gpui-component/crates/ui/src/input/blink_cursor.rs
Jason Lee 35cec4cf5c
Update to use better implementation of selection support for Input. (#31)
Co-authored-by: Conrad Irwin <conrad@zed.dev>
2024-07-13 09:40:42 +08:00

107 lines
2.7 KiB
Rust

use std::time::Duration;
use gpui::{ModelContext, Timer};
/// To manage the Input cursor blinking.
///
/// It will start blinking with a interval of 500ms.
/// Every loop will notify the view to update the `visable`, and Input will observe this update to touch repaint.
///
/// The input painter will check if this in visible state, then it will draw the cursor.
pub struct BlinkCursor {
interval: Duration,
blink_epoch: usize,
visible: bool,
paused: bool,
started: bool,
}
impl BlinkCursor {
pub fn new(_cx: &mut ModelContext<Self>) -> Self {
Self {
interval: Duration::from_millis(500),
visible: false,
paused: false,
started: false,
blink_epoch: 0,
}
}
/// Start the blinking
pub fn start(&mut self, cx: &mut ModelContext<Self>) {
if self.started {
return;
}
self.started = true;
self.blink(self.blink_epoch, cx);
}
pub fn stop(&mut self, cx: &mut ModelContext<Self>) {
self.started = false;
cx.notify();
}
fn next_epoch(&mut self) -> usize {
self.blink_epoch += 1;
self.blink_epoch
}
fn blink(&mut self, epoch: usize, cx: &mut ModelContext<Self>) {
if self.paused || !self.started {
return;
}
if epoch != self.blink_epoch {
return;
}
self.visible = !self.visible;
cx.notify();
let epoch = self.next_epoch();
// Schedule the next blink
let interval = self.interval;
cx.spawn(|this, mut cx| async move {
Timer::after(interval).await;
if let Some(this) = this.upgrade() {
this.update(&mut cx, |this, cx| this.blink(epoch, cx)).ok();
}
})
.detach();
}
pub fn visible(&self) -> bool {
// Keep showing the cursor if paused
if self.paused {
return true;
}
self.visible
}
/// Pause the blinking, and delay 500ms to resume the blinking.
pub fn pause(&mut self, cx: &mut ModelContext<Self>) {
self.paused = true;
self.next_epoch();
cx.notify();
let epoch = self.next_epoch();
// delay 500ms to start the blinking
cx.spawn(|this, mut cx| async move {
Timer::after(Duration::from_secs_f64(0.5)).await;
if let Some(this) = this.upgrade() {
this.update(&mut cx, |this, cx| {
if epoch != this.blink_epoch {
return;
}
this.paused = false;
this.blink(epoch, cx);
})
.ok();
}
})
.detach();
}
}