1 files changed, 95 insertions, 4 deletions

diff --git a/src/client/apis/recording/recordingApi.tsx b/src/client/apis/recording/recordingApi.ts
index cce19deec..2fd1d37a7 100644
--- a/src/client/apis/recording/recordingApi.tsx
+++ b/src/client/apis/recording/recordingApi.ts
@@ -32,7 +32,7 @@ export class RecordingApi {
     // create static instance and getter for global use
     @observable static _instance: RecordingApi;
     public static get instance(): RecordingApi { return RecordingApi._instance }
-    constructor() {
+    public constructor() {
         // init the global instance
         RecordingApi._instance = this;
 
@@ -46,6 +46,7 @@ export class RecordingApi {
 
         // for now, set playFFView
         this.playFFView = null;
+        this.timers = null;
     }
 
     // little helper :)
@@ -172,6 +173,7 @@ export class RecordingApi {
 
     // TODO: extract this into different class with pause and resume recording
     private playFFView: CollectionFreeFormView | null;
+    private timers: Timer[] | null;
 
     public followMovements = (presentation: Presentation): undefined | Error => {
         if (presentation.startDate === null || this.playFFView === null) {
@@ -180,16 +182,46 @@ export class RecordingApi {
 
         const document = this.playFFView.Document
         const { movements } = presentation
-        movements.forEach(movement => {
+        this.timers = movements.map(movement => {
             const { panX, panY, time } = movement
-            // set the pan to what was stored
-            setTimeout(() => {
+            return new Timer(() => {
                 document._panX = panX;
                 document._panY = panY;
+                // TODO: consider cleaning this array to null or some state
             }, time)
         })
     }
 
+    public pauseMovements = (): undefined | Error => {
+        if (this.playFFView === null) {
+            return new Error('[recordingApi.ts] pauseMovements() failed: no view')
+        }
+        this.timers?.forEach(timer => timer.pause())
+    }
+
+    public resumeMovements = (): undefined | Error => {
+        if (this.playFFView === null) {
+            return new Error('[recordingApi.ts] resumeMovements() failed: no view')
+        }
+        this.timers?.forEach(timer => timer.resume())
+    }
+
+    // public followMovements = (presentation: Presentation): undefined | Error => {
+    //     if (presentation.startDate === null || this.playFFView === null) {
+    //         return new Error('[recordingApi.ts] followMovements() failed: no presentation data or no view')
+    //     }
+
+    //     const document = this.playFFView.Document
+    //     const { movements } = presentation
+    //     movements.forEach(movement => {
+    //         const { panX, panY, time } = movement
+    //         // set the pan to what was stored
+    //         setTimeout(() => {
+    //             document._panX = panX;
+    //             document._panY = panY;
+    //         }, time)
+    //     })
+    // }
     // Unfinished code for tracing multiple free form views
     // export let pres: Map<CollectionFreeFormView, IReactionDisposer> = new Map()
 
@@ -205,4 +237,63 @@ export class RecordingApi {
     //     disposer?.();
     //     pres.delete(ffView)
     // }
+}
+
+/** Represents the `setTimeout` with an ability to perform pause/resume actions
+ * citation: https://stackoverflow.com/questions/3969475/javascript-pause-settimeout
+ */
+export class Timer {
+    private _start: Date;
+    private _remaining: number;
+    private _durationTimeoutId?: NodeJS.Timeout;
+    private _callback: (...args: any[]) => void;
+    private _done = false;
+    get done () {
+        return this._done;
+    }
+
+    public constructor(callback: (...args: any[]) => void, ms = 0) {
+        this._callback = () => {
+            callback();
+            this._done = true;
+        };
+        this._remaining = ms;
+        this.resume();
+    }
+
+    /** pauses the timer */
+    public pause(): Timer {
+        if (this._durationTimeoutId && !this._done) {
+            this._clearTimeoutRef();
+            this._remaining -= new Date().getTime() - this._start.getTime();
+        }
+        return this;
+    }
+
+    /** resumes the timer */
+    public resume(): Timer {
+        if (!this._durationTimeoutId && !this._done) {
+            this._start = new Date;
+            this._durationTimeoutId = setTimeout(this._callback, this._remaining);
+        }
+        return this;
+    }
+
+    /** 
+     * clears the timeout and marks it as done. 
+     * 
+     * After called, the timeout will not resume
+     */
+    public clearTimeout() {
+        this._clearTimeoutRef();
+        this._done = true;
+    }
+
+    private _clearTimeoutRef() {
+        if (this._durationTimeoutId) {
+            clearTimeout(this._durationTimeoutId);
+            this._durationTimeoutId = undefined;
+        }
+    }
+
 }
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