1/* 2 * Copyright (C) 2011 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 17package com.android.gallery3d.ui; 18 19import com.android.gallery3d.common.Utils; 20 21// FadeTexture is a texture which fades the given texture along the time. 22public abstract class FadeTexture implements Texture { 23 @SuppressWarnings("unused") 24 private static final String TAG = "FadeTexture"; 25 26 // The duration of the fading animation in milliseconds 27 public static final int DURATION = 180; 28 29 private final long mStartTime; 30 private final int mWidth; 31 private final int mHeight; 32 private final boolean mIsOpaque; 33 private boolean mIsAnimating; 34 35 public FadeTexture(int width, int height, boolean opaque) { 36 mWidth = width; 37 mHeight = height; 38 mIsOpaque = opaque; 39 mStartTime = now(); 40 mIsAnimating = true; 41 } 42 43 @Override 44 public void draw(GLCanvas canvas, int x, int y) { 45 draw(canvas, x, y, mWidth, mHeight); 46 } 47 48 @Override 49 public boolean isOpaque() { 50 return mIsOpaque; 51 } 52 53 @Override 54 public int getWidth() { 55 return mWidth; 56 } 57 58 @Override 59 public int getHeight() { 60 return mHeight; 61 } 62 63 public boolean isAnimating() { 64 if (mIsAnimating) { 65 if (now() - mStartTime >= DURATION) { 66 mIsAnimating = false; 67 } 68 } 69 return mIsAnimating; 70 } 71 72 protected float getRatio() { 73 float r = (float)(now() - mStartTime) / DURATION; 74 return Utils.clamp(1.0f - r, 0.0f, 1.0f); 75 } 76 77 private long now() { 78 return AnimationTime.get(); 79 } 80} 81