Version dropdown and Album Art

src/app/core/services/album-art.service.ts

@@ -0,0 +1,25 @@
+import { Injectable } from '@angular/core'
+import { ElectronService } from './electron.service'
+
+@Injectable({
+  providedIn: 'root'
+})
+export class AlbumArtService {
+
+  constructor(private electronService: ElectronService) { }
+
+  private imageCache: { [songID: number]: Buffer } = {}
+
+  async getImage(songID: number): Promise<Buffer | null> {
+    if (this.imageCache[songID] == undefined) {
+      const albumArtResult = await this.electronService.invoke('album-art', songID)
+      if (albumArtResult) {
+        this.imageCache[songID] = albumArtResult.art
+      } else {
+        this.imageCache[songID] = null
+      }
+    }
+
+    return this.imageCache[songID]
+  }
+}