Adds the ability to disable allows_automatic_window_tabbing on macOS.

[karolisr]

macOS intrusively adds certain global menu items if a certain menu item is present and if the underlying feature of the AppKit is enabled. For example, if a View global menu item is present and the allowsAutomaticWindowTabbing value is set to true, the Show/Hide Tab Bar item is added to the View submenu (see images). By default, allowsAutomaticWindowTabbing is set to true. This makes any application with a View menu item the ability to show/hide potentially useless tab bar. See attached images that show the described menu item and the tab bar in the window.

This PR exposes this setting in settings::Settings (core/src/settings.rs) and applies it in iced_winit::run function.

[dtzxporter]

This belongs in platform specific settings:

core/src/window/settings/macos.rs

[karolisr]

Hmm, I think/thought this was an application-wide setting for allowing tabbing in windows (although it is under NSWindow in Apple's API). If this is indeed a per-window setting, it is a method of winit::platform::macos::ActiveEventLoopExtMacOS as opposed to winit::platform::macos::WindowAttributesExtMacOS where other settings in core/src/window/settings/macos.rs live. The only place in iced where we have a reference to winit::event_loop::ActiveEventLoop is in winit/src/lib.rs. I am not quite familiar with iced enough to immediately understand where the call to the ActiveEventLoop::set_allows_automatic_window_tabbing(&self, enabled: bool) method should be placed as it does not appear to operate on a specific window instance, but on application windows as a whole.

P.S. To clarify, the tab-bar can be shown/hidden per window, the tabbing itself is a property of the application. Thus set_allows_automatic_window_tabbing should apply to the entire application. Is there a place for platform-specific application settings in iced?

[airstrike]

See https://docs.iced.rs/iced/window/struct.Settings.html#structfield.platform_specific

Which is what @dtzxporter was referring to in his previous comment

Also thanks for your work on this and menu bars in general. As a user, I truly appreciate it.

[karolisr]

See https://docs.iced.rs/iced/window/struct.Settings.html#structfield.platform_specific

Which is what @dtzxporter was referring to in his previous comment

Also thanks for your work on this and menu bars in general. As a user, I truly appreciate it.

Thanks, I think you may have missed my point, the link and the @dtzxporter comment references window specific settings, which I am aware of. This is not a window specific setting, it is an application-wide setting.

[pml68]

This is not a window specific setting, it is an application-wide setting.

In this case you'd ideally create a PlatformSpecific struct in a similar fashion to core/src/window/settings/* and add a corresponding platform_specific field to core::Settings, instead of adding a field that only exists on one platform to the struct directly.