Struct ColumnTreeSpec 

pub struct ColumnTreeSpec<'a> {
    pub id: &'a str,
    pub columns: &'a [ColumnSpec],
    pub root_label: Option<&'a str>,
    pub root_cells: Option<&'a HashMap<String, Value>>,
    pub empty_hint: Option<&'a str>,
    pub hits_prefix: &'a str,
}

Everything the consumer supplies. Borrowed; the widget holds no state of its own beyond egui memory.

Fields

id: &'a str

Scope key for this tree’s transient view state and widget ids. Must be STABLE and UNIQUE per tree — two trees sharing it share their drag state and their text buffers.

columns: &'a [ColumnSpec]

The columns, in spec order (the fallback order when layout.order does not name them).

root_label: Option<&'a str>

An optional always-open root row above the tree ("Assembly"), drawn with its own cells taken from root_cells.

root_cells: Option<&'a HashMap<String, Value>>

Cells for the root row, when there is one.

empty_hint: Option<&'a str>

Text drawn in place of the body when rows is empty.

hits_prefix: &'a str

Prefix for every published hit key. "" for a consumer that shows one tree at a time.