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 
17 package android.support.v14.preference;
18 
19 import android.app.AlertDialog;
20 import android.content.DialogInterface;
21 import android.os.Bundle;
22 import android.support.annotation.NonNull;
23 import android.support.v7.preference.ListPreference;
24 
25 public class ListPreferenceDialogFragment extends PreferenceDialogFragment {
26 
27     private static final String SAVE_STATE_INDEX = "ListPreferenceDialogFragment.index";
28     private static final String SAVE_STATE_ENTRIES = "ListPreferenceDialogFragment.entries";
29     private static final String SAVE_STATE_ENTRY_VALUES =
30             "ListPreferenceDialogFragment.entryValues";
31 
32     private int mClickedDialogEntryIndex;
33     private CharSequence[] mEntries;
34     private CharSequence[] mEntryValues;
35 
newInstance(String key)36     public static ListPreferenceDialogFragment newInstance(String key) {
37         final ListPreferenceDialogFragment fragment = new ListPreferenceDialogFragment();
38         final Bundle b = new Bundle(1);
39         b.putString(ARG_KEY, key);
40         fragment.setArguments(b);
41         return fragment;
42     }
43 
44     @Override
onCreate(Bundle savedInstanceState)45     public void onCreate(Bundle savedInstanceState) {
46         super.onCreate(savedInstanceState);
47         if (savedInstanceState == null) {
48             final ListPreference preference = getListPreference();
49 
50             if (preference.getEntries() == null || preference.getEntryValues() == null) {
51                 throw new IllegalStateException(
52                         "ListPreference requires an entries array and an entryValues array.");
53             }
54 
55             mClickedDialogEntryIndex = preference.findIndexOfValue(preference.getValue());
56             mEntries = preference.getEntries();
57             mEntryValues = preference.getEntryValues();
58         } else {
59             mClickedDialogEntryIndex = savedInstanceState.getInt(SAVE_STATE_INDEX, 0);
60             mEntries = savedInstanceState.getCharSequenceArray(SAVE_STATE_ENTRIES);
61             mEntryValues = savedInstanceState.getCharSequenceArray(SAVE_STATE_ENTRY_VALUES);
62         }
63     }
64 
65     @Override
onSaveInstanceState(@onNull Bundle outState)66     public void onSaveInstanceState(@NonNull Bundle outState) {
67         super.onSaveInstanceState(outState);
68         outState.putInt(SAVE_STATE_INDEX, mClickedDialogEntryIndex);
69         outState.putCharSequenceArray(SAVE_STATE_ENTRIES, mEntries);
70         outState.putCharSequenceArray(SAVE_STATE_ENTRY_VALUES, mEntryValues);
71     }
72 
getListPreference()73     private ListPreference getListPreference() {
74         return (ListPreference) getPreference();
75     }
76 
77     @Override
onPrepareDialogBuilder(AlertDialog.Builder builder)78     protected void onPrepareDialogBuilder(AlertDialog.Builder builder) {
79         super.onPrepareDialogBuilder(builder);
80 
81         builder.setSingleChoiceItems(mEntries, mClickedDialogEntryIndex,
82                 new DialogInterface.OnClickListener() {
83                     @Override
84                     public void onClick(DialogInterface dialog, int which) {
85                         mClickedDialogEntryIndex = which;
86 
87                         /*
88                          * Clicking on an item simulates the positive button
89                          * click, and dismisses the dialog.
90                          */
91                         ListPreferenceDialogFragment.this.onClick(dialog,
92                                 DialogInterface.BUTTON_POSITIVE);
93                         dialog.dismiss();
94                     }
95                 });
96 
97         /*
98          * The typical interaction for list-based dialogs is to have
99          * click-on-an-item dismiss the dialog instead of the user having to
100          * press 'Ok'.
101          */
102         builder.setPositiveButton(null, null);
103     }
104 
105     @Override
onDialogClosed(boolean positiveResult)106     public void onDialogClosed(boolean positiveResult) {
107         final ListPreference preference = getListPreference();
108         if (positiveResult && mClickedDialogEntryIndex >= 0) {
109             String value = mEntryValues[mClickedDialogEntryIndex].toString();
110             if (preference.callChangeListener(value)) {
111                 preference.setValue(value);
112             }
113         }
114     }
115 
116 }
117