1/*
2 * Copyright (C) 2016 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.incallui.answerproximitysensor;
18
19import android.util.ArraySet;
20import java.util.Set;
21
22/**
23 * Stores a fake screen on/off state for the {@link InCallActivity}. If InCallActivity see the state
24 * is off, it will draw a black view over the activity pretending the screen is off.
25 *
26 * <p>If the screen is already touched when the screen is turned on, the OS behavior is sending a
27 * new DOWN event once the point started moving and then behave as a normal gesture. To prevent
28 * accidental answer/rejects, touches that started when the screen is off should be ignored.
29 *
30 * <p>a bug on certain devices with N-DR1, if the screen is already touched when the screen is
31 * turned on, a "DOWN MOVE UP" will be sent for each movement before the touch is actually released.
32 * These events is hard to discern from other normal events, and keeping the screen on reduces its'
33 * probability.
34 */
35public class PseudoScreenState {
36
37  /** Notifies when the on state has changed. */
38  public interface StateChangedListener {
39    void onPseudoScreenStateChanged(boolean isOn);
40  }
41
42  private final Set<StateChangedListener> listeners = new ArraySet<>();
43
44  private boolean on = true;
45
46  public boolean isOn() {
47    return on;
48  }
49
50  public void setOn(boolean value) {
51    if (on != value) {
52      on = value;
53      for (StateChangedListener listener : listeners) {
54        listener.onPseudoScreenStateChanged(on);
55      }
56    }
57  }
58
59  public void addListener(StateChangedListener listener) {
60    listeners.add(listener);
61  }
62
63  public void removeListener(StateChangedListener listener) {
64    listeners.remove(listener);
65  }
66}
67