/**
 * @class Ext.layout.FormLayout
 * @extends Ext.layout.AnchorLayout
 * 
This layout manager is specifically designed for rendering and managing child Components of
 * {@link Ext.form.FormPanel forms}. It is responsible for rendering the labels of
 * {@link Ext.form.Field Field}s.
 *
 * 
This layout manager is used when a Container is configured with the layout:'form'
 * {@link Ext.Container#layout layout} config option, and should generally not need to be created directly
 * via the new keyword. See {@link Ext.Container#layout} for additional details.
 *
 * 
In an application, it will usually be preferrable to use a {@link Ext.form.FormPanel FormPanel}
 * (which is configured with FormLayout as its layout class by default) since it also provides built-in
 * functionality for {@link Ext.form.BasicForm#doAction loading, validating and submitting} the form.
 *
 * 
A {@link Ext.Container Container} using the FormLayout layout manager (e.g.
 * {@link Ext.form.FormPanel} or specifying layout:'form') can also accept the following
 * layout-specific config properties:

 * 
{@link Ext.form.FormPanel#hideLabels hideLabels}
 * 
{@link Ext.form.FormPanel#labelAlign labelAlign}
 * 
{@link Ext.form.FormPanel#labelPad labelPad}
 * 
{@link Ext.form.FormPanel#labelSeparator labelSeparator}
 * 
{@link Ext.form.FormPanel#labelWidth labelWidth}
 * 

 *
 * 
Any Component (including Fields) managed by FormLayout accepts the following as a config option:
 * 

 * 
{@link Ext.Component#anchor anchor}
 * 

 *
 * 
Any Component managed by FormLayout may be rendered as a form field (with an associated label) by
 * configuring it with a non-null {@link Ext.Component#fieldLabel fieldLabel}. Components configured
 * in this way may be configured with the following options which affect the way the FormLayout renders them:
 * 

 * 
{@link Ext.Component#clearCls clearCls}
 * 
{@link Ext.Component#fieldLabel fieldLabel}
 * 
{@link Ext.Component#hideLabel hideLabel}
 * 
{@link Ext.Component#itemCls itemCls}
 * 
{@link Ext.Component#labelSeparator labelSeparator}
 * 
{@link Ext.Component#labelStyle labelStyle}
 * 

 *
 * 
Example usage:
 * 

// Required if showing validation messages
Ext.QuickTips.init();

// While you can create a basic Panel with layout:'form', practically
// you should usually use a FormPanel to also get its form functionality
// since it already creates a FormLayout internally.
var form = new Ext.form.FormPanel({
    title: 'Form Layout',
    bodyStyle: 'padding:15px',
    width: 350,
    defaultType: 'textfield',
    defaults: {
        // applied to each contained item
        width: 230,
        msgTarget: 'side'
    },
    items: [{
            fieldLabel: 'First Name',
            name: 'first',
            allowBlank: false,
            {@link Ext.Component#labelSeparator labelSeparator}: ':' // override labelSeparator layout config
        },{
            fieldLabel: 'Last Name',
            name: 'last'
        },{
            fieldLabel: 'Email',
            name: 'email',
            vtype:'email'
        }, {
            xtype: 'textarea',
            hideLabel: true,     // override hideLabels layout config
            name: 'msg',
            anchor: '100% -53'
        }
    ],
    buttons: [
        {text: 'Save'},
        {text: 'Cancel'}
    ],
    layoutConfig: {
        {@link #labelSeparator}: '~' // superseded by assignment below
    },
    // config options applicable to container when layout='form':
    hideLabels: false,
    labelAlign: 'left',   // or 'right' or 'top'
    {@link Ext.form.FormPanel#labelSeparator labelSeparator}: '>>', // takes precedence over layoutConfig value
    labelWidth: 65,       // defaults to 100
    labelPad: 8           // defaults to 5, must specify labelWidth to be honored
});

 */
Ext.layout.FormLayout = Ext.extend(Ext.layout.AnchorLayout, {

    
/**
     * @cfg {String} labelSeparator
     * See {@link Ext.form.FormPanel}.{@link Ext.form.FormPanel#labelSeparator labelSeparator}.  Configuration
     * of this property at the container level takes precedence.
     */
    labelSeparator : ':',

    
/**
     * Read only. The CSS style specification string added to field labels in this layout if not
     * otherwise {@link Ext.Component#labelStyle specified by each contained field}.
     * @type String
     * @property labelStyle
     */

