<li><a href="#object-animator">Animating with ObjectAnimator</a></li>
- <li><a href="#type-evaluator">Using the TypeEvaluator</a></li>
+ <li><a href="#type-evaluator">Using a TypeEvaluator</a></li>
<li><a href="#interpolators">Using interpolators</a></li>
<p>The Android system provides a flexible animation system that allows you to animate
almost anything, either programmatically or declaratively with XML. There are two
- animation systems that you can choose from: <a href="property-animation">property
+ animation systems that you can choose from: <a href="#property-animation">property
animation</a> and <a href="#view-animation">view animation</a>. You can use whichever
system that matches your needs, but use only one system for each object that you
are animating.</p>
<p>Most of the property animation system's features can be found in
{@link android.animation android.animation}. Because the
- <a href="#view-animation>view animation</a> system already
+ <a href="#view-animation">view animation</a> system already
defines many interpolators in {@link android.view.animation android.view.animation},
you will use those to define your animation's interpolation in the property animation
system as well.
<p>The Android system provides a set of common interpolators in
{@link android.view.animation android.view.animation}. If none of these suits your needs, you
can implement the {@link android.animation.TimeInterpolator} interface and create
- your own. See <a href="#interpolators">Interpolators</a> for more information on
+ your own. See <a href="#interpolators">Using interpolators</a> for more information on
how to write a custom interpolator.</p>
</dd>
</dl>
android.animation.AnimatorListenerAdapter} for just the {@link
android.animation.Animator.AnimatorListener#onAnimationEnd onAnimationEnd()}
callback:</p>
+
<pre>ValueAnimator fadeAnim = ObjectAnimator.ofFloat(newBall, "alpha", 1f, 0f);
fadeAnim.setDuration(250);
fadeAnim.addListener(new AnimatorListenerAdapter() {
public void onAnimationEnd(Animator animation) {
balls.remove(((ObjectAnimator)animation).getTarget());
-}
-
-</pre>
+}</pre>
<h3 id="object-animator">Animating with ObjectAnimator</h3>
<p>Instantiating an {@link android.animation.ObjectAnimator} is similar to a {@link
android.animation.ValueAnimator}, but you also specify the object and that object's
property (as a String) that you want to animate:</p>
- <pre>
-ObjectAnimator anim = ObjectAnimator.ofFloat(foo, "alpha", 0f, 1f);
+ <pre>ObjectAnimator anim = ObjectAnimator.ofFloat(foo, "alpha", 0f, 1f);
anim.setDuration(1000);
-anim.start();
-</pre>
+anim.start();</pre>
<p>To have the {@link android.animation.ObjectAnimator} update properties correctly,
you must do the following:</p>
</li>
</ul>
- <h3 id="type-evaluator">Using the TypeEvaluator</h3>
+ <h3 id="type-evaluator">Using a TypeEvaluator</h3>
<p>If you want to animate a type that is unknown to the Android system,
you can create your own evaluator by implementing the {@link
This allows the animator that you are using to return an
appropriate value for your animated property at the current point of the animation. The
{@link android.animation.FloatEvaluator} class demonstrates how to do this:</p>
- <pre>
-public class FloatEvaluator implements TypeEvaluator {
+ <pre>public class FloatEvaluator implements TypeEvaluator {
public Object evaluate(float fraction, Object startValue, Object endValue) {
float startFloat = ((Number) startValue).floatValue();
return startFloat + fraction * (((Number) endValue).floatValue() - startFloat);
}
-}
-</pre>
+}</pre>
<p class="note"><strong>Note:</strong> When {@link android.animation.ValueAnimator} (or
{@link android.animation.ObjectAnimator}) runs, it calculates a current elapsed
parameter, so you do not have to take into account the interpolator
when calculating animated values.</p>
- <h3 id="interpolators">Using Interpolators</h3>
+ <h3 id="interpolators">Using interpolators</h3>
<p>An interpolator define how specific values in an animation are
calculated as a function of time. For example, you can specify animations to happen
<p><strong>AccelerateDecelerateInterpolator</strong></p>
<pre>public float getInterpolation(float input) {
return (float)(Math.cos((input + 1) * Math.PI) / 2.0f) + 0.5f;
- }</pre>
+}</pre>
<p><strong>LinearInterpolator</strong></p>
<pre>public float getInterpolation(float input) {
return input;
- }</pre>
+}</pre>
<p>The following table represents the approximate values that are calculated by these
interpolators for an animation that lasts 1000ms:</p>
{@link android.view.animation.LinearInterpolator} between 200ms and 600ms and slower
between 600ms and 1000ms.</p>
- <h3 id="keyframes">Specifying Keyframes</h3>
+ <h3 id="keyframes">Specifying keyframes</h3>
<p>A {@link android.animation.Keyframe} object consists of a time/value pair that lets
you define a specific state at a specific time of an animation. Each keyframe can also
object, you can obtain an animator by passing in the {@link
android.animation.PropertyValuesHolder} object and the object to animate. The following
code snippet demonstrates how to do this:</p>
- <pre>
- Keyframe kf0 = Keyframe.ofFloat(0f, 0f);
- Keyframe kf1 = Keyframe.ofFloat(.9999f, 360f);
- Keyframe kf2 = Keyframe.ofFloat(1f, 0f);
- PropertyValuesHolder pvhRotation = PropertyValuesHolder.ofKeyframe("rotation", kf0, kf1, kf2);
- ObjectAnimator rotationAnim = ObjectAnimator.ofPropertyValuesHolder(target, pvhRotation)
- rotationAnim.setDuration(5000ms);
-
-</pre>For a more complete example on how to use keyframes, see the <a href=
+ <pre>Keyframe kf0 = Keyframe.ofFloat(0f, 0f);
+Keyframe kf1 = Keyframe.ofFloat(.9999f, 360f);
+Keyframe kf2 = Keyframe.ofFloat(1f, 0f);
+PropertyValuesHolder pvhRotation = PropertyValuesHolder.ofKeyframe("rotation", kf0, kf1, kf2);
+ObjectAnimator rotationAnim = ObjectAnimator.ofPropertyValuesHolder(target, pvhRotation)
+rotationAnim.setDuration(5000ms);
+</pre>
+<p>For a more complete example on how to use keyframes, see the <a href=
"{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/animation/MultiPropertyAnimation.html">
- MultiPropertyAnimation</a> sample in APIDemos.
