Tab Handling¶

By default, the Tab key moves focus to the next UI element (standard Compose behavior). You can override this to indent code instead.

Tab extension¶

The demo defines a function that returns either an indent-with-tab extension or a literal-tab-insert extension:

    fun tabExtension(m: TabMode): Extension = when (m) {
        TabMode.INDENT -> keymapOf(indentWithTab)
        TabMode.INSERT -> keymapOf(
            KeyBinding(
                key = "Tab",
                run = { session ->
                    session.insertAt(session.state.selection.main.head, "\t")
                    true
                }
            )
        )
    }

• TabMode.INDENT uses indentWithTab from the :commands module, which maps Tab to indentMore and Shift-Tab to indentLess.
• TabMode.INSERT inserts a literal tab character at the cursor.

Accessibility note¶

Capturing Tab prevents keyboard-only users from tabbing out of the editor. Consider providing an alternative escape mechanism (e.g., Escape to release focus) if your editor is part of a larger form.

Related API¶

• KeyBinding — key binding data class
• keymapOf — create keymap extension
• indentWithTab — tab indentation binding

Based on the CodeMirror Tab Handling example.