Convert ext lib to typescript

ext/src/lib/utils.ts

@@ -0,0 +1,33 @@
+"use strict";
+
+export function getNextEllipsis (ellipsis: string): string {
+    /* tslint:disable:curly */
+    if (ellipsis === "") return ".";
+    if (ellipsis === ".") return "..";
+    if (ellipsis === "..") return "...";
+    if (ellipsis === "...") return "";
+    /* tslint:enable:curly */
+}
+
+
+interface WindowCenteredProps {
+    width: number;
+    height: number;
+    left: number;
+    top: number;
+}
+
+export function getWindowCenteredProps (
+        refWin: browser.windows.Window
+      , width: number
+      , height: number): WindowCenteredProps {
+
+    const centerX = refWin.left + (refWin.width / 2);
+    const centerY = refWin.top + (refWin.height / 3);
+
+    return {
+        width, height
+      , left: Math.floor(centerX - width / 2)
+      , top: Math.floor(centerY - height / 2)
+    };
+}