[−][src]Trait fui::cursive::backend::Backend
Trait defining the required methods to be a backend.
A backend is the interface between the abstract view tree and the actual input/output, like a terminal.
It usually delegates the work to a terminal-handling library like ncurses
or termion, or it can entirely simulate a terminal and show it as a
graphical window (BearLibTerminal
).
When creating a new cursive tree with Cursive::new()
, you will need to
provide a backend initializer - usually their init()
function.
Backends are responsible for handling input and converting it to Event
. Input must be
non-blocking, it will be polled regularly.
Required methods
fn poll_event(&mut self) -> Option<Event>
Polls the backend for any input.
Should return immediately.
fn finish(&mut self)
Prepares to close the backend.
This should clear any state in the terminal.
fn refresh(&mut self)
Refresh the screen.
This will be called each frame after drawing has been done.
A backend could, for example, buffer any print command, and apply everything when refresh() is called.
fn has_colors(&self) -> bool
Should return true
if this backend supports colors.
fn screen_size(&self) -> XY<usize>
Returns the screen size.
fn print_at(&self, pos: XY<usize>, text: &str)
Main method used for printing
fn clear(&self, color: Color)
Clears the screen with the given color.
fn set_color(&self, colors: ColorPair) -> ColorPair
Starts using a new color.
This should return the previously active color.
Any call to print_at
from now on should use the given color.
fn set_effect(&self, effect: Effect)
Enables the given effect.
Any call to print_at
from now on should use the given effect.
fn unset_effect(&self, effect: Effect)
Disables the given effect.
Provided methods
fn print_at_rep(&self, pos: XY<usize>, repetitions: usize, text: &str)
First positions the cursor, similar to print_at
, and then prints the given number of
repetitions
of text
.
fn name(&self) -> &str
Returns a name to identify the backend.
Mostly used for debugging.