+ MultiPropertyAnimation</a> sample in APIDemos.</p>
- <h3 id="choreography">Choreographing multiple animations with Animator Sets</h3>
+ <h3 id="choreography">Choreographing multiple animations with AnimatorSet</h3>
<p>In many cases, you want to play an animation that depends on when another animation
starts or finishes. The Android system lets you bundle animations together into an
<h3 id="declaring-xml">Declaring animations in XML</h3>
- <p>As with <a href="view-animation">view animation</a>, you can declare property animations with
+ <p>As with <a href="#view-animation">view animation</a>, you can declare property animations with
XML instead of doing it programmatically. The following Android classes also have XML
declaration support with the following XML tags:</p>
android:propertyName="y"
android:duration="500"
android:valueTo="300"
- android:valueType="int" >
- </set>
- <objectAnimator
- android:propertyName="alpha"
- android:duration="500"
- android:valueTo="0f"/>
- </set>
-</pre>
+ android:valueType="int"/>
+ </set>
+ <objectAnimator
+ android:propertyName="alpha"
+ android:duration="500"
+ android:valueTo="0f"/>
+</set></pre>
<p>In order to run this animation, you must inflate the XML resources in your code to
an {@link android.animation.AnimatorSet} object, and then set the target objects for all of
<p>The following XML from one of the ApiDemos is used to stretch, then simultaneously
spin and rotate a View object.</p>
- <pre>
-<set android:shareInterpolator="false">
- <scale
- android:interpolator="@android:anim/accelerate_decelerate_interpolator"
- android:fromXScale="1.0"
- android:toXScale="1.4"
- android:fromYScale="1.0"
- android:toYScale="0.6"
- android:pivotX="50%"
- android:pivotY="50%"
- android:fillAfter="false"
- android:duration="700" />
- <set android:interpolator="@android:anim/decelerate_interpolator">
- <scale
- android:fromXScale="1.4"
- android:toXScale="0.0"
- android:fromYScale="0.6"
- android:toYScale="0.0"
- android:pivotX="50%"
- android:pivotY="50%"
- android:startOffset="700"
- android:duration="400"
- android:fillBefore="false" />
- <rotate
- android:fromDegrees="0"
- android:toDegrees="-45"
- android:toYScale="0.0"
- android:pivotX="50%"
- android:pivotY="50%"
- android:startOffset="700"
- android:duration="400" />
- </set>
-</set>
-</pre>
+ <pre><set android:shareInterpolator="false">
+ <scale
+ android:interpolator="@android:anim/accelerate_decelerate_interpolator"
+ android:fromXScale="1.0"
+ android:toXScale="1.4"
+ android:fromYScale="1.0"
+ android:toYScale="0.6"
+ android:pivotX="50%"
+ android:pivotY="50%"
+ android:fillAfter="false"
+ android:duration="700" />
+ <set android:interpolator="@android:anim/decelerate_interpolator">
+ <scale
+ android:fromXScale="1.4"
+ android:toXScale="0.0"
+ android:fromYScale="0.6"
+ android:toYScale="0.0"
+ android:pivotX="50%"
+ android:pivotY="50%"
+ android:startOffset="700"
+ android:duration="400"
+ android:fillBefore="false" />
+ <rotate
+ android:fromDegrees="0"
+ android:toDegrees="-45"
+ android:toYScale="0.0"
+ android:pivotX="50%"
+ android:pivotY="50%"
+ android:startOffset="700"
+ android:duration="400" />
+ </set>
+</set></pre>
<p>Screen coordinates (not used in this example) are (0,0) at the upper left hand
corner, and increase as you go down and to the right.</p>
image to a View and then called to play. Here's an example Activity, in which the
animation is added to an {@link android.widget.ImageView} and then animated when the
screen is touched:</p>
- <pre>
-AnimationDrawable rocketAnimation;
+ <pre>AnimationDrawable rocketAnimation;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
return true;
}
return super.onTouchEvent(event);
-}
-</pre>
+}</pre>
<p>It's important to note that the <code>start()</code> method called on the
AnimationDrawable cannot be called during the <code>onCreate()</code> method of your
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