utils/helpers.js

@@ -1,3 +1,25 @@
+var isShiftPressed = false;
+var isCtrlPressed = false;
+
 function isHtmlElement(object) {
     return object instanceof HTMLElement;
 }
+
+document.addEventListener('keydown', event => handleKeyDown(event));
+document.addEventListener('keyup', event => handleKeyUp(event));
+
+function handleKeyDown(event) {
+    handleKeyToggle(event, true);
+}
+
+function handleKeyUp(event) {
+    handleKeyToggle(event, false);
+}
+
+function handleKeyToggle(event, isPressed) {
+    if (event.key === 'Shift') {
+        isShiftPressed = isPressed;
+    } else if (event.key === 'Control') {
+        isCtrlPressed = isPressed;
+    }
+}