FileDocCategorySizeDatePackage
AnimationDrawable.javaAPI DocAndroid 5.1 API14563Thu Mar 12 22:22:30 GMT 2015android.graphics.drawable

AnimationDrawable

public class AnimationDrawable extends DrawableContainer implements Runnable, Animatable
An object used to create frame-by-frame animations, defined by a series of Drawable objects, which can be used as a View object's background.

The simplest way to create a frame-by-frame animation is to define the animation in an XML file, placed in the res/drawable/ folder, and set it as the background to a View object. Then, call {@link #start()} to run the animation.

An AnimationDrawable defined in XML consists of a single <animation-list> element, and a series of nested <item> tags. Each item defines a frame of the animation. See the example below.

spin_animation.xml file in res/drawable/ folder:

<!-- Animation frames are wheel0.png -- wheel5.png files inside the
res/drawable/ folder -->
<animation-list android:id="@+id/selected" android:oneshot="false">
<item android:drawable="@drawable/wheel0" android:duration="50" />
<item android:drawable="@drawable/wheel1" android:duration="50" />
<item android:drawable="@drawable/wheel2" android:duration="50" />
<item android:drawable="@drawable/wheel3" android:duration="50" />
<item android:drawable="@drawable/wheel4" android:duration="50" />
<item android:drawable="@drawable/wheel5" android:duration="50" />
</animation-list>

Here is the code to load and play this animation.

// Load the ImageView that will host the animation and
// set its background to our AnimationDrawable XML resource.
ImageView img = (ImageView)findViewById(R.id.spinning_wheel_image);
img.setBackgroundResource(R.drawable.spin_animation);

// Get the background, which has been compiled to an AnimationDrawable object.
AnimationDrawable frameAnimation = (AnimationDrawable) img.getBackground();

// Start the animation (looped playback by default).
frameAnimation.start();

Developer Guides

For more information about animating with {@code AnimationDrawable}, read the Drawable Animation developer guide.

attr
ref android.R.styleable#AnimationDrawable_visible
attr
ref android.R.styleable#AnimationDrawable_variablePadding
attr
ref android.R.styleable#AnimationDrawable_oneshot
attr
ref android.R.styleable#AnimationDrawableItem_duration
attr
ref android.R.styleable#AnimationDrawableItem_drawable

Fields Summary
private AnimationState
mAnimationState
private int
mCurFrame
The current frame, may be -1 when not animating.
private boolean
mRunning
Whether the drawable has an animation callback posted.
private boolean
mAnimating
Whether the drawable should animate when visible.
private boolean
mMutated
Constructors Summary
public AnimationDrawable()


      
        this(null, null);
private AnimationDrawable(AnimationState state, android.content.res.Resources res)

        final AnimationState as = new AnimationState(state, this, res);
        setConstantState(as);
        if (state != null) {
            setFrame(0, true, false);
        }
Methods Summary
public voidaddFrame(Drawable frame, int duration)
Add a frame to the animation

param
frame The frame to add
param
duration How long in milliseconds the frame should appear

        mAnimationState.addFrame(frame, duration);
        if (mCurFrame < 0) {
            setFrame(0, true, false);
        }
public voidclearMutated()

hide

        super.clearMutated();
        mMutated = false;
android.graphics.drawable.AnimationDrawable$AnimationStatecloneConstantState()

        return new AnimationState(mAnimationState, this, null);
public intgetDuration(int i)

return
The duration in milliseconds of the frame at the specified index

        return mAnimationState.mDurations[i];
public DrawablegetFrame(int index)

return
The Drawable at the specified frame index

        return mAnimationState.getChild(index);
public intgetNumberOfFrames()

return
The number of frames in the animation

        return mAnimationState.getChildCount();
public voidinflate(android.content.res.Resources r, org.xmlpull.v1.XmlPullParser parser, android.util.AttributeSet attrs, android.content.res.Resources.Theme theme)

        final TypedArray a = obtainAttributes(r, theme, attrs, R.styleable.AnimationDrawable);
        super.inflateWithAttributes(r, parser, a, R.styleable.AnimationDrawable_visible);
        updateStateFromTypedArray(a);
        a.recycle();

        inflateChildElements(r, parser, attrs, theme);

        setFrame(0, true, false);
private voidinflateChildElements(android.content.res.Resources r, org.xmlpull.v1.XmlPullParser parser, android.util.AttributeSet attrs, android.content.res.Resources.Theme theme)

        int type;

        final int innerDepth = parser.getDepth()+1;
        int depth;
        while ((type=parser.next()) != XmlPullParser.END_DOCUMENT
                && ((depth = parser.getDepth()) >= innerDepth || type != XmlPullParser.END_TAG)) {
            if (type != XmlPullParser.START_TAG) {
                continue;
            }

            if (depth > innerDepth || !parser.getName().equals("item")) {
                continue;
            }

            final TypedArray a = obtainAttributes(r, theme, attrs,
                    R.styleable.AnimationDrawableItem);

            final int duration = a.getInt(R.styleable.AnimationDrawableItem_duration, -1);
            if (duration < 0) {
                throw new XmlPullParserException(parser.getPositionDescription()
                        + ": <item> tag requires a 'duration' attribute");
            }

