Uses a sidebar to switch between `GtkStack` pages.

<picture> <source srcset="sidebar-dark.png" media="(prefers-color-scheme: dark)"> <img alt="An example GtkStackSidebar" src="sidebar.png"> </picture>

In order to use a `GtkStackSidebar`, you simply use a `GtkStack` to organize your UI flow, and add the sidebar to your sidebar area. You can use [method@Gtk.StackSidebar.set_stack] to connect the `GtkStackSidebar` to the `GtkStack`.

CSS nodes

`GtkStackSidebar` has a single CSS node with name stacksidebar and style class .sidebar.

When circumstances require it, `GtkStackSidebar` adds the .needs-attention style class to the widgets representing the stack pages.