topics/resources/animation-resource.jd

page.title=Animation Resources
parent.title=Resource Types
parent.link=available-resources.html
@jd:body

<div id="qv-wrapper">
  <div id="qv">
    <h2>See also</h2>
    <ol>
      <li><a href="{@docRoot}guide/topics/graphics/2d-graphics.html#tween-animation">2D
Graphics</a></li>
    </ol>
  </div>
</div>


<p>An animation resource can define one of two types of animations:</p>
<dl>
  <dt><a href="#Tween">Tween Animation</a></dt>
  <dd>Creates an animation by performing a series of transformations on a single image.
    An {@link android.view.animation.Animation}.</dd>
  <dt><a href="#Frame">Frame Animation</a></dt>
  <dd>Creates an animation by showing a sequence of images in order.
    An {@link android.graphics.drawable.AnimationDrawable}.</dd>
</dl>


<h2 id="Tween">Tween Animation</h2>

<p>An animation defined in XML that performs transitions such as rotating,
fading, moving, and stretching on a graphic.
</p>

<dl class="xml">

<dt>file location:</dt>
<dd><code>res/anim/<em>filename</em>.xml</code><br/>
The filename will be used as the resource ID.</dd>

<dt>compiled resource datatype:</dt>
<dd>Resource pointer to an {@link android.view.animation.Animation}.</dd>

<dt>resource reference:</dt>
<dd>
In Java: <code>R.anim.<em>filename</em></code><br/>
In XML: <code>@[<em>package</em>:]anim/<em>filename</em></code>
</dd>

<dt>syntax:</dt>
<dd>
<pre class="stx">
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;<a href="#set-element">set</a> xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@[package:]anim/<em>interpolator_resource</em>"
    android:shareInterpolator=["true" | "false"] &gt;
    &lt;<a href="#alpha-element">alpha</a>
        android:fromAlpha="<em>float</em>"
        android:toAlpha="<em>float</em>" /&gt;
    &lt;<a href="#scale-element">scale</a>
        android:fromXScale="<em>float</em>"
        android:toXScale="<em>float</em>"
        android:fromYScale="<em>float</em>"
        android:toYScale="<em>float</em>"
        android:pivotX="<em>float</em>"
        android:pivotY="<em>float</em>" /&gt;
    &lt;<a href="#translate-element">translate</a>
        android:fromXDelta="<em>float</em>"
        android:toXDelta="<em>float</em>"
        android:fromYDelta="<em>float</em>"
        android:toYDelta="<em>float</em>" /&gt;
    &lt;<a href="#rotate-element">rotate</a>
        android:fromDegrees="<em>float</em>"
        android:toDegrees="<em>float</em>"
        android:pivotX="<em>float</em>"
        android:pivotY="<em>float</em>" /&gt;
    &lt;<a href="#set-element">set</a>&gt;
        ...
    &lt;/set&gt;
&lt;/set&gt;
</pre>

<p>The file must have a single root element: either an
<code>&lt;alpha&gt;</code>, <code>&lt;scale&gt;</code>, <code>&lt;translate&gt;</code>,
<code>&lt;rotate&gt;</code>, or <code>&lt;set&gt;</code> element that holds
a group (or groups) of other animation elements (even nested <code>&lt;set&gt;</code> elements).
</p>
</dd>

