Usage & Behaviour

General guidelines

Text

Label should address the primary action of the button. See additional guidelines in Buttons#Labels

Format structure

The split button is separated into two areas: the label/icon and the arrow icon. The separator between them signals that the two areas result in different actions. 

The icon which opens the menu act as a menu (see more information in <<menu link>>)

Order

For the items within the menu - by popularity - when there are a few available items (e.g. less than 5)

Internal Logic

• The primary button should appear in the menu and indicated as selected
• The Primary and and menu icon are treated as 2 distinct buttons with their own states
  See example for hover state:
  
  

Default Selection

The primary action should be the most common use case, while the dropdown menu shows a list of related actions. 

Persistent split button <<?Can the default be changed - according to the menu?>>. The default is kept until the user makes a different selection which then becomes default. The button label changes accordingly.

States

• Split buttons can be enabled or disabled
  • The menu can also contain specific disabled actions while the Primary is enable and vice versa
• If a split button is disabled, the colour of the button changes and the cursor indicates that you cannot click the split button

Interaction

• When you click the primary action on the left, the action is activated.
• When you click the arrow, it exposes a menu alternative actions
  • Clicking an action will commit the action and close the menu

If the split button is selected using keyboard actions and then Enter is pressed, the primary action occurs.

Best practice

• This pattern is used when there are many possible actions but only one primary action
• Use a split button only if the actions are related and only one of the actions in commonly used
• Typically placed in a main toolbar
• Used for actions not navigation

Design