Add a reason property to help the users track why the progress event …

…is being fired (#4647)

packages/model-viewer/src/features/ar.ts

@@ -415,7 +415,7 @@ configuration or device capabilities');
     }
 
     async prepareUSDZ(): Promise<string> {
-      const updateSourceProgress = this[$progressTracker].beginActivity();
+      const updateSourceProgress = this[$progressTracker].beginActivity('usdz-conversion');
 
       await this[$triggerLoad]();
 

packages/model-viewer/src/features/environment.ts

@@ -125,7 +125,7 @@ export const EnvironmentMixin = <T extends Constructor<ModelViewerElementBase>>(
         return;
       }
 
-      const updateEnvProgress = this[$progressTracker].beginActivity();
+      const updateEnvProgress = this[$progressTracker].beginActivity('environment-update');
 
       try {
         const {environmentMap, skybox} =

packages/model-viewer/src/features/scene-graph.ts

@@ -170,7 +170,7 @@ export const SceneGraphMixin = <T extends Constructor<ModelViewerElementBase>>(
       super.updated(changedProperties);
 
       if (changedProperties.has('variantName')) {
-        const updateVariantProgress = this[$progressTracker].beginActivity();
+        const updateVariantProgress = this[$progressTracker].beginActivity('variant-update');
         updateVariantProgress(0.1);
         const model = this[$model];
         const {variantName} = this;

packages/model-viewer/src/model-viewer-base.ts

@@ -613,7 +613,7 @@ export default class ModelViewerElementBase extends ReactiveElement {
     // throw exceptions and/or behave in unexpected ways:
     scene.stopAnimation();
 
-    const updateSourceProgress = this[$progressTracker].beginActivity();
+    const updateSourceProgress = this[$progressTracker].beginActivity('model-load');
     const source = this.src;
     try {
       const srcUpdated = scene.setSource(

packages/model-viewer/src/test/utilities/progress-tracker-spec.ts

@@ -19,6 +19,8 @@ import {waitForEvent} from '../../utilities.js';
 import {Activity, ProgressDetails, ProgressTracker} from '../../utilities/progress-tracker.js';
 
 suite('ProgressTracker', () => {
+  const progressReason = 'progress-test';
+
   let progressTracker: ProgressTracker;
   setup(() => {
     progressTracker = new ProgressTracker();
@@ -28,11 +30,23 @@ suite('ProgressTracker', () => {
     expect(progressTracker.ongoingActivityCount).to.be.equal(0);
   });
 
+  test('event includes the reason for the progress', async () => {
+    const activity = progressTracker.beginActivity(progressReason);
+
+    const progressEventDispatches =
+        waitForEvent<CustomEvent<ProgressDetails>>(
+            progressTracker, 'progress');
+    activity(0.5);
+    const event = await progressEventDispatches;
+
+    expect(event.detail.reason).to.be.equal(progressReason);
+  });
+
   suite('an activity', () => {
     let firstActivity: Activity;
 
     setup(() => {
-      firstActivity = progressTracker.beginActivity();
+      firstActivity = progressTracker.beginActivity(progressReason);
     });
 
     test('increases the ongoing activities count', () => {
@@ -73,12 +87,12 @@ suite('ProgressTracker', () => {
         });
 
         test('is added to the current stack of activities', () => {
-          progressTracker.beginActivity();
+          progressTracker.beginActivity(progressReason);
           expect(progressTracker.ongoingActivityCount).to.be.equal(2);
         });
 
         test('defers marking all activities completed', () => {
-          progressTracker.beginActivity();
+          progressTracker.beginActivity(progressReason);
           firstActivity(1.0);
           expect(progressTracker.ongoingActivityCount).to.be.equal(2);
         });
@@ -107,7 +121,7 @@ suite('ProgressTracker', () => {
       let secondActivity: Activity;
 
       setup(() => {
-        secondActivity = progressTracker.beginActivity();
+        secondActivity = progressTracker.beginActivity(progressReason);
       });
 
       test('increases the ongoing activity count', () => {
@@ -151,4 +165,4 @@ suite('ProgressTracker', () => {
       });
     });
   });
-});
+});

packages/model-viewer/src/utilities/progress-tracker.ts

@@ -38,6 +38,7 @@ export type Activity = (progress: number) => number;
  */
 export interface ProgressDetails {
   totalProgress: number;
+  reason: string;
 }
 
 /**
@@ -50,7 +51,7 @@ export interface ProgressDetails {
  *
  * The value of totalProgress is a number that progresses from 0 to 1. The
  * ProgressTracker allows for the lazy accumulation of tracked actions, so the
- * total progress represents a abstract, non-absolute progress towards the
+ * total progress represents an abstract, non-absolute progress towards the
  * completion of all currently tracked events.
  *
  * When all currently tracked activities are finished, the ProgressTracker
@@ -86,15 +87,15 @@ export class ProgressTracker extends EventTarget {
    * progress is reported than the previously reported progress, it will be
    * ignored.
    */
-  beginActivity(): Activity {
+  beginActivity(reason: string): Activity {
     const activity: OngoingActivity = {progress: 0, completed: false};
 
     this.ongoingActivities.add(activity);
 
     if (this.ongoingActivityCount === 1) {
       // Announce the first progress event (which should always be 0 / 1
       // total progress):
-      this.announceTotalProgress(activity, 0);
+      this.announceTotalProgress(activity, 0, reason);
     }
 
     return (progress: number): number => {
@@ -103,15 +104,15 @@ export class ProgressTracker extends EventTarget {
       nextProgress = Math.max(clamp(progress, 0, 1), activity.progress);
 
       if (nextProgress !== activity.progress) {
-        this.announceTotalProgress(activity, nextProgress);
+        this.announceTotalProgress(activity, nextProgress, reason);
       }
 
       return activity.progress;
     };
   }
 
   private announceTotalProgress(
-      updatedActivity: OngoingActivity, nextProgress: number) {
+      updatedActivity: OngoingActivity, nextProgress: number, reason: string) {
     let progressLeft = 0;
     let completedActivities = 0;
 
@@ -122,7 +123,7 @@ export class ProgressTracker extends EventTarget {
       const {progress} = activity;
       progressLeft += 1.0 - progress;
 
-      if (activity.completed === true) {
+      if (activity.completed) {
         completedActivities++;
       }
     }
@@ -140,7 +141,7 @@ export class ProgressTracker extends EventTarget {
         this.totalProgress;
 
     this.dispatchEvent(new CustomEvent<ProgressDetails>(
-        'progress', {detail: {totalProgress}}));
+        'progress', {detail: {totalProgress, reason }}));
 
     if (completedActivities === this.ongoingActivityCount) {
       this.totalProgress = 0.0;

packages/modelviewer.dev/data/docs.json

@@ -248,7 +248,7 @@
       {
         "name": "progress",
         "htmlName": "progress",
-        "description": "This event fires while a model, environment, and/or skybox is loading, during both download and processing. The progress of all of these concurrent tasks will be given by a value between 0 and 1: event.detail.totalProgress."
+        "description": "This event fires while a model, environment, skybox, variant, and/or a usdz conversion is loading, during both download and processing. The progress of all of these concurrent tasks will be given by a value between 0 and 1: event.detail.totalProgress. It also provides the reason why the event is fired ('model-load', 'environment-update', 'variant-update', 'usdz-conversion'): event.detail.reason."
       },
       {
         "name": "render-scale",
@@ -1147,4 +1147,4 @@
       }
     ]
   }
-]
+]