1/*
2 * Copyright (C) 2014 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;
18
19import android.animation.Animator;
20import android.animation.AnimatorListenerAdapter;
21import android.animation.ValueAnimator;
22import android.graphics.ColorMatrix;
23import android.graphics.ColorMatrixColorFilter;
24import android.graphics.Paint;
25import android.view.View;
26import android.view.animation.AnimationUtils;
27import android.view.animation.Interpolator;
28
29import com.android.systemui.statusbar.phone.NotificationPanelView;
30
31/**
32 * Helper to invert the colors of views and fade between the states.
33 */
34public class ViewInvertHelper {
35
36    private final Paint mDarkPaint = new Paint();
37    private final Interpolator mLinearOutSlowInInterpolator;
38    private final View mTarget;
39    private final ColorMatrix mMatrix = new ColorMatrix();
40    private final ColorMatrix mGrayscaleMatrix = new ColorMatrix();
41    private final long mFadeDuration;
42
43    public ViewInvertHelper(View target, long fadeDuration) {
44        mTarget = target;
45        mLinearOutSlowInInterpolator = AnimationUtils.loadInterpolator(mTarget.getContext(),
46                android.R.interpolator.linear_out_slow_in);
47        mFadeDuration = fadeDuration;
48    }
49
50    public void fade(final boolean invert, long delay) {
51        float startIntensity = invert ? 0f : 1f;
52        float endIntensity = invert ? 1f : 0f;
53        ValueAnimator animator = ValueAnimator.ofFloat(startIntensity, endIntensity);
54        animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
55            @Override
56            public void onAnimationUpdate(ValueAnimator animation) {
57                updateInvertPaint((Float) animation.getAnimatedValue());
58                mTarget.setLayerType(View.LAYER_TYPE_HARDWARE, mDarkPaint);
59            }
60        });
61        animator.addListener(new AnimatorListenerAdapter() {
62            @Override
63            public void onAnimationEnd(Animator animation) {
64                if (!invert) {
65                    mTarget.setLayerType(View.LAYER_TYPE_NONE, null);
66                }
67            }
68        });
69        animator.setDuration(mFadeDuration);
70        animator.setInterpolator(mLinearOutSlowInInterpolator);
71        animator.setStartDelay(delay);
72        animator.start();
73    }
74
75    public void update(boolean invert) {
76        if (invert) {
77            updateInvertPaint(1f);
78            mTarget.setLayerType(View.LAYER_TYPE_HARDWARE, mDarkPaint);
79        } else {
80            mTarget.setLayerType(View.LAYER_TYPE_NONE, null);
81        }
82    }
83
84    public View getTarget() {
85        return mTarget;
86    }
87
88    private void updateInvertPaint(float intensity) {
89        float components = 1 - 2 * intensity;
90        final float[] invert = {
91                components, 0f,         0f,         0f, 255f * intensity,
92                0f,         components, 0f,         0f, 255f * intensity,
93                0f,         0f,         components, 0f, 255f * intensity,
94                0f,         0f,         0f,         1f, 0f
95        };
96        mMatrix.set(invert);
97        mGrayscaleMatrix.setSaturation(1 - intensity);
98        mMatrix.preConcat(mGrayscaleMatrix);
99        mDarkPaint.setColorFilter(new ColorMatrixColorFilter(mMatrix));
100    }
101}