urls can be edited while playing; refactoring

state split into loading and playing
playing state is global
radonly defaultmedia, remove useless getter, reorder fns

src/App.vue

@@ -1,3 +1,4 @@
+import {PlayingState} from "@/common";
 <!--suppress HtmlFormInputWithoutLabel -->
 <template>
     <div id="app">
@@ -5,8 +6,8 @@
         <div class="channels-wrapper">
             <div class="channels">
                 <template v-for="i in N_CHANNELS">
-                    <Channel :name="names[i - 1]" :url="urls[i - 1]" :volume="volumes[i-1]"
-                             :key="i"
+                    <Channel :name="names[i - 1]" :url="urls[i - 1]" :volume="volumes[i-1]" :playing="playing"
+                             :key="i" @loadingState="(state) => {$set(states, i - 1, state)}"
                              class="channel" ref="channels"/>
                 </template>
             </div>
@@ -20,7 +21,7 @@
             </div>
         </div>
         <div class="controls">
-            <button @click="start">START</button>
+            <button @click="start" :disabled="!startEnabled">START</button>
         </div>
     </div>
 </template>
@@ -29,6 +30,7 @@
 <script lang="ts">
 import {Component, Vue} from "vue-property-decorator";
 import Channel from "@/components/Channel.vue";
+import {LoadingState, PlayingState} from "@/common";
 
 @Component({
   components: {
@@ -41,18 +43,22 @@ export default class App extends Vue {
   private readonly LFO_DEPTH = 33;
   private readonly LFO_OFFSET = 66;
 
+  private playing: PlayingState = PlayingState.STOPPED;
   private names = ["alpha", "beta", "gamma", "delta", "epsilon", "zeta", "eta", "theta", "iota", "kappa", "lambda", "mu"];
   private urls = Array(this.N_CHANNELS).fill("");
   private volumes = Array(this.N_CHANNELS).fill(50);
+  private states = Array(this.N_CHANNELS).fill(LoadingState.UNLOADED);
+
   private animateVolumeStart?: Date;
   private animateVolumeInterval?: number;
 
-  private defaultMedia = [
+  private readonly defaultMedia = [
     "https://www.youtube.com/watch?v=jX6kn9_U8qk",
     "https://www.youtube.com/watch?v=E77jmtut1Zc",
     "https://youtu.be/OW7TH2U4hps"
   ];
 
+
   private mounted() {
     this.defaultMedia.forEach((url, idx) => {
       this.$set(this.urls, idx, url);
@@ -60,10 +66,8 @@ export default class App extends Vue {
   }
 
   private start() {
-    (this.$refs.channels as Channel[]).forEach((channel) => {
-      channel.start();
-      this.animateVolume();
-    });
+    this.playing = PlayingState.PLAYING;
+    this.animateVolume();
   }
 
   private animateVolume() {
@@ -82,6 +86,10 @@ export default class App extends Vue {
       }
     }, 1000 / 60);
   }
+
+  private get startEnabled() {
+    return this.states.every((state) => state !== LoadingState.LOADING);
+  }
 }
 </script>
 

src/common.ts

@@ -0,0 +1,12 @@
+enum LoadingState {
+  UNLOADED = "unloaded",
+  LOADING = "loading",
+  LOADED = "loaded",
+}
+
+enum PlayingState {
+  STOPPED = "stopped",
+  PLAYING = "playing"
+}
+
+export {LoadingState, PlayingState};

src/components/Channel.vue

@@ -1,13 +1,13 @@
 <template>
-    <div :class="['channel', `channel-${state}`]">
+    <div :class="['channel', `channel-${loadingState}`]">
         <div class="volume-wrapper">
             <!--suppress HtmlFormInputWithoutLabel -->
-            <input class="volume" :disabled="state === 'unloaded'"
+            <input class="volume" :disabled="loadingState === 'unloaded'"
                    type="range" min="0" max="100" v-model="volume"/>
         </div>
         <div class="description">
             <div class="name">{{name}}</div>
-            <div class="title">{{state === "loading" ? "Loading..." : title}}</div>
+            <div class="title">{{loadingState === "loading" ? "Loading..." : title}}</div>
         </div>
         <div class="youtube-player" ref="ytpl"/>
     </div>
@@ -20,26 +20,22 @@ import YouTubePlayerFactory from "youtube-player";
 // noinspection TypeScriptCheckImport
 import {YouTubePlayer} from "youtube-player/dist/types";
 import PlayerStates from "youtube-player/dist/constants/PlayerStates";
+import {LoadingState, PlayingState} from "@/common";
 