            Drawable dr = a.getDrawable(R.styleable.AnimationDrawableItem_drawable);

            a.recycle();

            if (dr == null) {
                while ((type=parser.next()) == XmlPullParser.TEXT) {
                    // Empty
                }
                if (type != XmlPullParser.START_TAG) {
                    throw new XmlPullParserException(parser.getPositionDescription()
                            + ": <item> tag requires a 'drawable' attribute or child tag"
                            + " defining a drawable");
                }
                dr = Drawable.createFromXmlInner(r, parser, attrs, theme);
            }

            mAnimationState.addFrame(dr, duration);
            if (dr != null) {
                dr.setCallback(this);
            }
        }
public booleanisOneShot()

return
True of the animation will play once, false otherwise

        return mAnimationState.mOneShot;
public booleanisRunning()

Indicates whether the animation is currently running or not.

return
true if the animation is running, false otherwise

        return mRunning;
public Drawablemutate()

        if (!mMutated && super.mutate() == this) {
            mAnimationState.mutate();
            mMutated = true;
        }
        return this;
private voidnextFrame(boolean unschedule)

        int next = mCurFrame+1;
        final int N = mAnimationState.getChildCount();
        if (next >= N) {
            next = 0;
        }

        setFrame(next, unschedule, !mAnimationState.mOneShot || next < (N - 1));
public voidrun()

This method exists for implementation purpose only and should not be called directly. Invoke {@link #start()} instead.

see
#start()

        nextFrame(false);
protected voidsetConstantState(DrawableContainerState state)

        super.setConstantState(state);

        if (state instanceof AnimationState) {
            mAnimationState = (AnimationState) state;
        }
private voidsetFrame(int frame, boolean unschedule, boolean animate)

        if (frame >= mAnimationState.getChildCount()) {
            return;
        }
        mAnimating = animate;
        mCurFrame = frame;
        selectDrawable(frame);
        if (unschedule || animate) {
            unscheduleSelf(this);
        }
        if (animate) {
            // Unscheduling may have clobbered these values; restore them
            mCurFrame = frame;
            mRunning = true;
            scheduleSelf(this, SystemClock.uptimeMillis() + mAnimationState.mDurations[frame]);
        }
public voidsetOneShot(boolean oneShot)
Sets whether the animation should play once or repeat.

param
oneShot Pass true if the animation should only play once

        mAnimationState.mOneShot = oneShot;
public booleansetVisible(boolean visible, boolean restart)
Sets whether this AnimationDrawable is visible.

When the drawable becomes invisible, it will pause its animation. A subsequent change to visible with restart set to true will restart the animation from the first frame. If restart is false, the animation will resume from the most recent frame.

param
visible true if visible, false otherwise
param
restart when visible, true to force the animation to restart from the first frame
return
true if the new visibility is different than its previous state

        final boolean changed = super.setVisible(visible, restart);
        if (visible) {
            if (restart || changed) {
                boolean startFromZero = restart || mCurFrame < 0 ||
                        mCurFrame >= mAnimationState.getChildCount();
                setFrame(startFromZero ? 0 : mCurFrame, true, mAnimating);
            }
        } else {
            unscheduleSelf(this);
        }
        return changed;
public voidstart()

Starts the animation, looping if necessary. This method has no effect if the animation is running. Do not call this in the {@link android.app.Activity#onCreate} method of your activity, because the {@link android.graphics.drawable.AnimationDrawable} is not yet fully attached to the window. If you want to play the animation immediately, without requiring interaction, then you might want to call it from the {@link android.app.Activity#onWindowFocusChanged} method in your activity, which will get called when Android brings your window into focus.

see
#isRunning()
see
#stop()

        mAnimating = true;

        if (!isRunning()) {
            run();
        }
public voidstop()

Stops the animation. This method has no effect if the animation is not running.

see
#isRunning()
see
#start()

        mAnimating = false;

        if (isRunning()) {
            unscheduleSelf(this);
        }
public voidunscheduleSelf(java.lang.Runnable what)

        mCurFrame = -1;
        mRunning = false;
        super.unscheduleSelf(what);
private voidupdateStateFromTypedArray(android.content.res.TypedArray a)

        mAnimationState.mVariablePadding = a.getBoolean(
                R.styleable.AnimationDrawable_variablePadding, mAnimationState.mVariablePadding);

        mAnimationState.mOneShot = a.getBoolean(
                R.styleable.AnimationDrawable_oneshot, mAnimationState.mOneShot);