 1066 /** 1067 * Create a drawable from an inputstream, using the given resources and 1068 * value to determine density information. 1069 */ 1070 public static Drawable createFromResourceStream(Resources res, TypedValue value, 1071 InputStream is, String srcName) { 1072 Trace.traceBegin(Trace.TRACE_TAG_RESOURCES, srcName != null ? srcName : "Unknown drawable"); 1073 try { 1074 return createFromResourceStream(res, value, is, srcName, null); 1075 } finally { 1076 Trace.traceEnd(Trace.TRACE_TAG_RESOURCES); 1077 } 1078 } 1079 1080 /** 1081 * Create a drawable from an inputstream, using the given resources and 1082 * value to determine density information. 1083 */ 1084 public static Drawable createFromResourceStream(Resources res, TypedValue value, 1085 InputStream is, String srcName, BitmapFactory.Options opts) { 1086 if (is == null) { 1087 return null; 1088 } 1089 1090 /* ugh. The decodeStream contract is that we have already allocated 1091 the pad rect, but if the bitmap does not had a ninepatch chunk, 1092 then the pad will be ignored. If we could change this to lazily 1093 alloc/assign the rect, we could avoid the GC churn of making new 1094 Rects only to drop them on the floor. 1095 */ 1096 Rect pad = new Rect(); 1097 1098 // Special stuff for compatibility mode: if the target density is not 1099 // the same as the display density, but the resource -is- the same as 1100 // the display density, then don't scale it down to the target density. 1101 // This allows us to load the system's density-correct resources into 1102 // an application in compatibility mode, without scaling those down 1103 // to the compatibility density only to have them scaled back up when 1104 // drawn to the screen. 1105 if (opts == null) opts = new BitmapFactory.Options(); 1106 opts.inScreenDensity = Drawable.resolveDensity(res, 0); 1107 Bitmap bm = BitmapFactory.decodeResourceStream(res, value, is, pad, opts); 1108 if (bm != null) { 1109 byte[] np = bm.getNinePatchChunk(); 1110 if (np == null || !NinePatch.isNinePatchChunk(np)) { 1111 np = null; 1112 pad = null; 1113 } 1114 1115 final Rect opticalInsets = new Rect(); 1116 bm.getOpticalInsets(opticalInsets); 1117 return drawableFromBitmap(res, bm, np, pad, opticalInsets, srcName); 1118 } 1119 return null; 1120 } 1121 1122 /** 1123 * Create a drawable from an XML document. For more information on how to 1124 * create resources in XML, see 1125 * <a href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable Resources</a>. 1126 */ 1127 public static Drawable createFromXml(Resources r, XmlPullParser parser) 1128 throws XmlPullParserException, IOException { 1129 return createFromXml(r, parser, null); 1130 } 1131 1132 /** 1133 * Create a drawable from an XML document using an optional {@link Theme}. 1134 * For more information on how to create resources in XML, see 1135 * <a href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable Resources</a>. 1136 */ 1137 public static Drawable createFromXml(Resources r, XmlPullParser parser, Theme theme) 1138 throws XmlPullParserException, IOException { 1139 AttributeSet attrs = Xml.asAttributeSet(parser); 1140 1141 int type; 1142 //noinspection StatementWithEmptyBody 1143 while ((type=parser.next()) != XmlPullParser.START_TAG 1144 && type != XmlPullParser.END_DOCUMENT) { 1145 // Empty loop. 1146 } 1147 1148 if (type != XmlPullParser.START_TAG) { 1149 throw new XmlPullParserException("No start tag found"); 1150 } 1151 1152 Drawable drawable = createFromXmlInner(r, parser, attrs, theme); 1153 1154 if (drawable == null) { 1155 throw new RuntimeException("Unknown initial tag: " + parser.getName()); 1156 } 1157 1158 return drawable; 1159 } 1160 1161 /** 1162 * Create from inside an XML document. Called on a parser positioned at 1163 * a tag in an XML document, tries to create a Drawable from that tag. 1164 * Returns null if the tag is not a valid drawable. 