The drag handler is used to deal with sequences of browser events related to dragging. The handler is used by controls that want to know when a drag sequence begins, when a drag is happening, and when it has finished.
Controls that use the drag handler typically construct it with callbacks for ‘down’, ‘move’, and ‘done’. Callbacks for these keys are called when the drag begins, with each move, and when the drag is done. In addition, controls can have callbacks keyed to ‘up’ and ‘out’ if they care to differentiate between the types of events that correspond with the end of a drag sequence. If no drag actually occurs (no mouse move) the ‘down’ and ‘up’ callbacks will be called, but not the ‘done’ callback.
Create a new drag handler with the OpenLayers.Handler.Drag constructor.
| OpenLayers. | The drag handler is used to deal with sequences of browser events related to dragging. |
| Constructor | |
| OpenLayers. | Returns OpenLayers.Handler.Drag |
Returns OpenLayers.Handler.Drag
| control | {OpenLayers.Control} The control that is making use of this handler. If a handler is being used without a control, the handlers setMap method must be overridden to deal properly with the map. |
| callbacks | {Object} An object containing a single function to be called when the drag operation is finished. The callback should expect to recieve a single argument, the pixel location of the event. Callbacks for ‘move’ and ‘done’ are supported. You can also speficy callbacks for ‘down’, ‘up’, and ‘out’ to respond to those events. |
| options | {Object} |