/* * Copyright (C) 2007 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 com.example.android.apis.animation;import android.view.animation.Animation;import android.view.animation.Transformation;import android.graphics.Camera;import android.graphics.Matrix;/** * An animation that rotates the view on the Y axis between two specified angles. * This animation also adds a translation on the Z axis (depth) to improve the effect. */public class Rotate3dAnimation extends Animation {    private final float mFromDegrees;    private final float mToDegrees;    private final float mCenterX;    private final float mCenterY;    private final float mDepthZ;    private final boolean mReverse;    private Camera mCamera;    /**     * Creates a new 3D rotation on the Y axis. The rotation is defined by its     * start angle and its end angle. Both angles are in degrees. The rotation     * is performed around a center point on the 2D space, definied by a pair     * of X and Y coordinates, called centerX and centerY. When the animation     * starts, a translation on the Z axis (depth) is performed. The length     * of the translation can be specified, as well as whether the translation     * should be reversed in time.     *     * @param fromDegrees the start angle of the 3D rotation     * @param toDegrees the end angle of the 3D rotation     * @param centerX the X center of the 3D rotation     * @param centerY the Y center of the 3D rotation     * @param reverse true if the translation should be reversed, false otherwise     */    public Rotate3dAnimation(float fromDegrees, float toDegrees,            float centerX, float centerY, float depthZ, boolean reverse) {        mFromDegrees = fromDegrees;        mToDegrees = toDegrees;        mCenterX = centerX;        mCenterY = centerY;        mDepthZ = depthZ;        mReverse = reverse;    }    @Override    public void initialize(int width, int height, int parentWidth, int parentHeight) {        super.initialize(width, height, parentWidth, parentHeight);        mCamera = new Camera();    }    @Override    protected void applyTransformation(float interpolatedTime, Transformation t) {        final float fromDegrees = mFromDegrees;        float degrees = fromDegrees + ((mToDegrees - fromDegrees) * interpolatedTime);        final float centerX = mCenterX;        final float centerY = mCenterY;        final Camera camera = mCamera;        final Matrix matrix = t.getMatrix();        camera.save();        if (mReverse) {            camera.translate(0.0f, 0.0f, mDepthZ * interpolatedTime);        } else {            camera.translate(0.0f, 0.0f, mDepthZ * (1.0f - interpolatedTime));        }        camera.rotateY(degrees);        camera.getMatrix(matrix);        camera.restore();        matrix.preTranslate(-centerX, -centerY);        matrix.postTranslate(centerX, centerY);    }}