/* ************************************************************************

   qooxdoo - the new era of web development

   http://qooxdoo.org

   Copyright:
     2008 Bill Adams, http://mywebserve.com

   License:
     LGPL: http://www.gnu.org/licenses/lgpl.html
     EPL: http://www.eclipse.org/org/documents/epl-v10.php
     See the LICENSE file in the project's top-level directory for details.

   Authors:
     * Bill Adams (badams)

************************************************************************ */

/**
 * ColumnMenu
 *
 * Column Visibility Popup Menu for Table
 * 
  */
qx.Class.define("qx.ui.table.ColumnMenu",
{
  extend : qx.ui.popup.Popup,




  /*
  *****************************************************************************
     CONSTRUCTOR
  *****************************************************************************
  */

  /**
    * @param table {qx.ui.table.Table}
  */  	
  construct : function(table)
  {
    this.base(arguments);
    this.__table = table;
    this.setLayout(new qx.ui.layout.Grid);
  },



  /*
  *****************************************************************************
     MEMBERS
  *****************************************************************************
  */

  members :
  {
    __table : null,
    __showList : null,
    __hideList : null,
    __numRows : 0,

    
    /**
     * Empty the popup of all children
     */  	
    empty : function()
    {
        if (this.__showList) {
            var entries = this.__showList.getChildren();
            for (var i = 0, l = entries.length; i<l; i++) {
                entries[i].destroy();
            }
        }

        if (this.__hideList) {
            entries = this.__hideList.getChildren();
            for (var i = 0, l = entries.length; i<l; i++) {
                entries[i].destroy();
            }
        }

        entries = this.getChildren();
        for (var i=0,l=entries.length; i<l; i++) {
          entries[i].destroy();
        }
    },
    
    /**
     * Add a widget to the menu
     * 
     * @param {qx.ui.core.Widget} widget
     * @param {Map} options
     */
    add : function(widget, options)
    {
        if (options === undefined || options == null) {
            // Add widget in a new row
            var props = {
                row: this.__numRows,
                column: 0,
                colSpan: 2				
            }; 			
            this.__numRows++;
        } else {
            var props = options;
        }
        
        this.base(arguments, widget, props);
    },

    
    /**
     * Initialize the lists of visible and hidden table columns
     */  	
    initColumnLists : function()
    {
        var tableModel = this.__table.getTableModel();
        this.add(new qx.ui.basic.Atom("Visible").set({
            center: true
        }), {
            row: this.__numRows,
            column: 0
        });
        this.add(new qx.ui.basic.Atom("Hidden").set({
            center: true
        }), {
            row: this.__numRows,
            column: 1
        });
        this.__numRows++;

        var props = {
            selectionMode: "additive",
            draggable: true,
            droppable: true
        };
        this.__showList = new qx.ui.form.List().set(props);
        this.__hideList = new qx.ui.form.List().set(props);
        this.add(this.__showList, {
            row: this.__numRows,
            column: 0
        });
        this.add(this.__hideList, {
            row: this.__numRows,
            column: 1
        });
        this.__numRows++;

        this.__showList.addListener("dragstart", this._dragstart);
        this.__hideList.addListener("dragstart", this._dragstart)
        this.__hideList.addListener("drop", this._hide, this);
        this.__showList.addListener("drop", this._show, this);
        
        this.__table.addListener("resize", function(e) {
            var height = this.__table.getBounds().height * 0.8;
            height = Math.round(height);
            this.__showList.set({
                height: height
            });
            this.__hideList.set({
                height: height
            });
        }, this);
        
        for (var col=0, l=tableModel.getColumnCount(); col<l; col++)
        {
          this.__showList.add(
            new qx.ui.form.ListItem(tableModel.getColumnName(col), null, ''+col));
        }
    },

    
    /**
     * Enable dragging a showList or hideList item
     */
    _dragstart : function(e)
    {
        // disable dropping on myself - re-enable during drop event
        e.getTarget().set({droppable: false});
        e.addType("items");
        e.addAction("move");
    },


    /**
     * Handle drop event on the column hideList
     */
    _hide : function(e)
    {
        this.__showList.set({droppable: true});  // re-enable after dragstart
        this._setVisibility(false, this.__showList, this.__hideList);
    },

    
    /**
     * Handle drop event on the column showList
     */
    _show : function(e)
    {
        this.__hideList.set({droppable: true});  // re-enable after dragstart
        this._setVisibility(true, this.__hideList, this.__showList);
    },


    /**
     * Process one column visibility change and schedule next change, if any.
     * The event handlers can deal with only one change at a time.
     */
    _setVisibility : function(value, fromList, toList)
    {
        var selection = fromList.getSelection();
        var col = selection[0].getValue();
        var columnModel = this.__table.getTableColumnModel();
        columnModel.setColumnVisible(col, value);
        fromList.remove(selection[0]);
        
        // Preserve column order in lists
        var children = toList.getChildren();
        for (var i=0; i<children.length; i++) {
            var childCol = children[i].getValue();
            if (childCol > col) {
                break;
            }
        }
        
        if (i < children.length) {
            toList.addBefore(selection[0], children[i]);
        } else {
            toList.add(selection[0]);
        }
        
        if (selection.length > 1) {
            // Allow time to process this event before triggering next event
            if (value) {
                qx.event.Timer.once(this._show, this, 10);
            } else {
                qx.event.Timer.once(this._hide, this, 10);
            }
        }				
    }
  }
});