1 /*
2  * Copyright (C) 2014 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.location;
18 
19 import android.annotation.Nullable;
20 import android.content.Context;
21 import android.graphics.drawable.Drawable;
22 import android.preference.Preference;
23 import android.text.TextUtils;
24 import android.util.AttributeSet;
25 import android.view.View;
26 import android.widget.TextView;
27 
28 /**
29  * A preference item that can dim the icon when it's disabled, either directly or because its parent
30  * is disabled.
31  */
32 public class DimmableIconPreference extends Preference {
33     private static final int ICON_ALPHA_ENABLED = 255;
34     private static final int ICON_ALPHA_DISABLED = 102;
35 
36     private final CharSequence mContentDescription;
37 
DimmableIconPreference(Context context, AttributeSet attrs, int defStyle, @Nullable CharSequence contentDescription)38     public DimmableIconPreference(Context context, AttributeSet attrs, int defStyle,
39             @Nullable CharSequence contentDescription) {
40         super(context, attrs, defStyle);
41         mContentDescription = contentDescription;
42     }
43 
DimmableIconPreference(Context context, AttributeSet attrs, @Nullable CharSequence contentDescription)44     public DimmableIconPreference(Context context, AttributeSet attrs,
45             @Nullable CharSequence contentDescription) {
46         super(context, attrs);
47         mContentDescription = contentDescription;
48     }
49 
DimmableIconPreference(Context context, @Nullable CharSequence contentDescription)50     public DimmableIconPreference(Context context, @Nullable CharSequence contentDescription) {
51         super(context);
52         mContentDescription = contentDescription;
53     }
54 
dimIcon(boolean dimmed)55     private void dimIcon(boolean dimmed) {
56         Drawable icon = getIcon();
57         if (icon != null) {
58             icon.mutate().setAlpha(dimmed ? ICON_ALPHA_DISABLED : ICON_ALPHA_ENABLED);
59             setIcon(icon);
60         }
61     }
62 
63     @Override
onParentChanged(Preference parent, boolean disableChild)64     public void onParentChanged(Preference parent, boolean disableChild) {
65         dimIcon(disableChild);
66         super.onParentChanged(parent, disableChild);
67     }
68 
69     @Override
setEnabled(boolean enabled)70     public void setEnabled(boolean enabled) {
71         dimIcon(!enabled);
72         super.setEnabled(enabled);
73     }
74 
75     @Override
onBindView(View view)76     protected void onBindView(View view) {
77         super.onBindView(view);
78         if (!TextUtils.isEmpty(mContentDescription)) {
79             final TextView titleView = (TextView) view.findViewById(android.R.id.title);
80             titleView.setContentDescription(mContentDescription);
81         }
82     }
83 }
84