Java tutorial
/* * Copyright (C) 2014 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.animation; import android.content.pm.ActivityInfo.Config; import android.content.res.ConstantState; import android.util.StateSet; import android.view.View; import java.lang.ref.WeakReference; import java.util.ArrayList; /** * Lets you define a number of Animators that will run on the attached View depending on the View's * drawable state. * <p> * It can be defined in an XML file with the <code><selector></code> element. * Each State Animator is defined in a nested <code><item></code> element. * * @attr ref android.R.styleable#DrawableStates_state_focused * @attr ref android.R.styleable#DrawableStates_state_window_focused * @attr ref android.R.styleable#DrawableStates_state_enabled * @attr ref android.R.styleable#DrawableStates_state_checkable * @attr ref android.R.styleable#DrawableStates_state_checked * @attr ref android.R.styleable#DrawableStates_state_selected * @attr ref android.R.styleable#DrawableStates_state_activated * @attr ref android.R.styleable#DrawableStates_state_active * @attr ref android.R.styleable#DrawableStates_state_single * @attr ref android.R.styleable#DrawableStates_state_first * @attr ref android.R.styleable#DrawableStates_state_middle * @attr ref android.R.styleable#DrawableStates_state_last * @attr ref android.R.styleable#DrawableStates_state_pressed * @attr ref android.R.styleable#StateListAnimatorItem_animation */ public class StateListAnimator implements Cloneable { private ArrayList<Tuple> mTuples = new ArrayList<Tuple>(); private Tuple mLastMatch = null; private Animator mRunningAnimator = null; private WeakReference<View> mViewRef; private StateListAnimatorConstantState mConstantState; private AnimatorListenerAdapter mAnimatorListener; private @Config int mChangingConfigurations; public StateListAnimator() { initAnimatorListener(); } private void initAnimatorListener() { mAnimatorListener = new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { animation.setTarget(null); if (mRunningAnimator == animation) { mRunningAnimator = null; } } }; } /** * Associates the given animator with the provided drawable state specs so that it will be run * when the View's drawable state matches the specs. * * @param specs The drawable state specs to match against * @param animator The animator to run when the specs match */ public void addState(int[] specs, Animator animator) { Tuple tuple = new Tuple(specs, animator); tuple.mAnimator.addListener(mAnimatorListener); mTuples.add(tuple); mChangingConfigurations |= animator.getChangingConfigurations(); } /** * Returns the current {@link android.animation.Animator} which is started because of a state * change. * * @return The currently running Animator or null if no Animator is running * @hide */ public Animator getRunningAnimator() { return mRunningAnimator; } /** * @hide */ public View getTarget() { return mViewRef == null ? null : mViewRef.get(); } /** * Called by View * @hide */ public void setTarget(View view) { final View current = getTarget(); if (current == view) { return; } if (current != null) { clearTarget(); } if (view != null) { mViewRef = new WeakReference<View>(view); } } private void clearTarget() { final int size = mTuples.size(); for (int i = 0; i < size; i++) { mTuples.get(i).mAnimator.setTarget(null); } mViewRef = null; mLastMatch = null; mRunningAnimator = null; } @Override public StateListAnimator clone() { try { StateListAnimator clone = (StateListAnimator) super.clone(); clone.mTuples = new ArrayList<Tuple>(mTuples.size()); clone.mLastMatch = null; clone.mRunningAnimator = null; clone.mViewRef = null; clone.mAnimatorListener = null; clone.initAnimatorListener(); final int tupleSize = mTuples.size(); for (int i = 0; i < tupleSize; i++) { final Tuple tuple = mTuples.get(i); final Animator animatorClone = tuple.mAnimator.clone(); animatorClone.removeListener(mAnimatorListener); clone.addState(tuple.mSpecs, animatorClone); } clone.setChangingConfigurations(getChangingConfigurations()); return clone; } catch (CloneNotSupportedException e) { throw new AssertionError("cannot clone state list animator", e); } } /** * Called by View * @hide */ public void setState(int[] state) { Tuple match = null; final int count = mTuples.size(); for (int i = 0; i < count; i++) { final Tuple tuple = mTuples.get(i); if (StateSet.stateSetMatches(tuple.mSpecs, state)) { match = tuple; break; } } if (match == mLastMatch) { return; } if (mLastMatch != null) { cancel(); } mLastMatch = match; if (match != null) { start(match); } } private void start(Tuple match) { match.mAnimator.setTarget(getTarget()); mRunningAnimator = match.mAnimator; mRunningAnimator.start(); } private void cancel() { if (mRunningAnimator != null) { mRunningAnimator.cancel(); mRunningAnimator = null; } } /** * @hide */ public ArrayList<Tuple> getTuples() { return mTuples; } /** * If there is an animation running for a recent state change, ends it. * <p> * This causes the animation to assign the end value(s) to the View. */ public void jumpToCurrentState() { if (mRunningAnimator != null) { mRunningAnimator.end(); } } /** * Return a mask of the configuration parameters for which this animator may change, requiring * that it be re-created. The default implementation returns whatever was provided through * {@link #setChangingConfigurations(int)} or 0 by default. * * @return Returns a mask of the changing configuration parameters, as defined by * {@link android.content.pm.ActivityInfo}. * * @see android.content.pm.ActivityInfo * @hide */ public @Config int getChangingConfigurations() { return mChangingConfigurations; } /** * Set a mask of the configuration parameters for which this animator may change, requiring * that it should be recreated from resources instead of being cloned. * * @param configs A mask of the changing configuration parameters, as * defined by {@link android.content.pm.ActivityInfo}. * * @see android.content.pm.ActivityInfo * @hide */ public void setChangingConfigurations(@Config int configs) { mChangingConfigurations = configs; } /** * Sets the changing configurations value to the union of the current changing configurations * and the provided configs. * This method is called while loading the animator. * @hide */ public void appendChangingConfigurations(@Config int configs) { mChangingConfigurations |= configs; } /** * Return a {@link android.content.res.ConstantState} instance that holds the shared state of * this Animator. * <p> * This constant state is used to create new instances of this animator when needed. Default * implementation creates a new {@link StateListAnimatorConstantState}. You can override this * method to provide your custom logic or return null if you don't want this animator to be * cached. * * @return The {@link android.content.res.ConstantState} associated to this Animator. * @see android.content.res.ConstantState * @see #clone() * @hide */ public ConstantState<StateListAnimator> createConstantState() { return new StateListAnimatorConstantState(this); } /** * @hide */ public static class Tuple { final int[] mSpecs; final Animator mAnimator; private Tuple(int[] specs, Animator animator) { mSpecs = specs; mAnimator = animator; } /** * @hide */ public int[] getSpecs() { return mSpecs; } /** * @hide */ public Animator getAnimator() { return mAnimator; } } /** * Creates a constant state which holds changing configurations information associated with the * given Animator. * <p> * When new instance is called, default implementation clones the Animator. */ private static class StateListAnimatorConstantState extends ConstantState<StateListAnimator> { final StateListAnimator mAnimator; @Config int mChangingConf; public StateListAnimatorConstantState(StateListAnimator animator) { mAnimator = animator; mAnimator.mConstantState = this; mChangingConf = mAnimator.getChangingConfigurations(); } @Override public @Config int getChangingConfigurations() { return mChangingConf; } @Override public StateListAnimator newInstance() { final StateListAnimator clone = mAnimator.clone(); clone.mConstantState = this; return clone; } } }