1165 */ 1166 public static Drawable createFromXmlInner(Resources r, XmlPullParser parser, AttributeSet attrs) 1167 throws XmlPullParserException, IOException { 1168 return createFromXmlInner(r, parser, attrs, null); 1169 } 1170 1171 /** 1172 * Create a drawable from inside an XML document using an optional 1173 * {@link Theme}. Called on a parser positioned at a tag in an XML 1174 * document, tries to create a Drawable from that tag. Returns {@code null} 1175 * if the tag is not a valid drawable. 1176 */ 1177 public static Drawable createFromXmlInner(Resources r, XmlPullParser parser, AttributeSet attrs, 1178 Theme theme) throws XmlPullParserException, IOException { 1179 return r.getDrawableInflater().inflateFromXml(parser.getName(), parser, attrs, theme); 1180 } 1181 1182 /** 1183 * Create a drawable from file path name. 1184 */ 1185 public static Drawable createFromPath(String pathName) { 1186 if (pathName == null) { 1187 return null; 1188 } 1189 1190 Trace.traceBegin(Trace.TRACE_TAG_RESOURCES, pathName); 1191 try { 1192 Bitmap bm = BitmapFactory.decodeFile(pathName); 1193 if (bm != null) { 1194 return drawableFromBitmap(null, bm, null, null, null, pathName); 1195 } 1196 } finally { 1197 Trace.traceEnd(Trace.TRACE_TAG_RESOURCES); 1198 } 1199 1200 return null; 1201 } 1202 1203 /** 1204 * Inflate this Drawable from an XML resource. Does not apply a theme. 1205 * 1206 * @see #inflate(Resources, XmlPullParser, AttributeSet, Theme) 1207 */ 1208 public void inflate(@NonNull Resources r, @NonNull XmlPullParser parser, 1209 @NonNull AttributeSet attrs) throws XmlPullParserException, IOException { 1210 inflate(r, parser, attrs, null); 1211 } 1212 1213 /** 1214 * Inflate this Drawable from an XML resource optionally styled by a theme. 1215 * This can't be called more than once for each Drawable. Note that framework may have called 1216 * this once to create the Drawable instance from XML resource. 1217 * 1218 * @param r Resources used to resolve attribute values 1219 * @param parser XML parser from which to inflate this Drawable 1220 * @param attrs Base set of attribute values 1221 * @param theme Theme to apply, may be null 1222 * @throws XmlPullParserException 1223 * @throws IOException 1224 */ 1225 public void inflate(@NonNull Resources r, @NonNull XmlPullParser parser, 1226 @NonNull AttributeSet attrs, @Nullable Theme theme) 1227 throws XmlPullParserException, IOException { 1228 final TypedArray a = obtainAttributes(r, theme, attrs, R.styleable.Drawable); 1229 mVisible = a.getBoolean(R.styleable.Drawable_visible, mVisible); 1230 a.recycle(); 1231 } 1232 1233 /** 1234 * Inflate a Drawable from an XML resource. 1235 * 1236 * @throws XmlPullParserException 1237 * @throws IOException 1238 */ 1239 void inflateWithAttributes(@NonNull @SuppressWarnings("unused") Resources r, 1240 @NonNull @SuppressWarnings("unused") XmlPullParser parser, @NonNull TypedArray attrs, 1241 @AttrRes int visibleAttr) throws XmlPullParserException, IOException { 1242 mVisible = attrs.getBoolean(visibleAttr, mVisible); 1243 } 1244 1245 /** 1246 * This abstract class is used by {@link Drawable}s to store shared constant state and data 1247 * between Drawables. {@link BitmapDrawable}s created from the same resource will for instance 1248 * share a unique bitmap stored in their ConstantState. 1249 * 1250 * <p> 1251 * {@link #newDrawable(Resources)} can be used as a factory to create new Drawable instances 1252 * from this ConstantState. 1253 * </p> 1254 * 1255 * Use {@link Drawable#getConstantState()} to retrieve the ConstantState of a Drawable. Calling 1256 * {@link Drawable#mutate()} on a Drawable should typically create a new ConstantState for that 1257 * Drawable. 