Headers for tiles not contained in a tab container

[bcmpinc]

I'm trying to recreate the dock widgets from Qt5 in egui. Those widgets have a header with its title. This header is also a handle for dragging the widget around. If the widget is in a tab container, that header is hidden and its title is shown in the tab.

With egui_tiles I can get really close to recreating those dock widgets. However, within Behavior<Pane>::pane_ui I do not know whether the parent container is a tab container, so I cannot hide the header in that case.

I'm considering implementing support for this into egui_tiles, but want to hear your opinion about this first. Would this be a useful addition to the library? If yes, do you have any recommendation on how to implement this? Should this header be visible by default?

I see some ways to implement this:

1. Replace the calls to Tree<Pane>::tile_ui in linear.rs and grid.rs with a call to a new function Behavior::tile_with_header_ui that in turn calls Tree<Pane>::tile_ui.
2. Add a draw_header parameter to Tree<Pane>::tile_ui and prefix the call to Behavior.<Pane>::pane_ui with a conditional call to a new function Behavior.::header_ui`.
3. Add a draw_header parameter to Tree<Pane>::tile_ui and pass this on to Behavior.<Pane>::pane_ui, so the user can determine if and how to draw the header.

I personally think 2 is the best option.

Thanks for creating this library and reading my message.

[mitchmindtree]

Fwiw, you can kind of emulate this behaviour by providing an implementation for Behavior::simplification_options that specifies all_panes_must_have_tabs as true.

This way you can keep around the single-tab view as a kind of header that you can still use to drag the pane around. This might not help other use-cases, but suited mine!