1/*
2 * Copyright (C) 2016 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 */
16package com.android.systemui.recents.misc;
17
18import android.animation.TypeEvaluator;
19import android.graphics.RectF;
20
21/**
22 * This evaluator can be used to perform type interpolation between <code>RectF</code> values.
23 */
24public class RectFEvaluator implements TypeEvaluator<RectF> {
25
26    private RectF mRect = new RectF();
27
28    /**
29     * This function returns the result of linearly interpolating the start and
30     * end Rect values, with <code>fraction</code> representing the proportion
31     * between the start and end values. The calculation is a simple parametric
32     * calculation on each of the separate components in the Rect objects
33     * (left, top, right, and bottom).
34     *
35     * <p>The object returned will be the <code>reuseRect</code> passed into the constructor.</p>
36     *
37     * @param fraction   The fraction from the starting to the ending values
38     * @param startValue The start Rect
39     * @param endValue   The end Rect
40     * @return A linear interpolation between the start and end values, given the
41     *         <code>fraction</code> parameter.
42     */
43    @Override
44    public RectF evaluate(float fraction, RectF startValue, RectF endValue) {
45        float left = startValue.left + ((endValue.left - startValue.left) * fraction);
46        float top = startValue.top + ((endValue.top - startValue.top) * fraction);
47        float right = startValue.right + ((endValue.right - startValue.right) * fraction);
48        float bottom = startValue.bottom + ((endValue.bottom - startValue.bottom) * fraction);
49        mRect.set(left, top, right, bottom);
50        return mRect;
51    }
52}
53