<?php
/**
 * TCheckBoxColumn class file
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.pradosoft.com/
 * @copyright Copyright &copy; 2005-2008 PradoSoft
 * @license http://www.pradosoft.com/license/
 * @version $Id$
 * @package System.Web.UI.WebControls
 */

/**
 * TDataGridColumn class file
 */
Prado::using('System.Web.UI.WebControls.TDataGridColumn');
/**
 * TCheckBox class file
 */
Prado::using('System.Web.UI.WebControls.TCheckBox');

/**
 * TCheckBoxColumn class
 *
 * TCheckBoxColumn represents a checkbox column that is bound to a field in a data source.
 * The checked state of the checkboxes are determiend by the bound data at
 * {@link setDataField DataField}. If {@link setReadOnly ReadOnly} is false,
 * TCheckBoxColumn will display an enabled checkbox provided the cells are
 * in edit mode. Otherwise, the checkboxes will be disabled to prevent from editting.
 *
 * The checkbox control in the TCheckBoxColumn can be accessed by one of
 * the following two methods:
 * <code>
 * $datagridItem->CheckBoxColumnID->CheckBox
 * $datagridItem->CheckBoxColumnID->Controls[0]
 * </code>
 * The second method is possible because the checkbox control created within the
 * datagrid cell is the first child.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id$
 * @package System.Web.UI.WebControls
 * @since 3.0
 */
class TCheckBoxColumn extends TDataGridColumn
{
	/**
	 * @return string the field name from the data source to bind to the column
	 */
	public function getDataField()
	{
		return $this->getViewState('DataField','');
	}

	/**
	 * @param string the field name from the data source to bind to the column
	 */
	public function setDataField($value)
	{
		$this->setViewState('DataField',$value,'');
	}

	/**
	 * @return boolean whether the items in the column can be edited. Defaults to false.
	 */
	public function getReadOnly()
	{
		return $this->getViewState('ReadOnly',false);
	}

	/**
	 * @param boolean whether the items in the column can be edited
	 */
	public function setReadOnly($value)
	{
		$this->setViewState('ReadOnly',TPropertyValue::ensureBoolean($value),false);
	}

	/**
	 * Initializes the specified cell to its initial values.
	 * This method overrides the parent implementation.
	 * It creates a checkbox inside the cell.
	 * If the column is read-only or if the item is not in edit mode,
	 * the checkbox will be set disabled.
	 * @param TTableCell the cell to be initialized.
	 * @param integer the index to the Columns property that the cell resides in.
	 * @param string the type of cell (Header,Footer,Item,AlternatingItem,EditItem,SelectedItem)
	 */
	public function initializeCell($cell,$columnIndex,$itemType)
	{
		if($itemType===TListItemType::Item || $itemType===TListItemType::AlternatingItem || $itemType===TListItemType::SelectedItem || $itemType===TListItemType::EditItem)
		{
			$checkBox=new TCheckBox;
			if($this->getReadOnly() || $itemType!==TListItemType::EditItem)
				$checkBox->setEnabled(false);
			$cell->setHorizontalAlign('Center');
			$cell->getControls()->add($checkBox);
			$cell->registerObject('CheckBox',$checkBox);
			if($this->getDataField()!=='')
				$checkBox->attachEventHandler('OnDataBinding',array($this,'dataBindColumn'));
		}
		else
			parent::initializeCell($cell,$columnIndex,$itemType);
	}

	/**
	 * Databinds a cell in the column.
	 * This method is invoked when datagrid performs databinding.
	 * It populates the content of the cell with the relevant data from data source.
	 */
	public function dataBindColumn($sender,$param)
	{
		$item=$sender->getNamingContainer();
		$data=$item->getData();
		if(($field=$this->getDataField())!=='')
			$value=TPropertyValue::ensureBoolean($this->getDataFieldValue($data,$field));
		else
			$value=TPropertyValue::ensureBoolean($data);
		if($sender instanceof TCheckBox)
			$sender->setChecked($value);
	}
}