terminal_image ->input_focus: boolThe terminal gained (@on)
or lost (@off)
the keyboard focus. This is called from terminal_image->event
on the activate_keyboard_focus and
deactivate_keyboard_focus events. The default
implementation enables or disables the platform text input (the input
method), stops an incremental search -- it lives off the keyboard --,
updates the caret and, if the client asked to be told about the focus (CSI ? 1004 h),
sends it CSI I or CSI O.
A subclass may refine this to react on the terminal gaining or losing
the focus. A refinement should call the super method to keep the above
in sync.
Note that this is not graphical->keyboard_focus,
which works the other way around: it asks the window to give the focus
to this object.