1258 */ 1259 public static abstract class ConstantState { 1260 /** 1261 * Creates a new Drawable instance from its constant state. 1262 * <p> 1263 * <strong>Note:</strong> Using this method means density-dependent 1264 * properties, such as pixel dimensions or bitmap images, will not be 1265 * updated to match the density of the target display. To ensure 1266 * correct scaling, use {@link #newDrawable(Resources)} instead to 1267 * provide an appropriate Resources object. 1268 * 1269 * @return a new drawable object based on this constant state 1270 * @see {@link #newDrawable(Resources)} 1271 */ 1272 public abstract @NonNull Drawable newDrawable(); 1273 1274 /** 1275 * Creates a new Drawable instance from its constant state using the 1276 * specified resources. This method should be implemented for drawables 1277 * that have density-dependent properties. 1278 * <p> 1279 * The default implementation for this method calls through to 1280 * {@link #newDrawable()}. 1281 * 1282 * @param res the resources of the context in which the drawable will 1283 * be displayed 1284 * @return a new drawable object based on this constant state 1285 */ 1286 public @NonNull Drawable newDrawable(@Nullable Resources res) { 1287 return newDrawable(); 1288 } 1289 1290 /** 1291 * Creates a new Drawable instance from its constant state using the 1292 * specified resources and theme. This method should be implemented for 1293 * drawables that have theme-dependent properties. 1294 * <p> 1295 * The default implementation for this method calls through to 1296 * {@link #newDrawable(Resources)}. 1297 * 1298 * @param res the resources of the context in which the drawable will 1299 * be displayed 1300 * @param theme the theme of the context in which the drawable will be 1301 * displayed 1302 * @return a new drawable object based on this constant state 1303 */ 1304 public @NonNull Drawable newDrawable(@Nullable Resources res, 1305 @Nullable @SuppressWarnings("unused") Theme theme) { 1306 return newDrawable(res); 1307 } 1308 1309 /** 1310 * Return a bit mask of configuration changes that will impact 1311 * this drawable (and thus require completely reloading it). 1312 */ 1313 public abstract @Config int getChangingConfigurations(); 1314 1315 /** 1316 * @return Total pixel count 1317 * @hide 1318 */ 1319 public int addAtlasableBitmaps(@NonNull Collection<Bitmap> atlasList) { 1320 return 0; 1321 } 1322 1323 /** @hide */ 1324 protected final boolean isAtlasable(@Nullable Bitmap bitmap) { 1325 return bitmap != null && bitmap.getConfig() == Bitmap.Config.ARGB_8888; 1326 } 1327 1328 /** 1329 * Return whether this constant state can have a theme applied. 1330 */ 1331 public boolean canApplyTheme() { 1332 return false; 1333 } 1334 } 1335 1336 /** 1337 * Return a {@link ConstantState} instance that holds the shared state of this Drawable. 1338 * 1339 * @return The ConstantState associated to that Drawable. 1340 * @see ConstantState 1341 * @see Drawable#mutate() 1342 */ 1343 public @Nullable ConstantState getConstantState() { 1344 return null; 1345 } 1346 1347 private static Drawable drawableFromBitmap(Resources res, Bitmap bm, byte[] np, 1348 Rect pad, Rect layoutBounds, String srcName) { 1349 1350 if (np != null) { 1351 return new NinePatchDrawable(res, bm, np, pad, layoutBounds, srcName); 1352 } 1353 1354 return new BitmapDrawable(res, bm); 1355 } 1356 1357 /** 1358 * Ensures the tint filter is consistent with the current tint color and 1359 * mode. 1360 */ 1361 @Nullable PorterDuffColorFilter updateTintFilter(@Nullable PorterDuffColorFilter tintFilter, 1362 @Nullable ColorStateList tint, @Nullable PorterDuff.Mode tintMode) { 1363 if (tint == null || tintMode == null) { 1364 return null; 1365 } 1366 1367 final int color = tint.getColorForState(getState(), Color.TRANSPARENT); 1368 if (tintFilter == null) { 1369 return new PorterDuffColorFilter(color, tintMode); 1370 } 1371 1372 tintFilter.setColor(color); 1373 tintFilter.setMode(tintMode); 1374 return tintFilter; 1375 } 1376 1377 /** 1378 * Obtains styled attributes from the theme, if available, or unstyled 1379 * resources if the theme is null. 1380 */ 1381 static @NonNull TypedArray obtainAttributes(@NonNull Resources res, @Nullable Theme theme, 1382 @NonNull AttributeSet set, @NonNull int[] attrs) { 1383 if (theme == null) { 1384 return res.obtainAttributes(set, attrs); 1385 } 1386 return theme.obtainStyledAttributes(set, attrs, 0, 0); 1387 } 1388 1389 /** 1390 * Scales a floating-point pixel value from the source density to the 1391 * target density. 1392 * 1393 * @param pixels the pixel value for use in source density 1394 * @param sourceDensity the source density 1395 * @param targetDensity the target density 1396 * @return the scaled pixel value for use in target density 1397 */ 1398 static float scaleFromDensity(float pixels, int sourceDensity, int targetDensity) { 1399 return pixels * targetDensity / sourceDensity; 1400 } 1401 1402 /** 1403 * Scales a pixel value from the source density to the target density, 1404 * optionally handling the resulting pixel value as a size rather than an 1405 * offset. 1406 * <p> 1407 * A size conversion involves rounding the base value and ensuring that 1408 * a non-zero base value is at least one pixel in size. 1409 * <p> 1410 * An offset conversion involves simply truncating the base value to an 1411 * integer. 1412 * 1413 * @param pixels the pixel value for use in source density 1414 * @param sourceDensity the source density 1415 * @param targetDensity the target density 1416 * @param isSize {@code true} to handle the resulting scaled value as a 1417 * size, or {@code false} to handle it as an offset 1418 * @return the scaled pixel value for use in target density 1419 */ 1420 static int scaleFromDensity( 1421 int pixels, int sourceDensity, int targetDensity, boolean isSize) { 1422 if (pixels == 0 || sourceDensity == targetDensity) { 1423 return pixels; 1424 } 1425 1426 final float result = pixels * targetDensity / (float) sourceDensity; 1427 if (!isSize) { 1428 return (int) result; 1429 } 1430 1431 final int rounded = Math.round(result); 1432 if (rounded != 0) { 1433 return rounded; 1434 } else if (pixels > 0) { 1435 return 1; 1436 } else { 1437 return -1; 1438 } 1439 } 1440 1441 static int resolveDensity(@Nullable Resources r, int parentDensity) { 1442 final int densityDpi = r == null ? parentDensity : r.getDisplayMetrics().densityDpi; 1443 return densityDpi == 0 ? DisplayMetrics.DENSITY_DEFAULT : densityDpi; 1444 } 1445 1446 /** 1447 * Re-throws an exception as a {@link RuntimeException} with an empty stack 1448 * trace to avoid cluttering the log. The original exception's stack trace 1449 * will still be included. 1450 * 1451 * @param cause the exception to re-throw 1452 * @throws RuntimeException 1453 */ 1454 static void rethrowAsRuntimeException(@NonNull Exception cause) throws RuntimeException { 1455 final RuntimeException e = new RuntimeException(cause); 1456 e.setStackTrace(new StackTraceElement[0]); 1457 throw e; 1458 } 1459 1460 /** 1461 * Parses a {@link android.graphics.PorterDuff.Mode} from a tintMode 1462 * attribute's enum value. 1463 * 1464 * @hide 1465 */ 1466 public static PorterDuff.Mode parseTintMode(int value, Mode defaultMode) { 1467 switch (value) { 1468 case 3: return Mode.SRC_OVER; 1469 case 5: return Mode.SRC_IN; 1470 case 9: return Mode.SRC_ATOP; 1471 case 14: return Mode.MULTIPLY; 1472 case 15: return Mode.SCREEN; 1473 case 16: return Mode.ADD; 1474 default: return defaultMode; 1475 } 1476 } 1477} 1478 1479