[ticket/416] Add handler for module constraints

B3P-416

portal/modules/constraints_handler.php

@@ -0,0 +1,162 @@
+<?php
+/**
+ *
+ * @package Board3 Portal v2.1
+ * @copyright (c) 2014 Board3 Group ( www.board3.de )
+ * @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+ *
+ */
+
+namespace board3\portal\portal\modules;
+
+use board3\portal\portal\columns;
+
+class constraints_handler
+{
+	/** @var \board3\portal\portal\columns */
+	protected $portal_columns;
+
+	/** @var \phpbb\user */
+	protected $user;
+
+	/** @var string Form action (link) */
+	protected $u_action;
+
+	/** @var array Array with info about modules and their columns */
+	public $module_column = array();
+
+	/**
+	 * Constructor for constraints handler
+	 *
+	 * @param columns $portal_columns Portal columns
+	 * @param \phpbb\user $user phpBB user object
+	 */
+	public function __construct(columns $portal_columns, $user)
+	{
+		$this->portal_columns = $portal_columns;
+		$this->user = $user;
+	}
+
+	/**
+	 * Set u_action for module
+	 *
+	 * @param string $u_action u_action for module
+	 */
+	public function set_u_action($u_action)
+	{
+		$this->u_action = $u_action;
+	}
+
+	/**
+	 * Set module columns info
+	 *
+	 * @param array $module_column Array with info about modules and their columns
+	 */
+	public function set_module_column($module_column = array())
+	{
+		$this->module_column = $module_column;
+	}
+
+	/**
+	 * Check if there is conflict between the move action and existing modules
+	 *
+	 * @param array $module_data The module's data
+	 * @param int $move_action The move action
+	 *
+	 * @return null
+	 */
+	public function check_module_conflict($module_data, &$move_action)
+	{
+		/**
+		 * Moving only 1 column means we will either end up in a side column
+		 * or in the center column. This is not possible when moving 2 columns.
+		 * Therefore we only need to check if we won't end up with a duplicate
+		 * module in the new column (side columns (left & right) or center
+		 * columns (top, center, bottom)). Of course this does not apply to
+		 * custom modules.
+		 */
+		if ($module_data['module_classname'] != '\board3\portal\modules\custom' && abs($move_action) == 1)
+		{
+			$column_string = $this->portal_columns->number_to_string($module_data['module_column'] + $move_action);
+
+			// we can only move horizontally to center or side columns
+			if (in_array($column_string, array('right', 'left')) && !$this->can_move_module(array('right', 'left'), $module_data['module_classname']))
+			{
+				trigger_error($this->user->lang['UNABLE_TO_MOVE'] . adm_back_link($this->u_action));
+			}
+			else if ($column_string == 'center' && !$this->can_move_module(array('top', 'center', 'bottom'), $module_data['module_classname']))
+			{
+				// we are moving from the right to the center column so we should move to the left column instead
+				$move_action = 2 * $move_action;
+			}
+		}
+	}
+
+	/**
+	 * Check if module can be moved horizontally
+	 *
+	 * @param array $module_data Module's module data
+	 * @param int $direction Direction to move the module
+	 *
+	 * @return bool True if module can be moved, false if not
+	 */
+	public function can_move_horizontally($module_data, $direction)
+	{
+		if (isset($module_data['module_column']))
+		{
+			return ($direction === database_handler::MOVE_DIRECTION_RIGHT) ? $module_data['module_column'] < $this->portal_columns->string_to_number('right') : $module_data['module_column'] > $this->portal_columns->string_to_number('left');
+		}
+		else
+		{
+			return false;
+		}
+	}
+
+	/**
+	 * Check if module can be moved to desired column(s)
+	 *
+	 * @param array|int	$target_column Column(s) the module should be moved to
+	 * @param string		$module_class Class of the module
+	 * @return bool		True if module can be moved to desired column,
+	 *			false if not
+	 */
+	public function can_move_module($target_column, $module_class)
+	{
+		$submit = true;
+
+		if (is_array($target_column))
+		{
+			foreach ($target_column as $column)
+			{
+				if (!$this->can_move_module($column, $module_class))
+				{
+					$submit = false;
+				}
+			}
+		}
+
+		// do we want to add the module to the side columns or to the center columns?
+		if (in_array($target_column, array('left', 'right')))
+		{
+			// does the module already exist in the side columns?
+			if (isset($this->module_column[$module_class]) &&
+				(in_array('left', $this->module_column[$module_class]) || in_array('right', $this->module_column[$module_class])))
+			{
+				$submit = false;
+			}
+		}
+		else if (in_array($target_column, array('center', 'top', 'bottom')))
+		{
+			// does the module already exist in the center columns?
+			if (isset($this->module_column[$module_class]) &&
+				(in_array('center', $this->module_column[$module_class]) ||
+					in_array('top', $this->module_column[$module_class]) ||
+					in_array('bottom', $this->module_column[$module_class])))
+			{
+				$submit = false;
+			}
+		}
+
+		return $submit;
+	}
+}