package com.example.android.apis.animation;import com.example.android.apis.R;import android.app.Activity;import android.os.Bundle;import android.widget.ListView;import android.widget.ArrayAdapter;import android.widget.AdapterView;import android.widget.ImageView;import android.view.View;import android.view.ViewGroup;import android.view.animation.Animation;import android.view.animation.AccelerateInterpolator;import android.view.animation.DecelerateInterpolator;/** * This sample application shows how to use layout animation and various * transformations on views. The result is a 3D transition between a * ListView and an ImageView. When the user clicks the list, it flips to * show the picture. When the user clicks the picture, it flips to show the * list. The animation is made of two smaller animations: the first half * rotates the list by 90 degrees on the Y axis and the second half rotates * the picture by 90 degrees on the Y axis. When the first half finishes, the * list is made invisible and the picture is set visible. */public class Transition3d extends Activity implements        AdapterView.OnItemClickListener, View.OnClickListener {    private ListView mPhotosList;    private ViewGroup mContainer;    private ImageView mImageView;    // Names of the photos we show in the list    private static final String[] PHOTOS_NAMES = new String[] {            "Lyon",            "Livermore",            "Tahoe Pier",            "Lake Tahoe",            "Grand Canyon",            "Bodie"    };    // Resource identifiers for the photos we want to display    private static final int[] PHOTOS_RESOURCES = new int[] {            R.drawable.photo1,            R.drawable.photo2,            R.drawable.photo3,            R.drawable.photo4,            R.drawable.photo5,            R.drawable.photo6    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.animations_main_screen);        mPhotosList = (ListView) findViewById(android.R.id.list);        mImageView = (ImageView) findViewById(R.id.picture);        mContainer = (ViewGroup) findViewById(R.id.container);        // Prepare the ListView        final ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,                android.R.layout.simple_list_item_1, PHOTOS_NAMES);        mPhotosList.setAdapter(adapter);        mPhotosList.setOnItemClickListener(this);        // Prepare the ImageView        mImageView.setClickable(true);        mImageView.setFocusable(true);        mImageView.setOnClickListener(this);        // Since we are caching large views, we want to keep their cache        // between each animation        mContainer.setPersistentDrawingCache(ViewGroup.PERSISTENT_ANIMATION_CACHE);    }    /**     * Setup a new 3D rotation on the container view.     *     * @param position the item that was clicked to show a picture, or -1 to show the list     * @param start the start angle at which the rotation must begin     * @param end the end angle of the rotation     */    private void applyRotation(int position, float start, float end) {        // Find the center of the container        final float centerX = mContainer.getWidth() / 2.0f;        final float centerY = mContainer.getHeight() / 2.0f;        // Create a new 3D rotation with the supplied parameter        // The animation listener is used to trigger the next animation        final Rotate3dAnimation rotation =                new Rotate3dAnimation(start, end, centerX, centerY, 310.0f, true);        rotation.setDuration(500);        rotation.setFillAfter(true);        rotation.setInterpolator(new AccelerateInterpolator());        rotation.setAnimationListener(new DisplayNextView(position));        mContainer.startAnimation(rotation);    }    public void onItemClick(AdapterView parent, View v, int position, long id) {        // Pre-load the image then start the animation        mImageView.setImageResource(PHOTOS_RESOURCES[position]);        applyRotation(position, 0, 90);    }    public void onClick(View v) {        applyRotation(-1, 180, 90);    }    /**     * This class listens for the end of the first half of the animation.     * It then posts a new action that effectively swaps the views when the container     * is rotated 90 degrees and thus invisible.     */    private final class DisplayNextView implements Animation.AnimationListener {        private final int mPosition;        private DisplayNextView(int position) {            mPosition = position;        }        public void onAnimationStart(Animation animation) {        }        public void onAnimationEnd(Animation animation) {            mContainer.post(new SwapViews(mPosition));        }        public void onAnimationRepeat(Animation animation) {        }    }    /**     * This class is responsible for swapping the views and start the second     * half of the animation.     */    private final class SwapViews implements Runnable {        private final int mPosition;        public SwapViews(int position) {            mPosition = position;        }        public void run() {            final float centerX = mContainer.getWidth() / 2.0f;            final float centerY = mContainer.getHeight() / 2.0f;            Rotate3dAnimation rotation;                        if (mPosition > -1) {                mPhotosList.setVisibility(View.GONE);                mImageView.setVisibility(View.VISIBLE);                mImageView.requestFocus();                rotation = new Rotate3dAnimation(90, 180, centerX, centerY, 310.0f, false);            } else {                mImageView.setVisibility(View.GONE);                mPhotosList.setVisibility(View.VISIBLE);                mPhotosList.requestFocus();                rotation = new Rotate3dAnimation(90, 0, centerX, centerY, 310.0f, false);            }            rotation.setDuration(500);            rotation.setFillAfter(true);            rotation.setInterpolator(new DecelerateInterpolator());            mContainer.startAnimation(rotation);        }    }}