Class Ext.dd.DropZone

This class provides a container DD instance that allows dropping on multiple child target nodes.

By default, this class requires that child nodes accepting drop are registered with Ext.dd.Registry. However a simpler way to allow a DropZone to manage any number of target elements is to configure the DropZone with an implementation of getTargetFromEvent which interrogates the passed mouse event to see if it has taken place within an element, or class of elements. This is easily done by using the event's getTarget method to identify a node based on a Ext.DomQuery selector.

Once the DropZone has detected through calling getTargetFromEvent, that the mouse is over a drop target, that target is passed as the first parameter to onNodeEnter, onNodeOver, onNodeOut, onNodeDrop. You may configure the instance of DropZone with implementations of these methods to provide application-specific behaviour for these events to update both application state, and UI state.

For example to make a GridPanel a cooperating target with the example illustrated in DragZone, the following technique might be used:

myGridPanel.on('render', function() {
    myGridPanel.dropZone = new Ext.dd.DropZone(myGridPanel.getView().scroller, {

//      If the mouse is over a grid row, return that node. This is
//      provided as the "target" parameter in all "onNodeXXXX" node event handling functions
        getTargetFromEvent: function(e) {
            return e.getTarget(myGridPanel.getView().rowSelector);
        },

//      On entry into a target node, highlight that node.
        onNodeEnter : function(target, dd, e, data){ 
            Ext.fly(target).addClass('my-row-highlight-class');
        },

//      On exit from a target node, unhighlight that node.
        onNodeOut : function(target, dd, e, data){ 
            Ext.fly(target).removeClass('my-row-highlight-class');
        },

//      While over a target node, return the default drop allowed class which
//      places a "tick" icon into the drag proxy.
        onNodeOver : function(target, dd, e, data){ 
            return Ext.dd.DropZone.prototype.dropAllowed;
        },

//      On node drop we can interrogate the target to find the underlying
//      application object that is the real target of the dragged data.
//      In this case, it is a Record in the GridPanel's Store.
//      We can use the data set up by the DragZone's getDragData method to read
//      any data we decided to attach in the DragZone's getDragData method.
        onNodeDrop : function(target, dd, e, data){
            var rowIndex = myGridPanel.getView().findRowIndex(target);
            var r = myGridPanel.getStore().getAt(rowIndex);
            Ext.Msg.alert('Drop gesture', 'Dropped Record id ' + data.draggedRecord.id +
                ' on Record id ' + r.id);
            return true;
        }
    });
}