/**
+ * @class Ext.form.FieldAncestor
+
+A mixin for {@link Ext.container.Container} components that are likely to have form fields in their
+items subtree. Adds the following capabilities:
+
+- Methods for handling the addition and removal of {@link Ext.form.Labelable} and {@link Ext.form.field.Field}
+ instances at any depth within the container.
+- Events ({@link #fieldvaliditychange} and {@link #fielderrorchange}) for handling changes to the state
+ of individual fields at the container level.
+- Automatic application of {@link #fieldDefaults} config properties to each field added within the
+ container, to facilitate uniform configuration of all fields.
+
+This mixin is primarily for internal use by {@link Ext.form.Panel} and {@link Ext.form.FieldContainer},
+and should not normally need to be used directly.
+
+ * @markdown
+ * @docauthor Jason Johnston <jason@sencha.com>
+ */
+Ext.define('Ext.form.FieldAncestor', {
+
+ /**
+ * @cfg {Object} fieldDefaults
+ * <p>If specified, the properties in this object are used as default config values for each
+ * {@link Ext.form.Labelable} instance (e.g. {@link Ext.form.field.Base} or {@link Ext.form.FieldContainer})
+ * that is added as a descendant of this container. Corresponding values specified in an individual field's
+ * own configuration, or from the {@link Ext.container.Container#defaults defaults config} of its parent container,
+ * will take precedence. See the documentation for {@link Ext.form.Labelable} to see what config
+ * options may be specified in the <tt>fieldDefaults</tt>.</p>
+ * <p>Example:</p>
+ * <pre><code>new Ext.form.Panel({
+ fieldDefaults: {
+ labelAlign: 'left',
+ labelWidth: 100
+ },
+ items: [{
+ xtype: 'fieldset',
+ defaults: {
+ labelAlign: 'top'
+ },
+ items: [{
+ name: 'field1'
+ }, {
+ name: 'field2'
+ }]
+ }, {
+ xtype: 'fieldset',
+ items: [{
+ name: 'field3',
+ labelWidth: 150
+ }, {
+ name: 'field4'
+ }]
+ }]
+});</code></pre>
+ * <p>In this example, field1 and field2 will get labelAlign:'top' (from the fieldset's <tt>defaults</tt>)
+ * and labelWidth:100 (from <tt>fieldDefaults</tt>), field3 and field4 will both get labelAlign:'left' (from
+ * <tt>fieldDefaults</tt> and field3 will use the labelWidth:150 from its own config.</p>
+ */
+
+
+ /**
+ * @protected Initializes the FieldAncestor's state; this must be called from the initComponent method
+ * of any components importing this mixin.
+ */
+ initFieldAncestor: function() {
+ var me = this,
+ onSubtreeChange = me.onFieldAncestorSubtreeChange;
+
+ me.addEvents(
+ /**
+ * @event fielderrorchange
+ * Fires when the validity state of any one of the {@link Ext.form.field.Field} instances within this
+ * container changes.
+ * @param {Ext.form.FieldAncestor} this
+ * @param {Ext.form.Labelable} The Field instance whose validity changed
+ * @param {String} isValid The field's new validity state
+ */
+ 'fieldvaliditychange',
+
+ /**
+ * @event fielderrorchange
+ * Fires when the active error message is changed for any one of the {@link Ext.form.Labelable}
+ * instances within this container.
+ * @param {Ext.form.FieldAncestor} this
+ * @param {Ext.form.Labelable} The Labelable instance whose active error was changed
+ * @param {String} error The active error message
+ */
+ 'fielderrorchange'
+ );
+
+ // Catch addition and removal of descendant fields
+ me.on('add', onSubtreeChange, me);
+ me.on('remove', onSubtreeChange, me);
+
+ me.initFieldDefaults();
+ },
+
+ /**
+ * @private Initialize the {@link #fieldDefaults} object
+ */
+ initFieldDefaults: function() {
+ if (!this.fieldDefaults) {
+ this.fieldDefaults = {};
+ }
+ },
+
+ /**
+ * @private
+ * Handle the addition and removal of components in the FieldAncestor component's child tree.
+ */
+ onFieldAncestorSubtreeChange: function(parent, child) {
+ var me = this,
+ isAdding = !!child.ownerCt;
+
+ function handleCmp(cmp) {
+ var isLabelable = cmp.isFieldLabelable,
+ isField = cmp.isFormField;
+ if (isLabelable || isField) {
+ if (isLabelable) {
+ me['onLabelable' + (isAdding ? 'Added' : 'Removed')](cmp);
+ }
+ if (isField) {
+ me['onField' + (isAdding ? 'Added' : 'Removed')](cmp);
+ }
+ }
+ else if (cmp.isContainer) {
+ Ext.Array.forEach(cmp.getRefItems(), handleCmp);
+ }
+ }
+ handleCmp(child);
+ },
+
+ /**
+ * @protected Called when a {@link Ext.form.Labelable} instance is added to the container's subtree.
+ * @param {Ext.form.Labelable} labelable The instance that was added
+ */
+ onLabelableAdded: function(labelable) {
+ var me = this;
+
+ // buffer slightly to avoid excessive firing while sub-fields are changing en masse
+ me.mon(labelable, 'errorchange', me.handleFieldErrorChange, me, {buffer: 10});
+
+ labelable.setFieldDefaults(me.fieldDefaults);
+ },
+
+ /**
+ * @protected Called when a {@link Ext.form.field.Field} instance is added to the container's subtree.
+ * @param {Ext.form.field.Field} field The field which was added
+ */
+ onFieldAdded: function(field) {
+ var me = this;
+ me.mon(field, 'validitychange', me.handleFieldValidityChange, me);
+ },
+
+ /**
+ * @protected Called when a {@link Ext.form.Labelable} instance is removed from the container's subtree.
+ * @param {Ext.form.Labelable} labelable The instance that was removed
+ */
+ onLabelableRemoved: function(labelable) {
+ var me = this;
+ me.mun(labelable, 'errorchange', me.handleFieldErrorChange, me);
+ },
+
+ /**
+ * @protected Called when a {@link Ext.form.field.Field} instance is removed from the container's subtree.
+ * @param {Ext.form.field.Field} field The field which was removed
+ */
+ onFieldRemoved: function(field) {
+ var me = this;
+ me.mun(field, 'validitychange', me.handleFieldValidityChange, me);
+ },
+
+ /**
+ * @private Handle validitychange events on sub-fields; invoke the aggregated event and method
+ */
+ handleFieldValidityChange: function(field, isValid) {
+ var me = this;
+ me.fireEvent('fieldvaliditychange', me, field, isValid);
+ me.onFieldValidityChange();
+ },
+
+ /**
+ * @private Handle errorchange events on sub-fields; invoke the aggregated event and method
+ */
+ handleFieldErrorChange: function(labelable, activeError) {
+ var me = this;
+ me.fireEvent('fielderrorchange', me, labelable, activeError);
+ me.onFieldErrorChange();
+ },
+
+ /**
+ * @protected Fired when the validity of any field within the container changes.
+ * @param {Ext.form.field.Field} The sub-field whose validity changed
+ * @param {String} The new validity state
+ */
+ onFieldValidityChange: Ext.emptyFn,
+
+ /**
+ * @protected Fired when the error message of any field within the container changes.
+ * @param {Ext.form.Labelable} The sub-field whose active error changed
+ * @param {String} The new active error message
+ */
+ onFieldErrorChange: Ext.emptyFn
+
+});