Click an app to open or quit it: the small dot under its icon is the open-app indicator
Dock
/ NSDockTile · NSApplication.dockTile /
also called Mac Dock, app dock, application dock, taskbar (Windows term)
“The little black dot under an app icon” is the open-app indicator on the Dock, the Mac's floating bar of app icons at the bottom of the screen. The apps you keep sit first; after a thin divider come open apps you didn't keep plus up to three suggested and recent ones, and after a second divider the folders (stacks) and the Trash. The system draws all of it: an app controls only its own tile (NSDockTile), its right-click Dock menu, and whether it has a Dock icon at all. The dot is not the red count on an icon's corner (that is a Dock badge), the Dock is not the menu bar along the top, and Windows calls its version the taskbar.
If you called it…
…you meant Dock.
Anatomy — every part, named
- 1Open-app indicator (the dot)
“The little black dot under an app icon” is the open-app indicator: the system puts one under every app that is running, and the setting that hides it is called Show indicators for open applications.
- 2Divider (separator line)
“The extra line between my apps” is a divider, which Apple calls a separator line: one stands before the suggested and recent apps and one before the folders and the Trash, so the first one is gone when the recent apps section is empty.
- 3Recent apps section
“The apps I didn't add, between the two lines” are the suggested and recent apps: apps that are open but aren't kept in the Dock, plus up to three used lately, turned on and off by the setting Show suggested and recent apps in Dock.
- 4Stack (folder in the Dock)
“The folder shortcut next to the Trash” is a stack: a folder kept in the Dock, Downloads by default, that opens as a fan, a grid or a list when clicked.
Prompt — paste into your agent
Work with the macOS Dock. The system draws the shelf, the open-app indicator (the small dot under each running app), the divider lines and the stacks, so an app controls only its own tile (NSApp.dockTile), its Dock menu (applicationDockMenu(_:)) and whether it has a Dock icon at all (NSApplication.ActivationPolicy.accessory for none). To mock one, build a floating, rounded, translucent shelf that hugs its icons, with a small neutral dot under open apps and one thin line before the recent apps and one before the folders and Trash; never a full-width taskbar.
Debug prompt — when it misbehaves
Paste this, then describe what you’re seeing — it hands your agent the classic failure modes to rule out first.
Debug my app's presence in the macOS Dock (NSDockTile, applicationDockMenu(_:), NSApplication.ActivationPolicy). Rule out: expecting to draw, recolor or hide the open-app indicator, which only the system and the user's Desktop & Dock settings control; an .accessory or LSUIElement app that never gets a Dock icon or a dot; the dot staying after the last window closes because the app is still running; a Dock menu built once and never refreshed; custom NSDockTile.contentView drawing that never shows because display() was not called; looking for a divider API when the lines belong to the system. The symptom:
In code
The exact names this thing goes by in code — each row is one framework’s word for it. Use the row that matches your project (or paste it into your prompt).
| AppKit | NSDockTile | your app's own tile; the shelf, dots and lines are system drawn |
| AppKit | NSApplication.dockTile | |
| AppKit | NSApplicationDelegate.applicationDockMenu(_:) | the menu on a right-click of your icon |
| AppKit | NSApplication.ActivationPolicy.accessory | no Dock icon, so no dot; same as LSUIElement in Info.plist |
See also
From the maker of this site48h Icons · Custom Apple app icons in 48 hours48hicons.com →