Files
coop/crates/ui/src/input/blink_cursor.rs

97 lines
2.6 KiB
Rust

use std::time::Duration;
use gpui::{Context, Pixels, Task, px};
static INTERVAL: Duration = Duration::from_millis(500);
static PAUSE_DELAY: Duration = Duration::from_millis(300);
// On Windows, Linux, we should use integer to avoid blurry cursor.
#[cfg(not(target_os = "macos"))]
pub(super) const CURSOR_WIDTH: Pixels = px(2.);
#[cfg(target_os = "macos")]
pub(super) const CURSOR_WIDTH: Pixels = px(1.5);
/// To manage the Input cursor blinking.
///
/// It will start blinking with a interval of 500ms.
/// Every loop will notify the view to update the `visible`, 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(crate) struct BlinkCursor {
visible: bool,
paused: bool,
epoch: usize,
_task: Task<()>,
}
impl BlinkCursor {
pub fn new() -> Self {
Self {
visible: false,
paused: false,
epoch: 0,
_task: Task::ready(()),
}
}
/// Start the blinking
pub fn start(&mut self, cx: &mut Context<Self>) {
self.blink(self.epoch, cx);
}
pub fn stop(&mut self, cx: &mut Context<Self>) {
self.epoch = 0;
cx.notify();
}
fn next_epoch(&mut self) -> usize {
self.epoch += 1;
self.epoch
}
fn blink(&mut self, epoch: usize, cx: &mut Context<Self>) {
if self.paused || epoch != self.epoch {
self.visible = true;
return;
}
self.visible = !self.visible;
cx.notify();
// Schedule the next blink
let epoch = self.next_epoch();
self._task = cx.spawn(async move |this, cx| {
cx.background_executor().timer(INTERVAL).await;
if let Some(this) = this.upgrade() {
this.update(cx, |this, cx| this.blink(epoch, cx));
}
});
}
pub fn visible(&self) -> bool {
// Keep showing the cursor if paused
self.paused || self.visible
}
/// Pause the blinking, and delay 500ms to resume the blinking.
pub fn pause(&mut self, cx: &mut Context<Self>) {
self.paused = true;
self.visible = true;
cx.notify();
// delay 500ms to start the blinking
let epoch = self.next_epoch();
self._task = cx.spawn(async move |this, cx| {
cx.background_executor().timer(PAUSE_DELAY).await;
if let Some(this) = this.upgrade() {
this.update(cx, |this, cx| {
this.paused = false;
this.blink(epoch, cx);
});
}
});
}
}