Keyboard & Mouse Capture

NOTE - keyboard capture is currently formatted uniquely among the ports. For basic letters and numbers there is no great differences, but when you start adding Shift and Control or special keyus, they all behave slightly differently. Your best bet is to simply print what is being returned to you to determine what the format for the particular port is.

Beginning in version 2.10 you can capture keyboard key presses and mouse scroll-wheel events. Keyboard keys can be used, for example, to detect the page-up and page-down keys for a PDF viewer. To use this feature, there's a boolean setting in the Window call return_keyboard_events that is set to True in order to get keys returned along with buttons.

Keys and scroll-wheel events are returned in exactly the same way as buttons.

For scroll-wheel events, if the mouse is scrolled up, then the button text will be MouseWheel:Up. For downward scrolling, the text returned is MouseWheel:Down

Keyboard keys return 2 types of key events. For "normal" keys (a,b,c, etc.), a single character is returned that represents that key. Modifier and special keys are returned as a string with 2 parts:

Key Sym:Key Code

Key Sym is a string such as 'Control_L'. The Key Code is a numeric representation of that key. The left control key, when pressed will return the value 'Control_L:17'

import PySimpleGUI as sg

# Recipe for getting keys, one at a time as they are released
# If want to use the space bar, then be sure and disable the "default focus"

text_elem = sg.Text(size=(18, 1))

layout = [[sg.Text("Press a key or scroll mouse")],
          [text_elem],
          [sg.Button("OK")]]

window = sg.Window("Keyboard Test", layout,  return_keyboard_events=True, use_default_focus=False)

# ---===--- Loop taking in user input --- #
while True:
    event, value = window.read()

    if event == "OK" or event == sg.WIN_CLOSED:
        print(event, "exiting")
        break
    text_elem.update(event)

You want to turn off the default focus so that there no buttons that will be selected should you press the spacebar.