/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.graphics.drawable;
import java.io.IOException;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.os.SystemClock;
import android.util.AttributeSet;
/**
*
* 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.
* <p>
* 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 #run()} to start the animation.
* <p>
* An AnimationDrawable defined in XML consists of a single <code><animation-list></code> element,
* and a series of nested <code><item></code> tags. Each item defines a frame of the animation.
* See the example below.
* </p>
* <p>spin_animation.xml file in res/drawable/ folder:</p>
* <pre><!-- Animation frames are wheel0.png -- wheel5.png files inside the
* res/drawable/ folder -->
* <animation-list android: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></pre>
*
* <p>Here is the code to load and play this animation.</p>
* <pre>
* // 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()
* </pre>
*
* @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
*/
public class AnimationDrawable extends DrawableContainer implements Runnable {
private final AnimationState mAnimationState;
private int mCurFrame = -1;
private boolean mMutated;
public AnimationDrawable() {
this(null);
}
@Override
public boolean setVisible(boolean visible, boolean restart) {
boolean changed = super.setVisible(visible, restart);
if (visible) {
if (changed || restart) {
setFrame(0, true, true);
}
} else {
unscheduleSelf(this);
}
return changed;
}
/**
* <p>Starts the animation, looping if necessary. This method has no effect
* if the animation is running.</p>
*
* @see #isRunning()
* @see #stop()
*/
public void start() {
if (!isRunning()) {
run();
}
}
/**
* <p>Stops the animation. This method has no effect if the animation is
* not running.</p>
*
* @see #isRunning()
* @see #start()
*/
public void stop() {
if (isRunning()) {
unscheduleSelf(this);
}
}
/**
* <p>Indicates whether the animation is currently running or not.</p>
*
* @return true if the animation is running, false otherwise
*/
public boolean isRunning() {
return mCurFrame > -1;
}
/**
* <p>This method exists for implementation purpose only and should not be
* called directly. Invoke {@link #start()} instead.</p>
*
* @see #start()
*/
public void run() {
nextFrame(false);
}
@Override
public void unscheduleSelf(Runnable what) {
mCurFrame = -1;
super.unscheduleSelf(what);
}
/**
* @return The number of frames in the animation
*/
public int getNumberOfFrames() {
return mAnimationState.getChildCount();
}
/**
* @return The Drawable at the specified frame index
*/
public Drawable getFrame(int index) {
return mAnimationState.getChildren()[index];
}
/**
* @return The duration in milliseconds of the frame at the
* specified index
*/
public int getDuration(int i) {
return mAnimationState.mDurations[i];
}
/**
* @return True of the animation will play once, false otherwise
*/
public boolean isOneShot() {
return mAnimationState.mOneShot;
}
/**
* Sets whether the animation should play once or repeat.
*
* @param oneShot Pass true if the animation should only play once
*/
public void setOneShot(boolean oneShot) {
mAnimationState.mOneShot = oneShot;
}
/**
* Add a frame to the animation
*
* @param frame The frame to add
* @param duration How long in milliseconds the frame should appear
*/
public void addFrame(Drawable frame, int duration) {
mAnimationState.addFrame(frame, duration);
}
private void nextFrame(boolean unschedule) {
int next = mCurFrame+1;
final int N = mAnimationState.getChildCount();
if (next >= N) {
next = 0;
}
setFrame(next, unschedule, !mAnimationState.mOneShot || next < (N - 1));
}
private void setFrame(int frame, boolean unschedule, boolean animate) {
if (frame >= mAnimationState.getChildCount()) {
return;
}
mCurFrame = frame;
selectDrawable(frame);
if (unschedule) {
unscheduleSelf(this);
}
if (animate) {
scheduleSelf(this, SystemClock.uptimeMillis() + mAnimationState.mDurations[frame]);
}
}
@Override
public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs)
throws XmlPullParserException, IOException {
TypedArray a = r.obtainAttributes(attrs,
com.android.internal.R.styleable.AnimationDrawable);
super.inflateWithAttributes(r, parser, a,
com.android.internal.R.styleable.AnimationDrawable_visible);
mAnimationState.setVariablePadding(a.getBoolean(
com.android.internal.R.styleable.AnimationDrawable_variablePadding, false));
mAnimationState.mOneShot = a.getBoolean(
com.android.internal.R.styleable.AnimationDrawable_oneshot, false);
a.recycle();
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;
}
a = r.obtainAttributes(attrs, com.android.internal.R.styleable.AnimationDrawableItem);
int duration = a.getInt(
com.android.internal.R.styleable.AnimationDrawableItem_duration, -1);
if (duration < 0) {
throw new XmlPullParserException(
parser.getPositionDescription()
+ ": <item> tag requires a 'duration' attribute");
}
int drawableRes = a.getResourceId(
com.android.internal.R.styleable.AnimationDrawableItem_drawable, 0);
a.recycle();
Drawable dr;
if (drawableRes != 0) {
dr = r.getDrawable(drawableRes);
} else {
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);
}
mAnimationState.addFrame(dr, duration);
if (dr != null) {
dr.setCallback(this);
}
}
setFrame(0, true, false);
}
@Override
public Drawable mutate() {
if (!mMutated && super.mutate() == this) {
mAnimationState.mDurations = mAnimationState.mDurations.clone();
mMutated = true;
}
return this;
}
private final static class AnimationState extends DrawableContainerState {
private int[] mDurations;
private boolean mOneShot;
AnimationState(AnimationState orig, AnimationDrawable owner) {
super(orig, owner);
if (orig != null) {
mDurations = orig.mDurations;
mOneShot = orig.mOneShot;
} else {
mDurations = new int[getChildren().length];
mOneShot = true;
}
}
@Override
public Drawable newDrawable() {
return new AnimationDrawable(this);
}
public void addFrame(Drawable dr, int dur) {
// Do not combine the following. The array index must be evaluated before
// the array is accessed because super.addChild(dr) has a side effect on mDurations.
int pos = super.addChild(dr);
mDurations[pos] = dur;
}
@Override
public void growArray(int oldSize, int newSize) {
super.growArray(oldSize, newSize);
int[] newDurations = new int[newSize];
System.arraycopy(mDurations, 0, newDurations, 0, oldSize);
mDurations = newDurations;
}
}
private AnimationDrawable(AnimationState state) {
AnimationState as = new AnimationState(state, this);
mAnimationState = as;
setConstantState(as);
if (state != null) {
setFrame(0, true, false);
}
}
}
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