1/*
2 * Copyright (C) 2017 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.systemui.recents.views;
18
19import android.view.animation.PathInterpolator;
20
21/**
22 * A helper interpolator to stagger the entrance animation in recents by offsetting the start time
23 */
24public class RecentsEntrancePathInterpolator extends PathInterpolator {
25    final float mStartOffsetFraction;
26
27    /**
28     * Create an interpolator for a cubic Bezier curve with an offset play time. The end points
29     * <code>(0, 0)</code> and <code>(1, 1)</code> are assumed.
30     *
31     * @param controlX1 The x coordinate of the first control point of the cubic Bezier.
32     * @param controlY1 The y coordinate of the first control point of the cubic Bezier.
33     * @param controlX2 The x coordinate of the second control point of the cubic Bezier.
34     * @param controlY2 The y coordinate of the second control point of the cubic Bezier.
35     * @param startOffsetFraction The fraction from 0 to 1 to start the animation from
36     */
37    public RecentsEntrancePathInterpolator(float controlX1, float controlY1, float controlX2,
38            float controlY2, float startOffsetFraction) {
39        super(controlX1, controlY1, controlX2, controlY2);
40        mStartOffsetFraction = startOffsetFraction;
41    }
42
43    @Override
44    public float getInterpolation(float t) {
45        return super.getInterpolation(t + mStartOffsetFraction);
46    }
47}
48