Preference.java revision 9066cfe9886ac131c34d59ed0e2d287b0e3c0087
1/* 2 * Copyright (C) 2007 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 java.util.ArrayList; 20import java.util.List; 21 22import android.content.Context; 23import android.content.Intent; 24import android.content.SharedPreferences; 25import android.content.res.TypedArray; 26import android.os.Bundle; 27import android.os.Parcel; 28import android.os.Parcelable; 29import android.text.TextUtils; 30import android.util.AttributeSet; 31import com.android.internal.util.CharSequences; 32import android.view.AbsSavedState; 33import android.view.LayoutInflater; 34import android.view.View; 35import android.view.ViewGroup; 36import android.widget.ListView; 37import android.widget.TextView; 38 39/** 40 * Represents the basic Preference UI building 41 * block displayed by a {@link PreferenceActivity} in the form of a 42 * {@link ListView}. This class provides the {@link View} to be displayed in 43 * the activity and associates with a {@link SharedPreferences} to 44 * store/retrieve the preference data. 45 * <p> 46 * When specifying a preference hierarchy in XML, each element can point to a 47 * subclass of {@link Preference}, similar to the view hierarchy and layouts. 48 * <p> 49 * This class contains a {@code key} that will be used as the key into the 50 * {@link SharedPreferences}. It is up to the subclass to decide how to store 51 * the value. 52 * 53 * @attr ref android.R.styleable#Preference_key 54 * @attr ref android.R.styleable#Preference_title 55 * @attr ref android.R.styleable#Preference_summary 56 * @attr ref android.R.styleable#Preference_order 57 * @attr ref android.R.styleable#Preference_layout 58 * @attr ref android.R.styleable#Preference_widgetLayout 59 * @attr ref android.R.styleable#Preference_enabled 60 * @attr ref android.R.styleable#Preference_selectable 61 * @attr ref android.R.styleable#Preference_dependency 62 * @attr ref android.R.styleable#Preference_persistent 63 * @attr ref android.R.styleable#Preference_defaultValue 64 * @attr ref android.R.styleable#Preference_shouldDisableView 65 */ 66public class Preference implements Comparable<Preference>, OnDependencyChangeListener { 67 /** 68 * Specify for {@link #setOrder(int)} if a specific order is not required. 69 */ 70 public static final int DEFAULT_ORDER = Integer.MAX_VALUE; 71 72 private Context mContext; 73 private PreferenceManager mPreferenceManager; 74 75 /** 76 * Set when added to hierarchy since we need a unique ID within that 77 * hierarchy. 78 */ 79 private long mId; 80 81 private OnPreferenceChangeListener mOnChangeListener; 82 private OnPreferenceClickListener mOnClickListener; 83 84 private int mOrder = DEFAULT_ORDER; 85 private CharSequence mTitle; 86 private CharSequence mSummary; 87 private String mKey; 88 private Intent mIntent; 89 private boolean mEnabled = true; 90 private boolean mSelectable = true; 91 private boolean mRequiresKey; 92 private boolean mPersistent = true; 93 private String mDependencyKey; 94 private Object mDefaultValue; 95 96 /** 97 * @see #setShouldDisableView(boolean) 98 */ 99 private boolean mShouldDisableView = true; 100 101 private int mLayoutResId = com.android.internal.R.layout.preference; 102 private int mWidgetLayoutResId; 103 private boolean mHasSpecifiedLayout = false; 104 105 private OnPreferenceChangeInternalListener mListener; 106 107 private List<Preference> mDependents; 108 109 private boolean mBaseMethodCalled; 110 111 /** 112 * Interface definition for a callback to be invoked when the value of this 113 * {@link Preference} has been changed by the user and is 114 * about to be set and/or persisted. This gives the client a chance 115 * to prevent setting and/or persisting the value. 116 */ 117 public interface OnPreferenceChangeListener { 118 /** 119 * Called when a Preference has been changed by the user. This is 120 * called before the state of the Preference is about to be updated and 121 * before the state is persisted. 122 * 123 * @param preference The changed Preference. 124 * @param newValue The new value of the Preference. 125 * @return True to update the state of the Preference with the new value. 126 */ 127 boolean onPreferenceChange(Preference preference, Object newValue); 128 } 129 130 /** 131 * Interface definition for a callback to be invoked when a {@link Preference} is 132 * clicked. 133 */ 134 public interface OnPreferenceClickListener { 135 /** 136 * Called when a Preference has been clicked. 137 * 138 * @param preference The Preference that was clicked. 139 * @return True if the click was handled. 140 */ 141 boolean onPreferenceClick(Preference preference); 142 } 143 144 /** 145 * Interface definition for a callback to be invoked when this 146 * {@link Preference} is changed or, if this is a group, there is an 147 * addition/removal of {@link Preference}(s). This is used internally. 148 */ 149 interface OnPreferenceChangeInternalListener { 150 /** 151 * Called when this Preference has changed. 152 * 153 * @param preference This preference. 154 */ 155 void onPreferenceChange(Preference preference); 156 157 /** 158 * Called when this group has added/removed {@link Preference}(s). 159 * 160 * @param preference This Preference. 161 */ 162 void onPreferenceHierarchyChange(Preference preference); 163 } 164 165 /** 166 * Perform inflation from XML and apply a class-specific base style. This 167 * constructor of Preference allows subclasses to use their own base 168 * style when they are inflating. For example, a {@link CheckBoxPreference} 169 * constructor calls this version of the super class constructor and 170 * supplies {@code android.R.attr.checkBoxPreferenceStyle} for <var>defStyle</var>. 171 * This allows the theme's checkbox preference style to modify all of the base 172 * preference attributes as well as the {@link CheckBoxPreference} class's 173 * attributes. 174 * 175 * @param context The Context this is associated with, through which it can 176 * access the current theme, resources, {@link SharedPreferences}, 177 * etc. 178 * @param attrs The attributes of the XML tag that is inflating the preference. 179 * @param defStyle The default style to apply to this preference. If 0, no style 180 * will be applied (beyond what is included in the theme). This 181 * may either be an attribute resource, whose value will be 182 * retrieved from the current theme, or an explicit style 183 * resource. 