Struct RenderOutput 

pub struct RenderOutput {
    pub entries: Vec<TextPropertyEntry>,
    pub hits: Vec<HitArea>,
    pub instance_states: HashMap<String, WidgetInstanceState>,
    pub focus_key: String,
    pub tabbable: Vec<String>,
    pub focus_cursor: Option<FocusCursor>,
    pub embeds: Vec<EmbedRect>,
    pub overlays: Vec<OverlayRow>,
}

What a single render of a WidgetSpec produces.

• entries — the bytes for set_virtual_buffer_content.
• hits — click rectangles for the WidgetRegistry so a later mouse_click dispatches a semantic widget_event.
• instance_states — next-tick widget instance state (List scroll offsets / selection, TextInput value+cursor, …).
• focus_key — currently focused widget key, clamped to a tabbable that exists in the spec (or "" when there are no tabbables).
• tabbable — focusable widget keys collected in declaration order. The Tab-cycle command finds the current focus_key’s index in this list to advance it.
• focus_cursor — when a TextInput is focused, where the terminal cursor should land. Replaces the previous “overlay-as-cursor” hack — the actual hardware cursor blinks at the right byte, with no theme-color guesswork.

Fields

entries: Vec<TextPropertyEntry>

hits: Vec<HitArea>

instance_states: HashMap<String, WidgetInstanceState>

focus_key: String

tabbable: Vec<String>

focus_cursor: Option<FocusCursor>

embeds: Vec<EmbedRect>

Rectangles reserved by WindowEmbed widgets. Each entry names a window id and the cell range (relative to the rendered panel’s inner area) the host should paint that window into after laying down the regular entries.

overlays: Vec<OverlayRow>

Rows produced by WidgetSpec::Overlay children. Each row carries its anchor buffer_row (relative to the rendered panel’s inner area) and is painted by the host AFTER the main entries, on top of whatever is at that row. Used for dropdown completions, tooltips, hover popups — anything that should appear next to a focused widget without reflowing the rest of the layout when it shows or hides.