Theme mixins are partial theme files that are always applied on top of a base theme. The concept is very similar to JavaScript mixins.
You can edit a theme mixin in two ways:
Open a theme mixin file
Click the
Open Theme button on the toolbar and select the theme mixin file (.mixin.theme) to load.
Double click a theme mixin file
You can double click .mixin.theme file in a folder or in a Visual Studio project to load it in Theme Builder.
You cannot create a theme mixin using the Theme Builder. Theme mixins are created in Visual Studio by adding the Theme Mixin component to the project, or manually by creating a new .mixin.theme file.
Switch the Base Theme
While editing a theme mixin you can switch the base theme by selecting one of the preloaded themes, or by again clicking the
Open Theme button and selecting a .theme file.
When you change the base theme, the Theme Builder updates the previews but the tree and the editor are still limited to the elements defined in the mixin.