1 /*
2  * Copyright (C) 2019 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 
17 package com.android.settings.accessibility;
18 
19 import android.content.Context;
20 import android.media.AudioSystem;
21 import android.os.UserHandle;
22 import android.provider.Settings;
23 import android.util.AttributeSet;
24 import android.view.View;
25 import android.widget.ImageView;
26 import android.widget.SeekBar;
27 
28 import androidx.core.content.res.TypedArrayUtils;
29 import androidx.preference.Preference;
30 import androidx.preference.PreferenceViewHolder;
31 
32 import com.android.settings.R;
33 import com.android.settings.widget.SeekBarPreference;
34 
35 /** A slider preference that directly controls audio balance **/
36 public class BalanceSeekBarPreference extends SeekBarPreference {
37     private static final int BALANCE_CENTER_VALUE = 100;
38     private static final int BALANCE_MAX_VALUE = 200;
39 
40     private final Context mContext;
41     private BalanceSeekBar mSeekBar;
42     private ImageView mIconView;
43 
BalanceSeekBarPreference(Context context, AttributeSet attrs)44     public BalanceSeekBarPreference(Context context, AttributeSet attrs) {
45         super(context, attrs, TypedArrayUtils.getAttr(context,
46                 R.attr.preferenceStyle,
47                 android.R.attr.preferenceStyle));
48         mContext = context;
49         setLayoutResource(R.layout.preference_balance_slider);
50     }
51 
52     @Override
onBindViewHolder(PreferenceViewHolder view)53     public void onBindViewHolder(PreferenceViewHolder view) {
54         super.onBindViewHolder(view);
55         mSeekBar = (BalanceSeekBar) view.findViewById(com.android.internal.R.id.seekbar);
56         mIconView = (ImageView) view.findViewById(com.android.internal.R.id.icon);
57         init();
58     }
59 
init()60     private void init() {
61         if (mSeekBar == null) {
62             return;
63         }
64         final float balance = Settings.System.getFloatForUser(
65                 mContext.getContentResolver(), Settings.System.MASTER_BALANCE,
66                 0.f /* default */, UserHandle.USER_CURRENT);
67         // Rescale balance to range 0-BALANCE_MAX_VALUE centered at BALANCE_MAX_VALUE / 2.
68         mSeekBar.setMax(BALANCE_MAX_VALUE);
69         mSeekBar.setProgress((int) (balance * 100.f) + BALANCE_CENTER_VALUE);
70         mSeekBar.setEnabled(isEnabled());
71     }
72 }
73