Launch feedback

Show a busy cursor while an application starts. This API supplies feedback; it does not launch the application.

Availability

Launch feedback is built into the Gnoblin session. The CLI and shell clients can use it without installing a user script.

It uses the compositor's themed wait cursor. Application focus is unchanged.

Use the CLI

gnoblinctl launch begin example org.gnome.Nautilus 3000
gnoblinctl launch status
gnoblinctl launch end example

Here example is your request token, org.gnome.Nautilus identifies Files, and 3000 sets a three-second timeout. The commands alone show and clear the busy cursor; they do not open Files.

Wait for begin to return before launching the app. Use a unique token for each launch and call end if launch fails.

Requests end when a matching window appears or gains focus, on explicit end, or after the timeout. Overlapping requests keep the cursor busy until all end.

D-Bus API

Name/interface: org.gnoblin.LaunchFeedback. Object: /org/gnoblin/LaunchFeedback.

Method	Signature	Result
Begin	(ssu) → ()	Start feedback for (token, app hint, timeout in ms).
End	s → ()	End the request with this token; an unknown token is harmless.
GetState	() → s	Return a JSON state record.

Begin requires a nonempty token of at most 128 characters and an app hint of at most 512 characters. Up to 64 distinct requests can be pending. The timeout is clamped to 100–10000 ms. Reusing a token replaces its earlier request.

The app hint is matched case-insensitively against a window's GTK application ID, WM class, WM class instance, desktop ID or desktop name. A trailing .desktop is ignored. Windows marked skip-taskbar do not complete a request.

GetState returns these JSON fields:

Field	Meaning
busy	Whether the wait cursor is currently active.
pending	Number of launch requests still pending.
nativeCursor	Whether this Mutter build provides Gnoblin's cursor support.
pointerVisible	Whether the pointer is visible.
spinnerVisible	Whether the themed wait cursor is active.
cursorSource	Cursor theme source, or null before feedback has started.
position	Reserved; currently null.

Requests expire even if a launcher exits before sending End. The cursor override is also released when the Gnoblin session shuts down.

Test

GNOBLIN_TEST_DBUS_CLIENT="$PWD/tests/test-launch-feedback.py" scripts/run-gnome-shell.sh

Checks pointer output, overlapping requests, expiry, reload and window-map completion.