/**
+ * @class Ext.state.Stateful
+ * A mixin for being able to save the state of an object to an underlying
+ * {@link Ext.state.Provider}.
+ */
+Ext.define('Ext.state.Stateful', {
+
+ /* Begin Definitions */
+
+ mixins: {
+ observable: 'Ext.util.Observable'
+ },
+
+ requires: ['Ext.state.Manager'],
+
+ /* End Definitions */
+
+ /**
+ * @cfg {Boolean} stateful
+ * <p>A flag which causes the object to attempt to restore the state of
+ * internal properties from a saved state on startup. The object must have
+ * a <code>{@link #stateId}</code> for state to be managed.
+ * Auto-generated ids are not guaranteed to be stable across page loads and
+ * cannot be relied upon to save and restore the same state for a object.<p>
+ * <p>For state saving to work, the state manager's provider must have been
+ * set to an implementation of {@link Ext.state.Provider} which overrides the
+ * {@link Ext.state.Provider#set set} and {@link Ext.state.Provider#get get}
+ * methods to save and recall name/value pairs. A built-in implementation,
+ * {@link Ext.state.CookieProvider} is available.</p>
+ * <p>To set the state provider for the current page:</p>
+ * <pre><code>
+Ext.state.Manager.setProvider(new Ext.state.CookieProvider({
+ expires: new Date(new Date().getTime()+(1000*60*60*24*7)), //7 days from now
+}));
+ * </code></pre>
+ * <p>A stateful object attempts to save state when one of the events
+ * listed in the <code>{@link #stateEvents}</code> configuration fires.</p>
+ * <p>To save state, a stateful object first serializes its state by
+ * calling <b><code>{@link #getState}</code></b>. By default, this function does
+ * nothing. The developer must provide an implementation which returns an
+ * object hash which represents the restorable state of the object.</p>
+ * <p>The value yielded by getState is passed to {@link Ext.state.Manager#set}
+ * which uses the configured {@link Ext.state.Provider} to save the object
+ * keyed by the <code>{@link stateId}</code></p>.
+ * <p>During construction, a stateful object attempts to <i>restore</i>
+ * its state by calling {@link Ext.state.Manager#get} passing the
+ * <code>{@link #stateId}</code></p>
+ * <p>The resulting object is passed to <b><code>{@link #applyState}</code></b>.
+ * The default implementation of <code>{@link #applyState}</code> simply copies
+ * properties into the object, but a developer may override this to support
+ * more behaviour.</p>
+ * <p>You can perform extra processing on state save and restore by attaching
+ * handlers to the {@link #beforestaterestore}, {@link #staterestore},
+ * {@link #beforestatesave} and {@link #statesave} events.</p>
+ */
+ stateful: true,
+
+ /**
+ * @cfg {String} stateId
+ * The unique id for this object to use for state management purposes.
+ * <p>See {@link #stateful} for an explanation of saving and restoring state.</p>
+ */
+
+ /**
+ * @cfg {Array} stateEvents
+ * <p>An array of events that, when fired, should trigger this object to
+ * save its state (defaults to none). <code>stateEvents</code> may be any type
+ * of event supported by this object, including browser or custom events
+ * (e.g., <tt>['click', 'customerchange']</tt>).</p>
+ * <p>See <code>{@link #stateful}</code> for an explanation of saving and
+ * restoring object state.</p>
+ */
+
+ /**
+ * @cfg {Number} saveBuffer A buffer to be applied if many state events are fired within
+ * a short period. Defaults to 100.
+ */
+ saveDelay: 100,
+
+ autoGenIdRe: /^((\w+-)|(ext-comp-))\d{4,}$/i,
+
+ constructor: function(config) {
+ var me = this;
+
+ config = config || {};
+ if (Ext.isDefined(config.stateful)) {
+ me.stateful = config.stateful;
+ }
+ if (Ext.isDefined(config.saveDelay)) {
+ me.saveDelay = config.saveDelay;
+ }
+ me.stateId = config.stateId;
+
+ if (!me.stateEvents) {
+ me.stateEvents = [];
+ }
+ if (config.stateEvents) {
+ me.stateEvents.concat(config.stateEvents);
+ }
+ this.addEvents(
+ /**
+ * @event beforestaterestore
+ * Fires before the state of the object is restored. Return false from an event handler to stop the restore.
+ * @param {Ext.state.Stateful} this
+ * @param {Object} state The hash of state values returned from the StateProvider. If this
+ * event is not vetoed, then the state object is passed to <b><tt>applyState</tt></b>. By default,
+ * that simply copies property values into this object. The method maybe overriden to
+ * provide custom state restoration.
