1/*
2 * Copyright (C) 2013 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 android.animation;
17
18import android.graphics.Rect;
19
20/**
21 * This evaluator can be used to perform type interpolation between <code>Rect</code> values.
22 */
23public class RectEvaluator implements TypeEvaluator<Rect> {
24
25    /**
26     * This function returns the result of linearly interpolating the start and
27     * end Rect values, with <code>fraction</code> representing the proportion
28     * between the start and end values. The calculation is a simple parametric
29     * calculation on each of the separate components in the Rect objects
30     * (left, top, right, and bottom).
31     *
32     * @param fraction   The fraction from the starting to the ending values
33     * @param startValue The start Rect
34     * @param endValue   The end Rect
35     * @return A linear interpolation between the start and end values, given the
36     *         <code>fraction</code> parameter.
37     */
38    @Override
39    public Rect evaluate(float fraction, Rect startValue, Rect endValue) {
40        return new Rect(startValue.left + (int)((endValue.left - startValue.left) * fraction),
41                startValue.top + (int)((endValue.top - startValue.top) * fraction),
42                startValue.right + (int)((endValue.right - startValue.right) * fraction),
43                startValue.bottom + (int)((endValue.bottom - startValue.bottom) * fraction));
44    }
45}
46