1 /* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.example.android.apis.animation; 18 19 import android.view.animation.Animation; 20 import android.view.animation.Transformation; 21 import android.graphics.Camera; 22 import android.graphics.Matrix; 23 24 /** 25 * An animation that rotates the view on the Y axis between two specified angles. 26 * This animation also adds a translation on the Z axis (depth) to improve the effect. 27 */ 28 public class Rotate3dAnimation extends Animation { 29 private final float mFromDegrees; 30 private final float mToDegrees; 31 private final float mCenterX; 32 private final float mCenterY; 33 private final float mDepthZ; 34 private final boolean mReverse; 35 private Camera mCamera; 36 37 /** 38 * Creates a new 3D rotation on the Y axis. The rotation is defined by its 39 * start angle and its end angle. Both angles are in degrees. The rotation 40 * is performed around a center point on the 2D space, definied by a pair 41 * of X and Y coordinates, called centerX and centerY. When the animation 42 * starts, a translation on the Z axis (depth) is performed. The length 43 * of the translation can be specified, as well as whether the translation 44 * should be reversed in time. 45 * 46 * @param fromDegrees the start angle of the 3D rotation 47 * @param toDegrees the end angle of the 3D rotation 48 * @param centerX the X center of the 3D rotation 49 * @param centerY the Y center of the 3D rotation 50 * @param reverse true if the translation should be reversed, false otherwise 51 */ Rotate3dAnimation(float fromDegrees, float toDegrees, float centerX, float centerY, float depthZ, boolean reverse)52 public Rotate3dAnimation(float fromDegrees, float toDegrees, 53 float centerX, float centerY, float depthZ, boolean reverse) { 54 mFromDegrees = fromDegrees; 55 mToDegrees = toDegrees; 56 mCenterX = centerX; 57 mCenterY = centerY; 58 mDepthZ = depthZ; 59 mReverse = reverse; 60 } 61 62 @Override initialize(int width, int height, int parentWidth, int parentHeight)63 public void initialize(int width, int height, int parentWidth, int parentHeight) { 64 super.initialize(width, height, parentWidth, parentHeight); 65 mCamera = new Camera(); 66 } 67 68 @Override applyTransformation(float interpolatedTime, Transformation t)69 protected void applyTransformation(float interpolatedTime, Transformation t) { 70 final float fromDegrees = mFromDegrees; 71 float degrees = fromDegrees + ((mToDegrees - fromDegrees) * interpolatedTime); 72 73 final float centerX = mCenterX; 74 final float centerY = mCenterY; 75 final Camera camera = mCamera; 76 77 final Matrix matrix = t.getMatrix(); 78 79 camera.save(); 80 if (mReverse) { 81 camera.translate(0.0f, 0.0f, mDepthZ * interpolatedTime); 82 } else { 83 camera.translate(0.0f, 0.0f, mDepthZ * (1.0f - interpolatedTime)); 84 } 85 camera.rotateY(degrees); 86 camera.getMatrix(matrix); 87 camera.restore(); 88 89 matrix.preTranslate(-centerX, -centerY); 90 matrix.postTranslate(centerX, centerY); 91 } 92 } 93