Add ViewMode Year

example/src/App.tsx

@@ -10,7 +10,9 @@ const App = () => {
   const [tasks, setTasks] = React.useState<Task[]>(initTasks());
   const [isChecked, setIsChecked] = React.useState(true);
   let columnWidth = 65;
-  if (view === ViewMode.Month) {
+  if (view === ViewMode.Year) {
+    columnWidth = 350;
+  } else if (view === ViewMode.Month) {
     columnWidth = 300;
   } else if (view === ViewMode.Week) {
     columnWidth = 250;

example/src/components/view-switcher.tsx

@@ -46,7 +46,12 @@ export const ViewSwitcher: React.SFC<ViewSwitcherProps> = ({
       >
         Month
       </button>
-
+      <button
+        className="Button"
+        onClick={() => onViewModeChange(ViewMode.Year)}
+      >
+        Year
+      </button>
       <div className="Switch">
         <label className="Switch_Toggle">
           <input