Add more docs to menu (#7331)

Improves the docs a bit

crates/egui/src/containers/close_tag.rs

@@ -1,5 +1,13 @@
+#[expect(unused_imports)]
+use crate::{Ui, UiBuilder};
 use std::sync::atomic::AtomicBool;
 
+/// A tag to mark a container as closable.
+///
+/// Usually set via [`UiBuilder::closable`].
+///
+/// [`Ui::close`] will find the closest parent [`ClosableTag`] and set its `close` field to `true`.
+/// Use [`Ui::should_close`] to check if close has been called.
 #[derive(Debug, Default)]
 pub struct ClosableTag {
     pub close: AtomicBool,

crates/egui/src/containers/menu.rs

@@ -1,4 +1,12 @@
-//! See [`MenuBar`] for an example
+//! Popup menus, context menus and menu bars.
+//!
+//! Show menus via
+//! - [`Popup::menu`] and [`Popup::context_menu`]
+//! - [`Ui::menu_button`], [`MenuButton`] and [`SubMenuButton`]
+//! - [`MenuBar`]
+//! - [`Response::context_menu`]
+//!
+//! See [`MenuBar`] for an example.
 
 use crate::style::StyleModifier;
 use crate::{
@@ -52,6 +60,7 @@ pub fn is_in_menu(ui: &Ui) -> bool {
     false
 }
 
+/// Configuration and style for menus.
 #[derive(Clone, Debug)]
 pub struct MenuConfig {
     /// Is this a menu bar?
@@ -122,8 +131,10 @@ impl MenuConfig {
     }
 }
 
+/// Holds the state of the menu.
 #[derive(Clone)]
 pub struct MenuState {
+    /// The currently open sub menu in this menu.
     pub open_item: Option<Id>,
     last_visible_pass: u64,
 }
@@ -359,6 +370,10 @@ impl<'a> SubMenuButton<'a> {
     }
 }
 
+/// Show a submenu in a menu.
+///
+/// Useful if you want to make custom menu buttons.
+/// Usually, just use [`MenuButton`] or [`SubMenuButton`] instead.
 #[derive(Clone, Debug, Default)]
 pub struct SubMenu {
     config: Option<MenuConfig>,

crates/egui/src/containers/mod.rs

@@ -3,7 +3,7 @@
 //! For instance, a [`Frame`] adds a frame and background to some contained UI.
 
 pub(crate) mod area;
-pub mod close_tag;
+mod close_tag;
 pub mod collapsing_header;
 mod combo_box;
 pub mod frame;
@@ -21,6 +21,7 @@ pub(crate) mod window;
 
 pub use {
     area::{Area, AreaState},
+    close_tag::ClosableTag,
     collapsing_header::{CollapsingHeader, CollapsingResponse},
     combo_box::*,
     frame::Frame,

crates/egui/src/containers/popup.rs

@@ -162,6 +162,7 @@ impl From<PopupKind> for UiKind {
     }
 }
 
+/// A popup container.
 #[must_use = "Call `.show()` to actually display the popup"]
 pub struct Popup<'a> {
     id: Id,

crates/egui/src/ui.rs

@@ -5,9 +5,9 @@ use emath::GuiRounding as _;
 use epaint::mutex::RwLock;
 use std::{any::Any, hash::Hash, sync::Arc};
 
+use crate::ClosableTag;
 #[cfg(debug_assertions)]
 use crate::Stroke;
-use crate::close_tag::ClosableTag;
 use crate::containers::menu;
 use crate::{
     Align, Color32, Context, CursorIcon, DragAndDrop, Id, InnerResponse, InputState, IntoAtoms,

crates/egui/src/ui_builder.rs

@@ -1,8 +1,8 @@
 use std::{hash::Hash, sync::Arc};
 
+use crate::ClosableTag;
 #[expect(unused_imports)] // Used for doclinks
 use crate::Ui;
-use crate::close_tag::ClosableTag;
 use crate::{Id, LayerId, Layout, Rect, Sense, Style, UiStackInfo};
 
 /// Build a [`Ui`] as the child of another [`Ui`].