Layout Windows and What Owns Them

A short report from the workbench: the finer points of layout windows and how they relate to the piece window that owns them. What's happening in the video:
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1. I create a string quartet by first creating musicians for the two violins, the viola and the cello. Note how the violins are numbered automatically.
2. I then create the score by dragging all the musicians onto the layout pane.
3. A layout is created: I flip it open briefly so we can see the musicians inside.
4. I then drag each musician across individually to create their parts.
5. All of the above you've seen before: it's literally everything required to set up a complete score and its parts. However, what follows is new, and is what I've just finished.
6. I select all the layouts and press Enter to open them. A double-click would have done the same for the entire selection.
7. The layout windows open staggered, so you can see them all.
8. I delete the cello part, and its layout window closes with it.
9. Undo brings the cello part back: it returns to the list of layouts, and I can open it again.
10. Finally, I click the piece window's close button.
11. It asks for confirmation, the piece being unsaved.
12. When I confirm, the piece window and all its open layout windows fade away simultaneously, as a single unit.

That last moment is the point of the exercise. A layout window isn't a free-standing window that happens to show part of a piece: it belongs to the piece. Ownership is why deleting a part closes its window, what undo restores, why Save acts on the piece a window belongs to rather than on whatever happens to be in front, and why quitting takes the whole workspace away and gives it back when the piece is next opened.

So the piece window is finished, down to the edge cases and the pace at which things appear and disappear. Later today I start on the Piece Preferences window, which follows the Application Settings window closely enough that most of the path is already trodden.

(Ignore the notifications in the lower right. They're for development.)