move some shared stuff into a new baseclass for protocols to implement

will make greenfield (i.e: brand new non-Guac or whatever) protocol implementation a bit less boilerplatey

cvmts/src/GuacamoleProtocol.ts

@@ -1,31 +1,15 @@
 import pino from 'pino';
-import { IProtocol, IProtocolHandlers, ListEntry, ProtocolAddUser, ProtocolChatHistory, ScreenRect } from './Protocol';
+import { IProtocol, IProtocolHandlers, ListEntry, ProtocolAddUser, ProtocolBase, ProtocolChatHistory, ScreenRect } from './Protocol';
 import { User } from './User';
 
 import * as cvm from '@cvmts/cvm-rs';
 
 // CollabVM protocol implementation for Guacamole.
-export class GuacamoleProtocol implements IProtocol {
-	private handlers: IProtocolHandlers | null = null;
+export class GuacamoleProtocol extends ProtocolBase implements IProtocol {
 	private logger = pino({
 		name: 'CVMTS.GuacamoleProtocol'
 	});
 
-	protected user: User | null = null;
-
-	init(u: User): void {
-		this.user = u;
-	}
-
-	dispose(): void {
-		this.user = null;
-		this.handlers = null;
-	}
-
-	setHandler(handlers: IProtocolHandlers): void {
-		this.handlers = handlers;
-	}
-
 	private __processMessage_admin(decodedElements: string[]): boolean {
 		switch (decodedElements[1]) {
 			case '2':

cvmts/src/Protocol.ts

@@ -76,12 +76,15 @@ export interface IProtocolHandlers {
 
 // Abstracts away all of the CollabVM protocol details
 export interface IProtocol {
+	// don't implement this yourself, extend from ProtocolBase
 	init(u: User): void;
 	dispose(): void;
 
 	// Sets handler object.
 	setHandler(handlers: IProtocolHandlers): void;
 
+	// Protocol implementation stuff
+
 	// Parses a single CollabVM protocol message and fires the given handler.
 	// This function does not catch any thrown errors; it is the caller's responsibility
 	// to handle errors. It should, however, catch invalid parameters without failing.
@@ -117,6 +120,25 @@ export interface IProtocol {
 	sendScreenUpdate(rect: ScreenRect): void;
 }
 
+// base mixin for all protocols to use
+export class ProtocolBase {
+	protected handlers: IProtocolHandlers | null = null;
+	protected user: User | null = null;
+
+	init(u: User): void {
+		this.user = u;
+	}
+
+	dispose(): void {
+		this.user = null;
+		this.handlers = null;
+	}
+
+	setHandler(handlers: IProtocolHandlers): void {
+		this.handlers = handlers;
+	}
+}
+
 // Holds protocol factories.
 export class ProtocolManager {
 	private protocols = new Map<String, () => IProtocol>();