MultiSelectListPreference.java revision ece60fb243f6d1dcee24f5c8f925f449e0514f7e
1/* 2 * Copyright (C) 2010 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 17package android.preference; 18 19import android.app.AlertDialog.Builder; 20import android.content.Context; 21import android.content.DialogInterface; 22import android.content.res.TypedArray; 23import android.os.Parcel; 24import android.os.Parcelable; 25import android.util.AttributeSet; 26 27import java.util.HashSet; 28import java.util.Set; 29 30/** 31 * A {@link Preference} that displays a list of entries as 32 * a dialog. 33 * <p> 34 * This preference will store a set of strings into the SharedPreferences. 35 * This set will contain one or more values from the 36 * {@link #setEntryValues(CharSequence[])} array. 37 * 38 * @attr ref android.R.styleable#MultiSelectListPreference_entries 39 * @attr ref android.R.styleable#MultiSelectListPreference_entryValues 40 */ 41public class MultiSelectListPreference extends DialogPreference { 42 private CharSequence[] mEntries; 43 private CharSequence[] mEntryValues; 44 private Set<String> mValues = new HashSet<String>(); 45 private Set<String> mNewValues = new HashSet<String>(); 46 private boolean mPreferenceChanged; 47 48 public MultiSelectListPreference(Context context, AttributeSet attrs) { 49 super(context, attrs); 50 51 TypedArray a = context.obtainStyledAttributes(attrs, 52 com.android.internal.R.styleable.MultiSelectListPreference, 0, 0); 53 mEntries = a.getTextArray(com.android.internal.R.styleable.MultiSelectListPreference_entries); 54 mEntryValues = a.getTextArray(com.android.internal.R.styleable.MultiSelectListPreference_entryValues); 55 a.recycle(); 56 } 57 58 public MultiSelectListPreference(Context context) { 59 this(context, null); 60 } 61 62 /** 63 * Sets the human-readable entries to be shown in the list. This will be 64 * shown in subsequent dialogs. 65 * <p> 66 * Each entry must have a corresponding index in 67 * {@link #setEntryValues(CharSequence[])}. 68 * 69 * @param entries The entries. 70 * @see #setEntryValues(CharSequence[]) 71 */ 72 public void setEntries(CharSequence[] entries) { 73 mEntries = entries; 74 } 75 76 /** 77 * @see #setEntries(CharSequence[]) 78 * @param entriesResId The entries array as a resource. 79 */ 80 public void setEntries(int entriesResId) { 81 setEntries(getContext().getResources().getTextArray(entriesResId)); 82 } 83 84 /** 85 * The list of entries to be shown in the list in subsequent dialogs. 86 * 87 * @return The list as an array. 88 */ 89 public CharSequence[] getEntries() { 90 return mEntries; 91 } 92 93 /** 94 * The array to find the value to save for a preference when an entry from 95 * entries is selected. If a user clicks on the second item in entries, the 96 * second item in this array will be saved to the preference. 97 * 98 * @param entryValues The array to be used as values to save for the preference. 99 */ 100 public void setEntryValues(CharSequence[] entryValues) { 101 mEntryValues = entryValues; 102 } 103 104 /** 105 * @see #setEntryValues(CharSequence[]) 106 * @param entryValuesResId The entry values array as a resource. 107 */ 108 public void setEntryValues(int entryValuesResId) { 109 setEntryValues(getContext().getResources().getTextArray(entryValuesResId)); 110 } 111 112 /** 113 * Returns the array of values to be saved for the preference. 114 * 115 * @return The array of values. 116 */ 117 public CharSequence[] getEntryValues() { 118 return mEntryValues; 119 } 120 121 /** 122 * Sets the value of the key. This should contain entries in 123 * {@link #getEntryValues()}. 124 * 125 * @param values The values to set for the key. 126 */ 127 public void setValues(Set<String> values) { 128 mValues = values; 129 130 persistStringSet(values); 131 } 132 133 /** 134 * Retrieves the current value of the key. 135 */ 136 public Set<String> getValues() { 137 return mValues; 138 } 139 140 /** 141 * Returns the index of the given value (in the entry values array). 