Enum ScreenshotRequestPhase

pub(crate) enum ScreenshotRequestPhase {
    ConstellationRequest,
    WaitingOnPipelineDisplayLists(Rc<FxHashMap<PipelineId, Epoch>>),
    WaitingOnFrame,
}

Screenshots requests happen in three phases:

Variants

ConstellationRequest

A request is sent to the Constellation, asking each Pipeline in a WebView, to report the display list epoch to render for the screenshot. Each Pipeline will wait to send an epoch that happens after the Pipeline is ready in a variety of ways:

• The load event has fired.
• All render blocking elements are no longer blocking the rendering.
• All images are loaded and displayed.
• All web fonts are loaded.
• The reftest-wait and test-wait classes have been removed from the root element.
• The rendering is up-to-date

When all Pipelines have reported this epoch to the Constellation it sends a ScreenshotReadinessResponse back to the renderer.

WaitingOnPipelineDisplayLists(Rc<FxHashMap<PipelineId, Epoch>>)

The renderer has received the ScreenshotReadinessReponse from the Constellation and is now waiting for all display lists to be received from the Pipelines and sent to WebRender.

WaitingOnFrame

Once the renderer has received all of the Pipeline display lists necessary to take the screenshot and uploaded them to WebRender, it waits for an appropriate frame to be ready. Currently this just waits for the [FrameDelayer] to stop delaying frames and for there to be no pending WebRender frames (ones sent to WebRender that are not ready yet). Once that happens, and a potential extra repaint is triggered, the renderer will take the screenshot and fufill the request.

Trait Implementations

impl PartialEq for ScreenshotRequestPhase

fn eq(&self, other: &ScreenshotRequestPhase) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ScreenshotRequestPhase