Toggling draggable columns in a Flex DataGrid control

Toggling draggable columns in a Flex DataGrid control

By Peter deHaan On August 30, 2007 · Leave a Comment

The following example demonstrates how you can enable/disable draggable columns in a Flex DataGrid control using the DataGrid class’s draggableColumns property, as well as toggling specific column’s dragability using the DataGridColumn class’s draggable property.

Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/08/30/toggling-draggable-columns-in-a-flex-datagrid-control/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Array id="arr">
        <mx:Object label="User 1" data="1" />
        <mx:Object label="User 2" data="2" />
        <mx:Object label="User 3" data="3" />
        <mx:Object label="User 4" data="4" />
        <mx:Object label="User 5" data="5" />
        <mx:Object label="User 6" data="6" />
        <mx:Object label="User 7" data="7" />
        <mx:Object label="User 8" data="8" />
    </mx:Array>

    <mx:ApplicationControlBar dock="true">
        <mx:CheckBox id="draggableColumnsCh"
                label="draggableColumns"
                selected="true" />

        <mx:CheckBox id="labelDraggableCh"
                label="label.draggable"
                selected="true" />

        <mx:CheckBox id="dataDraggableCh"
                label="data.draggable"
                selected="true" />
    </mx:ApplicationControlBar>

    <mx:DataGrid id="dataGrid"
            draggableColumns="{draggableColumnsCh.selected}"
            dataProvider="{arr}">
        <mx:columns>
            <mx:DataGridColumn dataField="label"
                    draggable="{labelDraggableCh.selected}" />
            <mx:DataGridColumn dataField="data"
                    draggable="{dataDraggableCh.selected}" />
        </mx:columns>
    </mx:DataGrid>

</mx:Application>

View source is enabled in the following example.

If you want to detect when a data grid column has been reordered, you can listen for the headerShift event on the DataGrid control, as seen in the following example:

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/08/30/toggling-draggable-columns-in-a-flex-datagrid-control/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="horizontal"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            import mx.controls.dataGridClasses.DataGridColumn;
            import mx.controls.DataGrid;
            import mx.events.IndexChangedEvent;

            private function dataGrid_headerShift(evt:IndexChangedEvent):void {
                var dg:DataGrid = DataGrid(evt.currentTarget);
                var column:DataGridColumn = dg.columns[evt.newIndex];
                debug.text += column.dataField + " (oldIndex:" + evt.oldIndex + ", newIndex:" + evt.newIndex + ")" + "\\n";
            }
        ]]>
    </mx:Script>

    <mx:Array id="arr">
        <mx:Object label="User 1" data="1" />
        <mx:Object label="User 2" data="2" />
        <mx:Object label="User 3" data="3" />
        <mx:Object label="User 4" data="4" />
        <mx:Object label="User 5" data="5" />
        <mx:Object label="User 6" data="6" />
        <mx:Object label="User 7" data="7" />
        <mx:Object label="User 8" data="8" />
    </mx:Array>

    <mx:DataGrid id="dataGrid"
            dataProvider="{arr}"
            headerShift="dataGrid_headerShift(event)">
        <mx:columns>
            <mx:DataGridColumn dataField="label" />
            <mx:DataGridColumn dataField="data" />
        </mx:columns>
    </mx:DataGrid>

    <mx:TextArea id="debug"
            width="{dataGrid.width}"
            height="{dataGrid.height}" />

</mx:Application>

View source is enabled in the following example.