feat: Add the IFlyoutInflater interface. (#8581)

* feat: Add the IFlyoutInflater interface.

* fix: Add a return type for IFlyoutInflater.disposeElement().

* refactor: Add the gapForElement method.

core/interfaces/i_flyout_inflater.ts

@@ -0,0 +1,41 @@
+import type {IBoundedElement} from './i_bounded_element.js';
+import type {WorkspaceSvg} from '../workspace_svg.js';
+
+export interface IFlyoutInflater {
+  /**
+   * Loads the object represented by the given state onto the workspace.
+   *
+   * Note that this method's interface is identical to that in ISerializer, to
+   * allow for code reuse.
+   *
+   * @param state A JSON representation of an element to inflate on the flyout.
+   * @param flyoutWorkspace The flyout's workspace, where the inflated element
+   *    should be created. If the inflated element is an `IRenderedElement` it
+   *    itself or the inflater should append it to the workspace; the flyout
+   *    will not do so itself. The flyout is responsible for positioning the
+   *    element, however.
+   * @returns The newly inflated flyout element.
+   */
+  load(state: Object, flyoutWorkspace: WorkspaceSvg): IBoundedElement;
+
+  /**
+   * Returns the amount of spacing that should follow the element corresponding
+   * to the given JSON representation.
+   *
+   * @param state A JSON representation of the element preceding the gap.
+   * @param defaultGap The default gap for elements in this flyout.
+   * @returns The gap that should follow the given element.
+   */
+  gapForElement(state: Object, defaultGap: number): number;
+
+  /**
+   * Disposes of the given element.
+   *
+   * If the element in question resides on the flyout workspace, it should remove
+   * itself. Implementers are not otherwise required to fully dispose of the
+   * element; it may be e.g. cached for performance purposes.
+   *
+   * @param element The flyout element to dispose of.
+   */
+  disposeElement(element: IBoundedElement): void;
+}

core/registry.ts

@@ -10,6 +10,7 @@ import type {Abstract} from './events/events_abstract.js';
 import type {Field} from './field.js';
 import type {IConnectionChecker} from './interfaces/i_connection_checker.js';
 import type {IFlyout} from './interfaces/i_flyout.js';
+import type {IFlyoutInflater} from './interfaces/i_flyout_inflater.js';
 import type {IMetricsManager} from './interfaces/i_metrics_manager.js';
 import type {IIcon} from './interfaces/i_icon.js';
 import type {Input} from './inputs/input.js';
@@ -99,6 +100,8 @@ export class Type<_T> {
     'flyoutsHorizontalToolbox',
   );
 
+  static FLYOUT_INFLATER = new Type<IFlyoutInflater>('flyoutInflater');
+
   static METRICS_MANAGER = new Type<IMetricsManager>('metricsManager');
 
   /**