From 6ddc6167e2979918714305dff569dbcefdcec956 Mon Sep 17 00:00:00 2001
From: Atul R <atulanand94@gmail.com>
Date: Sat, 8 Jun 2019 18:14:19 +0200
Subject: [PATCH] Abstracted away the logic for event listeners from JS side

---
 src/lib/QtGui/QWidget/index.ts         |  2 +-
 src/lib/QtWidgets/QLayout/index.ts     |  2 +-
 src/lib/QtWidgets/QPushButton/index.ts | 21 ++++++++-------------
 src/lib/core/Component/index.ts        |  2 +-
 src/lib/core/EventNodeWidget/index.ts  | 19 +++++++++++++++++++
 5 files changed, 30 insertions(+), 16 deletions(-)
 create mode 100644 src/lib/core/EventNodeWidget/index.ts

diff --git a/src/lib/QtGui/QWidget/index.ts b/src/lib/QtGui/QWidget/index.ts
index 4033c339a..e5e856fc5 100644
--- a/src/lib/QtGui/QWidget/index.ts
+++ b/src/lib/QtGui/QWidget/index.ts
@@ -2,8 +2,8 @@ import addon from "../../core/addon";
 import { YogaWidget } from "../../core/YogaWidget";
 import { NodeLayout } from "../../QtWidgets/QLayout";
 
-// Implement all native QWidget methods here so that all widgets get access to those aswell
 // All Widgets should extend from NodeWidget
+// Implement all native QWidget methods here so that all widgets get access to those aswell
 export abstract class NodeWidget extends YogaWidget {
   type = "widget";
   layout?: NodeLayout;
diff --git a/src/lib/QtWidgets/QLayout/index.ts b/src/lib/QtWidgets/QLayout/index.ts
index bc00f9d12..bb13efe92 100644
--- a/src/lib/QtWidgets/QLayout/index.ts
+++ b/src/lib/QtWidgets/QLayout/index.ts
@@ -2,7 +2,7 @@ import { Component } from "../../core/Component";
 
 // All Layouts should extend this abstract class.
 export abstract class NodeLayout extends Component {
-  type: string = "Layout";
+  type: string = "layout";
 }
 
 // export class QLayout extends NodeLayout { //Dont need QLayout for now
diff --git a/src/lib/QtWidgets/QPushButton/index.ts b/src/lib/QtWidgets/QPushButton/index.ts
index e206752ec..0605fefee 100644
--- a/src/lib/QtWidgets/QPushButton/index.ts
+++ b/src/lib/QtWidgets/QPushButton/index.ts
@@ -1,6 +1,6 @@
 import addon from "../../core/addon";
 import { NodeWidget } from "../../QtGui/QWidget";
-import { EventEmitter } from "events";
+import { EventNodeWidget } from "../../core/EventNodeWidget";
 
 export enum QPushButtonEvents {
   clicked = "clicked",
@@ -9,26 +9,21 @@ export enum QPushButtonEvents {
   toggled = "toggled"
 }
 
-type EventCallback = (payload?: any) => void;
-export class QPushButton extends NodeWidget {
+export class QPushButton extends EventNodeWidget {
   native: any;
-  private emitter: EventEmitter;
   constructor(parent?: NodeWidget) {
-    super();
+    let native;
     if (parent) {
-      this.native = new addon.QPushButton(parent.native);
-      this.parent = parent;
+      native = new addon.QPushButton(parent.native);
     } else {
-      this.native = new addon.QPushButton();
+      native = new addon.QPushButton();
     }
-    this.emitter = new EventEmitter();
-    this.native.setupEventListeners(this.emitter.emit.bind(this.emitter));
+    super(native);
+    this.parent = parent;
+    this.native = native;
   }
 
   setText(text: string) {
     this.native.setText(text);
   }
-  setEventListener(eventType: QPushButtonEvents, callback: EventCallback) {
-    this.emitter.on(eventType, callback);
-  }
 }
diff --git a/src/lib/core/Component/index.ts b/src/lib/core/Component/index.ts
index 918bc8698..ff6543e29 100644
--- a/src/lib/core/Component/index.ts
+++ b/src/lib/core/Component/index.ts
@@ -1,5 +1,5 @@
 export abstract class Component {
   protected children = new Set<Component>(); //TODO if react stub these as react will manage the instances from beings gc'ed better.
-  protected parent: Component | null = null;
+  protected parent?: Component;
   abstract native: any;
 }
diff --git a/src/lib/core/EventNodeWidget/index.ts b/src/lib/core/EventNodeWidget/index.ts
new file mode 100644
index 000000000..7a6d38b0b
--- /dev/null
+++ b/src/lib/core/EventNodeWidget/index.ts
@@ -0,0 +1,19 @@
+import { NodeWidget } from "../../QtGui/QWidget";
+import { EventEmitter } from "events";
+
+export abstract class EventNodeWidget extends NodeWidget {
+  private emitter: EventEmitter;
+  constructor(native: any) {
+    super();
+    if (native.setupEventListeners) {
+      this.emitter = new EventEmitter();
+      native.setupEventListeners(this.emitter.emit.bind(this.emitter));
+    } else {
+      throw new Error("Event Listeners not implemented on native side");
+    }
+  }
+
+  setEventListener(eventType: string, callback: (payload?: any) => void) {
+    this.emitter.on(eventType, callback);
+  }
+}