Home | History | Annotate | Download | only in preference 
      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 androidx.preference;
     18 
     19 import android.app.AlertDialog;
     20 import android.content.DialogInterface;
     21 import android.os.Bundle;
     22 
     23 import androidx.annotation.NonNull;
     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 
     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
     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
     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 
     73     private ListPreference getListPreference() {
     74         return (ListPreference) getPreference();
     75     }
     76 
     77     @Override
     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
    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