ObjectAnimator.java revision b39f051631250c49936a475d0e64584afb7f1b93
1/* 2 * Copyright (C) 2010 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.animation; 18 19import android.util.Log; 20import android.util.Property; 21 22import java.lang.reflect.Method; 23import java.util.ArrayList; 24 25/** 26 * This subclass of {@link ValueAnimator} provides support for animating properties on target objects. 27 * The constructors of this class take parameters to define the target object that will be animated 28 * as well as the name of the property that will be animated. Appropriate set/get functions 29 * are then determined internally and the animation will call these functions as necessary to 30 * animate the property. 31 * 32 * @see #setPropertyName(String) 33 * 34 */ 35public final class ObjectAnimator extends ValueAnimator { 36 private static final boolean DBG = false; 37 38 // The target object on which the property exists, set in the constructor 39 private Object mTarget; 40 41 private String mPropertyName; 42 43 private Property mProperty; 44 45 /** 46 * Sets the name of the property that will be animated. This name is used to derive 47 * a setter function that will be called to set animated values. 48 * For example, a property name of <code>foo</code> will result 49 * in a call to the function <code>setFoo()</code> on the target object. If either 50 * <code>valueFrom</code> or <code>valueTo</code> is null, then a getter function will 51 * also be derived and called. 52 * 53 * <p>For best performance of the mechanism that calls the setter function determined by the 54 * name of the property being animated, use <code>float</code> or <code>int</code> typed values, 55 * and make the setter function for those properties have a <code>void</code> return value. This 56 * will cause the code to take an optimized path for these constrained circumstances. Other 57 * property types and return types will work, but will have more overhead in processing 58 * the requests due to normal reflection mechanisms.</p> 59 * 60 * <p>Note that the setter function derived from this property name 61 * must take the same parameter type as the 62 * <code>valueFrom</code> and <code>valueTo</code> properties, otherwise the call to 63 * the setter function will fail.</p> 64 * 65 * <p>If this ObjectAnimator has been set up to animate several properties together, 66 * using more than one PropertyValuesHolder objects, then setting the propertyName simply 67 * sets the propertyName in the first of those PropertyValuesHolder objects.</p> 68 * 69 * @param propertyName The name of the property being animated. Should not be null. 70 */ 71 public void setPropertyName(String propertyName) { 72 // mValues could be null if this is being constructed piecemeal. Just record the 73 // propertyName to be used later when setValues() is called if so. 74 if (mValues != null) { 75 PropertyValuesHolder valuesHolder = mValues[0]; 76 String oldName = valuesHolder.getPropertyName(); 77 valuesHolder.setPropertyName(propertyName); 78 mValuesMap.remove(oldName); 79 mValuesMap.put(propertyName, valuesHolder); 80 } 81 mPropertyName = propertyName; 82 // New property/values/target should cause re-initialization prior to starting 83 mInitialized = false; 84 } 85 86 /** 87 * Sets the property that will be animated. Property objects will take precedence over 88 * properties specified by the {@link #setPropertyName(String)} method. Animations should 89 * be set up to use one or the other, not both. 90 * 91 * @param property The property being animated. Should not be null. 92 */ 93 public void setProperty(Property property) { 94 // mValues could be null if this is being constructed piecemeal. Just record the 95 // propertyName to be used later when setValues() is called if so. 96 if (mValues != null) { 97 PropertyValuesHolder valuesHolder = mValues[0]; 98 String oldName = valuesHolder.getPropertyName(); 99 valuesHolder.setProperty(property); 100 mValuesMap.remove(oldName); 101 mValuesMap.put(mPropertyName, valuesHolder); 102 } 103 if (mProperty != null) { 104 mPropertyName = property.getName(); 105 } 106 mProperty = property; 107 // New property/values/target should cause re-initialization prior to starting 108 mInitialized = false; 109 } 110 111 /** 112 * Gets the name of the property that will be animated. This name will be used to derive 113 * a setter function that will be called to set animated values. 114 * For example, a property name of <code>foo</code> will result 115 * in a call to the function <code>setFoo()</code> on the target object. If either 116 * <code>valueFrom</code> or <code>valueTo</code> is null, then a getter function will 117 * also be derived and called. 118 */ 119 public String getPropertyName() { 120 return mPropertyName; 121 } 122 123 /** 124 * Creates a new ObjectAnimator object. This default constructor is primarily for 125 * use internally; the other constructors which take parameters are more generally 126 * useful. 