Interface ThemeRegistry

public interface ThemeRegistry
Themes and overrides added in code, for every host in the process. Get it from Strata.themes(). Do not implement this interface. 
// Every screen that shows the engine's theme gets these buttons
Subscription buttons = Strata.themes().override(engineTheme, ThemeOverrides.of()
        .with(Button.STYLE_NORMAL, Paint.nineSlice(SpriteId.of("myapp", "button"), Insets.of(3f))));

// A theme of the application's own that follows packs for every key it leaves alone
Strata.themes().define(ThemeId.of("myapp", "dark"), engineTheme, ThemeOverrides.of()
        .with(Window.STYLE_BACKGROUND, Paint.solid(0xF0101010)));

Nothing here is written to a theme, a theme file or the engine's packs. The keys apply each time a theme resolves, and once a subscription is closed, the keys it set resolve as they did before it. Every change here makes each host that shows a ThemeRef resolve it again at the start of its next layout or render, so open screens pick the change up. Every method may be called from any thread.

  • Method Details

    • override

      Subscription override(ThemeId id, ThemeOverrides overrides)
      Sets keys on a theme for every screen that uses it, until the subscription is closed. The keys apply above the base and every theme file for the id, so code has the final say over packs. Overrides for one id apply in the order they were added, and a ThemeRef's own overrides apply after all of them. The keys report the layer code from Theme.layer(String).

      The id need not resolve yet; the overrides wait until it does. Overrides for Themes.PLATFORM apply to whichever theme is the platform's default, above that theme's own overrides.

      Parameters:
      id - the theme to change
      overrides - the keys to set
      Returns:
      a subscription that removes the overrides when closed

    • define

      Subscription define(ThemeId id, ThemeId parent, ThemeOverrides overrides)
      Defines a theme that starts from another and sets the overrides' keys, until the subscription is closed. The defined theme resolves as one whose base is its parent, resolved in full, with the overrides above it. Theme files for the id still apply on top, as for any theme, but their parent is ignored. The overrides' keys report the layer code from Theme.layer(String).

      An id that the engine adapter already gives a base, in code or as base files, cannot be defined. That is found when the theme resolves, which then throws ThemeException.

      Parameters:
      id - the theme to define
      parent - the theme it starts from
      overrides - the keys it sets on the parent
      Returns:
      a subscription that removes the definition when closed, after which the id can be defined again
      Throws:
      ThemeException - if the id is already defined in code and that definition is still open, is Themes.FLAT, which Strata builds in code, or is Themes.PLATFORM, which stands for the platform's default theme