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.clear(); 129 mValues.addAll(values); 130 131 persistStringSet(values); 132 } 133 134 /** 135 * Retrieves the current value of the key. 136 */ 137 public Set<String> getValues() { 138 return mValues; 139 } 140 141 /** 142 * Returns the index of the given value (in the entry values array). 143 * 144 * @param value The value whose index should be returned. 145 * @return The index of the value, or -1 if not found. 146 */ 147 public int findIndexOfValue(String value) { 148 if (value != null && mEntryValues != null) { 149 for (int i = mEntryValues.length - 1; i >= 0; i--) { 150 if (mEntryValues[i].equals(value)) { 151 return i; 152 } 153 } 154 } 155 return -1; 156 } 157 158 @Override 159 protected void onPrepareDialogBuilder(Builder builder) { 160 super.onPrepareDialogBuilder(builder); 161 162 if (mEntries == null || mEntryValues == null) { 163 throw new IllegalStateException( 164 "MultiSelectListPreference requires an entries array and " + 165 "an entryValues array."); 166 } 167 168 boolean[] checkedItems = getSelectedItems(); 169 builder.setMultiChoiceItems(mEntries, checkedItems, 170 new DialogInterface.OnMultiChoiceClickListener() { 171 public void onClick(DialogInterface dialog, int which, boolean isChecked) { 172 if (isChecked) { 173 mPreferenceChanged |= mNewValues.add(mEntryValues[which].toString()); 174 } else { 175 mPreferenceChanged |= mNewValues.remove(mEntryValues[which].toString()); 176 } 177 } 178 }); 179 mNewValues.clear(); 180 mNewValues.addAll(mValues); 181 } 182 183 private boolean[] getSelectedItems() { 184 final CharSequence[] entries = mEntryValues; 185 final int entryCount = entries.length; 186 final Set<String> values = mValues; 187 boolean[] result = new boolean[entryCount]; 188 189 for (int i = 0; i < entryCount; i++) { 190 result[i] = values.contains(entries[i].toString()); 191 } 192 193 return result; 194 } 195 196 @Override 197 protected void onDialogClosed(boolean positiveResult) { 198 super.onDialogClosed(positiveResult); 199 200 if (positiveResult && mPreferenceChanged) { 201 final Set<String> values = mNewValues; 202 if (callChangeListener(values)) { 203 setValues(values); 204 } 205 } 206 mPreferenceChanged = false; 207 } 208 209 @Override 210 protected Object onGetDefaultValue(TypedArray a, int index) { 211 final CharSequence[] defaultValues = a.getTextArray(index); 212 final int valueCount = defaultValues.length; 213 final Set<String> result = new HashSet<String>(); 214 215 for (int i = 0; i < valueCount; i++) { 216 result.add(defaultValues[i].toString()); 217 } 218 219 return result; 220 } 221 222 @Override 223 protected void onSetInitialValue(boolean restoreValue, Object defaultValue) { 224 setValues(restoreValue ? getPersistedStringSet(mValues) : (Set<String>) defaultValue); 225 } 226 227 @Override 228 protected Parcelable onSaveInstanceState() { 229 final Parcelable superState = super.onSaveInstanceState(); 230 if (isPersistent()) { 231 // No need to save instance state 232 return superState; 233 } 234 235 final SavedState myState = new SavedState(superState); 236 myState.values = getValues(); 237 return myState; 238 } 239 240 private static class SavedState extends BaseSavedState { 241 Set<String> values; 242 243 public SavedState(Parcel source) { 244 super(source); 245 values = new HashSet<String>(); 246 String[] strings = source.readStringArray(); 247 248 final int stringCount = strings.length; 249 for (int i = 0; i < stringCount; i++) { 250 values.add(strings[i]); 251 } 252 } 253 254 public SavedState(Parcelable superState) { 255 super(superState); 256 } 257 258 @Override 259 public void writeToParcel(Parcel dest, int flags) { 260 super.writeToParcel(dest, flags); 261 dest.writeStringArray(values.toArray(new String[0])); 262 } 263 264 public static final Parcelable.Creator<SavedState> CREATOR = 265 new Parcelable.Creator<SavedState>() { 266 public SavedState createFromParcel(Parcel in) { 267 return new SavedState(in); 268 } 269 270 public SavedState[] newArray(int size) { 271 return new SavedState[size]; 272 } 273 }; 274 } 275} 276