Implements #5: Add link_values option

src/models/time.ts

@@ -0,0 +1,23 @@
+import { Hour } from './hour';
+import { Minute } from './minute';
+import { Direction } from '../types';
+
+export class Time {
+  constructor(public hour: Hour, public minute: Minute, private _linkValues: boolean = false) {}
+
+  hourStep(direction: Direction): void {
+    this.hour.stepUpdate(direction);
+  }
+
+  minuteStep(direction: Direction): void {
+    if (this._linkValues && this.minute.willOverflow(direction)) {
+      this.hour.stepUpdate(direction, 1);
+    }
+
+    this.minute.stepUpdate(direction);
+  }
+
+  get value(): string {
+    return `${this.hour.value}:${this.minute.value}`;
+  }
+}