【实例简介】

【实例截图】

【核心代码】

package com.flavienlaurent.notboringactionbar;

import android.animation.Animator;

import android.animation.AnimatorListenerAdapter;

import android.animation.AnimatorSet;

import android.animation.ObjectAnimator;

import android.content.Context;

import android.os.Handler;

import android.util.AttributeSet;

import android.util.Log;

import android.view.View;

import android.view.ViewPropertyAnimator;

import android.widget.FrameLayout;

import android.widget.ImageView;

import java.util.Random;

/**

* Created by f.laurent on 21/11/13.

*/

public class KenBurnsView extends FrameLayout {

private static final String TAG = "KenBurnsView";

private final Handler mHandler;

private int[] mResourceIds;

private ImageView[] mImageViews;

private int mActiveImageIndex = -1;

private final Random random = new Random();

private int mSwapMs = 10000;

private int mFadeInOutMs = 400;

private float maxScaleFactor = 1.5F;

private float minScaleFactor = 1.2F;

private Runnable mSwapImageRunnable = new Runnable() {

@Override

public void run() {

swapImage();

mHandler.postDelayed(mSwapImageRunnable, mSwapMs - mFadeInOutMs*2);

}

};

public KenBurnsView(Context context) {

this(context, null);

}

public KenBurnsView(Context context, AttributeSet attrs) {

this(context, attrs, 0);

}

public KenBurnsView(Context context, AttributeSet attrs, int defStyle) {

super(context, attrs, defStyle);

mHandler = new Handler();

}

public void setResourceIds(int... resourceIds) {

mResourceIds = resourceIds;

fillImageViews();

}

private void swapImage() {

Log.d(TAG, "swapImage active=" mActiveImageIndex);

if(mActiveImageIndex == -1) {

mActiveImageIndex = 1;

animate(mImageViews[mActiveImageIndex]);

return;

}

int inactiveIndex = mActiveImageIndex;

mActiveImageIndex = (1 mActiveImageIndex) % mImageViews.length;

Log.d(TAG, "new active=" mActiveImageIndex);

final ImageView activeImageView = mImageViews[mActiveImageIndex];

activeImageView.setAlpha(0.0f);

ImageView inactiveImageView = mImageViews[inactiveIndex];

animate(activeImageView);

AnimatorSet animatorSet = new AnimatorSet();

animatorSet.setDuration(mFadeInOutMs);

animatorSet.playTogether(

ObjectAnimator.ofFloat(inactiveImageView, "alpha", 1.0f, 0.0f),

ObjectAnimator.ofFloat(activeImageView, "alpha", 0.0f, 1.0f)

);

animatorSet.start();

}

private void start(View view, long duration, float fromScale, float toScale, float fromTranslationX, float fromTranslationY, float toTranslationX, float toTranslationY) {

view.setScaleX(fromScale);

view.setScaleY(fromScale);

view.setTranslationX(fromTranslationX);

view.setTranslationY(fromTranslationY);

ViewPropertyAnimator propertyAnimator = view.animate().translationX(toTranslationX).translationY(toTranslationY).scaleX(toScale).scaleY(toScale).setDuration(duration);

propertyAnimator.start();

Log.d(TAG, "starting Ken Burns animation " propertyAnimator);

}

private float pickScale() {

return this.minScaleFactor this.random.nextFloat() * (this.maxScaleFactor - this.minScaleFactor);

}

private float pickTranslation(int value, float ratio) {

return value * (ratio - 1.0f) * (this.random.nextFloat() - 0.5f);

}

public void animate(View view) {

float fromScale = pickScale();

float toScale = pickScale();

float fromTranslationX = pickTranslation(view.getWidth(), fromScale);

float fromTranslationY = pickTranslation(view.getHeight(), fromScale);

float toTranslationX = pickTranslation(view.getWidth(), toScale);

float toTranslationY = pickTranslation(view.getHeight(), toScale);

start(view, this.mSwapMs, fromScale, toScale, fromTranslationX, fromTranslationY, toTranslationX, toTranslationY);

}

@Override

protected void onAttachedToWindow() {

super.onAttachedToWindow();

startKenBurnsAnimation();

}

@Override

protected void onDetachedFromWindow() {

super.onDetachedFromWindow();

mHandler.removeCallbacks(mSwapImageRunnable);

}

private void startKenBurnsAnimation() {

mHandler.post(mSwapImageRunnable);

}

@Override

protected void onFinishInflate() {

super.onFinishInflate();

View view = inflate(getContext(), R.layout.view_kenburns, this);

mImageViews = new ImageView[2];

mImageViews[0] = (ImageView) view.findViewById(R.id.image0);

mImageViews[1] = (ImageView) view.findViewById(R.id.image1);

}

private void fillImageViews() {

for (int i = 0; i < mImageViews.length; i ) {

mImageViews[i].setImageResource(mResourceIds[i]);

}

}

}