Add getEventTarget() to PDF Viewer Controller interface

Simultaneously, put existing event types in enums.

Bug: 1134208
Change-Id: Ia4a3d7f6d03c0969b1f18961db0899a8a7f51b9e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2512368
Commit-Queue: Daniel Hosseinian <dhoss@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824589}

chrome/browser/resources/pdf/controller.js

@@ -67,6 +67,9 @@ function createToken() {
 export class ContentController {
   constructor() {}
 
+  /** @return {!EventTarget} */
+  getEventTarget() {}
+
   /** @return {boolean} */
   get isActive() {}
 
@@ -127,11 +130,19 @@ export class ContentController {
   unload() {}
 }
 
+/**
+ * Event types dispatched by the plugin controller.
+ * @enum {string}
+ */
+export const PluginControllerEventType = {
+  PLUGIN_MESSAGE: 'PluginControllerEventType.PLUGIN_MESSAGE',
+};
+
 /**
  * PDF plugin controller singleton, responsible for communicating with the
- * embedded plugin element. Dispatches a 'plugin-message' event containing the
- * message from the plugin, if a message type not handled by this controller is
- * received.
+ * embedded plugin element. Dispatches a
+ * `PluginControllerEventType.PLUGIN_MESSAGE` event containing the message from
+ * the plugin, if a message type not handled by this controller is received.
  * @implements {ContentController}
  */
 export class PluginController {
@@ -200,7 +211,10 @@ export class PluginController {
     return this.uidCounter_++;
   }
 
-  /** @return {!EventTarget} */
+  /**
+   * @return {!EventTarget}
+   * @override
+   */
   getEventTarget() {
     return this.eventTarget_;
   }
@@ -482,8 +496,8 @@ export class PluginController {
         resolver.resolve(null);
         break;
       default:
-        this.eventTarget_.dispatchEvent(
-            new CustomEvent('plugin-message', {detail: messageData}));
+        this.eventTarget_.dispatchEvent(new CustomEvent(
+            PluginControllerEventType.PLUGIN_MESSAGE, {detail: messageData}));
     }
   }
 

chrome/browser/resources/pdf/elements/viewer-annotations-bar.js

@@ -12,7 +12,7 @@ import './viewer-pen-options.js';
 import {EventTracker} from 'chrome://resources/js/event_tracker.m.js';
 import {html, PolymerElement} from 'chrome://resources/polymer/v3_0/polymer/polymer_bundled.min.js';
 
-import {InkController} from '../ink_controller.js';
+import {InkController, InkControllerEventType} from '../ink_controller.js';
 
 export class ViewerAnnotationsBarElement extends PolymerElement {
   static get is() {
@@ -67,13 +67,16 @@ export class ViewerAnnotationsBarElement extends PolymerElement {
     }
 
     this.tracker_.add(
-        this.inkController.getEventTarget(), 'set-annotation-undo-state',
+        this.inkController.getEventTarget(),
+        InkControllerEventType.SET_ANNOTATION_UNDO_STATE,
         e => this.setAnnotationUndoState_(e));
-    this.tracker_.add(this.inkController.getEventTarget(), 'loaded', () => {
-      if (this.annotationTool_) {
-        this.inkController.setAnnotationTool(this.annotationTool_);
-      }
-    });
+    this.tracker_.add(
+        this.inkController.getEventTarget(), InkControllerEventType.LOADED,
+        () => {
+          if (this.annotationTool_) {
+            this.inkController.setAnnotationTool(this.annotationTool_);
+          }
+        });
   }
 
   /**

chrome/browser/resources/pdf/ink_controller.js

@@ -24,13 +24,23 @@ import {Viewport} from './viewport.js';
  */
 let ViewerInkHostElement;
 
