editor's name, a string that identifies editor among
other editors. For example, UI form might have two editor: "GUI Designer"
and "Text". So "GUI Designer" can be a name of one editor and "Text"
can be a name of other editor. The method should never return null.
whether the editor is valid or not. An editor is valid if the contents displayed in it still exists. For example, an editor
displaying the contents of a file stops being valid if the file is deleted.
selectNotify
defaultvoidselectNotify()
This method is invoked each time when the editor is selected.
This can happen in two cases: editor is selected because the selected file
has been changed or editor for the selected file has been changed.
deselectNotify
defaultvoiddeselectNotify()
This method is invoked each time when the editor is deselected.