1use std::time::Duration;
  2
  3use gpui::{Entity, ModelContext};
  4use settings::Settings;
  5use smol::Timer;
  6
  7pub struct BlinkManager {
  8    blink_interval: Duration,
  9
 10    blink_epoch: usize,
 11    blinking_paused: bool,
 12    visible: bool,
 13    enabled: bool,
 14}
 15
 16impl BlinkManager {
 17    pub fn new(blink_interval: Duration, cx: &mut ModelContext<Self>) -> Self {
 18        let weak_handle = cx.weak_handle();
 19        cx.observe_global::<Settings, _>(move |_, cx| {
 20            if let Some(this) = weak_handle.upgrade(cx) {
 21                // Make sure we blink the cursors if the setting is re-enabled
 22                this.update(cx, |this, cx| this.blink_cursors(this.blink_epoch, cx));
 23            }
 24        })
 25        .detach();
 26
 27        Self {
 28            blink_interval,
 29
 30            blink_epoch: 0,
 31            blinking_paused: false,
 32            visible: true,
 33            enabled: false,
 34        }
 35    }
 36
 37    fn next_blink_epoch(&mut self) -> usize {
 38        self.blink_epoch += 1;
 39        self.blink_epoch
 40    }
 41
 42    pub fn pause_blinking(&mut self, cx: &mut ModelContext<Self>) {
 43        if !self.visible {
 44            self.visible = true;
 45            cx.notify();
 46        }
 47
 48        let epoch = self.next_blink_epoch();
 49        let interval = self.blink_interval;
 50        cx.spawn(|this, mut cx| {
 51            let this = this.downgrade();
 52            async move {
 53                Timer::after(interval).await;
 54                if let Some(this) = this.upgrade(&cx) {
 55                    this.update(&mut cx, |this, cx| this.resume_cursor_blinking(epoch, cx))
 56                }
 57            }
 58        })
 59        .detach();
 60    }
 61
 62    fn resume_cursor_blinking(&mut self, epoch: usize, cx: &mut ModelContext<Self>) {
 63        if epoch == self.blink_epoch {
 64            self.blinking_paused = false;
 65            self.blink_cursors(epoch, cx);
 66        }
 67    }
 68
 69    fn blink_cursors(&mut self, epoch: usize, cx: &mut ModelContext<Self>) {
 70        if cx.global::<Settings>().cursor_blink {
 71            if epoch == self.blink_epoch && self.enabled && !self.blinking_paused {
 72                self.visible = !self.visible;
 73                cx.notify();
 74
 75                let epoch = self.next_blink_epoch();
 76                let interval = self.blink_interval;
 77                cx.spawn(|this, mut cx| {
 78                    let this = this.downgrade();
 79                    async move {
 80                        Timer::after(interval).await;
 81                        if let Some(this) = this.upgrade(&cx) {
 82                            this.update(&mut cx, |this, cx| this.blink_cursors(epoch, cx));
 83                        }
 84                    }
 85                })
 86                .detach();
 87            }
 88        } else if !self.visible {
 89            self.visible = true;
 90            cx.notify();
 91        }
 92    }
 93
 94    pub fn enable(&mut self, cx: &mut ModelContext<Self>) {
 95        self.enabled = true;
 96        // Set cursors as invisible and start blinking: this causes cursors
 97        // to be visible during the next render.
 98        self.visible = false;
 99        self.blink_cursors(self.blink_epoch, cx);
100    }
101
102    pub fn disable(&mut self, _cx: &mut ModelContext<Self>) {
103        self.enabled = false;
104    }
105
106    pub fn visible(&self) -> bool {
107        self.visible
108    }
109}
110
111impl Entity for BlinkManager {
112    type Event = ();
113}