127 */ 128 public ObjectAnimator() { 129 } 130 131 /** 132 * Private utility constructor that initializes the target object and name of the 133 * property being animated. 134 * 135 * @param target The object whose property is to be animated. This object should 136 * have a public method on it called <code>setName()</code>, where <code>name</code> is 137 * the value of the <code>propertyName</code> parameter. 138 * @param propertyName The name of the property being animated. 139 */ 140 private ObjectAnimator(Object target, String propertyName) { 141 mTarget = target; 142 setPropertyName(propertyName); 143 } 144 145 /** 146 * Private utility constructor that initializes the target object and property being animated. 147 * 148 * @param target The object whose property is to be animated. 149 * @param property The property being animated. 150 */ 151 private <T> ObjectAnimator(T target, Property<T, ?> property) { 152 mTarget = target; 153 setProperty(property); 154 } 155 156 /** 157 * Constructs and returns an ObjectAnimator that animates between int values. A single 158 * value implies that that value is the one being animated to. Two values imply a starting 159 * and ending values. More than two values imply a starting value, values to animate through 160 * along the way, and an ending value (these values will be distributed evenly across 161 * the duration of the animation). 162 * 163 * @param target The object whose property is to be animated. This object should 164 * have a public method on it called <code>setName()</code>, where <code>name</code> is 165 * the value of the <code>propertyName</code> parameter. 166 * @param propertyName The name of the property being animated. 167 * @param values A set of values that the animation will animate between over time. 168 * @return An ObjectAnimator object that is set up to animate between the given values. 169 */ 170 public static ObjectAnimator ofInt(Object target, String propertyName, int... values) { 171 ObjectAnimator anim = new ObjectAnimator(target, propertyName); 172 anim.setIntValues(values); 173 return anim; 174 } 175 176 /** 177 * Constructs and returns an ObjectAnimator that animates between int values. A single 178 * value implies that that value is the one being animated to. Two values imply a starting 179 * and ending values. More than two values imply a starting value, values to animate through 180 * along the way, and an ending value (these values will be distributed evenly across 181 * the duration of the animation). 182 * 183 * @param target The object whose property is to be animated. 184 * @param property The property being animated. 185 * @param values A set of values that the animation will animate between over time. 186 * @return An ObjectAnimator object that is set up to animate between the given values. 187 */ 188 public static <T> ObjectAnimator ofInt(T target, Property<T, Integer> property, int... values) { 189 ObjectAnimator anim = new ObjectAnimator(target, property); 190 anim.setIntValues(values); 191 return anim; 192 } 193 194 /** 195 * Constructs and returns an ObjectAnimator that animates between float values. A single 196 * value implies that that value is the one being animated to. Two values imply a starting 197 * and ending values. More than two values imply a starting value, values to animate through 198 * along the way, and an ending value (these values will be distributed evenly across 199 * the duration of the animation). 200 * 201 * @param target The object whose property is to be animated. This object should 202 * have a public method on it called <code>setName()</code>, where <code>name</code> is 203 * the value of the <code>propertyName</code> parameter. 204 * @param propertyName The name of the property being animated. 205 * @param values A set of values that the animation will animate between over time. 206 * @return An ObjectAnimator object that is set up to animate between the given values. 207 */ 208 public static ObjectAnimator ofFloat(Object target, String propertyName, float... values) { 209 ObjectAnimator anim = new ObjectAnimator(target, propertyName); 210 anim.setFloatValues(values); 211 return anim; 212 } 213 214 /** 215 * Constructs and returns an ObjectAnimator that animates between float values. A single 216 * value implies that that value is the one being animated to. Two values imply a starting 217 * and ending values. More than two values imply a starting value, values to animate through 218 * along the way, and an ending value (these values will be distributed evenly across 219 * the duration of the animation). 220 * 221 * @param target The object whose property is to be animated. 222 * @param property The property being animated. 223 * @param values A set of values that the animation will animate between over time. 224 * @return An ObjectAnimator object that is set up to animate between the given values. 