Trait cursive_core::backend::Backend
source · pub trait Backend {
fn poll_event(&mut self) -> Option<Event>;
fn set_title(&mut self, title: String);
fn refresh(&mut self);
fn has_colors(&self) -> bool;
fn screen_size(&self) -> Vec2;
fn print_at(&self, pos: Vec2, text: &str);
fn clear(&self, color: Color);
fn set_color(&self, colors: ColorPair) -> ColorPair;
fn set_effect(&self, effect: Effect);
fn unset_effect(&self, effect: Effect);
fn print_at_rep(&self, pos: Vec2, repetitions: usize, text: &str) { ... }
fn name(&self) -> &str { ... }
}
Expand description
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§
sourcefn poll_event(&mut self) -> Option<Event>
fn poll_event(&mut self) -> Option<Event>
Polls the backend for any input.
Should return immediately:
None
if no event is currently available.Some(event)
for each event to process.
sourcefn set_title(&mut self, title: String)
fn set_title(&mut self, title: String)
Sets the title for the backend.
This usually sets the terminal window title.
sourcefn refresh(&mut self)
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.
sourcefn has_colors(&self) -> bool
fn has_colors(&self) -> bool
Should return true
if this backend supports colors.
sourcefn screen_size(&self) -> Vec2
fn screen_size(&self) -> Vec2
Returns the screen size.
sourcefn set_color(&self, colors: ColorPair) -> ColorPair
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.
sourcefn set_effect(&self, effect: Effect)
fn set_effect(&self, effect: Effect)
Enables the given effect.
Any call to print_at
from now on should use the given effect.
sourcefn unset_effect(&self, effect: Effect)
fn unset_effect(&self, effect: Effect)
Disables the given effect.
Provided Methods§
sourcefn print_at_rep(&self, pos: Vec2, repetitions: usize, text: &str)
fn print_at_rep(&self, pos: Vec2, repetitions: usize, text: &str)
Efficient method to print repetitions of the same text.
Usually used to draw horizontal lines/borders.
It is a small optimization to avoid moving the cursor after each step.