142 * 143 * @param value The value whose index should be returned. 144 * @return The index of the value, or -1 if not found. 145 */ 146 public int findIndexOfValue(String value) { 147 if (value != null && mEntryValues != null) { 148 for (int i = mEntryValues.length - 1; i >= 0; i--) { 149 if (mEntryValues[i].equals(value)) { 150 return i; 151 } 152 } 153 } 154 return -1; 155 } 156 157 @Override 158 protected void onPrepareDialogBuilder(Builder builder) { 159 super.onPrepareDialogBuilder(builder); 160 161 if (mEntries == null || mEntryValues == null) { 162 throw new IllegalStateException( 163 "MultiSelectListPreference requires an entries array and " + 164 "an entryValues array."); 165 } 166 167 boolean[] checkedItems = getSelectedItems(); 168 builder.setMultiChoiceItems(mEntries, checkedItems, 169 new DialogInterface.OnMultiChoiceClickListener() { 170 public void onClick(DialogInterface dialog, int which, boolean isChecked) { 171 if (isChecked) { 172 mPreferenceChanged |= mNewValues.add(mEntryValues[which].toString()); 173 } else { 174 mPreferenceChanged |= mNewValues.remove(mEntryValues[which].toString()); 175 } 176 } 177 }); 178 mNewValues.clear(); 179 mNewValues.addAll(mValues); 180 } 181 182 private boolean[] getSelectedItems() { 183 final CharSequence[] entries = mEntryValues; 184 final int entryCount = entries.length; 185 final Set<String> values = mValues; 186 boolean[] result = new boolean[entryCount]; 187 188 for (int i = 0; i < entryCount; i++) { 189 result[i] = values.contains(entries[i].toString()); 190 } 191 192 return result; 193 } 194 195 @Override 196 protected void onDialogClosed(boolean positiveResult) { 197 super.onDialogClosed(positiveResult); 198 199 if (positiveResult && mPreferenceChanged) { 200 final Set<String> values = mNewValues; 201 if (callChangeListener(values)) { 202 setValues(values); 203 } 204 } 205 mPreferenceChanged = false; 206 } 207 208 @Override 209 protected Object onGetDefaultValue(TypedArray a, int index) { 210 final CharSequence[] defaultValues = a.getTextArray(index); 211 final int valueCount = defaultValues.length; 212 final Set<String> result = new HashSet<String>(); 213 214 for (int i = 0; i < valueCount; i++) { 215 result.add(defaultValues[i].toString()); 216 } 217 218 return result; 219 } 220 221 @Override 222 protected void onSetInitialValue(boolean restoreValue, Object defaultValue) { 223 setValues(restoreValue ? getPersistedStringSet(mValues) : (Set<String>) defaultValue); 224 } 225 226 @Override 227 protected Parcelable onSaveInstanceState() { 228 final Parcelable superState = super.onSaveInstanceState(); 229 if (isPersistent()) { 230 // No need to save instance state 231 return superState; 232 } 233 234 final SavedState myState = new SavedState(superState); 235 myState.values = getValues(); 236 return myState; 237 } 238 239 private static class SavedState extends BaseSavedState { 240 Set<String> values; 241 242 public SavedState(Parcel source) { 243 super(source); 244 values = new HashSet<String>(); 245 String[] strings = source.readStringArray(); 246 247 final int stringCount = strings.length; 248 for (int i = 0; i < stringCount; i++) { 249 values.add(strings[i]); 250 } 251 } 252 253 public SavedState(Parcelable superState) { 254 super(superState); 255 } 256 257 @Override 258 public void writeToParcel(Parcel dest, int flags) { 259 super.writeToParcel(dest, flags); 260 dest.writeStringArray(values.toArray(new String[0])); 261 } 262 263 public static final Parcelable.Creator<SavedState> CREATOR = 264 new Parcelable.Creator<SavedState>() { 265 public SavedState createFromParcel(Parcel in) { 266 return new SavedState(in); 267 } 268 269 public SavedState[] newArray(int size) { 270 return new SavedState[size]; 271 } 272 }; 273 } 274} 275