AbRotate3dAnimation.java

/*
 * Copyright (C) 2012 www.amsoft.cn
 * 
 * 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.ab.view.app;

import android.view.animation.Animation;
import android.view.animation.Transformation;
import android.graphics.Camera;
import android.graphics.Matrix;

// TODO: Auto-generated Javadoc

/**
 * © 2012 amsoft.cn
 * 名称：AbRotate3dAnimation.java 
 * 描述： 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.
 *
 * @author 还如一梦中
 * @version v1.0
 * @date：2013-8-23 下午2:03:29
 */
public class AbRotate3dAnimation extends Animation {
    
    /** The m from degrees. */
    private final float mFromDegrees;
    
    /** The m to degrees. */
    private final float mToDegrees;
    
    /** The m center x. */
    private final float mCenterX;
    
    /** The m center y. */
    private final float mCenterY;
    
    /** The m depth z. */
    private final float mDepthZ;
    
    /** The m reverse. */
    private final boolean mReverse;
    
    /** The m camera. */
    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 depthZ the depth z
     * @param reverse true if the translation should be reversed, false otherwise
     */
    public AbRotate3dAnimation(float fromDegrees, float toDegrees,
            float centerX, float centerY, float depthZ, boolean reverse) {
        mFromDegrees = fromDegrees;
        mToDegrees = toDegrees;
        mCenterX = centerX;
        mCenterY = centerY;
        mDepthZ = depthZ;
        mReverse = reverse;
    }

    /* (non-Javadoc)
     * @see android.view.animation.Animation#initialize(int, int, int, int)
     */
    @Override
    public void initialize(int width, int height, int parentWidth, int parentHeight) {
        super.initialize(width, height, parentWidth, parentHeight);
        mCamera = new Camera();
    }

    /* (non-Javadoc)
     * @see android.view.animation.Animation#applyTransformation(float, android.view.animation.Transformation)
     */
    @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);
    }
}