UXMenuBar

UXMenuBar is the app-level menu model. A menu is not a widget: the platform assembles it, draws it, tracks the pull-down, highlights the hover, and hit-tests the pick. GEM does this inside evnt_multi, AppKit as a real NSMenu, Win32 as a per-window HMENU. The model contains no drawing, no tracking and no hit-testing. It describes the menu, hands that description to the driver in install, and turns the resulting selection back into a callback call. This follows the same approach as UXButton (no drawing) and UXTextField (no editing).

#use <UXKit>

Overview

UXMenuBar* bar = new UXMenuBar();
UXMenu* file = bar.addMenu((u8*)" File ");
file.addItem((u8*)"  Open...  ", &controller.onOpen);
file.addSeparator();
file.addItem((u8*)"  Quit  ", &controller.onQuit);
bar.install(screenW);              // from here on the bar is the platform's

A handler receives the item, so one method can serve several:

void onOpen(UXMenuItem* sender) { ... }

Topics

Building · addMenu · install Selections · handleSelection Live state · setChecked · setEnabled

addMenu

UXMenu* addMenu(u8* title)

Appends a titled menu (see UXMenu) and returns it for item building.

install

void install(i32 screenW)

Hands the whole model to the driver and shows the bar. Build the model completely first, because the platform realizes it once.

handleSelection

void handleSelection(i32 titleObj, i32 itemObj)

The selection decoder the run loop calls with the platform’s message (GEM’s MN_SELECTED shape). It resolves the ordinals and fires the item’s action. Separators never fire, and stale indices fire nothing. App code never calls this directly.

setChecked

void setChecked(u16 mi, u16 ii, bool on)

Sets the item’s tick in the model and the live menu together. The platform redraws.

setEnabled

void setEnabled(u16 mi, u16 ii, bool on)

Enables or greys the item in the model and the live menu together.

Platform notes

One neutral model has three realizations. GEM builds a bar of G_TITLEs with dropdown boxes and delivers MN_SELECTED. AppKit builds a real NSMenu on the system bar. Win32 has no screen bar, so it attaches the same model as an HMENU to every window, and a window opened after install still gets it. The iOS and Android realizations are milestones in their drivers’ menu work.

Example

A checkable view option:

UXMenu* view = bar.addMenu((u8*)" View ");
view.addItem((u8*)"  Show Ruler  ", &controller.onRuler);

void onRuler(UXMenuItem* sender) {
    showRuler = !showRuler;
    bar.setChecked((u16)1, (u16)0, showRuler);
}