<dt>elements:</dt>
<dd>
<dl class="tag-list">
  <dt id="set-element"><code>&lt;set&gt;</code></dt>
    <dd>A container that holds other animation elements
(<code>&lt;alpha&gt;</code>, <code>&lt;scale&gt;</code>, <code>&lt;translate&gt;</code>,
<code>&lt;rotate&gt;</code>) or other <code>&lt;set&gt;</code> elements. Represents an {@link
android.view.animation.AnimationSet}.
      <p class="caps">attributes:</p>
      <dl class="atn-list">
        <dt><code>android:interpolator</code></dt>
          <dd><em>Interpolator resource</em>.
          An {@link android.view.animation.Interpolator} to apply on the animation.
          The value must be a reference to a resource that specifies an interpolator
          (not an interpolator class name). There are default interpolator
          resources available from the platform or you can create your own interpolator resource.
          See the discussion below for more about <a href="#Interpolators">Interpolators</a>.</dd>
        <dt><code>android:shareInterpolator</code></dt>
          <dd><em>Boolean</em>. "true" if you want to share the same interpolator among all child
elements.</dd>
      </dl>
    </dd>
  <dt id="alpha-element"><code>&lt;alpha&gt;</code></dt>
    <dd>A fade-in or fade-out animation. Represents an {@link
android.view.animation.AlphaAnimation}.
      <p class="caps">attributes:</p>
      <dl class="atn-list">
        <dt><code>android:fromAlpha</code></dt>
          <dd><em>Float</em>. Starting opacity offset, where 0.0 is transparent and 1.0
is opaque.</dd>
        <dt><code>android:toAlpha</code></dt>
          <dd><em>Float</em>. Ending opacity offset, where 0.0 is transparent and 1.0
is opaque.</dd>
      </dl>
      <p>For more attributes supported by <code>&lt;alpha&gt;</code>, see the
{@link android.view.animation.Animation} class reference (of which, all XML attributes are
inherrited by this element).</p>
    </dd>
  <dt id="scale-element"><code>&lt;scale&gt;</code></dt>
    <dd>A resizing animation. You can specify the center point of the image from which it grows
outward (or inward) by specifying {@code pivotX} and {@code pivotY}. For example, if these values
are 0, 0 (top-left corner), all growth will be down and to the right. Represents a {@link
android.view.animation.ScaleAnimation}.
      <p class="caps">attributes:</p>
      <dl class="atn-list">
        <dt><code>android:fromXScale</code></dt>
          <dd><em>Float</em>. Starting X size offset, where 1.0 is no change.</dd>
        <dt><code>android:toXScale</code></dt>
          <dd><em>Float</em>. Ending X size offset, where 1.0 is no change.</dd>
        <dt><code>android:fromYScale</code></dt>
          <dd><em>Float</em>. Starting Y size offset, where 1.0 is no change.</dd>
        <dt><code>android:toYScale</code></dt>
          <dd><em>Float</em>. Ending Y size offset, where 1.0 is no change.</dd>
        <dt><code>android:pivotX</code></dt>
          <dd><em>Float</em>. The X coordinate to remain fixed when the object is scaled.</dd>
        <dt><code>android:pivotY</code></dt>
          <dd><em>Float</em>. The Y coordinate to remain fixed when the object is scaled.</dd>
      </dl>
      <p>For more attributes supported by <code>&lt;scale&gt;</code>, see the
{@link android.view.animation.Animation} class reference (of which, all XML attributes are
inherrited by this element).</p>
    </dd>
  <dt id="translate-element"><code>&lt;translate&gt;</code></dt>
    <dd>A vertical and/or horizontal motion. Supports the following attributes in any of
the following three formats: values from -100 to 100 ending with "%", indicating a percentage
relative to itself; values from -100 to 100 ending in "%p", indicating a percentage relative to its
parent; a float value with no suffix, indicating an absolute value. Represents a {@link
android.view.animation.TranslateAnimation}.
      <p class="caps">attributes:</p>
      <dl class="atn-list">
        <dt><code>android:fromXDelta</code></dt>
          <dd><em>Float or percentage</em>. Starting X offset. Expressed either: in pixels relative
to the normal position (such as {@code "5"}), in percentage relative to the element width (such as
{@code "5%"}), or in percentage relative to the parent width (such as {@code "5%p"}).</dd>
        <dt><code>android:toXDelta</code></dt>
          <dd><em>Float or percentage</em>. Ending X offset. Expressed either: in pixels relative
to the normal position (such as {@code "5"}), in percentage relative to the element width (such as
{@code "5%"}), or in percentage relative to the parent width (such as {@code "5%p"}).</dd>
        <dt><code>android:fromYDelta</code></dt>
          <dd><em>Float or percentage</em>. Starting Y offset. Expressed either: in pixels relative
to the normal position (such as {@code "5"}), in percentage relative to the element height (such as
{@code "5%"}), or in percentage relative to the parent height (such as {@code "5%p"}).</dd>
        <dt><code>android:toYDelta</code></dt>
          <dd><em>Float or percentage</em>. Ending Y offset. Expressed either: in pixels relative
to the normal position (such as {@code "5"}), in percentage relative to the element height (such as
{@code "5%"}), or in percentage relative to the parent height (such as {@code "5%p"}).</dd>
      </dl>
      <p>For more attributes supported by <code>&lt;translate&gt;</code>, see the
{@link android.view.animation.Animation} class reference (of which, all XML attributes are
inherrited by this element).</p>
    </dd>
  <dt id="rotate-element"><code>&lt;rotate&gt;</code></dt>
    <dd>A rotation animation. Represents a {@link android.view.animation.RotateAnimation}.
      <p class="caps">attributes:</p>
      <dl class="atn-list">
        <dt><code>android:fromDegrees</code></dt>
          <dd><em>Float</em>. Starting angular position, in degrees.</dd>
        <dt><code>android:toDegrees</code></dt>
          <dd><em>Float</em>. Ending angular position, in degrees.</dd>
        <dt><code>android:pivotX</code></dt>
          <dd><em>Float or percentage</em>. The X coordinate of the center of rotation. Expressed
either: in pixels relative to the object's left edge (such as {@code "5"}), in percentage relative
to the object's left edge (such as {@code "5%"}), or in percentage relative to the parent
container's left edge (such as {@code "5%p"}).</dd>
        <dt><code>android:pivotY</code></dt>
          <dd><em>Float or percentage</em>. The Y coordinate of the center of rotation. Expressed
either: in pixels relative to the object's top edge (such as {@code "5"}), in percentage relative
to the object's top edge (such as {@code "5%"}), or in percentage relative to the parent
container's top edge (such as {@code "5%p"}).</dd>
        </dl>
      <p>For more attributes supported by <code>&lt;rotate&gt;</code>, see the
{@link android.view.animation.Animation} class reference (of which, all XML attributes are
inherrited by this element).</p>
    </dd>
</dl>
</dd> <!-- end  elements and attributes -->