 enum SOURCE {
   YouTube,
   DIRECT
 }
 
-enum ChannelState {
-  UNLOADED = "unloaded",
-  LOADING = "loading",
-  READY = "ready",
-  PLAYING = "playing"
-}
-
 @Component
 export default class Channel extends Vue {
   @Prop() public name: string = "Channel";
   @Prop() public volume: number = 50;
   @Prop() public url: string | undefined;
+  @Prop() public playing: PlayingState = PlayingState.STOPPED;
+
   private youtubePlayer?: YouTubePlayer;
-  private state = ChannelState.UNLOADED;
+  private loadingState = LoadingState.UNLOADED;
   private title = "";
 
   private get source() {
@@ -50,20 +46,18 @@ export default class Channel extends Vue {
     }
   }
 
-  private get ytVideoId() {
-    if (this.url) {
-      const match = this.url.match(/v=([\w_\-]+)/);
-      if (match !== null && match.length == 2) {
-        return match[1];
-      }
-    }
-  }
-
-  public start() {
+  @Watch("playing")
+  private onPlayingChange() {
     if (this.youtubePlayer) {
-      this.youtubePlayer.setVolume(this.volume);
-      this.youtubePlayer.playVideo();
-      this.state = ChannelState.PLAYING;
+      switch (this.playing) {
+        case PlayingState.PLAYING:
+          this.youtubePlayer.setVolume(this.volume);
+          this.youtubePlayer.playVideo();
+          break;
+        case PlayingState.STOPPED:
+          this.youtubePlayer.stopVideo();
+          break;
+      }
     }
   }
 
@@ -76,8 +70,11 @@ export default class Channel extends Vue {
         });
         this.youtubePlayer.on("stateChange", (event) => {
           switch (event.data) {
-            case  PlayerStates.BUFFERING:
-              this.state = ChannelState.READY;
+            case PlayerStates.BUFFERING:
+              this.loadingState = LoadingState.LOADED;
+              if (this.playing == PlayingState.PLAYING) {
+                this.youtubePlayer!.playVideo();
+              }
               break;
             case PlayerStates.ENDED:
               this.youtubePlayer!.playVideo();
@@ -87,7 +84,7 @@ export default class Channel extends Vue {
       }
       const videoId = Channel.extractYoutubeId(this.url);
       if (videoId !== undefined) {
-        this.state = ChannelState.LOADING;
+        this.loadingState = LoadingState.LOADING;
         console.log(`Loading YouTube video "${videoId}"`);
         this.youtubePlayer.loadVideoById(videoId);
         this.title = "Loading...";
@@ -101,14 +98,11 @@ export default class Channel extends Vue {
         console.error(`Something went wrong trying to parse ${this.url}`);
       }
     } else {
+      this.loadingState = LoadingState.UNLOADED;
       this.title = "N/A";
-    }
-  }
-
-  private static extractYoutubeId(url: string): string | undefined {
-    const videoIdMatch = url.match(/(v=|youtu\.be\/)([^&]+)/);
-    if (videoIdMatch !== null && videoIdMatch.length == 3) {
-      return videoIdMatch[2];
+      if (this.youtubePlayer) {
+        this.youtubePlayer.stopVideo();
+      }
     }
   }
 
@@ -119,10 +113,22 @@ export default class Channel extends Vue {
     }
   }
 
+  @Watch("loadingState")
+  private onLoadingStateChange() {
+    this.$emit("loadingState", this.loadingState);
+  }
+
   private mounted() {
     this.onUrlChange();
   }
 
+  private static extractYoutubeId(url: string): string | undefined {
+    const videoIdMatch = url.match(/(v=|youtu\.be\/)([^&]+)/);
+    if (videoIdMatch !== null && videoIdMatch.length == 3) {
+      return videoIdMatch[2];
+    }
+  }
+
   private static fetchYoutubeTitle(videoId: string): Promise<string> {
     return new Promise((resolve, reject) => {
       let url = `https://www.googleapis.com/youtube/v3/videos?part=snippet&id=${videoId}`;