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Camera

One camera, two surfaces. Open Camera is a launcher command that puts a live preview on screen, mirrors it, switches between the Mac's cameras and copies a photo to the clipboard. Calendar's pre-meeting preview is the other, and it rides the same session, panel and stage — the join-specific controller and footer are all that stay in calendar.md.

Invariants

  • Nothing runs until the command is run. CameraCoordinator is lazy on AppCore, and CameraSession.init stores a Purpose and touches nothing else — no device, no discovery session, no TCC read. The camera permission prompt is raised by start(), from the gesture that asked for it, and never on launch.
  • The camera settles before the panel opens, and stops after it closes. start() resolves access and blocks on startRunning first, then hands a settled Feed up — so the first frame is live video rather than a stage swapped out from under the user, and the TCC prompt never takes key from a panel already up. stop() runs from the fade-out's completion, so the camera light never outlives the panel but is never torn down under a visible one either.
  • Escape, click-away and the shot all end the same way. Every route goes through CameraCoordinator.close(), which drops the panel and stops the session; windowDidResignKey is what covers clicking away. Taking a photo closes too — the command is done, so the camera goes out with it rather than idling for a second shot.
  • The preview and the photo are mirrored together. Mirroring is isVideoMirrored on a connection — the preview layer's, and the photo output's at capture time — never a scaleEffect on the view, which would hand back a photo that is not what the user framed.
  • A photo reaches the clipboard as PNG. The camera's own encoding is decoded and re-encoded off main, because ClipboardManager records .png and .tiff and nothing else.
  • AVCaptureSession is not Sendable, and only CaptureBox crosses that line. The blocking calls — startRunning, stopRunning, and the begin/commit around a device swap — run in Task.detached behind that one @unchecked Sendable box, which is private to CameraSession.swift. There is no second actor.

How it is put together

Piece Holds
Service/CameraSession.swift access, start/stop, device cycling, the photo, and the box
UI/CameraCoordinator.swift the standalone panel's lifecycle, mirror state, the clipboard write
UI/CameraView.swift the standalone surface: stage over a footer of controls
UI/CameraStage.swift the shared stage — the hosted preview layer, or why there is no video
UI/CameraPanel.swift the shared borderless panel: ↵ and Esc, and cursor-screen centring
UI/CameraButton.swift the shared capsule button both footers use

Purpose is the session's one knob. .preview is the cheap one Calendar takes — a .medium preset and no output. .capture raises the preset to .photo and adds an AVCapturePhotoOutput, which is the whole cost of being able to take a photo, and it is paid only by the command that does.

CameraCoordinator is @Observable and the view reads it directly, so toggling Mirror re-renders through Observation rather than through a hand-reassigned rootView. mirrored lives on the coordinator rather than in AppSettings: it is remembered for the launch, and a display preference that grants nothing is not worth a settings key or a line in a backup.

Switching cameras swaps the input inside one beginConfiguration/commitConfiguration while the session keeps running, so the stage never blanks. Switch Camera only appears when hasMultipleDevices says the discovery session found more than one.

Where it is reachable from

The launcher, as CommandID.openCamera — so it takes aliases and a global shortcut like any other command, and hides with the Command category. It has no Settings pane and no enable switch: there is nothing to configure and nothing to leave running.