ScrimController.java revision ecc798e6668046c2f67cf30c6ab1db2eba80cab1 
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.statusbar.phone;
18
19import android.animation.Animator;
20import android.animation.AnimatorListenerAdapter;
21import android.animation.ValueAnimator;
22import android.content.res.Resources;
23import android.graphics.Color;
24import android.graphics.drawable.ColorDrawable;
25import android.view.View;
26import android.view.ViewTreeObserver;
27import android.view.animation.AccelerateInterpolator;
28import android.view.animation.AnimationUtils;
29import android.view.animation.DecelerateInterpolator;
30import android.view.animation.Interpolator;
31import android.view.animation.LinearInterpolator;
32
33/**
34 * Controls both the scrim behind the notifications and in front of the notifications (when a
35 * security method gets shown).
36 */
37public class ScrimController implements ViewTreeObserver.OnPreDrawListener {
38
39    private static final float SCRIM_BEHIND_ALPHA = 0.62f;
40    private static final float SCRIM_BEHIND_ALPHA_KEYGUARD = 0.5f;
41    private static final float SCRIM_IN_FRONT_ALPHA = 0.75f;
42    private static final long ANIMATION_DURATION = 220;
43
44    private final View mScrimBehind;
45    private final View mScrimInFront;
46    private final UnlockMethodCache mUnlockMethodCache;
47
48    private boolean mKeyguardShowing;
49    private float mFraction;
50
51    private boolean mDarkenWhileDragging;
52    private boolean mBouncerShowing;
53    private boolean mAnimateChange;
54    private boolean mUpdatePending;
55
56    private final Interpolator mInterpolator = new DecelerateInterpolator();
57
58    public ScrimController(View scrimBehind, View scrimInFront) {
59        mScrimBehind = scrimBehind;
60        mScrimInFront = scrimInFront;
61        mUnlockMethodCache = UnlockMethodCache.getInstance(scrimBehind.getContext());
62    }
63
64    public void setKeyguardShowing(boolean showing) {
65        mKeyguardShowing = showing;
66        scheduleUpdate();
67    }
68
69    public void onTrackingStarted() {
70        mDarkenWhileDragging = !mUnlockMethodCache.isMethodInsecure();
71    }
72
73    public void setPanelExpansion(float fraction) {
74        mFraction = fraction;
75        scheduleUpdate();
76    }
77
78    public void setBouncerShowing(boolean showing) {
79        mBouncerShowing = showing;
80        mAnimateChange = true;
81        scheduleUpdate();
82    }
83
84    private void scheduleUpdate() {
85        if (mUpdatePending) return;
86        mScrimBehind.getViewTreeObserver().addOnPreDrawListener(this);
87        mUpdatePending = true;
88    }
89
90    private void updateScrims() {
91        if (!mKeyguardShowing) {
92            updateScrimNormal();
93            setScrimInFrontColor(0);
94        } else {
95            updateScrimKeyguard();
96        }
97        mAnimateChange = false;
98    }
99
100    private void updateScrimKeyguard() {
101        if (mBouncerShowing) {
102            setScrimInFrontColor(SCRIM_IN_FRONT_ALPHA);
103            setScrimBehindColor(0f);
104        } else if (mDarkenWhileDragging) {
105            float behindFraction = Math.max(0, Math.min(mFraction, 1));
106            float fraction = 1 - behindFraction;
107            setScrimInFrontColor(fraction * SCRIM_IN_FRONT_ALPHA);
108            setScrimBehindColor(behindFraction * SCRIM_BEHIND_ALPHA_KEYGUARD);
109        } else {
110            setScrimInFrontColor(0f);
111            setScrimBehindColor(SCRIM_BEHIND_ALPHA_KEYGUARD);
112        }
113    }
114
115    private void updateScrimNormal() {
116        float frac = mFraction;
117        // let's start this 20% of the way down the screen
118        frac = frac * 1.2f - 0.2f;
119        if (frac <= 0) {
120            setScrimBehindColor(0);
121        } else {
122            // woo, special effects
123            final float k = (float)(1f-0.5f*(1f-Math.cos(3.14159f * Math.pow(1f-frac, 2f))));
124            setScrimBehindColor(k * SCRIM_BEHIND_ALPHA);
125        }
126    }
127
128    private void setScrimBehindColor(float alpha) {
129        setScrimColor(mScrimBehind, alpha);
130    }
131
132    private void setScrimInFrontColor(float alpha) {
133        setScrimColor(mScrimInFront, alpha);
134        if (alpha == 0f) {
135            mScrimInFront.setClickable(false);
136        } else {
137
138            // Eat touch events.
139            mScrimInFront.setClickable(true);
140        }
141    }
142
143    private void setScrimColor(View scrim, float alpha) {
144        int color = Color.argb((int) (alpha * 255), 0, 0, 0);
145        if (mAnimateChange) {
146            startScrimAnimation(scrim, color);
147        } else {
148            scrim.setBackgroundColor(color);
149        }
150    }
151
152    private void startScrimAnimation(final View scrim, int targetColor) {
153        int current = getBackgroundAlpha(scrim);
154        int target = Color.alpha(targetColor);
155        if (current == targetColor) {
156            return;
157        }
158        ValueAnimator anim = ValueAnimator.ofInt(current, target);
159        anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
160            @Override
161            public void onAnimationUpdate(ValueAnimator animation) {
162                int value = (int) animation.getAnimatedValue();
163                scrim.setBackgroundColor(Color.argb(value, 0, 0, 0));
164            }
165        });
166        anim.setInterpolator(mInterpolator);
167        anim.setDuration(ANIMATION_DURATION);
168        anim.start();
169    }
170
171    private int getBackgroundAlpha(View scrim) {
172        if (scrim.getBackground() instanceof ColorDrawable) {
173            ColorDrawable drawable = (ColorDrawable) scrim.getBackground();
174            return Color.alpha(drawable.getColor());
175        } else {
176            return 0;
177        }
178    }
179
180    @Override
181    public boolean onPreDraw() {
182        mScrimBehind.getViewTreeObserver().removeOnPreDrawListener(this);
183        mUpdatePending = false;
184        updateScrims();
185        return true;
186    }
187}
188