    /**
     * @class Ext.form.FieldContainer
     * @extends Ext.container.Container

    FieldContainer is a derivation of {@link Ext.container.Container Container} that implements the
    {@link Ext.form.Labelable Labelable} mixin. This allows it to be configured so that it is rendered with
    a {@link #fieldLabel field label} and optional {@link #msgTarget error message} around its sub-items.
    This is useful for arranging a group of fields or other components within a single item in a form, so
    that it lines up nicely with other fields. A common use is for grouping a set of related fields under
    a single label in a form.

    The container's configured {@link #items} will be layed out within the field body area according to the
    configured {@link #layout} type. The default layout is `'autocontainer'`.

    Like regular fields, FieldContainer can inherit its decoration configuration from the
    {@link Ext.form.Panel#fieldDefaults fieldDefaults} of an enclosing FormPanel. In addition,
    FieldContainer itself can pass {@link #fieldDefaults} to any {@link Ext.form.Labelable fields}
    it may itself contain.

    If you are grouping a set of {@link Ext.form.field.Checkbox Checkbox} or {@link Ext.form.field.Radio Radio}
    fields in a single labeled container, consider using a {@link Ext.form.CheckboxGroup}
    or {@link Ext.form.RadioGroup} instead as they are specialized for handling those types.
    {@img Ext.form.FieldContainer/Ext.form.FieldContainer1.png Ext.form.FieldContainer component}
    __Example usage:__

        Ext.create('Ext.form.Panel', {
            title: 'FieldContainer Example',
            width: 550,
            bodyPadding: 10,

            items: [{
                xtype: 'fieldcontainer',
                fieldLabel: 'Last Three Jobs',
                labelWidth: 100,

                // The body area will contain three text fields, arranged
                // horizontally, separated by draggable splitters.
                layout: 'hbox',
                items: [{
                    xtype: 'textfield',
                    flex: 1
                }, {
                    xtype: 'splitter'
                }, {
                    xtype: 'textfield',
                    flex: 1
                }, {
                    xtype: 'splitter'
                }, {
                    xtype: 'textfield',
                    flex: 1
                }]
            }],
            renderTo: Ext.getBody()
        });

    __Usage of {@link #fieldDefaults}:__
    {@img Ext.form.FieldContainer/Ext.form.FieldContainer2.png Ext.form.FieldContainer component}

        Ext.create('Ext.form.Panel', {
            title: 'FieldContainer Example',
            width: 350,
            bodyPadding: 10,

            items: [{
                xtype: 'fieldcontainer',
                fieldLabel: 'Your Name',
                labelWidth: 75,
                defaultType: 'textfield',

                // Arrange fields vertically, stretched to full width
                layout: 'anchor',
                defaults: {
                    layout: '100%'
                },

                // These config values will be applied to both sub-fields, except
                // for Last Name which will use its own msgTarget.
                fieldDefaults: {
                    msgTarget: 'under',
                    labelAlign: 'top'
                },

                items: [{
                    fieldLabel: 'First Name',
                    name: 'firstName'
                }, {
                    fieldLabel: 'Last Name',
                    name: 'lastName',
                    msgTarget: 'under'
                }]
            }],
            renderTo: Ext.getBody()
        });

     * @markdown
     * @docauthor Jason Johnston <jason@sencha.com>
     */
    Ext.define('Ext.form.FieldContainer', {
        extend: 'Ext.container.Container',
        mixins: {
            labelable: 'Ext.form.Labelable',
            fieldAncestor: 'Ext.form.FieldAncestor'
        },
        alias: 'widget.fieldcontainer',

        componentLayout: 'field',

        /**
         * @cfg {Boolean} combineLabels
         * If set to true, and there is no defined {@link #fieldLabel}, the field container will automatically
         * generate its label by combining the labels of all the fields it contains. Defaults to false.
         */
        combineLabels: false,

        /**
         * @cfg {String} labelConnector
         * The string to use when joining the labels of individual sub-fields, when {@link #combineLabels} is
         * set to true. Defaults to ', '.
         */
        labelConnector: ', ',

        /**
         * @cfg {Boolean} combineErrors
         * If set to true, the field container will automatically combine and display the validation errors from
         * all the fields it contains as a single error on the container, according to the configured
         * {@link #msgTarget}. Defaults to false.
         */
        combineErrors: false,

        maskOnDisable: false,

        initComponent: function() {
            var me = this,
                onSubCmpAddOrRemove = me.onSubCmpAddOrRemove;

            // Init mixins
            me.initLabelable();
            me.initFieldAncestor();

            me.callParent();
        },

        /**
         * @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;
            me.mixins.fieldAncestor.onLabelableAdded.call(this, labelable);
            me.updateLabel();
        },

        /**
         * @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.mixins.fieldAncestor.onLabelableRemoved.call(this, labelable);
            me.updateLabel();
        },

        onRender: function() {
            var me = this,
                renderSelectors = me.renderSelectors,
                applyIf = Ext.applyIf;

            applyIf(renderSelectors, me.getLabelableSelectors());

            me.callParent(arguments);
        },

        initRenderTpl: function() {
            var me = this;
            if (!me.hasOwnProperty('renderTpl')) {
                me.renderTpl = me.getTpl('labelableRenderTpl');
            }
            return me.callParent();
        },

        initRenderData: function() {
            return Ext.applyIf(this.callParent(), this.getLabelableRenderData());
        },

        /**
         * Returns the combined field label if {@link #combineLabels} is set to true and if there is no
         * set {@link #fieldLabel}. Otherwise returns the fieldLabel like normal. You can also override
         * this method to provide a custom generated label.
         */
        getFieldLabel: function() {
            var label = this.fieldLabel || '';
            if (!label && this.combineLabels) {
                label = Ext.Array.map(this.query('[isFieldLabelable]'), function(field) {
                    return field.getFieldLabel();
                }).join(this.labelConnector);
            }
            return label;
        },

        /**
         * @private Updates the content of the labelEl if it is rendered
         */
        updateLabel: function() {
            var me = this,
                label = me.labelEl;
            if (label) {
                label.update(me.getFieldLabel());
            }
        },

        /**
         * @private Fired when the error message of any field within the container changes, and updates the
         * combined error message to match.
         */
        onFieldErrorChange: function(field, activeError) {
            if (this.combineErrors) {
                var me = this,
                    oldError = me.getActiveError(),
                    invalidFields = Ext.Array.filter(me.query('[isFormField]'), function(field) {
                        return field.hasActiveError();
                    }),
                    newErrors = me.getCombinedErrors(invalidFields);

                if (newErrors) {
                    me.setActiveErrors(newErrors);
                } else {
                    me.unsetActiveError();
                }

                if (oldError !== me.getActiveError()) {
                    me.doComponentLayout();
                }
            }
        },

        /**
         * Takes an Array of invalid {@link Ext.form.field.Field} objects and builds a combined list of error
         * messages from them. Defaults to prepending each message by the field name and a colon. This
         * can be overridden to provide custom combined error message handling, for instance changing
         * the format of each message or sorting the array (it is sorted in order of appearance by default).
         * @param {Array} invalidFields An Array of the sub-fields which are currently invalid.
         * @return {Array} The combined list of error messages
         */
        getCombinedErrors: function(invalidFields) {
            var forEach = Ext.Array.forEach,
                errors = [];
            forEach(invalidFields, function(field) {
                forEach(field.getActiveErrors(), function(error) {
                    var label = field.getFieldLabel();
                    errors.push((label ? label + ': ' : '') + error);
                });
            });
            return errors;
        },

        getTargetEl: function() {
            return this.bodyEl || this.callParent();
        }
    });