| /* |
| * Copyright (C) 2006 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 android.view.animation; |
| |
| import android.content.Context; |
| import android.content.res.Resources; |
| import android.content.res.Resources.Theme; |
| import android.content.res.TypedArray; |
| import android.util.AttributeSet; |
| |
| import com.android.internal.R; |
| import com.android.internal.view.animation.HasNativeInterpolator; |
| import com.android.internal.view.animation.NativeInterpolatorFactory; |
| import com.android.internal.view.animation.NativeInterpolatorFactoryHelper; |
| |
| /** |
| * An interpolator where the rate of change starts out slowly and |
| * and then accelerates. |
| * |
| */ |
| @HasNativeInterpolator |
| public class AccelerateInterpolator extends BaseInterpolator implements NativeInterpolatorFactory { |
| private final float mFactor; |
| private final double mDoubleFactor; |
| |
| public AccelerateInterpolator() { |
| mFactor = 1.0f; |
| mDoubleFactor = 2.0; |
| } |
| |
| /** |
| * Constructor |
| * |
| * @param factor Degree to which the animation should be eased. Seting |
| * factor to 1.0f produces a y=x^2 parabola. Increasing factor above |
| * 1.0f exaggerates the ease-in effect (i.e., it starts even |
| * slower and ends evens faster) |
| */ |
| public AccelerateInterpolator(float factor) { |
| mFactor = factor; |
| mDoubleFactor = 2 * mFactor; |
| } |
| |
| public AccelerateInterpolator(Context context, AttributeSet attrs) { |
| this(context.getResources(), context.getTheme(), attrs); |
| } |
| |
| /** @hide */ |
| public AccelerateInterpolator(Resources res, Theme theme, AttributeSet attrs) { |
| TypedArray a; |
| if (theme != null) { |
| a = theme.obtainStyledAttributes(attrs, R.styleable.AccelerateInterpolator, 0, 0); |
| } else { |
| a = res.obtainAttributes(attrs, R.styleable.AccelerateInterpolator); |
| } |
| |
| mFactor = a.getFloat(R.styleable.AccelerateInterpolator_factor, 1.0f); |
| mDoubleFactor = 2 * mFactor; |
| setChangingConfiguration(a.getChangingConfigurations()); |
| a.recycle(); |
| } |
| |
| public float getInterpolation(float input) { |
| if (mFactor == 1.0f) { |
| return input * input; |
| } else { |
| return (float)Math.pow(input, mDoubleFactor); |
| } |
| } |
| |
| /** @hide */ |
| @Override |
| public long createNativeInterpolator() { |
| return NativeInterpolatorFactoryHelper.createAccelerateInterpolator(mFactor); |
| } |
| } |