Struct RefreshDriver

pub(crate) struct RefreshDriver {
    pub(crate) constellation_sender: Sender<EmbedderToConstellationMessage>,
    pub(crate) animating: Cell<bool>,
    pub(crate) waiting_for_frame_timeout: Arc<AtomicBool>,
    timer_thread: TimerThread,
    event_loop_waker: Box<dyn EventLoopWaker>,
}

The RefreshDriver is responsible for controlling updates to aall WebViews onscreen presentation. Currently, it only manages controlling animation update requests.

The implementation is very basic at the moment, only requesting new animation frames at a constant time after a repaint.

Fields

constellation_sender: Sender<EmbedderToConstellationMessage>

The channel on which messages can be sent to the Constellation.

animating: Cell<bool>

Whether or not we are currently animating via a timer.

waiting_for_frame_timeout: Arc<AtomicBool>

Whether or not we are waiting for our frame timeout to trigger

timer_thread: TimerThread

A TimerThread which is used to schedule frame timeouts in the future.

event_loop_waker: Box<dyn EventLoopWaker>

An EventLoopWaker to be used to wake up the embedder when it is time to paint a frame.

Implementations

impl RefreshDriver

pub(crate) fn new( constellation_sender: Sender<EmbedderToConstellationMessage>, event_loop_waker: Box<dyn EventLoopWaker>, ) -> Self

fn timer_callback(&self) -> BoxedTimerCallback

pub(crate) fn notify_will_paint( &self, webview_renderers: Values<'_, WebViewId, WebViewRenderer>, )

Notify the RefreshDriver that a paint is about to happen. This will trigger new animation frames for all active WebViews and schedule a new frame deadline.

pub(crate) fn notify_animation_state_changed( &self, webview_renderer: &WebViewRenderer, )

Notify the RefreshDriver that the animation state of a particular WebView via its associated WebViewRenderer has changed. In the case that a WebView has started animating, the RefreshDriver will request a new frame from it immediately, but only render that frame at the next frame deadline.

pub(crate) fn wait_to_paint(&self, repaint_reason: RepaintReason) -> bool

Whether or not the renderer should trigger a message to the embedder to request a repaint. This might be false if: we are animating and the repaint reason is just for a new frame. In that case, the renderer should wait until the frame timeout to ask the embedder to repaint.