message: extend IActionBarItem interface
diff: @@ -12,11 +12,11 @@ export interface IActionBarItem {
  /**
  * Set this property to false to make the toolbar item invisible.
  */
  - visible?: boolean;
  + visible?: (() => boolean) | boolean;
  /**
  * Toolbar item title
  */
  - title?: string;
  + title?: (() => string) | string;
  /**
  * Toolbar item tooltip
  */
  @@ -24,7 +24,7 @@ export interface IActionBarItem {
  /**
  * Set this property to false to disable the toolbar item.
  */
  - enabled?: boolean;
  + enabled?: (() => boolean) | boolean;
  /**
  * Set this property to false to hide the toolbar item title.
  */
  @@ -75,10 +75,10 @@ export class ActionBarItem extends Base implements IActionBarItem {
  Object.assign(this, item);
  }
  @property() id: string;
  - @property() visible?: boolean;
  - @property() title?: string;
  + @property() visible?: (() => boolean) | boolean;
  + @property() title?: (() => string) | string;
  @property() tooltip?: string;
  - @property() enabled?: boolean;
  + @property() enabled?: (() => boolean) | boolean;
  @property() showTitle?: boolean;
  @property() action?: (context?: any) => void;
  @property() css?: (() => string) | string;
  