184 * @see #Preference(Context, AttributeSet) 185 */ 186 public Preference(Context context, AttributeSet attrs, int defStyle) { 187 mContext = context; 188 189 TypedArray a = context.obtainStyledAttributes(attrs, 190 com.android.internal.R.styleable.Preference); 191 if (a.hasValue(com.android.internal.R.styleable.Preference_layout) || 192 a.hasValue(com.android.internal.R.styleable.Preference_widgetLayout)) { 193 // This preference has a custom layout defined (not one taken from 194 // the default style) 195 mHasSpecifiedLayout = true; 196 } 197 a.recycle(); 198 199 a = context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.Preference, 200 defStyle, 0); 201 for (int i = a.getIndexCount(); i >= 0; i--) { 202 int attr = a.getIndex(i); 203 switch (attr) { 204 case com.android.internal.R.styleable.Preference_key: 205 mKey = a.getString(attr); 206 break; 207 208 case com.android.internal.R.styleable.Preference_title: 209 mTitle = a.getString(attr); 210 break; 211 212 case com.android.internal.R.styleable.Preference_summary: 213 mSummary = a.getString(attr); 214 break; 215 216 case com.android.internal.R.styleable.Preference_order: 217 mOrder = a.getInt(attr, mOrder); 218 break; 219 220 case com.android.internal.R.styleable.Preference_layout: 221 mLayoutResId = a.getResourceId(attr, mLayoutResId); 222 break; 223 224 case com.android.internal.R.styleable.Preference_widgetLayout: 225 mWidgetLayoutResId = a.getResourceId(attr, mWidgetLayoutResId); 226 break; 227 228 case com.android.internal.R.styleable.Preference_enabled: 229 mEnabled = a.getBoolean(attr, true); 230 break; 231 232 case com.android.internal.R.styleable.Preference_selectable: 233 mSelectable = a.getBoolean(attr, true); 234 break; 235 236 case com.android.internal.R.styleable.Preference_persistent: 237 mPersistent = a.getBoolean(attr, mPersistent); 238 break; 239 240 case com.android.internal.R.styleable.Preference_dependency: 241 mDependencyKey = a.getString(attr); 242 break; 243 244 case com.android.internal.R.styleable.Preference_defaultValue: 245 mDefaultValue = onGetDefaultValue(a, attr); 246 break; 247 248 case com.android.internal.R.styleable.Preference_shouldDisableView: 249 mShouldDisableView = a.getBoolean(attr, mShouldDisableView); 250 break; 251 } 252 } 253 a.recycle(); 254 } 255 256 /** 257 * Constructor that is called when inflating a Preference from XML. This is 258 * called when a Preference is being constructed from an XML file, supplying 259 * attributes that were specified in the XML file. This version uses a 260 * default style of 0, so the only attribute values applied are those in the 261 * Context's Theme and the given AttributeSet. 262 * 263 * @param context The Context this is associated with, through which it can 264 * access the current theme, resources, {@link SharedPreferences}, 265 * etc. 266 * @param attrs The attributes of the XML tag that is inflating the 267 * preference. 268 * @see #Preference(Context, AttributeSet, int) 269 */ 270 public Preference(Context context, AttributeSet attrs) { 271 this(context, attrs, 0); 272 } 273 274 /** 275 * Constructor to create a Preference. 276 * 277 * @param context The Context in which to store Preference values. 278 */ 279 public Preference(Context context) { 280 this(context, null); 281 } 282 283 /** 284 * Called when a Preference is being inflated and the default value 285 * attribute needs to be read. Since different Preference types have 286 * different value types, the subclass should get and return the default 287 * value which will be its value type. 288 * <p> 289 * For example, if the value type is String, the body of the method would 290 * proxy to {@link TypedArray#getString(int)}. 291 * 292 * @param a The set of attributes. 293 * @param index The index of the default value attribute. 294 * @return The default value of this preference type. 295 */ 296 protected Object onGetDefaultValue(TypedArray a, int index) { 297 return null; 298 } 299 300 /** 301 * Sets an {@link Intent} to be used for 302 * {@link Context#startActivity(Intent)} when this Preference is clicked. 303 * 304 * @param intent The intent associated with this Preference. 305 */ 306 public void setIntent(Intent intent) { 307 mIntent = intent; 308 } 309 310 /** 311 * Return the {@link Intent} associated with this Preference. 312 * 313 * @return The {@link Intent} last set via {@link #setIntent(Intent)} or XML. 314 */ 315 public Intent getIntent() { 316 return mIntent; 317 } 318 319 /** 320 * Sets the layout resource that is inflated as the {@link View} to be shown 321 * for this Preference. In most cases, the default layout is sufficient for 322 * custom Preference objects and only the widget layout needs to be changed. 323 * <p> 324 * This layout should contain a {@link ViewGroup} with ID 325 * {@link android.R.id#widget_frame} to be the parent of the specific widget 326 * for this Preference. It should similarly contain 327 * {@link android.R.id#title} and {@link android.R.id#summary}. 328 * 329 * @param layoutResId The layout resource ID to be inflated and returned as 330 * a {@link View}. 331 * @see #setWidgetLayoutResource(int) 332 */ 333 public void setLayoutResource(int layoutResId) { 334 335 if (!mHasSpecifiedLayout) { 336 mHasSpecifiedLayout = true; 337 } 338 339 mLayoutResId = layoutResId; 340 } 341 342 /** 343 * Gets the layout resource that will be shown as the {@link View} for this Preference. 344 * 345 * @return The layout resource ID. 346 */ 347 public int getLayoutResource() { 348 return mLayoutResId; 349 } 350 351 /** 352 * Sets The layout for the controllable widget portion of this Preference. This 353 * is inflated into the main layout. For example, a {@link CheckBoxPreference} 354 * would specify a custom layout (consisting of just the CheckBox) here, 355 * instead of creating its own main layout. 356 * 357 * @param widgetLayoutResId The layout resource ID to be inflated into the 358 * main layout. 359 * @see #setLayoutResource(int) 360 */ 361 public void setWidgetLayoutResource(int widgetLayoutResId) { 362 mWidgetLayoutResId = widgetLayoutResId; 363 } 364 365 /** 366 * Gets the layout resource for the controllable widget portion of this Preference. 367 * 368 * @return The layout resource ID. 369 */ 370 public int getWidgetLayoutResource() { 371 return mWidgetLayoutResId; 372 } 373 374 /** 375 * Gets the View that will be shown in the {@link PreferenceActivity}. 376 * 377 * @param convertView The old View to reuse, if possible. Note: You should 378 * check that this View is non-null and of an appropriate type 379 * before using. If it is not possible to convert this View to 380 * display the correct data, this method can create a new View. 381 * @param parent The parent that this View will eventually be attached to. 382 * @return Returns the same Preference object, for chaining multiple calls 383 * into a single statement. 384 * @see #onCreateView(ViewGroup) 385 * @see #onBindView(View) 386 */ 387 public View getView(View convertView, ViewGroup parent) { 388 if (convertView == null) { 389 convertView = onCreateView(parent); 390 } 391 onBindView(convertView); 392 return convertView; 393 } 394 395 /** 396 * Creates the View to be shown for this Preference in the 397 * {@link PreferenceActivity}. The default behavior is to inflate the main 398 * layout of this Preference (see {@link #setLayoutResource(int)}. If 399 * changing this behavior, please specify a {@link ViewGroup} with ID 400 * {@link android.R.id#widget_frame}. 401 * <p> 402 * Make sure to call through to the superclass's implementation. 403 * 404 * @param parent The parent that this View will eventually be attached to. 405 * @return The View that displays this Preference. 406 * @see #onBindView(View) 407 */ 408 protected View onCreateView(ViewGroup parent) { 409 final LayoutInflater layoutInflater = 410 (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 411 412 final View layout = layoutInflater.inflate(mLayoutResId, parent, false); 413 414 if (mWidgetLayoutResId != 0) { 415 final ViewGroup widgetFrame = (ViewGroup)layout.findViewById(com.android.internal.R.id.widget_frame); 416 layoutInflater.inflate(mWidgetLayoutResId, widgetFrame); 417 } 418 419 return layout; 420 } 421 422 /** 423 * Binds the created View to the data for this Preference. 424 * <p> 425 * This is a good place to grab references to custom Views in the layout and 426 * set properties on them. 427 * <p> 428 * Make sure to call through to the superclass's implementation. 429 * 430 * @param view The View that shows this Preference. 431 * @see #onCreateView(ViewGroup) 432 */ 433 protected void onBindView(View view) { 434 TextView textView = (TextView) view.findViewById(com.android.internal.R.id.title); 435 if (textView != null) { 436 textView.setText(getTitle()); 437 } 438 439 textView = (TextView) view.findViewById(com.android.internal.R.id.summary); 440 if (textView != null) { 441 final CharSequence summary = getSummary(); 442 if (!TextUtils.isEmpty(summary)) { 443 if (textView.getVisibility() != View.VISIBLE) { 444 textView.setVisibility(View.VISIBLE); 445 } 446 447 textView.setText(getSummary()); 448 } else { 449 if (textView.getVisibility() != View.GONE) { 450 textView.setVisibility(View.GONE); 451 } 452 } 453 } 454 455 if (mShouldDisableView) { 456 setEnabledStateOnViews(view, isEnabled()); 457 } 458 } 459 460 /** 461 * Makes sure the view (and any children) get the enabled state changed. 462 */ 463 private void setEnabledStateOnViews(View v, boolean enabled) { 464 v.setEnabled(enabled); 465 466 if (v instanceof ViewGroup) { 467 final ViewGroup vg = (ViewGroup) v; 468 for (int i = vg.getChildCount() - 1; i >= 0; i--) { 469 setEnabledStateOnViews(vg.getChildAt(i), enabled); 470 } 471 } 472 } 473 474 /** 475 * Sets the order of this Preference with respect to other 476 * Preference objects on the same level. If this is not specified, the 477 * default behavior is to sort alphabetically. The 478 * {@link PreferenceGroup#setOrderingAsAdded(boolean)} can be used to order 479 * Preference objects based on the order they appear in the XML. 480 * 481 * @param order The order for this Preference. A lower value will be shown 482 * first. Use {@link #DEFAULT_ORDER} to sort alphabetically or 483 * allow ordering from XML. 484 * @see PreferenceGroup#setOrderingAsAdded(boolean) 485 * @see #DEFAULT_ORDER 486 */ 487 public void setOrder(int order) { 488 if (order != mOrder) { 489 mOrder = order; 490 491 // Reorder the list 492 notifyHierarchyChanged(); 493 } 494 } 495 496 /** 497 * Gets the order of this Preference with respect to other Preference objects 498 * on the same level. 499 * 500 * @return The order of this Preference. 501 * @see #setOrder(int) 502 */ 503 public int getOrder() { 504 return mOrder; 505 } 506 507 /** 508 * Sets the title for this Preference with a CharSequence. 509 * This title will be placed into the ID 510 * {@link android.R.id#title} within the View created by 511 * {@link #onCreateView(ViewGroup)}. 512 * 513 * @param title The title for this Preference. 514 */ 515 public void setTitle(CharSequence title) { 516 if (title == null && mTitle != null || title != null && !title.equals(mTitle)) { 517 mTitle = title; 518 notifyChanged(); 519 } 520 } 521 522 /** 523 * Sets the title for this Preference with a resource ID. 524 * 525 * @see #setTitle(CharSequence) 526 * @param titleResId The title as a resource ID. 527 */ 528 public void setTitle(int titleResId) { 529 setTitle(mContext.getString(titleResId)); 530 } 531 532 /** 533 * Returns the title of this Preference. 534 * 535 * @return The title. 536 * @see #setTitle(CharSequence) 537 */ 538 public CharSequence getTitle() { 539 return mTitle; 540 } 541 542 /** 543 * Returns the summary of this Preference. 544 * 545 * @return The summary. 546 * @see #setSummary(CharSequence) 547 */ 548 public CharSequence getSummary() { 549 return mSummary; 550 } 551 552 /** 553 * Sets the summary for this Preference with a CharSequence. 554 * 555 * @param summary The summary for the preference. 556 */ 557 public void setSummary(CharSequence summary) { 558 if (summary == null && mSummary != null || summary != null && !summary.equals(mSummary)) { 559 mSummary = summary; 560 notifyChanged(); 561 } 562 } 563 564 /** 565 * Sets the summary for this Preference with a resource ID. 566 * 567 * @see #setSummary(CharSequence) 568 * @param summaryResId The summary as a resource. 569 */ 570 public void setSummary(int summaryResId) { 571 setSummary(mContext.getString(summaryResId)); 572 } 573 574 /** 575 * Sets whether this Preference is enabled. If disabled, it will 576 * not handle clicks. 577 * 578 * @param enabled Set true to enable it. 579 */ 580 public void setEnabled(boolean enabled) { 581 if (mEnabled != enabled) { 582 mEnabled = enabled; 583 584 // Enabled state can change dependent preferences' states, so notify 585 notifyDependencyChange(shouldDisableDependents()); 586 587 notifyChanged(); 588 } 589 } 590 591 /** 592 * Checks whether this Preference should be enabled in the list. 593 * 594 * @return True if this Preference is enabled, false otherwise. 595 */ 596 public boolean isEnabled() { 597 return mEnabled; 598 } 599 600 /** 601 * Sets whether this Preference is selectable. 