Menus

What it is and when to use it#

MenuBar declares the app’s menus (the app menu, File, Edit, View, …, Window, Help) as lists of command ids. The labels, shortcuts, enabled or disabled state with its reason, and ticks all come from the commands, so a menu item never has a handler of its own: picking it runs the action. A live section is a function read each time the bar is resolved (open windows, the screensets). The same bar is drawn natively on macOS, through dbusmenu on Linux, with UIMenuBuilder on iPadOS, and in the window where there is no global menu.

Use it for every app’s menu bar. Design: App menus.

A minimal example#

The model is in the default build of architect-commands; ui adds InWindowMenus, native adds NativeMenus. From apps/ui/src/lib.rs:

let menus = architect_commands::MenuBar::standard("Architect Lab")
    .menu("File", |m| m
        .commands(["LAB_CAPTURE", "COMMAND_PALETTE_OPEN_ANYTHING"])
        .separator()
        .command("WORKSPACE_CLOSE_TAB"))
    .menu("View", |m| m
        .command("LAB_TOGGLE_DETAILS")
        .separator()
        .section("Screensets", move || sets.read().menu_rows("VIEW_RECALL_SCREENSET")))
    .menu("Help", |m| m.command("COMMAND_PALETTE_OPEN"));

rsx! {
    architect_commands::NativeMenus { bar: menus.clone() }   // macOS, Linux, iPadOS
    architect_commands::InWindowMenus { bar: menus }         // stands aside under a global menu
}

A toggle gets its tick from the list: list.set_checked("VIEW_MIXER", || mixer_open())?. When what an enabled or checked test reads changes outside an action run, call list.changed(..), or the bar keeps the old state.

Code tour#

1. features/commands/src/menu.rs MenuBar: standard, menu (a new menu goes before Window and Help), resolve against the commands there are.
2. Same file, Menu: command, commands, group, separator, submenu, section; Live rows (args, checked, disabled); without_platform.
3. Same file, Tree: the resolved bar numbered for a backend; pick says what a picked item runs.
4. crates/architect/src/action_list.rs ActionList::set_checked: a toggle’s tick, carried to the command by features/commands/src/ui.rs.
5. features/commands/src/native_menu.rs NativeMenus (macOS), features/commands/src/linux_menu.rs with features/commands/src/dbusmenu.rs, and features/commands/src/ios_menu.rs: the same component per platform.
6. features/commands/src/menu_view.rs InWindowMenus; Commands::has_global_menu and Commands::run_pick in features/commands/src/ui.rs.
7. features/workspace/src/screenset.rs Screensets::menu_rows: the screensets as live rows, the current one ticked.

NativeMenus resolves the bar against Commands::all(): live sections run, missing ids and stray separators drop out, and the result becomes a Tree the platform backend draws. A pick comes back as a tree id; Tree::pick turns it into a command and its arguments, and Commands::run_pick runs it on the UI thread. The bar resolves again when the commands’ event counter moves (a run, list.changed, a registration) or a signal a section reads changes, never on a timer.

Tests to read#

• features/commands/tests/commands.rs: a bar resolves against the commands there are; a new menu goes before Window and Help; a toggle resolves with its tick; a live section is read when the bar is resolved; platform items go without the platform; a tree numbers the bar and says what a pick runs.
• features/workspace/tests/workspace.rs: the View menu lists the screensets with the current one ticked.

Status#

Done in architect. The Linux and iPadOS bars build but have not been run on a device. Open: the macOS About, Services and Hide items; a shortcut the menu shows but the keymap does not bind.

• Task has no menu bar.
• Studio has its own (studio:apps/signal/desktop/src/mac_menu.rs, and Session’s dbusmenu in studio:apps/session/daw/src/app_menu/bus.rs); both are to move onto MenuBar.