Struct PreparedRoots 

pub struct PreparedRoots {
    pub root: AnyElement,
    pub prompt: Option<AnyElement>,
    pub tooltip: Option<AnyElement>,
    pub drag: Option<(AnyElement, Point<Pixels>)>,
    pub inspector: Option<AnyElement>,
}

The roots a frame draws, assembled before they are laid out.

A frame draws the window’s own view tree, plus at most one overlay: a prompt, a drag image, or a tooltip. Roots are gathered by Window::evaluate_roots, laid out and prepainted by Window::layout_roots, and drawn by Window::paint_roots, so a FramePipeline can sit between the passes.

Only root is laid out like the window’s view tree, filling it unless the view sizes itself. The others are placed as their own conventions require, which is why the carrier records what each one is rather than letting callers guess from the element.

Fields

root: AnyElement

The window’s own view tree.

prompt: Option<AnyElement>

A prompt, laid out like the root: it covers the window.

tooltip: Option<AnyElement>

A tooltip, already laid out where the request that asked for it wanted it.

drag: Option<(AnyElement, Point<Pixels>)>

A drag image, and the point it hangs from: the pointer, less the offset recorded when the drag started.

inspector: Option<AnyElement>

The inspector’s root, when the inspector is open.