602 * 603 * @param selectable Set true to make it selectable. 604 */ 605 public void setSelectable(boolean selectable) { 606 if (mSelectable != selectable) { 607 mSelectable = selectable; 608 notifyChanged(); 609 } 610 } 611 612 /** 613 * Checks whether this Preference should be selectable in the list. 614 * 615 * @return True if it is selectable, false otherwise. 616 */ 617 public boolean isSelectable() { 618 return mSelectable; 619 } 620 621 /** 622 * Sets whether this Preference should disable its view when it gets 623 * disabled. 624 * <p> 625 * For example, set this and {@link #setEnabled(boolean)} to false for 626 * preferences that are only displaying information and 1) should not be 627 * clickable 2) should not have the view set to the disabled state. 628 * 629 * @param shouldDisableView Set true if this preference should disable its view 630 * when the preference is disabled. 631 */ 632 public void setShouldDisableView(boolean shouldDisableView) { 633 mShouldDisableView = shouldDisableView; 634 notifyChanged(); 635 } 636 637 /** 638 * Checks whether this Preference should disable its view when it's action is disabled. 639 * @see #setShouldDisableView(boolean) 640 * @return True if it should disable the view. 641 */ 642 public boolean getShouldDisableView() { 643 return mShouldDisableView; 644 } 645 646 /** 647 * Returns a unique ID for this Preference. This ID should be unique across all 648 * Preference objects in a hierarchy. 649 * 650 * @return A unique ID for this Preference. 651 */ 652 long getId() { 653 return mId; 654 } 655 656 /** 657 * Processes a click on the preference. This includes saving the value to 658 * the {@link SharedPreferences}. However, the overridden method should 659 * call {@link #callChangeListener(Object)} to make sure the client wants to 660 * update the preference's state with the new value. 661 */ 662 protected void onClick() { 663 } 664 665 /** 666 * Sets the key for this Preference, which is used as a key to the 667 * {@link SharedPreferences}. This should be unique for the package. 668 * 669 * @param key The key for the preference. 670 */ 671 public void setKey(String key) { 672 mKey = key; 673 674 if (mRequiresKey && !hasKey()) { 675 requireKey(); 676 } 677 } 678 679 /** 680 * Gets the key for this Preference, which is also the key used for storing 681 * values into SharedPreferences. 682 * 683 * @return The key. 684 */ 685 public String getKey() { 686 return mKey; 687 } 688 689 /** 690 * Checks whether the key is present, and if it isn't throws an 691 * exception. This should be called by subclasses that store preferences in 692 * the {@link SharedPreferences}. 693 * 694 * @throws IllegalStateException If there is no key assigned. 695 */ 696 void requireKey() { 697 if (mKey == null) { 698 throw new IllegalStateException("Preference does not have a key assigned."); 699 } 700 701 mRequiresKey = true; 702 } 703 704 /** 705 * Checks whether this Preference has a valid key. 706 * 707 * @return True if the key exists and is not a blank string, false otherwise. 708 */ 709 public boolean hasKey() { 710 return !TextUtils.isEmpty(mKey); 711 } 712 713 /** 714 * Checks whether this Preference is persistent. If it is, it stores its value(s) into 715 * the persistent {@link SharedPreferences} storage. 716 * 717 * @return True if it is persistent. 718 */ 719 public boolean isPersistent() { 720 return mPersistent; 721 } 722 723 /** 724 * Checks whether, at the given time this method is called, 725 * this Preference should store/restore its value(s) into the 726 * {@link SharedPreferences}. This, at minimum, checks whether this 727 * Preference is persistent and it currently has a key. Before you 728 * save/restore from the {@link SharedPreferences}, check this first. 729 * 730 * @return True if it should persist the value. 731 */ 732 protected boolean shouldPersist() { 733 return mPreferenceManager != null && isPersistent() && hasKey(); 734 } 735 736 /** 737 * Sets whether this Preference is persistent. When persistent, 738 * it stores its value(s) into the persistent {@link SharedPreferences} 739 * storage. 740 * 741 * @param persistent Set true if it should store its value(s) into the {@link SharedPreferences}. 742 */ 743 public void setPersistent(boolean persistent) { 744 mPersistent = persistent; 745 } 746 747 /** 748 * Call this method after the user changes the preference, but before the 749 * internal state is set. This allows the client to ignore the user value. 750 * 751 * @param newValue The new value of this Preference. 752 * @return True if the user value should be set as the preference 753 * value (and persisted). 754 */ 755 protected boolean callChangeListener(Object newValue) { 756 return mOnChangeListener == null ? true : mOnChangeListener.onPreferenceChange(this, newValue); 757 } 758 759 /** 760 * Sets the callback to be invoked when this Preference is changed by the 761 * user (but before the internal state has been updated). 762 * 763 * @param onPreferenceChangeListener The callback to be invoked. 764 */ 765 public void setOnPreferenceChangeListener(OnPreferenceChangeListener onPreferenceChangeListener) { 766 mOnChangeListener = onPreferenceChangeListener; 767 } 768 769 /** 770 * Returns the callback to be invoked when this Preference is changed by the 771 * user (but before the internal state has been updated). 772 * 773 * @return The callback to be invoked. 774 */ 775 public OnPreferenceChangeListener getOnPreferenceChangeListener() { 776 return mOnChangeListener; 777 } 778 779 /** 780 * Sets the callback to be invoked when this Preference is clicked. 781 * 782 * @param onPreferenceClickListener The callback to be invoked. 783 */ 784 public void setOnPreferenceClickListener(OnPreferenceClickListener onPreferenceClickListener) { 785 mOnClickListener = onPreferenceClickListener; 786 } 787 788 /** 789 * Returns the callback to be invoked when this Preference is clicked. 790 * 791 * @return The callback to be invoked. 792 */ 793 public OnPreferenceClickListener getOnPreferenceClickListener() { 794 return mOnClickListener; 795 } 796 797 /** 798 * Called when a click should be performed. 