Adding CoWebsiteManager + first working version of flex video

front/src/WebRtc/CoWebsiteManager.ts

@@ -0,0 +1,56 @@
+import {HtmlUtils} from "./HtmlUtils";
+
+export type CoWebsiteStateChangedCallback = () => void;
+
+export class CoWebsiteManager {
+
+    private static observers = new Array<CoWebsiteStateChangedCallback>();
+
+    public static loadCoWebsite(url: string): void {
+        const cowebsiteDiv = HtmlUtils.getElementByIdOrFail<HTMLDivElement>("cowebsite");
+        cowebsiteDiv.innerHTML = '';
+
+        const iframe = document.createElement('iframe');
+        iframe.id = 'cowebsite-iframe';
+        iframe.src = url;
+        cowebsiteDiv.appendChild(iframe);
+        CoWebsiteManager.fire();
+    }
+
+    public static closeCoWebsite(): void {
+        const cowebsiteDiv = HtmlUtils.getElementByIdOrFail<HTMLDivElement>("cowebsite");
+        cowebsiteDiv.innerHTML = '';
+        CoWebsiteManager.fire();
+    }
+
+    public static getGameSize(): {width: number, height: number} {
+        const iframe = document.getElementById('cowebsite-iframe');
+        if (iframe === null) {
+            return {
+                width: window.innerWidth,
+                height: window.innerHeight
+            }
+        }
+        if (window.innerWidth >= window.innerHeight) {
+            return {
+                width: window.innerWidth / 2,
+                height: window.innerHeight
+            }
+        } else {
+            return {
+                width: window.innerWidth,
+                height: window.innerHeight / 2
+            }
+        }
+    }
+
+    public static onStateChange(observer: CoWebsiteStateChangedCallback) {
+        CoWebsiteManager.observers.push(observer);
+    }
+
+    private static fire(): void {
+        for (const callback of CoWebsiteManager.observers) {
+            callback();
+        }
+    }
+}