+ */
+ 'beforestaterestore',
+
+ /**
+ * @event staterestore
+ * Fires after the state of the object is restored.
+ * @param {Ext.state.Stateful} this
+ * @param {Object} state The hash of state values returned from the StateProvider. This is passed
+ * to <b><tt>applyState</tt></b>. By default, that simply copies property values into this
+ * object. The method maybe overriden to provide custom state restoration.
+ */
+ 'staterestore',
+
+ /**
+ * @event beforestatesave
+ * Fires before the state of the object is saved to the configured state provider. Return false to stop the save.
+ * @param {Ext.state.Stateful} this
+ * @param {Object} state The hash of state values. This is determined by calling
+ * <b><tt>getState()</tt></b> on the object. This method must be provided by the
+ * developer to return whetever representation of state is required, by default, Ext.state.Stateful
+ * has a null implementation.
+ */
+ 'beforestatesave',
+
+ /**
+ * @event statesave
+ * Fires after the state of the object is saved to the configured state provider.
+ * @param {Ext.state.Stateful} this
+ * @param {Object} state The hash of state values. This is determined by calling
+ * <b><tt>getState()</tt></b> on the object. This method must be provided by the
+ * developer to return whetever representation of state is required, by default, Ext.state.Stateful
+ * has a null implementation.
+ */
+ 'statesave'
+ );
+ me.mixins.observable.constructor.call(me);
+ if (me.stateful !== false) {
+ me.initStateEvents();
+ me.initState();
+ }
+ },
+
+ /**
+ * Initializes any state events for this object.
+ * @private
+ */
+ initStateEvents: function() {
+ this.addStateEvents(this.stateEvents);
+ },
+
+ /**
+ * Add events that will trigger the state to be saved.
+ * @param {String/Array} events The event name or an array of event names.
+ */
+ addStateEvents: function(events){
+ if (!Ext.isArray(events)) {
+ events = [events];
+ }
+
+ var me = this,
+ i = 0,
+ len = events.length;
+
+ for (; i < len; ++i) {
+ me.on(events[i], me.onStateChange, me);
+ }
+ },
+
+ /**
+ * This method is called when any of the {@link #stateEvents} are fired.
+ * @private
+ */
+ onStateChange: function(){
+ var me = this,
+ delay = me.saveDelay;
+
+ if (delay > 0) {
+ if (!me.stateTask) {
+ me.stateTask = Ext.create('Ext.util.DelayedTask', me.saveState, me);
+ }
+ me.stateTask.delay(me.saveDelay);
+ } else {
+ me.saveState();
+ }
+ },
+
+ /**
+ * Saves the state of the object to the persistence store.
+ * @private
+ */
+ saveState: function() {
+ var me = this,
+ id,
+ state;
+
+ if (me.stateful !== false) {
+ id = me.getStateId();
+ if (id) {
+ state = me.getState();
+ if (me.fireEvent('beforestatesave', me, state) !== false) {
+ Ext.state.Manager.set(id, state);
+ me.fireEvent('statesave', me, state);
+ }
+ }
+ }
+ },
+
+ /**
+ * Gets the current state of the object. By default this function returns null,
+ * it should be overridden in subclasses to implement methods for getting the state.
+ * @return {Object} The current state
+ */
+ getState: function(){
+ return null;
+ },
+
+ /**
+ * Applies the state to the object. This should be overridden in subclasses to do
+ * more complex state operations. By default it applies the state properties onto
+ * the current object.
+ * @param {Object} state The state
+ */
+ applyState: function(state) {
+ if (state) {
+ Ext.apply(this, state);
+ }
+ },
+
+ /**
+ * Gets the state id for this object.
+ * @return {String} The state id, null if not found.
+ */
+ getStateId: function() {
+ var me = this,
+ id = me.stateId;
+
+ if (!id) {
+ id = me.autoGenIdRe.test(String(me.id)) ? null : me.id;
+ }
+ return id;
+ },
+
+ /**
+ * Initializes the state of the object upon construction.
+ * @private
+ */
+ initState: function(){
+ var me = this,
+ id = me.getStateId(),
+ state;
+
+ if (me.stateful !== false) {
+ if (id) {
+ state = Ext.state.Manager.get(id);
+ if (state) {
+ state = Ext.apply({}, state);
+ if (me.fireEvent('beforestaterestore', me, state) !== false) {
+ me.applyState(state);
+ me.fireEvent('staterestore', me, state);
+ }
+ }
+ }
+ }
+ },
+
+ /**
+ * Destroys this stateful object.
+ */
+ destroy: function(){
+ var task = this.stateTask;
+ if (task) {
+ task.cancel();
+ }
+ this.clearListeners();
+
+ }
+
+});
+