799 * 800 * @param preferenceScreen A {@link PreferenceScreen} whose hierarchy click 801 * listener should be called in the proper order (between other 802 * processing). May be null. 803 */ 804 void performClick(PreferenceScreen preferenceScreen) { 805 806 if (!isEnabled()) { 807 return; 808 } 809 810 onClick(); 811 812 if (mOnClickListener != null && mOnClickListener.onPreferenceClick(this)) { 813 return; 814 } 815 816 PreferenceManager preferenceManager = getPreferenceManager(); 817 if (preferenceManager != null) { 818 PreferenceManager.OnPreferenceTreeClickListener listener = preferenceManager 819 .getOnPreferenceTreeClickListener(); 820 if (preferenceScreen != null && listener != null 821 && listener.onPreferenceTreeClick(preferenceScreen, this)) { 822 return; 823 } 824 } 825 826 if (mIntent != null) { 827 Context context = getContext(); 828 context.startActivity(mIntent); 829 } 830 } 831 832 /** 833 * Returns the {@link android.content.Context} of this Preference. 834 * Each Preference in a Preference hierarchy can be 835 * from different Context (for example, if multiple activities provide preferences into a single 836 * {@link PreferenceActivity}). This Context will be used to save the Preference values. 837 * 838 * @return The Context of this Preference. 839 */ 840 public Context getContext() { 841 return mContext; 842 } 843 844 /** 845 * Returns the {@link SharedPreferences} where this Preference can read its 846 * value(s). Usually, it's easier to use one of the helper read methods: 847 * {@link #getPersistedBoolean(boolean)}, {@link #getPersistedFloat(float)}, 848 * {@link #getPersistedInt(int)}, {@link #getPersistedLong(long)}, 849 * {@link #getPersistedString(String)}. To save values, see 850 * {@link #getEditor()}. 851 * <p> 852 * In some cases, writes to the {@link #getEditor()} will not be committed 853 * right away and hence not show up in the returned 854 * {@link SharedPreferences}, this is intended behavior to improve 855 * performance. 856 * 857 * @return The {@link SharedPreferences} where this Preference reads its 858 * value(s), or null if it isn't attached to a Preference hierarchy. 859 * @see #getEditor() 860 */ 861 public SharedPreferences getSharedPreferences() { 862 if (mPreferenceManager == null) { 863 return null; 864 } 865 866 return mPreferenceManager.getSharedPreferences(); 867 } 868 869 /** 870 * Returns an {@link SharedPreferences.Editor} where this Preference can 871 * save its value(s). Usually it's easier to use one of the helper save 872 * methods: {@link #persistBoolean(boolean)}, {@link #persistFloat(float)}, 873 * {@link #persistInt(int)}, {@link #persistLong(long)}, 874 * {@link #persistString(String)}. To read values, see 875 * {@link #getSharedPreferences()}. If {@link #shouldCommit()} returns 876 * true, it is this Preference's responsibility to commit. 877 * <p> 878 * In some cases, writes to this will not be committed right away and hence 879 * not show up in the SharedPreferences, this is intended behavior to 880 * improve performance. 881 * 882 * @return A {@link SharedPreferences.Editor} where this preference saves 883 * its value(s), or null if it isn't attached to a Preference 884 * hierarchy. 885 * @see #shouldCommit() 886 * @see #getSharedPreferences() 887 */ 888 public SharedPreferences.Editor getEditor() { 889 if (mPreferenceManager == null) { 890 return null; 891 } 892 893 return mPreferenceManager.getEditor(); 894 } 895 896 /** 897 * Returns whether the {@link Preference} should commit its saved value(s) in 898 * {@link #getEditor()}. This may return false in situations where batch 899 * committing is being done (by the manager) to improve performance. 900 * 901 * @return Whether the Preference should commit its saved value(s). 902 * @see #getEditor() 903 */ 904 public boolean shouldCommit() { 905 if (mPreferenceManager == null) { 906 return false; 907 } 908 909 return mPreferenceManager.shouldCommit(); 910 } 911 912 /** 913 * Compares Preference objects based on order (if set), otherwise alphabetically on the titles. 914 * 915 * @param another The Preference to compare to this one. 916 * @return 0 if the same; less than 0 if this Preference sorts ahead of <var>another</var>; 917 * greater than 0 if this Preference sorts after <var>another</var>. 918 */ 919 public int compareTo(Preference another) { 920 if (mOrder != DEFAULT_ORDER 921 || (mOrder == DEFAULT_ORDER && another.mOrder != DEFAULT_ORDER)) { 922 // Do order comparison 923 return mOrder - another.mOrder; 924 } else if (mTitle == null) { 925 return 1; 926 } else if (another.mTitle == null) { 927 return -1; 928 } else { 929 // Do name comparison 930 return CharSequences.compareToIgnoreCase(mTitle, another.mTitle); 931 } 932 } 933 934 /** 935 * Sets the internal change listener. 936 * 937 * @param listener The listener. 938 * @see #notifyChanged() 939 */ 940 final void setOnPreferenceChangeInternalListener(OnPreferenceChangeInternalListener listener) { 941 mListener = listener; 942 } 943 944 /** 945 * Should be called when the data of this {@link Preference} has changed. 946 */ 947 protected void notifyChanged() { 948 if (mListener != null) { 949 mListener.onPreferenceChange(this); 950 } 951 } 952 953 /** 954 * Should be called when a Preference has been 955 * added/removed from this group, or the ordering should be 956 * re-evaluated. 957 */ 958 protected void notifyHierarchyChanged() { 959 if (mListener != null) { 960 mListener.onPreferenceHierarchyChange(this); 961 } 962 } 963 964 /** 965 * Gets the {@link PreferenceManager} that manages this Preference object's tree. 966 * 967 * @return The {@link PreferenceManager}. 968 */ 969 public PreferenceManager getPreferenceManager() { 970 return mPreferenceManager; 971 } 972 973 /** 974 * Called when this Preference has been attached to a Preference hierarchy. 975 * Make sure to call the super implementation. 976 * 977 * @param preferenceManager The PreferenceManager of the hierarchy. 978 */ 979 protected void onAttachedToHierarchy(PreferenceManager preferenceManager) { 980 mPreferenceManager = preferenceManager; 981 982 mId = preferenceManager.getNextId(); 983 984 dispatchSetInitialValue(); 985 } 986 987 /** 988 * Called when the Preference hierarchy has been attached to the 989 * {@link PreferenceActivity}. This can also be called when this 990 * Preference has been attached to a group that was already attached 991 * to the {@link PreferenceActivity}. 992 */ 993 protected void onAttachedToActivity() { 994 // At this point, the hierarchy that this preference is in is connected 995 // with all other preferences. 