# SourceDestData

If a [script add-in](../../../scripting/script_add-ins)implements the [**OnSourceDestChange**](../scripting_events/onsourcedestchange) event, the method receives a **SourceDestData** object to indicate which tab's state changed.

| Property Name | Return Type             | Description                                                                                                                                                                                                                                                                                                          |
| ------------- | ----------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| dest          | _bool_                  | Returns **True** if the tab is now the destination.                                                                                                                                                                                                                                                                  |
| source        | _bool_                  | Returns **True** if the tab is now the source. If both **source** and **dest** return False it indicates that the tab is now "off".                                                                                                                                                                                  |
| qualifiers    | _string_                | <p>Returns a string indicating any qualifier keys that were held down by the user when the event was triggered.<br>The string can contain any or all of the following: <em>shift</em> <em>ctrl</em>, <em>alt</em>, <em>lwin</em>, <em>rwin</em><br>If no qualifiers were down, the string will be: <em>none</em></p> |
| tab           | _object:_[**Tab**](tab) | Returns a [**Tab**](tab) object representing the tab.                                                                                                                                                                                                                                                                |
