Function checkModifierKeys

packages/base/src/Keys.ts:255–255

(event: KeyboardEvent, bCtrlKey: boolean, bAltKey: boolean, bShiftKey: boolean)

const getCtrlKey = (event: KeyboardEvent): boolean => !!(event.metaKey || event.ctrlKey); // double negation doesn't have effect on boolean but ensures null and undefined are equivalent to false.

const checkModifierKeys = (event: KeyboardEvent, bCtrlKey: boolean, bAltKey: boolean, bShiftKey: boolean):boolean => event.shiftKey === bShiftKey && event.altKey === bAltKey && getCtrlKey(event) === bCtrlKey;

const isNumber = (event: KeyboardEvent): boolean => ((event.key ? "0123456789".indexOf(event.key) !== -1 : event.keyCode >= KeyCodes.DIGIT_0 && event.keyCode <= KeyCodes.DIGIT_9) && checkModifierKeys(event, false, false, false));