996 registerDependency(); 997 } 998 999 private void registerDependency() { 1000 1001 if (TextUtils.isEmpty(mDependencyKey)) return; 1002 1003 Preference preference = findPreferenceInHierarchy(mDependencyKey); 1004 if (preference != null) { 1005 preference.registerDependent(this); 1006 } else { 1007 throw new IllegalStateException("Dependency \"" + mDependencyKey 1008 + "\" not found for preference \"" + mKey + "\" (title: \"" + mTitle + "\""); 1009 } 1010 } 1011 1012 private void unregisterDependency() { 1013 if (mDependencyKey != null) { 1014 final Preference oldDependency = findPreferenceInHierarchy(mDependencyKey); 1015 if (oldDependency != null) { 1016 oldDependency.unregisterDependent(this); 1017 } 1018 } 1019 } 1020 1021 /** 1022 * Finds a Preference in this hierarchy (the whole thing, 1023 * even above/below your {@link PreferenceScreen} screen break) with the given 1024 * key. 1025 * <p> 1026 * This only functions after we have been attached to a hierarchy. 1027 * 1028 * @param key The key of the Preference to find. 1029 * @return The Preference that uses the given key. 1030 */ 1031 protected Preference findPreferenceInHierarchy(String key) { 1032 if (TextUtils.isEmpty(key) || mPreferenceManager == null) { 1033 return null; 1034 } 1035 1036 return mPreferenceManager.findPreference(key); 1037 } 1038 1039 /** 1040 * Adds a dependent Preference on this Preference so we can notify it. 1041 * Usually, the dependent Preference registers itself (it's good for it to 1042 * know it depends on something), so please use 1043 * {@link Preference#setDependency(String)} on the dependent Preference. 1044 * 1045 * @param dependent The dependent Preference that will be enabled/disabled 1046 * according to the state of this Preference. 1047 */ 1048 private void registerDependent(Preference dependent) { 1049 if (mDependents == null) { 1050 mDependents = new ArrayList<Preference>(); 1051 } 1052 1053 mDependents.add(dependent); 1054 1055 dependent.onDependencyChanged(this, shouldDisableDependents()); 1056 } 1057 1058 /** 1059 * Removes a dependent Preference on this Preference. 1060 * 1061 * @param dependent The dependent Preference that will be enabled/disabled 1062 * according to the state of this Preference. 1063 * @return Returns the same Preference object, for chaining multiple calls 1064 * into a single statement. 1065 */ 1066 private void unregisterDependent(Preference dependent) { 1067 if (mDependents != null) { 1068 mDependents.remove(dependent); 1069 } 1070 } 1071 1072 /** 1073 * Notifies any listening dependents of a change that affects the 1074 * dependency. 1075 * 1076 * @param disableDependents Whether this Preference should disable 1077 * its dependents. 1078 */ 1079 public void notifyDependencyChange(boolean disableDependents) { 1080 final List<Preference> dependents = mDependents; 1081 1082 if (dependents == null) { 1083 return; 1084 } 1085 1086 final int dependentsCount = dependents.size(); 1087 for (int i = 0; i < dependentsCount; i++) { 1088 dependents.get(i).onDependencyChanged(this, disableDependents); 1089 } 1090 } 1091 1092 /** 1093 * Called when the dependency changes. 1094 * 1095 * @param dependency The Preference that this Preference depends on. 1096 * @param disableDependent Set true to disable this Preference. 1097 */ 1098 public void onDependencyChanged(Preference dependency, boolean disableDependent) { 1099 setEnabled(!disableDependent); 1100 } 1101 1102 /** 1103 * Checks whether this preference's dependents should currently be 1104 * disabled. 1105 * 1106 * @return True if the dependents should be disabled, otherwise false. 1107 */ 1108 public boolean shouldDisableDependents() { 1109 return !isEnabled(); 1110 } 1111 1112 /** 1113 * Sets the key of a Preference that this Preference will depend on. If that 1114 * Preference is not set or is off, this Preference will be disabled. 1115 * 1116 * @param dependencyKey The key of the Preference that this depends on. 1117 */ 1118 public void setDependency(String dependencyKey) { 1119 // Unregister the old dependency, if we had one 1120 unregisterDependency(); 1121 1122 // Register the new 1123 mDependencyKey = dependencyKey; 1124 registerDependency(); 1125 } 1126 1127 /** 1128 * Returns the key of the dependency on this Preference. 1129 * 1130 * @return The key of the dependency. 1131 * @see #setDependency(String) 1132 */ 1133 public String getDependency() { 1134 return mDependencyKey; 1135 } 1136 1137 /** 1138 * Called when this Preference is being removed from the hierarchy. You 1139 * should remove any references to this Preference that you know about. Make 1140 * sure to call through to the superclass implementation. 1141 */ 1142 protected void onPrepareForRemoval() { 1143 unregisterDependency(); 1144 } 1145 1146 /** 1147 * Sets the default value for this Preference, which will be set either if 1148 * persistence is off or persistence is on and the preference is not found 1149 * in the persistent storage. 1150 * 1151 * @param defaultValue The default value. 1152 */ 1153 public void setDefaultValue(Object defaultValue) { 1154 mDefaultValue = defaultValue; 1155 } 1156 1157 private void dispatchSetInitialValue() { 1158 // By now, we know if we are persistent. 1159 final boolean shouldPersist = shouldPersist(); 1160 if (!shouldPersist || !getSharedPreferences().contains(mKey)) { 1161 if (mDefaultValue != null) { 1162 onSetInitialValue(false, mDefaultValue); 1163 } 1164 } else { 1165 onSetInitialValue(true, null); 1166 } 1167 } 1168 1169 /** 1170 * Implement this to set the initial value of the Preference. 1171 * <p> 1172 * If <var>restorePersistedValue</var> is true, you should restore the 1173 * Preference value from the {@link android.content.SharedPreferences}. If 1174 * <var>restorePersistedValue</var> is false, you should set the Preference 1175 * value to defaultValue that is given (and possibly store to SharedPreferences 1176 * if {@link #shouldPersist()} is true). 1177 * <p> 1178 * This may not always be called. One example is if it should not persist 1179 * but there is no default value given. 1180 * 1181 * @param restorePersistedValue True to restore the persisted value; 1182 * false to use the given <var>defaultValue</var>. 1183 * @param defaultValue The default value for this Preference. Only use this 1184 * if <var>restorePersistedValue</var> is false. 1185 */ 1186 protected void onSetInitialValue(boolean restorePersistedValue, Object defaultValue) { 1187 } 1188 1189 private void tryCommit(SharedPreferences.Editor editor) { 1190 if (mPreferenceManager.shouldCommit()) { 1191 editor.commit(); 1192 } 1193 } 1194 1195 /** 1196 * Attempts to persist a String to the {@link android.content.SharedPreferences}. 1197 * <p> 1198 * This will check if this Preference is persistent, get an editor from 1199 * the {@link PreferenceManager}, put in the string, and check if we should commit (and 1200 * commit if so). 