ScrimController.java revision 2fbad7b6a724cf0a5b98b66fe639d58f5ab10af3 
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    private boolean mExpanding;
56
57    private final Interpolator mInterpolator = new DecelerateInterpolator();
58
59    public ScrimController(View scrimBehind, View scrimInFront) {
60        mScrimBehind = scrimBehind;
61        mScrimInFront = scrimInFront;
62        mUnlockMethodCache = UnlockMethodCache.getInstance(scrimBehind.getContext());
63    }
64
65    public void setKeyguardShowing(boolean showing) {
66        mKeyguardShowing = showing;
67        scheduleUpdate();
68    }
69
70    public void onTrackingStarted() {
71        mExpanding = true;
72        mDarkenWhileDragging = !mUnlockMethodCache.isMethodInsecure();
73    }
74
75    public void onExpandingFinished() {
76        mExpanding = false;
77    }
78
79    public void setPanelExpansion(float fraction) {
80        mFraction = fraction;
81        scheduleUpdate();
82    }
83
84    public void setBouncerShowing(boolean showing) {
85        mBouncerShowing = showing;
86        mAnimateChange = !mExpanding;
87        scheduleUpdate();
88    }
89
90    private void scheduleUpdate() {
91        if (mUpdatePending) return;
92        mScrimBehind.getViewTreeObserver().addOnPreDrawListener(this);
93        mUpdatePending = true;
94    }
95
96    private void updateScrims() {
97        if (!mKeyguardShowing) {
98            updateScrimNormal();
99            setScrimInFrontColor(0);
100        } else {
101            updateScrimKeyguard();
102        }
103        mAnimateChange = false;
104    }
105
106    private void updateScrimKeyguard() {
107        if (mExpanding && mDarkenWhileDragging) {
108            float behindFraction = Math.max(0, Math.min(mFraction, 1));
109            float fraction = 1 - behindFraction;
110            setScrimInFrontColor(fraction * SCRIM_IN_FRONT_ALPHA);
111            setScrimBehindColor(behindFraction * SCRIM_BEHIND_ALPHA_KEYGUARD);
112        } else if (mBouncerShowing) {
113            setScrimInFrontColor(SCRIM_IN_FRONT_ALPHA);
114            setScrimBehindColor(0f);
115        } else {
116            setScrimInFrontColor(0f);
117            setScrimBehindColor(SCRIM_BEHIND_ALPHA_KEYGUARD);
118        }
119    }
120
121    private void updateScrimNormal() {
122        float frac = mFraction;
123        // let's start this 20% of the way down the screen
124        frac = frac * 1.2f - 0.2f;
125        if (frac <= 0) {
126            setScrimBehindColor(0);
127        } else {
128            // woo, special effects
129            final float k = (float)(1f-0.5f*(1f-Math.cos(3.14159f * Math.pow(1f-frac, 2f))));
130            setScrimBehindColor(k * SCRIM_BEHIND_ALPHA);
131        }
132    }
133
134    private void setScrimBehindColor(float alpha) {
135        setScrimColor(mScrimBehind, alpha);
136    }
137
138    private void setScrimInFrontColor(float alpha) {
139        setScrimColor(mScrimInFront, alpha);
140        if (alpha == 0f) {
141            mScrimInFront.setClickable(false);
142        } else {
143
144            // Eat touch events.
145            mScrimInFront.setClickable(true);
146        }
147    }
148
149    private void setScrimColor(View scrim, float alpha) {
150        int color = Color.argb((int) (alpha * 255), 0, 0, 0);
151        if (mAnimateChange) {
152            startScrimAnimation(scrim, color);
153        } else {
154            scrim.setBackgroundColor(color);
155        }
156    }
157
158    private void startScrimAnimation(final View scrim, int targetColor) {
159        int current = getBackgroundAlpha(scrim);
160        int target = Color.alpha(targetColor);
161        if (current == targetColor) {
162            return;
163        }
164        ValueAnimator anim = ValueAnimator.ofInt(current, target);
165        anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
166            @Override
167            public void onAnimationUpdate(ValueAnimator animation) {
168                int value = (int) animation.getAnimatedValue();
169                scrim.setBackgroundColor(Color.argb(value, 0, 0, 0));
170            }
171        });
172        anim.setInterpolator(mInterpolator);
173        anim.setDuration(ANIMATION_DURATION);
174        anim.start();
175    }
176
177    private int getBackgroundAlpha(View scrim) {
178        if (scrim.getBackground() instanceof ColorDrawable) {
179            ColorDrawable drawable = (ColorDrawable) scrim.getBackground();
180            return Color.alpha(drawable.getColor());
181        } else {
182            return 0;
183        }
184    }
185
186    @Override
187    public boolean onPreDraw() {
188        mScrimBehind.getViewTreeObserver().removeOnPreDrawListener(this);
189        mUpdatePending = false;
190        updateScrims();
191        return true;
192    }
193}
194