Merge pull request #3909 from PySimpleGUI/Dev-latest

New Demo - Changing Window theme on the fly

DemoPrograms/Demo_Theme_Change_Window_Theme.py

@@ -0,0 +1,42 @@
+import PySimpleGUI as sg
+
+"""
+    Demo - Changing your window's theme at runtime
+    * Create your window using a "window create function"
+    * When your window's theme changes, close the window, call the "window create function"
+    
+    Copyright 2021 PySimpleGUI
+"""
+
+
+# ------------------- Create the window -------------------
+def make_window(theme=None):
+    if theme:
+        sg.theme(theme)
+    # -----  Layout & Window Create  -----
+    layout = [[sg.T('This is your layout')],
+              [sg.Button('Ok'), sg.Button('Change Theme'), sg.Button('Exit')]]
+
+    return sg.Window('Pattern for changing theme', layout)
+
+
+# ------------------- Main Program and Event Loop -------------------
+def main():
+    window = make_window()
+
+    while True:
+        event, values = window.read()
+        if event == sg.WINDOW_CLOSED or event == 'Exit':
+            break
+        if event == 'Change Theme':      # Theme button clicked, so get new theme and restart window
+            event, values = sg.Window('Choose Theme', [[sg.Combo(sg.theme_list(), readonly=True, k='-THEME LIST-'), sg.OK(), sg.Cancel()]]).read(close=True)
+            print(event, values)
+            if event == 'OK':
+                window.close()
+                window = make_window(values['-THEME LIST-'])
+
+    window.close()
+
+
+if __name__ == '__main__':
+    main()