225 */ 226 public static <T> ObjectAnimator ofFloat(T target, Property<T, Float> property, 227 float... values) { 228 ObjectAnimator anim = new ObjectAnimator(target, property); 229 anim.setFloatValues(values); 230 return anim; 231 } 232 233 /** 234 * Constructs and returns an ObjectAnimator that animates between Object values. A single 235 * value implies that that value is the one being animated to. Two values imply a starting 236 * and ending values. More than two values imply a starting value, values to animate through 237 * along the way, and an ending value (these values will be distributed evenly across 238 * the duration of the animation). 239 * 240 * @param target The object whose property is to be animated. This object should 241 * have a public method on it called <code>setName()</code>, where <code>name</code> is 242 * the value of the <code>propertyName</code> parameter. 243 * @param propertyName The name of the property being animated. 244 * @param evaluator A TypeEvaluator that will be called on each animation frame to 245 * provide the necessary interpolation between the Object values to derive the animated 246 * value. 247 * @param values A set of values that the animation will animate between over time. 248 * @return An ObjectAnimator object that is set up to animate between the given values. 249 */ 250 public static ObjectAnimator ofObject(Object target, String propertyName, 251 TypeEvaluator evaluator, Object... values) { 252 ObjectAnimator anim = new ObjectAnimator(target, propertyName); 253 anim.setObjectValues(values); 254 anim.setEvaluator(evaluator); 255 return anim; 256 } 257 258 /** 259 * Constructs and returns an ObjectAnimator that animates between Object values. A single 260 * value implies that that value is the one being animated to. Two values imply a starting 261 * and ending values. More than two values imply a starting value, values to animate through 262 * along the way, and an ending value (these values will be distributed evenly across 263 * the duration of the animation). 264 * 265 * @param target The object whose property is to be animated. 266 * @param property The property being animated. 267 * @param evaluator A TypeEvaluator that will be called on each animation frame to 268 * provide the necessary interpolation between the Object values to derive the animated 269 * value. 270 * @param values A set of values that the animation will animate between over time. 271 * @return An ObjectAnimator object that is set up to animate between the given values. 272 */ 273 public static <T, V> ObjectAnimator ofObject(T target, Property<T, V> property, 274 TypeEvaluator<V> evaluator, V... values) { 275 ObjectAnimator anim = new ObjectAnimator(target, property); 276 anim.setObjectValues(values); 277 anim.setEvaluator(evaluator); 278 return anim; 279 } 280 281 /** 282 * Constructs and returns an ObjectAnimator that animates between the sets of values specified 283 * in <code>PropertyValueHolder</code> objects. This variant should be used when animating 284 * several properties at once with the same ObjectAnimator, since PropertyValuesHolder allows 285 * you to associate a set of animation values with a property name. 286 * 287 * @param target The object whose property is to be animated. Depending on how the 288 * PropertyValuesObjects were constructed, the target object should either have the {@link 289 * android.util.Property} objects used to construct the PropertyValuesHolder objects or (if the 290 * PropertyValuesHOlder objects were created with property names) the target object should have 291 * public methods on it called <code>setName()</code>, where <code>name</code> is the name of 292 * the property passed in as the <code>propertyName</code> parameter for each of the 293 * PropertyValuesHolder objects. 294 * @param values A set of PropertyValuesHolder objects whose values will be animated between 295 * over time. 296 * @return An ObjectAnimator object that is set up to animate between the given values. 297 */ 298 public static ObjectAnimator ofPropertyValuesHolder(Object target, 299 PropertyValuesHolder... values) { 300 ObjectAnimator anim = new ObjectAnimator(); 301 anim.mTarget = target; 302 anim.setValues(values); 303 return anim; 304 } 305 306 @Override 307 public void setIntValues(int... values) { 308 if (mValues == null || mValues.length == 0) { 309 // No values yet - this animator is being constructed piecemeal. Init the values with 310 // whatever the current propertyName is 311 if (mProperty != null) { 312 setValues(PropertyValuesHolder.ofInt(mProperty, values)); 313 } else { 314 setValues(PropertyValuesHolder.ofInt(mPropertyName, values)); 315 } 316 } else { 317 super.setIntValues(values); 318 } 319 } 320 321 @Override 322 public void setFloatValues(float... values) { 323 if (mValues == null || mValues.length == 0) { 324 // No values yet - this animator is being constructed piecemeal. Init the values with 325 // whatever the current propertyName is 326 if (mProperty != null) { 327 setValues(PropertyValuesHolder.ofFloat(mProperty, values)); 328 } else { 329 setValues(PropertyValuesHolder.ofFloat(mPropertyName, values)); 330 } 331 } else { 332 super.setFloatValues(values); 333 } 334 } 335 336 @Override 337 public void