example.tsx

  // Adds a hotkey and returns a function to remove that specific hotkey
  private addHotkey = (hotkey: HotkeyType): (() => void) => {
    const { key } = hotkey;

    // if this is not a iOS system, we replace any hotkey that has been defined to be used with `meta`
    // with a `ctrl` version of itself.
    if (
      hotkey.modifiers &&
      hotkey.modifiers[HotkeyModifiers.Meta] &&
      !isOsMac(this.props.browserInfo)
    ) {
      hotkey.modifiers[HotkeyModifiers.Meta] = false;
      hotkey.modifiers[HotkeyModifiers.Ctrl] = true;
    }
    const id = this.idGen.next();
    if (this.hotkeys[key]) {
      // If hotkey already exists, add it to the array of hotkey functions
      this.hotkeys[key]?.push({ ...hotkey, id });
    } else {
      // If hotkey didn't exist, add it to the list
      this.hotkeys[key] = [{ ...hotkey, id }];
    }
    return () => this.removeHotkey(key, id);
  };

  private removeHotkey = (key: Hotkeys, idToRemove: string): void => {
    if (this.hotkeys[key]) {
      // Remove hotkey of specific index
      this.hotkeys[key] = this.hotkeys[key]?.filter(({ id }) => idToRemove !== id);
      if (this.hotkeys[key]?.length === 0) {
        // If array is empty make value null
        this.hotkeys[key] = undefined;
      }
    }
  };