1 /* 2 * Copyright (C) 2009 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.cooliris.media; 18 19 import android.util.FloatMath; 20 21 public final class FloatAnim { 22 private float mValue; 23 private float mDelta; 24 private float mDuration; 25 private long mStartTime; 26 27 public FloatAnim(float value) { 28 mValue = value; 29 mStartTime = 0; 30 } 31 32 public boolean isAnimating() { 33 return mStartTime != 0; 34 } 35 36 public float getTimeRemaining(long currentTime) { 37 float duration = (currentTime - mStartTime) * 0.001f; 38 if (mDuration > duration) // CR: braces 39 return mDuration - duration; 40 else 41 return 0.0f; 42 } 43 44 public float getValue(long currentTime) { 45 if (mStartTime == 0) { 46 return mValue; 47 } else { 48 return getInterpolatedValue(currentTime); 49 } 50 } 51 52 public void animateValue(float value, float duration, long currentTime) { 53 mDelta = getValue(currentTime) - value; 54 mValue = value; 55 mDuration = duration; 56 mStartTime = currentTime; 57 } 58 59 public void setValue(float value) { 60 mValue = value; 61 mStartTime = 0; 62 } 63 64 public void skip() { 65 mStartTime = 0; 66 } 67 68 private float getInterpolatedValue(long currentTime) { 69 float ratio = (float) (currentTime - mStartTime) * 0.001f / mDuration; 70 if (ratio >= 1f) { // CR: 1.0f 71 mStartTime = 0; 72 return mValue; 73 } else { 74 ratio = 0.5f - 0.5f * FloatMath.cos(ratio * 3.14159265f); // CR: 75 // (float)Math.PI 76 return mValue + (1f - ratio) * mDelta; 77 } 78 } 79 } 80