continuing refactoring

src/public/javascripts/widgets/component.js

@@ -0,0 +1,24 @@
+export default class Component {
+    /** @param {AppContext} appContext */
+    constructor(appContext) {
+        this.appContext = appContext;
+        /** @type Component[] */
+        this.children = [];
+    }
+
+    eventReceived(name, data) {
+        const fun = this[name + 'Listener'];
+
+        if (typeof fun === 'function') {
+            fun.call(this, data);
+        }
+
+        for (const child of this.children) {
+            child.eventReceived(name, data);
+        }
+    }
+
+    trigger(name, data) {
+        this.appContext.trigger(name, data);
+    }
+}