1201 * 1202 * @param value The value to persist. 1203 * @return True if the Preference is persistent. (This is not whether the 1204 * value was persisted, since we may not necessarily commit if there 1205 * will be a batch commit later.) 1206 * @see #getPersistedString(String) 1207 */ 1208 protected boolean persistString(String value) { 1209 if (shouldPersist()) { 1210 // Shouldn't store null 1211 if (value == getPersistedString(null)) { 1212 // It's already there, so the same as persisting 1213 return true; 1214 } 1215 1216 SharedPreferences.Editor editor = mPreferenceManager.getEditor(); 1217 editor.putString(mKey, value); 1218 tryCommit(editor); 1219 return true; 1220 } 1221 return false; 1222 } 1223 1224 /** 1225 * Attempts to get a persisted String from the {@link android.content.SharedPreferences}. 1226 * <p> 1227 * This will check if this Preference is persistent, get the SharedPreferences 1228 * from the {@link PreferenceManager}, and get the value. 1229 * 1230 * @param defaultReturnValue The default value to return if either the 1231 * Preference is not persistent or the Preference is not in the 1232 * shared preferences. 1233 * @return The value from the SharedPreferences or the default return 1234 * value. 1235 * @see #persistString(String) 1236 */ 1237 protected String getPersistedString(String defaultReturnValue) { 1238 if (!shouldPersist()) { 1239 return defaultReturnValue; 1240 } 1241 1242 return mPreferenceManager.getSharedPreferences().getString(mKey, defaultReturnValue); 1243 } 1244 1245 /** 1246 * Attempts to persist an int to the {@link android.content.SharedPreferences}. 1247 * 1248 * @param value The value to persist. 1249 * @return True if the Preference is persistent. (This is not whether the 1250 * value was persisted, since we may not necessarily commit if there 1251 * will be a batch commit later.) 1252 * @see #persistString(String) 1253 * @see #getPersistedInt(int) 1254 */ 1255 protected boolean persistInt(int value) { 1256 if (shouldPersist()) { 1257 if (value == getPersistedInt(~value)) { 1258 // It's already there, so the same as persisting 1259 return true; 1260 } 1261 1262 SharedPreferences.Editor editor = mPreferenceManager.getEditor(); 1263 editor.putInt(mKey, value); 1264 tryCommit(editor); 1265 return true; 1266 } 1267 return false; 1268 } 1269 1270 /** 1271 * Attempts to get a persisted int from the {@link android.content.SharedPreferences}. 1272 * 1273 * @param defaultReturnValue The default value to return if either this 1274 * Preference is not persistent or this Preference is not in the 1275 * SharedPreferences. 1276 * @return The value from the SharedPreferences or the default return 1277 * value. 1278 * @see #getPersistedString(String) 1279 * @see #persistInt(int) 1280 */ 1281 protected int getPersistedInt(int defaultReturnValue) { 1282 if (!shouldPersist()) { 1283 return defaultReturnValue; 1284 } 1285 1286 return mPreferenceManager.getSharedPreferences().getInt(mKey, defaultReturnValue); 1287 } 1288 1289 /** 1290 * Attempts to persist a float to the {@link android.content.SharedPreferences}. 1291 * 1292 * @param value The value to persist. 1293 * @return True if this Preference is persistent. (This is not whether the 1294 * value was persisted, since we may not necessarily commit if there 1295 * will be a batch commit later.) 1296 * @see #persistString(String) 1297 * @see #getPersistedFloat(float) 1298 */ 1299 protected boolean persistFloat(float value) { 1300 if (shouldPersist()) { 1301 if (value == getPersistedFloat(Float.NaN)) { 1302 // It's already there, so the same as persisting 1303 return true; 1304 } 1305 1306 SharedPreferences.Editor editor = mPreferenceManager.getEditor(); 1307 editor.putFloat(mKey, value); 1308 tryCommit(editor); 1309 return true; 1310 } 1311 return false; 1312 } 1313 1314 /** 1315 * Attempts to get a persisted float from the {@link android.content.SharedPreferences}. 1316 * 1317 * @param defaultReturnValue The default value to return if either this 1318 * Preference is not persistent or this Preference is not in the 1319 * SharedPreferences. 1320 * @return The value from the SharedPreferences or the default return 1321 * value. 1322 * @see #getPersistedString(String) 1323 * @see #persistFloat(float) 1324 */ 1325 protected float getPersistedFloat(float defaultReturnValue) { 1326 if (!shouldPersist()) { 1327 return defaultReturnValue; 1328 } 1329 1330 return mPreferenceManager.getSharedPreferences().getFloat(mKey, defaultReturnValue); 1331 } 1332 1333 /** 1334 * Attempts to persist a long to the {@link android.content.SharedPreferences}. 1335 * 1336 * @param value The value to persist. 1337 * @return True if this Preference is persistent. (This is not whether the 1338 * value was persisted, since we may not necessarily commit if there 1339 * will be a batch commit later.) 1340 * @see #persistString(String) 1341 * @see #getPersistedLong(long) 1342 */ 1343 protected boolean persistLong(long value) { 1344 if (shouldPersist()) { 1345 if (value == getPersistedLong(~value)) { 1346 // It's already there, so the same as persisting 1347 return true; 1348 } 1349 1350 SharedPreferences.Editor editor = mPreferenceManager.getEditor(); 1351 editor.putLong(mKey, value); 1352 tryCommit(editor); 1353 return true; 1354 } 1355 return false; 1356 } 1357 1358 /** 1359 * Attempts to get a persisted long from the {@link android.content.SharedPreferences}. 1360 * 1361 * @param defaultReturnValue The default value to return if either this 1362 * Preference is not persistent or this Preference is not in the 1363 * SharedPreferences. 1364 * @return The value from the SharedPreferences or the default return 1365 * value. 1366 * @see #getPersistedString(String) 1367 * @see #persistLong(long) 1368 */ 1369 protected long getPersistedLong(long defaultReturnValue) { 1370 if (!shouldPersist()) { 1371 return defaultReturnValue; 1372 } 1373 1374 return mPreferenceManager.getSharedPreferences().getLong(mKey, defaultReturnValue); 1375 } 1376 1377 /** 1378 * Attempts to persist a boolean to the {@link android.content.SharedPreferences}. 1379 * 1380 * @param value The value to persist. 1381 * @return True if this Preference is persistent. (This is not whether the 1382 * value was persisted, since we may not necessarily commit if there 1383 * will be a batch commit later.) 