1 /*
2  * Copyright (C) 2015 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 package com.android.tv.ui;
17 
18 import android.os.Message;
19 import android.support.annotation.NonNull;
20 import androidx.leanback.widget.VerticalGridView;
21 import android.util.Log;
22 import android.view.KeyEvent;
23 import android.view.View;
24 import com.android.tv.common.WeakHandler;
25 
26 /** Listener to make focus change faster over time. */
27 public class OnRepeatedKeyInterceptListener implements VerticalGridView.OnKeyInterceptListener {
28     private static final String TAG = "OnRepeatedKeyListener";
29     private static final boolean DEBUG = false;
30 
31     private static final int[] THRESHOLD_FAST_FOCUS_CHANGE_TIME_MS = {2000, 5000};
32     private static final int[] MAX_SKIPPED_VIEW_COUNT = {1, 4};
33     private static final int MSG_MOVE_FOCUS = 1000;
34 
35     private final VerticalGridView mView;
36     private final MyHandler mHandler = new MyHandler(this);
37     private int mDirection;
38     private boolean mFocusAccelerated;
39     private long mRepeatedKeyInterval;
40 
OnRepeatedKeyInterceptListener(VerticalGridView view)41     public OnRepeatedKeyInterceptListener(VerticalGridView view) {
42         mView = view;
43     }
44 
isFocusAccelerated()45     public boolean isFocusAccelerated() {
46         return mFocusAccelerated;
47     }
48 
49     @Override
onInterceptKeyEvent(KeyEvent event)50     public boolean onInterceptKeyEvent(KeyEvent event) {
51         mHandler.removeMessages(MSG_MOVE_FOCUS);
52         if (event.getKeyCode() != KeyEvent.KEYCODE_DPAD_UP
53                 && event.getKeyCode() != KeyEvent.KEYCODE_DPAD_DOWN) {
54             return false;
55         }
56 
57         long duration = event.getEventTime() - event.getDownTime();
58         if (duration < THRESHOLD_FAST_FOCUS_CHANGE_TIME_MS[0] || event.isCanceled()) {
59             mFocusAccelerated = false;
60             return false;
61         }
62         mDirection =
63                 event.getKeyCode() == KeyEvent.KEYCODE_DPAD_UP ? View.FOCUS_UP : View.FOCUS_DOWN;
64         int skippedViewCount = MAX_SKIPPED_VIEW_COUNT[0];
65         for (int i = 1; i < THRESHOLD_FAST_FOCUS_CHANGE_TIME_MS.length; ++i) {
66             if (THRESHOLD_FAST_FOCUS_CHANGE_TIME_MS[i] < duration) {
67                 skippedViewCount = MAX_SKIPPED_VIEW_COUNT[i];
68             } else {
69                 break;
70             }
71         }
72         if (event.getAction() == KeyEvent.ACTION_DOWN) {
73             mRepeatedKeyInterval = duration / event.getRepeatCount();
74             mFocusAccelerated = true;
75         } else {
76             // HACK: we move focus skippedViewCount times more even after ACTION_UP. Without this
77             // hack, a focused view's position doesn't reach to the desired position
78             // in ProgramGrid.
79             mFocusAccelerated = false;
80         }
81         for (int i = 0; i < skippedViewCount; ++i) {
82             mHandler.sendEmptyMessageDelayed(
83                     MSG_MOVE_FOCUS, mRepeatedKeyInterval * i / (skippedViewCount + 1));
84         }
85         if (DEBUG) Log.d(TAG, "onInterceptKeyEvent: focused view " + mView.findFocus());
86         return false;
87     }
88 
89     private static class MyHandler extends WeakHandler<OnRepeatedKeyInterceptListener> {
MyHandler(OnRepeatedKeyInterceptListener listener)90         private MyHandler(OnRepeatedKeyInterceptListener listener) {
91             super(listener);
92         }
93 
94         @Override
handleMessage(Message msg, @NonNull OnRepeatedKeyInterceptListener listener)95         public void handleMessage(Message msg, @NonNull OnRepeatedKeyInterceptListener listener) {
96             if (msg.what == MSG_MOVE_FOCUS) {
97                 View focused = listener.mView.findFocus();
98                 if (DEBUG) Log.d(TAG, "MSG_MOVE_FOCUS: focused view " + focused);
99                 if (focused != null) {
100                     View v = focused.focusSearch(listener.mDirection);
101                     if (v != null && v != focused) {
102                         v.requestFocus(listener.mDirection);
103                     }
104                 }
105             }
106         }
107     }
108 }
109