var NodeBuilder = require('./node-builder');

/**
 * Represents a grid column. This is an abstract class and should not be
 * instantiated directly.
 */
module.exports = new Class
({
	Extends: NodeBuilder
	,Tag: 'htk-column'
	,Properties:
	{
		value:
		{
			type: String
			,value: null
		},
		column:
		{
			type: String
			,value: null
		},
		columnIndex:
		{
			type: Number
			,value: -1
		},
		title:
		{
			 type: String
			 ,value: null
		},
		editable:
		{
			type: Boolean
			,value: false
		},
		renderer:
		{
			type: Function
			,value: false
		},
		class:
		{
			type: String
			,set: function(x) {
				this._userCssClass = x;
				
				if (this._cssClass)
					this._cssClass = x +' '+ this._cssClass;
				else
					this._cssClass = x;
			}
			,get: function() {
				return this._userCssClass;
			}
		}
	}
	
	,_cssClass: null
	,_userCssClass: null

	/**
	 * Initializes the column.
	 */
	,initialize: function(props) {
		this.parent(props);
		this.td = this.createElement('td');
	}
	
	,renderHeader: function() {
		var th = this.createElement('th');
		
		if (this.title)
			th.appendChild(this.createTextNode(this.title));
			
		return th;
	}

	/**
	 * Draws the cell and returns its associated td.
	 *
	 * @return {HTMLTableData} the rendered cell
	 */
	,render: function() {
		var td = this.td.cloneNode(true);

		if (this._cssClass)
			td.className = this._cssClass;
			
		return td;
	}

	,updateColumnIndex: function(model) {
		if (this.column)
			this.columnIndex = model.getColumnIndex(this.column);
	}

	,changed: function(tr, newValue) {
		this.signalEmit('changed', tr.rowIndex - 1, newValue);
	}
});