| /* |
| * Copyright (C) 2007 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 quickly and |
| * and then decelerates. |
| * |
| */ |
| @HasNativeInterpolator |
| public class DecelerateInterpolator extends BaseInterpolator implements NativeInterpolatorFactory { |
| public DecelerateInterpolator() { |
| } |
| |
| /** |
| * Constructor |
| * |
| * @param factor Degree to which the animation should be eased. Setting factor to 1.0f produces |
| * an upside-down y=x^2 parabola. Increasing factor above 1.0f exaggerates the |
| * ease-out effect (i.e., it starts even faster and ends evens slower). |
| */ |
| public DecelerateInterpolator(float factor) { |
| mFactor = factor; |
| } |
| |
| public DecelerateInterpolator(Context context, AttributeSet attrs) { |
| this(context.getResources(), context.getTheme(), attrs); |
| } |
| |
| /** @hide */ |
| public DecelerateInterpolator(Resources res, Theme theme, AttributeSet attrs) { |
| TypedArray a; |
| if (theme != null) { |
| a = theme.obtainStyledAttributes(attrs, R.styleable.DecelerateInterpolator, 0, 0); |
| } else { |
| a = res.obtainAttributes(attrs, R.styleable.DecelerateInterpolator); |
| } |
| |
| mFactor = a.getFloat(R.styleable.DecelerateInterpolator_factor, 1.0f); |
| setChangingConfiguration(a.getChangingConfigurations()); |
| a.recycle(); |
| } |
| |
| public float getInterpolation(float input) { |
| float result; |
| if (mFactor == 1.0f) { |
| result = (float)(1.0f - (1.0f - input) * (1.0f - input)); |
| } else { |
| result = (float)(1.0f - Math.pow((1.0f - input), 2 * mFactor)); |
| } |
| return result; |
| } |
| |
| private float mFactor = 1.0f; |
| |
| /** @hide */ |
| @Override |
| public long createNativeInterpolator() { |
| return NativeInterpolatorFactoryHelper.createDecelerateInterpolator(mFactor); |
| } |
| } |