setObjectValues(Object... values) { 338 if (mValues == null || mValues.length == 0) { 339 // No values yet - this animator is being constructed piecemeal. Init the values with 340 // whatever the current propertyName is 341 if (mProperty != null) { 342 setValues(PropertyValuesHolder.ofObject(mProperty, (TypeEvaluator)null, values)); 343 } else { 344 setValues(PropertyValuesHolder.ofObject(mPropertyName, (TypeEvaluator)null, values)); 345 } 346 } else { 347 super.setObjectValues(values); 348 } 349 } 350 351 @Override 352 public void start() { 353 if (DBG) { 354 Log.d("ObjectAnimator", "Anim target, duration" + mTarget + ", " + getDuration()); 355 for (int i = 0; i < mValues.length; ++i) { 356 PropertyValuesHolder pvh = mValues[i]; 357 ArrayList<Keyframe> keyframes = pvh.mKeyframeSet.mKeyframes; 358 Log.d("ObjectAnimator", " Values[" + i + "]: " + 359 pvh.getPropertyName() + ", " + keyframes.get(0).getValue() + ", " + 360 keyframes.get(pvh.mKeyframeSet.mNumKeyframes - 1).getValue()); 361 } 362 } 363 super.start(); 364 } 365 366 /** 367 * This function is called immediately before processing the first animation 368 * frame of an animation. If there is a nonzero <code>startDelay</code>, the 369 * function is called after that delay ends. 370 * It takes care of the final initialization steps for the 371 * animation. This includes setting mEvaluator, if the user has not yet 372 * set it up, and the setter/getter methods, if the user did not supply 373 * them. 374 * 375 * <p>Overriders of this method should call the superclass method to cause 376 * internal mechanisms to be set up correctly.</p> 377 */ 378 @Override 379 void initAnimation() { 380 if (!mInitialized) { 381 // mValueType may change due to setter/getter setup; do this before calling super.init(), 382 // which uses mValueType to set up the default type evaluator. 383 int numValues = mValues.length; 384 for (int i = 0; i < numValues; ++i) { 385 mValues[i].setupSetterAndGetter(mTarget); 386 } 387 super.initAnimation(); 388 } 389 } 390 391 /** 392 * Sets the length of the animation. The default duration is 300 milliseconds. 393 * 394 * @param duration The length of the animation, in milliseconds. 395 * @return ObjectAnimator The object called with setDuration(). This return 396 * value makes it easier to compose statements together that construct and then set the 397 * duration, as in 398 * <code>ObjectAnimator.ofInt(target, propertyName, 0, 10).setDuration(500).start()</code>. 399 */ 400 @Override 401 public ObjectAnimator setDuration(long duration) { 402 super.setDuration(duration); 403 return this; 404 } 405 406 407 /** 408 * The target object whose property will be animated by this animation 409 * 410 * @return The object being animated 411 */ 412 public Object getTarget() { 413 return mTarget; 414 } 415 416 /** 417 * Sets the target object whose property will be animated by this animation 418 * 419 * @param target The object being animated 420 */ 421 @Override 422 public void setTarget(Object target) { 423 if (mTarget != target) { 424 final Object oldTarget = mTarget; 425 mTarget = target; 426 if (oldTarget != null && target != null && oldTarget.getClass() == target.getClass()) { 427 return; 428 } 429 // New target type should cause re-initialization prior to starting 430 mInitialized = false; 431 } 432 } 433 434 @Override 435 public void setupStartValues() { 436 initAnimation(); 437 int numValues = mValues.length; 438 for (int i = 0; i < numValues; ++i) { 439 mValues[i].setupStartValue(mTarget); 440 } 441 } 442 443 @Override 444 public void setupEndValues() { 445 initAnimation(); 446 int numValues = mValues.length; 447 for (int i = 0; i < numValues; ++i) { 448 mValues[i].setupEndValue(mTarget); 449 } 450 } 451 452 /** 453 * This method is called with the elapsed fraction of the animation during every 454 * animation frame. This function turns the elapsed fraction into an interpolated fraction 455 * and then into an animated value (from the evaluator. The function is called mostly during 456 * animation updates, but it is also called when the <code>end()</code> 457 * function is called, to set the final value on the property. 458 * 459 * <p>Overrides of this method must call the superclass to perform the calculation 460 * of the animated value.</p> 461 * 462 * @param fraction The elapsed fraction of the animation. 463 */ 464 @Override 465 void animateValue(float fraction) { 466 super.animateValue(fraction); 467 int numValues = mValues.length; 468 for (int i = 0; i < numValues; ++i) { 469 mValues[i].setAnimatedValue(mTarget); 470 } 471 } 472 473 @Override 474 public ObjectAnimator clone() { 475 final ObjectAnimator anim = (ObjectAnimator) super.clone(); 476 return anim; 477 } 478 479 @Override 480 public String toString() { 481 String returnVal = "ObjectAnimator@" + Integer.toHexString(hashCode()) + ", target " + 482 mTarget; 483 if (mValues != null) { 484 for (int i = 0; i < mValues.length; ++i) { 485 returnVal += "\n " + mValues[i].toString(); 486 } 487 } 488 return returnVal; 489 } 490} 491