Android-Annotations

Android-Annotations

Reference : https://developer.android.com/studio/write/annotations.html#enum-annotations

public class FilterColorDescriptor {
  public static final String FILTER_BLUE = "blue";
  public static final String FILTER_RED = "red";
  public static final String FILTER_GRAY = "gray";

  public final String filterColor;

  public FilterColorDescriptor(String filterColor) {
    this.filterColor = filterColor;
  }
}

public class FilterColorDescriptor {
  // ... type definitions
  // Describes when the annotation will be discarded
  @Retention(RetentionPolicy.SOURCE)
  // Enumerate valid values for this interface
  @StringDef({ FILTER_BLUE, FILTER_RED, FILTER_GRAY })
  // Create an interface for validating String types
  public @interface FilterColorDef { }
  // Mark the argument as restricted to these enumerated types
  public FilterColorDescriptor(@FilterColorDef String filterColor) {
    this.filterColor = filterColor;
  }
}