If a script add-inimplements the **OnActivateTab**event, the method receives an ActivateTabData object whenever the activation state of a tab changes.
| Property Name | Return Type | Description |
|---|---|---|
| closing |
bool |
Returns True if the activation change is due to the old tab being closed. |
| newtab |
object:Tab |
Returns a Tab object representing the tab that has become active. |
| oldtab |
object:Tab |
Returns a Tab object representing the tab that has gone inactive. |
| qualifiers |
string |
Returns a string indicating any qualifier keys that were held down by the user when the event was triggered. |