Merge pull request #3259 from PySimpleGUI/Dev-latest

Multiple windows active & visible at the same time

DemoPrograms/Demo_Design_Pattern_Multiple_Windows_Both_Visible.py

@@ -0,0 +1,52 @@
+import PySimpleGUI as sg
+"""
+    Demo - 2 simultaneous windows using read_all_window
+
+    Both windows are immediately visible.  Each window updates the other.
+        
+    Copyright 2020 PySimpleGUI.org
+"""
+
+def make_win1():
+    layout = [[sg.Text('Window 1')],
+              [sg.Text('Enter something to output to Window 2')],
+              [sg.Input(key='-IN-')],
+              [sg.Text(size=(25,1), key='-OUTPUT-')],
+              [sg.Button('Output to Window 2'), sg.Button('Exit')]]
+    return sg.Window('Window Title', layout, finalize=True)
+
+
+def make_win2():
+    layout = [[sg.Text('Window 2')],
+              [sg.Text('Enter something to output to Window 1')],
+              [sg.Input(key='-IN-')],
+              [sg.Text(size=(25,1), key='-OUTPUT-')],
+              [sg.Button('Output to Window 1'), sg.Button('Exit')]]
+    return sg.Window('Window Title', layout, finalize=True)
+
+
+def main():
+    window1, window2 = make_win1(), make_win2()
+
+    window2.move(window1.current_location()[0], window1.current_location()[1]+200)
+
+    while True:             # Event Loop
+        window, event, values = sg.read_all_windows()
+        if window == sg.WIN_CLOSED:     # if all windows were closed
+            break
+        if event == sg.WIN_CLOSED or event == 'Exit':
+            window.close()
+            if window == window2:       # if closing win 2, mark as closed
+                window2 = None
+            elif window == window1:     # if closing win 1, exit program
+                window1 = None
+        elif event.startswith('Output to'):
+            output_window = window2 if window == window1 else window1
+            if output_window:           # if a valid window, then output to it
+                output_window['-OUTPUT-'].update(values['-IN-'])
+            else:
+                window['-OUTPUT-'].update('Other window is closed')
+
+
+if __name__ == '__main__':
+    main()