Built-in Unity variables

Unity’s built-in style sheets define USS variables that specify default values for Editor and runtime UI(User Interface) Allows a user to interact with your application. Unity currently supports three UI systems. More info
See in Glossary. You can use these variables in your own style sheets to ensure that your custom interfaces match Unity style.

For information about specific variables, see the List of built-in Unity variables.

Unity variable names

Unity uses a specific naming convention for built-in variables to indicate how and where it uses them. A variable name consists of one or more parts, separated by hyphens. Each part consists of one or more words separated by underscores.

--unity-{group}-{role_and_control}-{sub_element}-{pseudo_state_sequence}

Each part of the name tells you something about the types of USS rules that use the variable.

• Group: the kind of data the variable represents.
• Role/Control: a conceptual grouping for the elements the variable affects.
• Sub-Element: the part of an element or control the variable affects.
• Pseudo States: lists the states Unity uses the variable for.

For example, the following variable name:

--unity-colors-button-text-hover

Provides the following information about how Unity uses the variable:

In other words, Unity uses this variable in styles that change the color of button text when a user hovers over the button.

The rest of this section provides detailed information about each part of the variable name format.

Group

The group specifies what kind of data the variable represents. Each group has several possible sub-elements.

Unity variable names can have the following groups:

Role and Control

Roles and controls are two ways of grouping elements conceptually.

• Role refers to a group of elements that have the same purpose, regardless of what type each element is. For example, the error role includes all elements that are involved in displaying an error message to users.
• Control refers to a group of elements of the same type, regardless of what they do. For example, buttons includes all buttons in the editor.

Every Unity variable has either a role or a control. It cannot have both.

Unity variable names can have the following roles and controls:

Roles:

Controls:

Sub-Element

The sub-element is the part of an element that the variable affects. Together with a variable’s group, the sub-element tells you exactly what kind of data the variable represents.

For example, when you see a variable name with the colors group and the text sub-element, it means Unity uses the variable in styles that affect text color.

Unity variable names can have the following sub-elements:

Pseudo-States

The pseudo-state sequence is a list of UI states that Unity uses a variable for.

For example, when you see a variable name with the hover pseudo state, it means Unity uses the variable in styles that affect elements when a user hovers the pointer over them.

For example: --unity-colors-toolbar_button-text-hover.

A variable name can have more than one pseudo-state. Multiple pseudo states appear in alphabetical order, separated by underscores _.

For example: --unity-colors-toolbar_button-text-focus_selected.

Unity variable names can have any combination of the following pseudo-states:

List of built-in Unity variables