Utils for dealing with keyboard events and figuring out what was pressed

event.util.ts

export const enum KeyCodes {
    BACKSPACE = 8,
    TAB = 9,
    ENTER = 13,
    SPACE = 32,
    DELETE = 46
}

export class EventUtil {

    /**
     * Util for checking if pressed key is number
     */
    static isNumberKey(key): boolean {
        if (key >= 96 && key <= 105) {
            // Num pad keys
            key -= 48;
        }
        return key > 47 && key < 58;
    }

    /**
     * Check if pressed key is arrow key
     */
    static isArrowKey(key: number): boolean {
        return key > 36 && key < 41;
    }

    /**
     * Check if press key is allowed
     */
    static isAllowedKeyType(event): boolean {
        const keyCode = event.keyCode;
        return event.metaKey || event.ctrlKey ||
            event.altKey || event.shiftKey ||
            keyCode === KeyCodes.TAB ||
            keyCode === KeyCodes.DELETE ||
            keyCode === KeyCodes.BACKSPACE ||
            keyCode === KeyCodes.ENTER;
    }

    /**
     * Check if Delete or Backspace
     */
    static isRemoveKey(pressedKeyCode): boolean {
        return pressedKeyCode === KeyCodes.DELETE || pressedKeyCode === KeyCodes.BACKSPACE;
    }

    /**
     * Check if pressed button is control or command
     */
    static isMetaOrCtrlKey(event): boolean {
        return event.metaKey || event.ctrlKey;
    }
}