A split view manages the presentation of two or more panes of content. Each pane can contain any variety of elements, including buttons, tables, column views, text fields, and even other split views. In Keynote, for example, split views form the navigator, editor, inspector, and presenter notes areas of a presentation document.
The panes of a split view can be arranged horizontally or vertically, and are separated by a divider that can typically be dragged to resize the panes. Each pane can have a minimum and maximum size, which affects how much it can be resized. Many apps let the user hide specific panes on request. For example, in Keynote, the user can hide the navigator and presenter notes areas in order to focus on editing slide content.
Vertical split view
Horizontal split view
Multiple split views
Allow panes to be hidden when it make sense. If your app includes an editor area, for example, consider letting the user hide other panes to reduce distractions or allow more room for editing.
Provide multiple ways to access hidden panes. On layouts where panes may be hidden, provide toolbar buttons or menu items with keyboard shortcuts for revealing the panes again.
Set appropriate minimum and maximum pane sizes. The divider can get lost when a pane gets too small. To prevent this, give your panes minimum and maximum sizes so the splitter always remains visible.
For developer guidance, see NSSplitViewController and NSSplitView.
A split view can adopt one of the following divider styles. You can also change the divider color, change the divider thickness, or design a completely custom divider.
Thin. 1pt width.
Thick. 9pt width. Clear by default.
Pane splitter. 10pt width.
The user can click any part of a divider and drag to resize. For thin dividers, the clickable area also includes two points on each side of the divider.
Prefer the thin divider style. Users are accustomed to the appearance of the thin divider. Consider the thick or pane splitter style when you need to indicate a stronger visual distinction between panes. For example, when each side of a split view contains a table, a wider divider can help people differentiate between the two tables.