New System Tray Icon demo using psgtray - Tray only version (no window is ever shown). Renamed other psgtray demo program to a similar name

DemoPrograms/Demo_System_Tray_Icon_psgtray_No_Window.py

@@ -0,0 +1,69 @@
+import PySimpleGUI as sg
+from psgtray import SystemTray
+
+"""
+    A System Tray Icon using pystray - No visible window version
+
+    Import the SystemTray object with this line of code:
+    from psgtray import SystemTray
+
+    Key for the system tray icon is: 
+        tray = SystemTray()
+        tray.key
+
+    values[key] contains the menu item chosen.
+
+    One trick employed here is to change the window's event to be the event from the System Tray.
+
+    This demo program keeps the Window hidden all the time so that it's a pure "System Tray" application.
+    Because the PySimpleGUI architecture implemented the tray icon using the psgtray package combined with the
+    overall window event loop, a Window object is still required.  The point of this demo is to show that this
+    window does not need to ever appear to the user.
+
+    Copyright PySimpleGUI 2022
+"""
+
+
+def main():
+    menu = ['', ['---', '!Disabled Item', 'Change Icon', ['Happy', 'Sad', 'Plain'], 'Exit']]
+    tooltip = 'Tooltip'
+
+    layout = [[sg.T('Empty Window', key='-T-')]]
+
+    window = sg.Window('Window Title', layout, finalize=True, enable_close_attempted_event=True, alpha_channel=0)
+    window.hide()
+
+    tray = SystemTray(menu, single_click_events=False, window=window, tooltip=tooltip, icon=sg.DEFAULT_BASE64_ICON, key='-TRAY-')
+    tray.show_message('System Tray', 'System Tray Icon Started!')
+    print(sg.get_versions())
+    while True:
+        event, values = window.read()
+        # IMPORTANT step. It's not required, but convenient. Set event to value from tray
+        # if it's a tray event, change the event variable to be whatever the tray sent
+        if event == tray.key:
+            event = values[event]  # use the System Tray's event as if was from the window
+
+        if event in (sg.WIN_CLOSED, 'Exit'):
+            break
+
+        tray.show_message(title=event, message=values)
+
+        if event == 'Happy':
+            tray.change_icon(sg.EMOJI_BASE64_HAPPY_JOY)
+        elif event == 'Sad':
+            tray.change_icon(sg.EMOJI_BASE64_FRUSTRATED)
+        elif event == 'Plain':
+            tray.change_icon(sg.DEFAULT_BASE64_ICON)
+        elif event == 'Hide Icon':
+            tray.hide_icon()
+        elif event == 'Show Icon':
+            tray.show_icon()
+        elif event == 'Change Tooltip':
+            tray.set_tooltip(values['-IN-'])
+
+    tray.close()  # optional but without a close, the icon may "linger" until moused over
+    window.close()
+
+
+if __name__ == '__main__':
+    main()