    
/**
     * @cfg {Boolean} trackLabels
     * True to show/hide the field label when the field is hidden. Defaults to false.
     */
    trackLabels: false,

    type: 'form',


    onRemove: function(c){
        Ext.layout.FormLayout.superclass.onRemove.call(this, c);
        if(this.trackLabels){
            c.un('show', this.onFieldShow, this);
            c.un('hide', this.onFieldHide, this);
        }
        // check for itemCt, since we may be removing a fieldset or something similar
        var el = c.getPositionEl(),
                ct = c.getItemCt && c.getItemCt();
        if(c.rendered && ct){
            if (el && el.dom) {
                el.insertAfter(ct);
            }
            Ext.destroy(ct);
            Ext.destroyMembers(c, 'label', 'itemCt');
            if(c.customItemCt){
                Ext.destroyMembers(c, 'getItemCt', 'customItemCt');
            }
        }
    },

    // private
    setContainer : function(ct){
        Ext.layout.FormLayout.superclass.setContainer.call(this, ct);
        if(ct.labelAlign){
            ct.addClass('x-form-label-'+ct.labelAlign);
        }

        if(ct.hideLabels){
            Ext.apply(this, {
                labelStyle: 'display:none',
                elementStyle: 'padding-left:0;',
                labelAdjust: 0
            });
        }else{
            this.labelSeparator = ct.labelSeparator || this.labelSeparator;
            ct.labelWidth = ct.labelWidth || 100;
            if(Ext.isNumber(ct.labelWidth)){
                var pad = Ext.isNumber(ct.labelPad) ? ct.labelPad : 5;
                Ext.apply(this, {
                    labelAdjust: ct.labelWidth + pad,
                    labelStyle: 'width:' + ct.labelWidth + 'px;',
                    elementStyle: 'padding-left:' + (ct.labelWidth + pad) + 'px'
                });
            }
            if(ct.labelAlign == 'top'){
                Ext.apply(this, {
                    labelStyle: 'width:auto;',
                    labelAdjust: 0,
                    elementStyle: 'padding-left:0;'
                });
            }
        }
    },

    // private
    isHide: function(c){
        return c.hideLabel || this.container.hideLabels;
    },

    onFieldShow: function(c){
        c.getItemCt().removeClass('x-hide-' + c.hideMode);
    },

    onFieldHide: function(c){
        c.getItemCt().addClass('x-hide-' + c.hideMode);
    },

    //private
    getLabelStyle: function(s){
        var ls = '', items = [this.labelStyle, s];
        for (var i = 0, len = items.length; i < len; ++i){
            if (items[i]){
                ls += items[i];
                if (ls.substr(-1, 1) != ';'){
                    ls += ';'
                }
            }
        }
        return ls;
    },

    
/**
     * @cfg {Ext.Template} fieldTpl
     * A {@link Ext.Template#compile compile}d {@link Ext.Template} for rendering
     * the fully wrapped, labeled and styled form Field. Defaults to:

new Ext.Template(
    '<div class="x-form-item {itemCls}" tabIndex="-1">',
        '<label for="{id}" style="{labelStyle}" class="x-form-item-label">{label}{labelSeparator}</label>',
        '<div class="x-form-element" id="x-form-el-{id}" style="{elementStyle}">',
        '</div><div class="{clearCls}"></div>',
    '</div>'
);

     * 
This may be specified to produce a different DOM structure when rendering form Fields.
     * 
A description of the properties within the template follows:

     * 
itemCls : String
The CSS class applied to the outermost div wrapper
     * that contains this field label and field element (the default class is 'x-form-item' and itemCls
     * will be added to that). If supplied, itemCls at the field level will override the default itemCls
     * supplied at the container level.
     * 
id : String
The id of the Field
     * 
{@link #labelStyle} : String

     * A CSS style specification string to add to the field label for this field (defaults to '' or the
     * {@link #labelStyle layout's value for labelStyle}).
     * 
label : String
The text to display as the label for this
     * field (defaults to '')
     * 
{@link #labelSeparator} : String
The separator to display after
     * the text of the label for this field (defaults to a colon ':' or the
     * {@link #labelSeparator layout's value for labelSeparator}). To hide the separator use empty string ''.
     * 
elementStyle : String
The styles text for the input element's wrapper.
     * 
clearCls : String
The CSS class to apply to the special clearing div
     * rendered directly after each form field wrapper (defaults to 'x-form-clear-left')
     * 
     * 
Also see {@link #getTemplateArgs}
     */

