Merge core into common

Part of #1507

src/common/buffer/Marker.ts

@@ -0,0 +1,35 @@
+/**
+ * Copyright (c) 2018 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { EventEmitter2, IEvent } from 'common/EventEmitter2';
+import { Disposable } from 'common/Lifecycle';
+import { IMarker } from 'common/Types';
+
+export class Marker extends Disposable implements IMarker {
+  private static _nextId = 1;
+
+  private _id: number = Marker._nextId++;
+  public isDisposed: boolean = false;
+
+  public get id(): number { return this._id; }
+
+  private _onDispose = new EventEmitter2<void>();
+  public get onDispose(): IEvent<void> { return this._onDispose.event; }
+
+  constructor(
+    public line: number
+  ) {
+    super();
+  }
+
+  public dispose(): void {
+    if (this.isDisposed) {
+      return;
+    }
+    this.isDisposed = true;
+    // Emit before super.dispose such that dispose listeners get a change to react
+    this._onDispose.fire();
+  }
+}