improved quality 🚀

refactored some code to improve quality

Author: odahcam

src/app/modules/zxing-scanner/browser-code-reader.ts

@@ -132,7 +132,7 @@ export class BrowserCodeReader {
      */
     private startDecodeFromStream(stream: MediaStream, callbackFn?: (result: Result) => any): void {
         this.stream = stream;
-        this.bindSrc(this.videoElement, this.stream);
+        this.bindVideoSrc(this.videoElement, this.stream);
         this.bindEvents(this.videoElement, callbackFn);
         this.checkTorchCompatibility(this.stream);
     }
@@ -143,8 +143,8 @@ export class BrowserCodeReader {
      * @param videoElement
      * @param stream
      */
-    private bindSrc(videoElement: HTMLVideoElement, stream: MediaStream): void {
-        // Older browsers may not have srcObject
+    public bindVideoSrc(videoElement: HTMLVideoElement, stream: MediaStream): void {
+        // Older browsers may not have `srcObject`
         try {
             // @NOTE Throws Exception if interrupted by a new loaded request
             videoElement.srcObject = stream;
@@ -154,6 +154,19 @@ export class BrowserCodeReader {
         }
     }
 
+    /**
+     * Unbinds a HTML video src property.
+     *
+     * @param videoElement
+     */
+    public unbindVideoSrc(videoElement: HTMLVideoElement): void {
+        try {
+            this.videoElement.srcObject = null;
+        } catch (err) {
+            this.videoElement.src = '';
+        }
+    }
+
     /**
      * Binds listeners and callbacks to the videoElement.
      *
@@ -383,11 +396,8 @@ export class BrowserCodeReader {
 
             // then forgets about that element 😢
 
-            try {
-                this.videoElement.srcObject = null;
-            } catch (err) {
-                this.videoElement.src = '';
-            }
+            this.unbindVideoSrc(this.videoElement);
+
             this.videoElement.removeAttribute('src');
             this.videoElement = undefined;
         }

src/app/modules/zxing-scanner/zxing-scanner.component.ts

@@ -320,23 +320,17 @@ export class ZXingScannerComponent implements AfterViewInit, OnDestroy, OnChange
             .then((stream: MediaStream) => {
 
                 try {
-                    // Start stream so Browser can display permission-dialog ("Website wants to access your camera, allow?")
-                    try {
-                        this.previewElemRef.nativeElement.srcObject = stream;
-                    } catch (err) {
-                        this.previewElemRef.nativeElement.src = window.URL.createObjectURL(stream);
-                    }
+
+                    // Start stream so Browser can display its permission-dialog
+                    this.codeReader.bindVideoSrc(this.previewElemRef.nativeElement, stream);
 
                     // After permission was granted, we can stop it again
                     stream.getVideoTracks().forEach(track => {
                         track.stop();
                     });
 
-                    try {
-                        this.previewElemRef.nativeElement.srcObject = null;
-                    } catch (err) {
-                        this.previewElemRef.nativeElement.src = '';
-                    }
+                    // should stop the opened stream
+                    this.codeReader.unbindVideoSrc(this.previewElemRef.nativeElement);
 
                     // if the scripts lives until here, that's only one mean: