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