+/**
+ * Event types dispatched by the ink controller.
+ * @enum {string}
+ */
+export const InkControllerEventType = {
+  HAS_UNSAVED_CHANGES: 'InkControllerEventType.HAS_UNSAVED_CHANGES',
+  LOADED: 'InkControllerEventType.LOADED',
+  SET_ANNOTATION_UNDO_STATE: 'InkControllerEventType.SET_ANNOTATION_UNDO_STATE',
+};
+
 /**
  * Controller for annotation mode, on Chrome OS only. Fires the following events
  * from its event target:
- *   has-unsaved-changes: Fired to indicate there are ink annotations that have
- *       not been saved.
- *   set-annotation-undo-state: Contains information about whether undo or redo
- *       options are available.
+ *   InkControllerEventType.HAS_UNSAVED_CHANGES: Fired to indicate there are ink
+ *       annotations that have not been saved.
+ *   InkControllerEventType.SET_ANNOTATION_UNDO_STATE: Contains information
+ *       about whether undo or redo options are available.
  *  @implements {ContentController}
  */
 export class InkController {
@@ -72,7 +82,10 @@ export class InkController {
     // TODO(crbug.com/1134208): Implement when InkController is a singleton.
   }
 
-  /** @return {!EventTarget} */
+  /**
+   * @return {!EventTarget}
+   * @override
+   */
   getEventTarget() {
     return this.eventTarget_;
   }
@@ -140,15 +153,18 @@ export class InkController {
       this.inkHost_ = /** @type {!ViewerInkHostElement} */ (inkHost);
       this.inkHost_.viewport = this.viewport_;
       inkHost.addEventListener('stroke-added', e => {
-        this.eventTarget_.dispatchEvent(new CustomEvent('has-unsaved-changes'));
+        this.eventTarget_.dispatchEvent(
+            new CustomEvent(InkControllerEventType.HAS_UNSAVED_CHANGES));
       });
       inkHost.addEventListener('undo-state-changed', e => {
-        this.eventTarget_.dispatchEvent(
-            new CustomEvent('set-annotation-undo-state', {detail: e.detail}));
+        this.eventTarget_.dispatchEvent(new CustomEvent(
+            InkControllerEventType.SET_ANNOTATION_UNDO_STATE,
+            {detail: e.detail}));
       });
     }
     return this.inkHost_.load(filename, data).then(() => {
-      this.eventTarget_.dispatchEvent(new CustomEvent('loaded'));
+      this.eventTarget_.dispatchEvent(
+          new CustomEvent(InkControllerEventType.LOADED));
     });
   }
 

chrome/browser/resources/pdf/pdf_viewer.js

@@ -28,7 +28,7 @@ import {PluginController} from './controller.js';
 import {ViewerPdfSidenavElement} from './elements/viewer-pdf-sidenav.js';
 import {ViewerPdfToolbarNewElement} from './elements/viewer-pdf-toolbar-new.js';
 // <if expr="chromeos">
-import {InkController} from './ink_controller.js';
+import {InkController, InkControllerEventType} from './ink_controller.js';
 //</if>
 import {LocalStorageProxyImpl} from './local_storage_proxy.js';
 import {PDFMetrics, UserAction} from './metrics.js';
@@ -388,7 +388,8 @@ export class PDFViewerElement extends PDFViewerBaseElement {
     this.inkController_ = new InkController(
         this.viewport, /** @type {!HTMLDivElement} */ (this.getContent()));
     this.tracker.add(
-        this.inkController_.getEventTarget(), 'has-unsaved-changes',
+        this.inkController_.getEventTarget(),
+        InkControllerEventType.HAS_UNSAVED_CHANGES,
         () => chrome.mimeHandlerPrivate.setShowBeforeUnloadDialog(true));
     // </if>
 

chrome/browser/resources/pdf/pdf_viewer_base.js

@@ -10,7 +10,7 @@ import {html, PolymerElement} from 'chrome://resources/polymer/v3_0/polymer/poly
 
 import {BrowserApi, ZoomBehavior} from './browser_api.js';
 import {FittingType, Point} from './constants.js';
-import {ContentController, MessageData, PluginController} from './controller.js';
+import {ContentController, MessageData, PluginController, PluginControllerEventType} from './controller.js';
 import {PDFMetrics, UserAction} from './metrics.js';
 import {OpenPdfParamsParser} from './open_pdf_params_parser.js';
 import {LoadState} from './pdf_scripting_api.js';
@@ -280,7 +280,8 @@ export class PDFViewerBaseElement extends PolymerElement {
     this.currentController = pluginController;
 
     this.tracker.add(
-        pluginController.getEventTarget(), 'plugin-message',
+        pluginController.getEventTarget(),
+        PluginControllerEventType.PLUGIN_MESSAGE,
         e => this.handlePluginMessage(e));
 
     document.body.addEventListener('change-page-and-xy', e => {