1/*
2 * Copyright (C) 2012 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.gallery3d.ui;
18
19import android.view.animation.AccelerateDecelerateInterpolator;
20import android.view.animation.AccelerateInterpolator;
21import android.view.animation.DecelerateInterpolator;
22import android.view.animation.Interpolator;
23
24public class CaptureAnimation {
25    // The amount of change for zooming out.
26    private static final float ZOOM_DELTA = 0.2f;
27    // Pre-calculated value for convenience.
28    private static final float ZOOM_IN_BEGIN = 1f - ZOOM_DELTA;
29
30    private static final Interpolator sZoomOutInterpolator =
31            new DecelerateInterpolator();
32    private static final Interpolator sZoomInInterpolator =
33            new AccelerateInterpolator();
34    private static final Interpolator sSlideInterpolator =
35        new AccelerateDecelerateInterpolator();
36
37    // Calculate the slide factor based on the give time fraction.
38    public static float calculateSlide(float fraction) {
39        return sSlideInterpolator.getInterpolation(fraction);
40    }
41
42    // Calculate the scale factor based on the given time fraction.
43    public static float calculateScale(float fraction) {
44        float value;
45        if (fraction <= 0.5f) {
46            // Zoom in for the beginning.
47            value = 1f - ZOOM_DELTA *
48                    sZoomOutInterpolator.getInterpolation(fraction * 2);
49        } else {
50            // Zoom out for the ending.
51            value = ZOOM_IN_BEGIN + ZOOM_DELTA *
52                    sZoomInInterpolator.getInterpolation((fraction - 0.5f) * 2f);
53        }
54        return value;
55    }
56}
57