Bug description

A clear and concise description of what the bug is.

After selecting a file, when the "Choose a file" window closes, the main window stays out of focus, meaning that when "unpause" is pressed, nothing happens and the machine seems broken.

Steps to reproduce the behavior:

1. Run the Turing Machine
2. Select a file and click "open"
3. Press any key
4. Machine seems stuck

Expected behavior

A clear and concise description of what you expected to happen.

When the file is selected, the main window gains focus and is ready to run.

Platform

Desktop (please complete the following information):

• OS: Windows 10
• Version: Latest