<dt>example:</dt>
<dd>
  <pp>XML file saved at <code>res/anim/hyperspace_jump.xml</code>:</p>
<pre>
&lt;set xmlns:android="http://schemas.android.com/apk/res/android"
    android:shareInterpolator="false">
    &lt;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" />
    &lt;set
        android:interpolator="@android:anim/accelerate_interpolator"
        android:startOffset="700">
        &lt;scale
            android:fromXScale="1.4"
            android:toXScale="0.0"
            android:fromYScale="0.6"
            android:toYScale="0.0"
            android:pivotX="50%"
            android:pivotY="50%"
            android:duration="400" />
        &lt;rotate
            android:fromDegrees="0"
            android:toDegrees="-45"
            android:toYScale="0.0"
            android:pivotX="50%"
            android:pivotY="50%"
            android:duration="400" />
    &lt;/set>
&lt;/set>
</pre>
  <p>This application code will apply the animation to an {@link android.widget.ImageView} and
start the animation:</p>
<pre>
ImageView image = (ImageView) findViewById(R.id.image);
Animation hyperspaceJump = AnimationUtils.{@link android.view.animation.AnimationUtils#loadAnimation(Context,int) loadAnimation}(this, R.anim.hyperspace_jump);
image.{@link android.view.View#startAnimation(Animation) startAnimation}(hyperspaceJump);
</pre>
</dd> <!-- end example -->


<dt>see also:</dt>
<dd>
<ul>
  <li><a href="{@docRoot}guide/topics/graphics/2d-graphics.html#tween-animation">2D
Graphics: Tween Animation</a></li>
</ul>
</dd>

</dl>


<h3 id="Interpolators">Interpolators</h3>

<p>An interpolator is an animation modifier defined in XML that affects the rate of change in an
animation. This allows your existing animation effects to be accelerated, decelerated, repeated,
bounced, etc.</p>

<p>An interpolator is applied to an animation element with the {@code android:interpolator}
attribute, the value of which is a reference to an interpolator resource.</p>

<p>All interpolators available in Android are subclasses of the {@link
android.view.animation.Interpolator} class. For each interpolator class, Android
includes a public resource you can reference in order to apply the interpolator to an animation
using the the {@code android:interpolator} attribute.
The following table specifies the resource to use for each interpolator:</p>

<table>
  <tr><th>Interpolator class</th><th>Resource ID</th></tr>
  <tr>
    <td>{@link android.view.animation.AccelerateDecelerateInterpolator}</td>
    <td>{@code @android:anim/accelerate_decelerate_interpolator}</td>
  </tr>
  <tr>
    <td>{@link android.view.animation.AccelerateInterpolator}</td>
    <td>{@code @android:anim/accelerate_interpolator}</td>
  </tr>
  <tr>
    <td>{@link android.view.animation.AnticipateInterpolator}</td>
    <td>{@code @android:anim/anticipate_interpolator}</td>
  </tr>
  <tr>
    <td>{@link android.view.animation.AnticipateOvershootInterpolator}</td>
    <td>{@code @android:anim/anticipate_overshoot_interpolator}</td>
  </tr>
  <tr>
    <td>{@link android.view.animation.BounceInterpolator}</td>
    <td>{@code @android:anim/bounce_interpolator}</td>
  </tr>
  <tr>
    <td>{@link android.view.animation.CycleInterpolator}</td>
    <td>{@code @android:anim/cycle_interpolator}</td>
  </tr>
  <tr>
    <td>{@link android.view.animation.DecelerateInterpolator}</td>
    <td>{@code @android:anim/decelerate_interpolator}</td>
  </tr>
  <tr>
    <td>{@link android.view.animation.LinearInterpolator}</td>
    <td>{@code @android:anim/linear_interpolator}</td>
  </tr>
  <tr>
    <td>{@link android.view.animation.OvershootInterpolator}</td>
    <td>{@code @android:anim/overshoot_interpolator}</td>
  </tr>
</table>

