Editor windows operate in two modes: overwrite mode and insert mode. The mode is a property of individual editor window. That means that each opened window may be in a different mode.
To switch between modes use the Edit » Insert Mode command (Ins
key by default). The state of the command item denotes the current mode - pressed (or checked) means insert mode and unpressed (unchecked) means overwrite mode. Insert mode for the current editor window is also displayed on the status bar.
By default, each opened editor window is in overwrite mode.
Insert mode changes the behavior of several editor commands. Below is a list of commands whose behavior changes when insert mode is enabled:
Other editor commands are not influenced by the insert mode. Insert mode fully supports multiple cursors feature.
Scripts running in the editor may query and change the editor window's insert mode using the IDocumentView.insertMode property.