Decision — shipped system dialogs

Status: accepted 2026-10-12. Widens the scene loader's v1 rule that only the Scene Editor may be a dialog.

The problem

The scene host has one dialog seat. A dialog takes it when it loads, keeps it while loaded, takes the keyboard when it shows and gives it back when it hides. The loader therefore refused window.kind: "dialog" for every installation except the Scene Editor, so no other part of the desktop could ask a short question, such as the name for a workspace.

The decision

  • A system dialog is a shipped scene template that:

    • is marked hidden: true in its shipped template.conf.mix;
    • declares window.kind: "dialog" in its shipped scene.mix;
    • is installed under its own template name.

    The loader allows it to load as a dialog. The permission is read from the shipped files under the templates root, never from the user-editable installed copy. A shipped dialog that is not hidden, a system dialog installed (or forked) under another name, and any other scene edited into a dialog are all still refused. The installed copy of a system dialog is the person's own, like any installed scene, and keeps the permission its name carries.

  • Hidden templates stay out of the gallery, so people still see one dialog scene, the Scene Editor.

  • A system dialog holds the seat only while it shows. Its owner installs it disabled and enables it to ask. The dialog disables itself once its dialog is hidden by Save, Cancel or Esc, or by another dialog taking the seat.

  • The Scene Editor. By default the Scene Editor is a native application window, not a dialog scene. It never uses the dialog seat, so it and a system dialog can both be open. The legacy scene frontend (SCENES_EDITOR_APP=0) is a dialog scene and keeps priority:

    • opening it pre-empts a system dialog;
    • it holds the seat for as long as it is loaded, hidden or not, so a system dialog asked for meanwhile is refused (DIALOG_BUSY) and its owner says so;
    • unloading it (scenes.editor.close {unload: true}) frees the seat.

  • One system dialog at a time. A dialog asked to show for something else while it is already showing (another workspace) refuses until it is saved or cancelled. A failed start is rolled back (the scene is disabled again), and the dialog releases the seat only when the host's current state shows it hidden, never on a stale notice.

  • Focus. A dialog takes the keyboard when it maps and gives it back when it hides. Its window.autofocus field gets focus as it opens.

The first system dialog is share/scenes/workspace-rename. Right-clicking a pager button opens it for that workspace, and it names the workspace through comp.workspace.rename.

This page as Markdown · This page describes the current main branch of MixOS.