Add Panel to replace SidePanel and TopBottomPanel (#5659)

This combines `SidePanel` and `TopBottomPanel` into a single `Panel`.

The old types are still there as type aliases, but are deprecated.

`.min_width(…)` etc are now called `.min_size(…)` etc.

Again, the old names are still there, but deprecated.

(edited by @emilk)

---------

Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>

crates/egui/src/containers/mod.rs

@@ -1,4 +1,4 @@
-//! Containers are pieces of the UI which wraps other pieces of UI. Examples: [`Window`], [`ScrollArea`], [`Resize`], [`SidePanel`], etc.
+//! Containers are pieces of the UI which wraps other pieces of UI. Examples: [`Window`], [`ScrollArea`], [`Resize`], [`Panel`], etc.
 //!
 //! For instance, a [`Frame`] adds a frame and background to some contained UI.
 
@@ -27,7 +27,7 @@ pub use {
     frame::Frame,
     modal::{Modal, ModalResponse},
     old_popup::*,
-    panel::{CentralPanel, SidePanel, TopBottomPanel},
+    panel::*,
     popup::*,
     resize::Resize,
     scene::{DragPanButtons, Scene},

crates/egui/src/context.rs

@@ -764,7 +764,7 @@ impl Context {
     /// and only on the rare occasion that [`Context::request_discard`] is called.
     /// Usually, it `run_ui` will only be called once.
     ///
-    /// Put your widgets into a [`crate::SidePanel`], [`crate::TopBottomPanel`], [`crate::CentralPanel`], [`crate::Window`] or [`crate::Area`].
+    /// Put your widgets into a [`crate::Panel`], [`crate::CentralPanel`], [`crate::Window`] or [`crate::Area`].
     ///
     /// Instead of calling `run`, you can alternatively use [`Self::begin_pass`] and [`Context::end_pass`].
     ///

crates/egui/src/lib.rs

@@ -9,7 +9,7 @@
 //! which uses [`eframe`](https://docs.rs/eframe).
 //!
 //! To create a GUI using egui you first need a [`Context`] (by convention referred to by `ctx`).
-//! Then you add a [`Window`] or a [`SidePanel`] to get a [`Ui`], which is what you'll be using to add all the buttons and labels that you need.
+//! Then you add a [`Window`] or a [`Panel`] to get a [`Ui`], which is what you'll be using to add all the buttons and labels that you need.
 //!
 //!
 //! ## Feature flags
@@ -45,7 +45,7 @@
 //!
 //! ### Getting a [`Ui`]
 //!
-//! Use one of [`SidePanel`], [`TopBottomPanel`], [`CentralPanel`], [`Window`] or [`Area`] to
+//! Use one of [`Panel`], [`CentralPanel`], [`Window`] or [`Area`] to
 //! get access to an [`Ui`] where you can put widgets. For example:
 //!
 //! ```
@@ -322,7 +322,7 @@
 //! when you release the panel/window shrinks again.
 //! This is an artifact of immediate mode, and here are some alternatives on how to avoid it:
 //!
-//! 1. Turn off resizing with [`Window::resizable`], [`SidePanel::resizable`], [`TopBottomPanel::resizable`].
+//! 1. Turn off resizing with [`Window::resizable`], [`Panel::resizable`].
 //! 2. Wrap your panel contents in a [`ScrollArea`], or use [`Window::vscroll`] and [`Window::hscroll`].
 //! 3. Use a justified layout:
 //!

crates/egui/src/menu.rs

@@ -84,7 +84,7 @@ fn set_menu_style(style: &mut Style) {
     }
 }
 
-/// The menu bar goes well in a [`crate::TopBottomPanel::top`],
+/// The menu bar goes well in a [`crate::Panel::top`],
 /// but can also be placed in a [`crate::Window`].
 /// In the latter case you may want to wrap it in [`Frame`].
 #[deprecated = "Use `egui::MenuBar::new().ui(` instead"]

crates/egui/src/ui.rs

@@ -119,7 +119,7 @@ impl Ui {
     /// Create a new top-level [`Ui`].
     ///
     /// Normally you would not use this directly, but instead use
-    /// [`crate::SidePanel`], [`crate::TopBottomPanel`], [`crate::CentralPanel`], [`crate::Window`] or [`crate::Area`].
+    /// [`crate::Panel`], [`crate::CentralPanel`], [`crate::Window`] or [`crate::Area`].
     pub fn new(ctx: Context, id: Id, ui_builder: UiBuilder) -> Self {
         let UiBuilder {
             id_salt,

crates/egui/src/ui_stack.rs

@@ -12,16 +12,16 @@ pub enum UiKind {
     /// A [`crate::CentralPanel`].
     CentralPanel,
 
-    /// A left [`crate::SidePanel`].
+    /// A left [`crate::Panel`].
     LeftPanel,
 
-    /// A right [`crate::SidePanel`].
+    /// A right [`crate::Panel`].
     RightPanel,
 
-    /// A top [`crate::TopBottomPanel`].
+    /// A top [`crate::Panel`].
     TopPanel,
 
-    /// A bottom [`crate::TopBottomPanel`].
+    /// A bottom [`crate::Panel`].
     BottomPanel,
 
     /// A modal [`crate::Modal`].