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      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 android.support.v17.leanback.widget.VerticalGridView;
     21 import android.util.Log;
     22 import android.view.KeyEvent;
     23 import android.view.View;
     24 
     25 import com.android.tv.common.WeakHandler;
     26 
     27 /**
     28  * Listener to make focus change faster over time.
     29  */
     30 public class OnRepeatedKeyInterceptListener implements VerticalGridView.OnKeyInterceptListener {
     31     private static final String TAG = "OnRepeatedKeyListener";
     32     private static final boolean DEBUG = false;
     33 
     34     private static final int[] THRESHOLD_FAST_FOCUS_CHANGE_TIME_MS = { 2000, 5000 };
     35     private static final int[] MAX_SKIPPED_VIEW_COUNT = { 1, 4 };
     36     private static final int MSG_MOVE_FOCUS = 1000;
     37 
     38     private final VerticalGridView mView;
     39     private final MyHandler mHandler = new MyHandler(this);
     40     private int mDirection;
     41     private boolean mFocusAccelerated;
     42     private long mRepeatedKeyInterval;
     43 
     44     public OnRepeatedKeyInterceptListener(VerticalGridView view) {
     45         mView = view;
     46     }
     47 
     48     public boolean isFocusAccelerated() {
     49         return mFocusAccelerated;
     50     }
     51 
     52     @Override
     53     public boolean onInterceptKeyEvent(KeyEvent event) {
     54         mHandler.removeMessages(MSG_MOVE_FOCUS);
     55         if (event.getKeyCode() != KeyEvent.KEYCODE_DPAD_UP &&
     56                 event.getKeyCode() != KeyEvent.KEYCODE_DPAD_DOWN) {
     57             return false;
     58         }
     59 
     60         long duration = event.getEventTime() - event.getDownTime();
     61         if (duration < THRESHOLD_FAST_FOCUS_CHANGE_TIME_MS[0]
     62                 || event.isCanceled()) {
     63             mFocusAccelerated = false;
     64             return false;
     65         }
     66         mDirection = event.getKeyCode() == KeyEvent.KEYCODE_DPAD_UP ? View.FOCUS_UP
     67                 : View.FOCUS_DOWN;
     68         int skippedViewCount = MAX_SKIPPED_VIEW_COUNT[0];
     69         for (int i = 1 ;i < THRESHOLD_FAST_FOCUS_CHANGE_TIME_MS.length; ++i) {
     70             if (THRESHOLD_FAST_FOCUS_CHANGE_TIME_MS[i] < duration) {
     71                 skippedViewCount = MAX_SKIPPED_VIEW_COUNT[i];
     72             } else {
     73                 break;
     74             }
     75         }
     76         if (event.getAction() == KeyEvent.ACTION_DOWN) {
     77             mRepeatedKeyInterval = duration / event.getRepeatCount();
     78             mFocusAccelerated = true;
     79         } else {
     80             // HACK: we move focus skippedViewCount times more even after ACTION_UP. Without this
     81             // hack, a focused view's position doesn't reach to the desired position
     82             // in ProgramGrid.
     83             mFocusAccelerated = false;
     84         }
     85         for (int i = 0; i < skippedViewCount; ++i) {
     86             mHandler.sendEmptyMessageDelayed(MSG_MOVE_FOCUS,
     87                     mRepeatedKeyInterval * i / (skippedViewCount + 1));
     88         }
     89         if (DEBUG) Log.d(TAG, "onInterceptKeyEvent: focused view " + mView.findFocus());
     90         return false;
     91     }
     92 
     93     private static class MyHandler extends WeakHandler<OnRepeatedKeyInterceptListener> {
     94         private MyHandler(OnRepeatedKeyInterceptListener listener) {
     95             super(listener);
     96         }
     97 
     98         @Override
     99         public void handleMessage(Message msg, @NonNull OnRepeatedKeyInterceptListener listener) {
    100             if (msg.what == MSG_MOVE_FOCUS) {
    101                 View focused = listener.mView.findFocus();
    102                 if (DEBUG) Log.d(TAG, "MSG_MOVE_FOCUS: focused view " + focused);
    103                 if (focused != null) {
    104                     View v = focused.focusSearch(listener.mDirection);
    105                     if (v != null && v != focused) {
    106                         v.requestFocus(listener.mDirection);
    107                     }
    108                 }
    109             }
    110         }
    111     }
    112 }
    113