1384 * @see #persistString(String) 1385 * @see #getPersistedBoolean(boolean) 1386 */ 1387 protected boolean persistBoolean(boolean value) { 1388 if (shouldPersist()) { 1389 if (value == getPersistedBoolean(!value)) { 1390 // It's already there, so the same as persisting 1391 return true; 1392 } 1393 1394 SharedPreferences.Editor editor = mPreferenceManager.getEditor(); 1395 editor.putBoolean(mKey, value); 1396 tryCommit(editor); 1397 return true; 1398 } 1399 return false; 1400 } 1401 1402 /** 1403 * Attempts to get a persisted boolean from the {@link android.content.SharedPreferences}. 1404 * 1405 * @param defaultReturnValue The default value to return if either this 1406 * Preference is not persistent or this Preference is not in the 1407 * SharedPreferences. 1408 * @return The value from the SharedPreferences or the default return 1409 * value. 1410 * @see #getPersistedString(String) 1411 * @see #persistBoolean(boolean) 1412 */ 1413 protected boolean getPersistedBoolean(boolean defaultReturnValue) { 1414 if (!shouldPersist()) { 1415 return defaultReturnValue; 1416 } 1417 1418 return mPreferenceManager.getSharedPreferences().getBoolean(mKey, defaultReturnValue); 1419 } 1420 1421 boolean hasSpecifiedLayout() { 1422 return mHasSpecifiedLayout; 1423 } 1424 1425 @Override 1426 public String toString() { 1427 return getFilterableStringBuilder().toString(); 1428 } 1429 1430 /** 1431 * Returns the text that will be used to filter this Preference depending on 1432 * user input. 1433 * <p> 1434 * If overridding and calling through to the superclass, make sure to prepend 1435 * your additions with a space. 1436 * 1437 * @return Text as a {@link StringBuilder} that will be used to filter this 1438 * preference. By default, this is the title and summary 1439 * (concatenated with a space). 1440 */ 1441 StringBuilder getFilterableStringBuilder() { 1442 StringBuilder sb = new StringBuilder(); 1443 CharSequence title = getTitle(); 1444 if (!TextUtils.isEmpty(title)) { 1445 sb.append(title).append(' '); 1446 } 1447 CharSequence summary = getSummary(); 1448 if (!TextUtils.isEmpty(summary)) { 1449 sb.append(summary).append(' '); 1450 } 1451 // Drop the last space 1452 sb.setLength(sb.length() - 1); 1453 return sb; 1454 } 1455 1456 /** 1457 * Store this Preference hierarchy's frozen state into the given container. 1458 * 1459 * @param container The Bundle in which to save the instance of this Preference. 1460 * 1461 * @see #restoreHierarchyState 1462 * @see #onSaveInstanceState 1463 */ 1464 public void saveHierarchyState(Bundle container) { 1465 dispatchSaveInstanceState(container); 1466 } 1467 1468 /** 1469 * Called by {@link #saveHierarchyState} to store the instance for this Preference and its children. 1470 * May be overridden to modify how the save happens for children. For example, some 1471 * Preference objects may want to not store an instance for their children. 1472 * 1473 * @param container The Bundle in which to save the instance of this Preference. 1474 * 1475 * @see #saveHierarchyState 1476 * @see #onSaveInstanceState 1477 */ 1478 void dispatchSaveInstanceState(Bundle container) { 1479 if (hasKey()) { 1480 mBaseMethodCalled = false; 1481 Parcelable state = onSaveInstanceState(); 1482 if (!mBaseMethodCalled) { 1483 throw new IllegalStateException( 1484 "Derived class did not call super.onSaveInstanceState()"); 1485 } 1486 if (state != null) { 1487 container.putParcelable(mKey, state); 1488 } 1489 } 1490 } 1491 1492 /** 1493 * Hook allowing a Preference to generate a representation of its internal 1494 * state that can later be used to create a new instance with that same 1495 * state. This state should only contain information that is not persistent 1496 * or can be reconstructed later. 1497 * 1498 * @return A Parcelable object containing the current dynamic state of 1499 * this Preference, or null if there is nothing interesting to save. 1500 * The default implementation returns null. 1501 * @see #onRestoreInstanceState 1502 * @see #saveHierarchyState 1503 */ 1504 protected Parcelable onSaveInstanceState() { 1505 mBaseMethodCalled = true; 1506 return BaseSavedState.EMPTY_STATE; 1507 } 1508 1509 /** 1510 * Restore this Preference hierarchy's previously saved state from the given container. 1511 * 1512 * @param container The Bundle that holds the previously saved state. 1513 * 1514 * @see #saveHierarchyState 1515 * @see #onRestoreInstanceState 1516 */ 1517 public void restoreHierarchyState(Bundle container) { 1518 dispatchRestoreInstanceState(container); 1519 } 1520 1521 /** 1522 * Called by {@link #restoreHierarchyState} to retrieve the saved state for this 1523 * Preference and its children. May be overridden to modify how restoring 1524 * happens to the children of a Preference. For example, some Preference objects may 1525 * not want to save state for their children. 1526 * 1527 * @param container The Bundle that holds the previously saved state. 1528 * @see #restoreHierarchyState 1529 * @see #onRestoreInstanceState 1530 */ 1531 void dispatchRestoreInstanceState(Bundle container) { 1532 if (hasKey()) { 1533 Parcelable state = container.getParcelable(mKey); 1534 if (state != null) { 1535 mBaseMethodCalled = false; 1536 onRestoreInstanceState(state); 1537 if (!mBaseMethodCalled) { 1538 throw new IllegalStateException( 1539 "Derived class did not call super.onRestoreInstanceState()"); 1540 } 1541 } 1542 } 1543 } 1544 1545 /** 1546 * Hook allowing a Preference to re-apply a representation of its internal 1547 * state that had previously been generated by {@link #onSaveInstanceState}. 1548 * This function will never be called with a null state. 1549 * 1550 * @param state The saved state that had previously been returned by 1551 * {@link #onSaveInstanceState}. 1552 * @see #onSaveInstanceState 1553 * @see #restoreHierarchyState 1554 */ 1555 protected void onRestoreInstanceState(Parcelable state) { 1556 mBaseMethodCalled = true; 1557 if (state != BaseSavedState.EMPTY_STATE && state != null) { 1558 throw new IllegalArgumentException("Wrong state class -- expecting Preference State"); 1559 } 1560 } 1561 1562 /** 1563 * A base class for managing the instance state of a {@link Preference}. 1564 */ 1565 public static class BaseSavedState extends AbsSavedState { 1566 public BaseSavedState(Parcel source) { 1567 super(source); 1568 } 1569 1570 public BaseSavedState(Parcelable superState) { 1571 super(superState); 1572 } 1573 1574 public static final Parcelable.Creator<BaseSavedState> CREATOR = 1575 new Parcelable.Creator<BaseSavedState>() { 1576 public BaseSavedState createFromParcel(Parcel in) { 1577 return new BaseSavedState(in); 1578 } 1579 1580 public BaseSavedState[] newArray(int size) { 1581 return new BaseSavedState[size]; 1582 } 1583 }; 1584 } 1585 1586} 1587