<p>Here's how you can apply one of these with the {@code android:interpolator} attribute:</p>
<pre>
&lt;set android:interpolator="@android:anim/accelerate_interpolator"&gt;
    ...
&lt;/set&gt;
</pre>


<h4>Custom interpolators</h4>

<p>If you're not satisfied with the interpolators provided by the platform (listed in the
table above), you can create a custom interpolator resource with modified attributes.
For example, you can adjust the rate of
acceleration for the {@link android.view.animation.AnticipateInterpolator}, or adjust the number of
cycles for the {@link android.view.animation.CycleInterpolator}. In order to do so, you need to
create your own interpolator resource in an XML file.
</p>

<dl class="xml">

<dt>file location:</dt>
<dd><code>res/anim/<em>filename</em>.xml</code><br/>
The filename will be used as the resource ID.</dd>

<dt>compiled resource datatype:</dt>
<dd>Resource pointer to the corresponding interpolator object.</dd>

<dt>resource reference:</dt>
<dd>
In XML: <code>@[<em>package</em>:]anim/<em>filename</em></code>
</dd>

<dt>syntax:</dt>
<dd>
<pre class="stx">
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;<em>InterpolatorName</em> xmlns:android="http://schemas.android.com/apk/res/android"
    android:<em>attribute_name</em>="<em>value</em>"
    />
</pre>
<p>If you don't apply any attributes, then your interpolator will function exactly the same as
those provided by the platform (listed in the table above).</p>
</dd>

<dt>elements:</dt>
<dd>Notice that each {@link android.view.animation.Interpolator} implementation, when
defined in XML, begins its name in lowercase.</p>

<dl class="tag-list">
  <dt><code>&lt;accelerateDecelerateInterpolator&gt;</code></dt>
    <dd>The rate of change starts and ends slowly but accelerates through the
middle. <p>No attributes.</p></dd>
  <dt><code>&lt;accelerateInterpolator&gt;</code></dt>
    <dd>The rate of change starts out slowly, then accelerates.
      <p class="caps">attributes:</p>
      <dl class="atn-list">
        <dt><code>android:factor</code></dt>
        <dd><em>Float</em>. The acceleration rate (default is 1).</dd>
      </dl>
    </dd>
  <dt><code>&lt;anticipateInterpolator&gt;</code></dt>
    <dd>The change starts backward then flings forward.
      <p class="caps">attributes:</p>
      <dl class="atn-list">
        <dt><code>android:tension</code></dt>
        <dd><em>Float</em>. The amount of tension to apply (default is 2).</dd>
      </dl>
    </dd>
  <dt><code>&lt;anticipateOvershootInterpolator&gt;</code></dt>
    <dd>The change starts backward, flings forward and overshoots the target value, then
settles at the final value.
      <p class="caps">attributes:</p>
      <dl class="atn-list">
        <dt><code>android:tension</code></dt>
        <dd><em>Float</em>. The amount of tension to apply (default is 2).</dd>
        <dt><code>android:extraTension</code></dt>
        <dd><em>Float</em>. The amount by which to multiply the tension (default is
          1.5).</dd>
      </dl>
    </dd>
  <dt><code>&lt;bounceInterpolator&gt;</code></dt>
    <dd>The change bounces at the end. <p>No attributes</p></dd>
  <dt><code>&lt;cycleInterpolator&gt;</code></dt>
    <dd>Repeats the animation for a specified number of cycles. The rate of change follows a
sinusoidal pattern.
      <p class="caps">attributes:</p>
      <dl class="atn-list">
        <dt><code>android:cycles</code></dt>
        <dd><em>Integer</em>. The number of cycles (default is 1).</dd>
      </dl>
    </dd>
  <dt><code>&lt;decelerateInterpolator&gt;</code></dt>
    <dd>The rate of change starts out quickly, then decelerates.
      <p class="caps">attributes:</p>
      <dl class="atn-list">
        <dt><code>android:factor</code></dt>
        <dd><em>Float</em>. The deceleration rate (default is 1).</dd>
      </dl>
    </dd>
  <dt><code>&lt;linearInterpolator&gt;</code></dt>
    <dd>The rate of change is constant. <p>No attributes.</p></dd>
  <dt><code>&lt;overshootInterpolator&gt;</code></dt>
    <dd>The change flings forward and overshoots the last value, then comes back.
      <p class="caps">attributes:</p>
      <dl class="atn-list">
        <dt><code>android:tension</code></dt>
        <dd><em>Float</em>. The amount of tension to apply (default is 2).</dd>
      </dl>
    </dd>
</dl>

