More LibreOffice work.

internal/atspi/libreoffice.go

@@ -21,8 +21,28 @@ type LibreOfficeContext struct {
 	CellText         string
 	Coordinates      string
 	Formula          string
+	Selection        *LibreOfficeSelection
 }
 
+// LibreOfficeSelection never expands a sheet. Complete small selections carry
+// at most 64 positions; larger selections carry counts and boundary samples.
+// Kind is cells, rows, columns, or all. Count is a lower bound when
+// CountLimited is true.
+type LibreOfficeSelection struct {
+	Kind         string
+	Count        int
+	CountLimited bool
+	Complete     bool
+	Cells        []LibreOfficeCell
+	// Boundary samples distinguish equal-sized large selections. They do
+	// not prove that every cell between the endpoints is selected.
+	First, Last LibreOfficeCell
+}
+
+type LibreOfficeCell struct{ Row, Column int }
+
+const libreOfficeSelectionLimit = 64
+
 // IsLibreOfficeProcess uses /proc identity verified by the adapter. An
 // accessible name or document title must never enable application policy.
 func IsLibreOfficeProcess(process string) bool {