Emitted when a context menu is opened or closed for @page.
If the menu has been closed, @page will be set to NULL.
It can be used to set up menu actions before showing the menu, for example disable actions not applicable to @page.
1.0
See Implementation
Emitted when a context menu is opened or closed for @page.
If the menu has been closed, @page will be set to NULL.
It can be used to set up menu actions before showing the menu, for example disable actions not applicable to @page.