fix(cdk/a11y): add ConfigurableFocusTrapConfig to the public API (angular#22138)

- `ConfigurableFocusTrap` is already in the public API and it depends on this class
- convert `ConfigurableFocusTrapConfig` from a class to an interface
- fix alphabetization of exports

Relates to angular#18201. Relates to angular#22136.

Author: Splaktar

src/cdk/a11y/focus-trap/configurable-focus-trap-config.ts

@@ -7,13 +7,11 @@
  */
 
 /**
- * Configuration for creating a ConfigurableFocusTrap.
+ * Options for creating a ConfigurableFocusTrap.
  */
-export class ConfigurableFocusTrapConfig {
+export interface ConfigurableFocusTrapConfig {
   /**
-   * Whether to defer the creation of FocusTrap elements to be
-   * done manually by the user. Default is to create them
-   * automatically.
+   * Whether to defer the creation of FocusTrap elements to be done manually by the user.
    */
-  defer: boolean = false;
+  defer: boolean;
 }

src/cdk/a11y/focus-trap/configurable-focus-trap-factory.ts

@@ -52,12 +52,11 @@ export class ConfigurableFocusTrapFactory {
    */
   create(element: HTMLElement, deferCaptureElements: boolean): ConfigurableFocusTrap;
 
-  create(element: HTMLElement, config: ConfigurableFocusTrapConfig | boolean =
-    new ConfigurableFocusTrapConfig()): ConfigurableFocusTrap {
+  create(element: HTMLElement, config: ConfigurableFocusTrapConfig|boolean = {defer: false}):
+      ConfigurableFocusTrap {
     let configObject: ConfigurableFocusTrapConfig;
     if (typeof config === 'boolean') {
-      configObject = new ConfigurableFocusTrapConfig();
-      configObject.defer = config;
+      configObject = {defer: config};
     } else {
       configObject = config;
     }

src/cdk/a11y/public-api.ts

@@ -10,9 +10,10 @@ export * from './key-manager/activedescendant-key-manager';
 export * from './key-manager/focus-key-manager';
 export * from './key-manager/list-key-manager';
 export * from './focus-trap/configurable-focus-trap';
+export * from './focus-trap/configurable-focus-trap-config';
+export * from './focus-trap/configurable-focus-trap-factory';
 export * from './focus-trap/event-listener-inert-strategy';
 export * from './focus-trap/focus-trap';
-export * from './focus-trap/configurable-focus-trap-factory';
 export * from './focus-trap/focus-trap-inert-strategy';
 export * from './interactivity-checker/interactivity-checker';
 export * from './live-announcer/live-announcer';

tools/public_api_guard/cdk/a11y.d.ts

@@ -71,6 +71,10 @@ export declare class ConfigurableFocusTrap extends FocusTrap implements ManagedF
     destroy(): void;
 }
 
+export interface ConfigurableFocusTrapConfig {
+    defer: boolean;
+}
+
 export declare class ConfigurableFocusTrapFactory {
     constructor(_checker: InteractivityChecker, _ngZone: NgZone, _focusTrapManager: FocusTrapManager, _document: any, _inertStrategy?: FocusTrapInertStrategy);
     create(element: HTMLElement, config?: ConfigurableFocusTrapConfig): ConfigurableFocusTrap;