    // private
    renderItem : function(c, position, target){
        if(c && (c.isFormField || c.fieldLabel) && c.inputType != 'hidden'){
            var args = this.getTemplateArgs(c);
            if(Ext.isNumber(position)){
                position = target.dom.childNodes[position] || null;
            }
            if(position){
                c.itemCt = this.fieldTpl.insertBefore(position, args, true);
            }else{
                c.itemCt = this.fieldTpl.append(target, args, true);
            }
            if(!c.getItemCt){
                // Non form fields don't have getItemCt, apply it here
                // This will get cleaned up in onRemove
                Ext.apply(c, {
                    getItemCt: function(){
                        return c.itemCt;
                    },
                    customItemCt: true
                });
            }
            c.label = c.getItemCt().child('label.x-form-item-label');
            if(!c.rendered){
                c.render('x-form-el-' + c.id);
            }else if(!this.isValidParent(c, target)){
                Ext.fly('x-form-el-' + c.id).appendChild(c.getPositionEl());
            }
            if(this.trackLabels){
                if(c.hidden){
                    this.onFieldHide(c);
                }
                c.on({
                    scope: this,
                    show: this.onFieldShow,
                    hide: this.onFieldHide
                });
            }
            this.configureItem(c);
        }else {
            Ext.layout.FormLayout.superclass.renderItem.apply(this, arguments);
        }
    },

    
/**
     * 
Provides template arguments for rendering the fully wrapped, labeled and styled form Field.
     * 
This method returns an object hash containing properties used by the layout's {@link #fieldTpl}
     * to create a correctly wrapped, labeled and styled form Field. This may be overriden to
     * create custom layouts. The properties which must be returned are:

     * 
itemCls : String
The CSS class applied to the outermost div wrapper
     * that contains this field label and field element (the default class is 'x-form-item' and itemCls
     * will be added to that). If supplied, itemCls at the field level will override the default itemCls
     * supplied at the container level.
     * 
id : String
The id of the Field
     * 
{@link #labelStyle} : String

     * A CSS style specification string to add to the field label for this field (defaults to '' or the
     * {@link #labelStyle layout's value for labelStyle}).
     * 
label : String
The text to display as the label for this
     * field (defaults to '')
     * 
{@link #labelSeparator} : String
The separator to display after
     * the text of the label for this field (defaults to a colon ':' or the
     * {@link #labelSeparator layout's value for labelSeparator}). To hide the separator use empty string ''.
     * 
elementStyle : String
The styles text for the input element's wrapper.
     * 
clearCls : String
The CSS class to apply to the special clearing div
     * rendered directly after each form field wrapper (defaults to 'x-form-clear-left')
     * 
     * @param (Ext.form.Field} field The {@link Ext.form.Field Field} being rendered.
     * @return An object hash containing the properties required to render the Field.
     */
    getTemplateArgs: function(field) {
        var noLabelSep = !field.fieldLabel || field.hideLabel;
        return {
            id: field.id,
            label: field.fieldLabel,
            labelStyle: this.getLabelStyle(field.labelStyle),
            elementStyle: this.elementStyle||'',
            labelSeparator: noLabelSep ? '' : (Ext.isDefined(field.labelSeparator) ? field.labelSeparator : this.labelSeparator),
            itemCls: (field.itemCls||this.container.itemCls||'') + (field.hideLabel ? ' x-hide-label' : ''),
            clearCls: field.clearCls || 'x-form-clear-left'
        };
    },

    // private
    adjustWidthAnchor: function(value, c){
        if(c.label && !this.isHide(c) && (this.container.labelAlign != 'top')){
            var adjust = Ext.isIE6 || (Ext.isIE && !Ext.isStrict);
            return value - this.labelAdjust + (adjust ? -3 : 0);
        }
        return value;
    },

    adjustHeightAnchor : function(value, c){
        if(c.label && !this.isHide(c) && (this.container.labelAlign == 'top')){
            return value - c.label.getHeight();
        }
        return value;
    },

    // private
    isValidParent : function(c, target){
        return target && this.container.getEl().contains(c.getPositionEl());
    }

    
/**
     * @property activeItem
     * @hide
     */
});

Ext.Container.LAYOUTS['form'] = Ext.layout.FormLayout;