<dt>example:</dt>
<dd>
  <p>XML file saved at <code>res/anim/my_overshoot_interpolator.xml</code>:</p>
<pre>
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;overshootInterpolator xmlns:android="http://schemas.android.com/apk/res/android"
    android:tension="7.0"
    />
</pre>
  <p>This animation XML will apply the interpolator:</p>
<pre>
&lt;scale xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@anim/my_overshoot_interpolator"
    android:fromXScale="1.0"
    android:toXScale="3.0"
    android:fromYScale="1.0"
    android:toYScale="3.0"
    android:pivotX="50%"
    android:pivotY="50%"
    android:duration="700" />
</pre>
</dd>
</dl>


<h2 id="Frame">Frame Animation</h2>

<p>An animation defined in XML that shows a sequence of images in order (like a film).
</p>


<dl class="xml">

<dt>file location:</dt>
<dd><code>res/drawable/<em>filename</em>.xml</code><br/>
The filename will be used as the resource ID.</dd>

<dt>compiled resource datatype:</dt>
<dd>Resource pointer to an {@link android.graphics.drawable.AnimationDrawable}.</dd>

<dt>resource reference:</dt>
<dd>
In Java: <code>R.drawable.<em>filename</em></code><br/>
In XML: <code>@[<em>package</em>:]drawable.<em>filename</em></code>
</dd>

<dt>syntax:</dt>
<dd>
<pre class="stx">
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;<a href="#animation-list-element">animation-list</a> xmlns:android="http://schemas.android.com/apk/res/android"
    android:oneshot=["true" | "false"] >
    &lt;<a href="#item-element">item</a>
        android:drawable="@[package:]drawable/<em>drawable_resource_name</em>"
        android:duration="<em>integer</em>" />
&lt;/animation-list>
</pre>
</dd>

<dt>elements:</dt>
<dd>
<dl class="tag-list">
<dt id="animation-list-element"><code>&lt;animation-list&gt;</code></dt>
  <dd><strong>Required</strong>. This must be the root element. Contains one or more
<code>&lt;item&gt;</code> elements.
  <p class="caps">attributes:</p>
    <dl class="atn-list">
      <dt><code>android:oneshot</code></dt>
      <dd><em>Boolean</em>. "true" if you want to perform the animation once; "false" to loop the
animation.</dd>
    </dl>
  </dd>
<dt id="item-element"><code>&lt;item&gt;</code></dt>
  <dd>A single frame of animation. Must be a child of a <code>&lt;animation-list&gt;</code> element.
  <p class="caps">attributes:</p>
    <dl class="atn-list">
      <dt><code>android:drawable</code></dt>
      <dd><em>Drawable resource</em>. The drawable to use for this frame.</dd>
      <dt><code>android:duration</code></dt>
      <dd><em>Integer</em>. The duration to show this frame, in milliseconds.</dd>
    </dl>
  </dd>
</dl>
</dd> <!-- end  elements and attributes -->

<dt>example:</dt>
<dd>
  <dl>
    <dt>XML file saved at <code>res/anim/rocket.xml</code>:</dt>
    <dd>
<pre>
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;animation-list xmlns:android="http://schemas.android.com/apk/res/android"
    android:oneshot="false">
    &lt;item android:drawable="@drawable/rocket_thrust1" android:duration="200" />
    &lt;item android:drawable="@drawable/rocket_thrust2" android:duration="200" />
    &lt;item android:drawable="@drawable/rocket_thrust3" android:duration="200" />
&lt;/animation-list>
</pre>
    </dd>

    <dt>This application code will set the animation as the background for a View,
      then play the animation:</dt>
    <dd>
<pre>
ImageView rocketImage = (ImageView) findViewById(R.id.rocket_image);
rocketImage.{@link android.view.View#setBackgroundResource(int) setBackgroundResource}(R.drawable.rocket_thrust);

rocketAnimation = (AnimationDrawable) rocketImage.{@link android.view.View#getBackground()};
rocketAnimation.{@link android.graphics.drawable.AnimationDrawable#start()};
</pre>
    </dd>

  </dl>
</dd> <!-- end example -->

</dl>