Merge pull request #3573 from PySimpleGUI/Dev-latest

New demo - center a column in the window

DemoPrograms/Demo_Layout_Vertical_Centered.py

@@ -0,0 +1,42 @@
+import PySimpleGUI as sg
+
+"""
+    Center a column in a window
+
+    Solves a very specific kind of layout.
+    If you want to have something centered in a Window, this is a good way to do it
+    The "trick" here is:
+        * the first row of the layout has a Text element that expands vertically
+        * the row with the Column has a text element that expands horizontally
+    
+    This expanding Text element is what will cause the Column element to be centered
+
+    Copyright 2020 PySimpleGUI.org
+"""
+
+def main():
+    column_to_be_centered = [  [sg.Text('My Window')],
+                [sg.Input(key='-IN-')],
+                [sg.Text(size=(12,1), key='-OUT-')],
+                [sg.Button('Go'), sg.Button('Exit')]  ]
+
+    layout = [[sg.Text(key='-EXPAND-', font='ANY 1', pad=(0, 0))],  # the thing that expands from top
+              [sg.Text('', pad=(0,0),key='-EXPAND2-'),              # the thing that expands from left
+               sg.Column(column_to_be_centered, vertical_alignment='center', justification='center',  k='-C-')]]
+
+    window = sg.Window('Window Title', layout, resizable=True,finalize=True)
+    window['-C-'].expand(True, True, True)
+    window['-EXPAND-'].expand(True, True, True)
+    window['-EXPAND2-'].expand(True, False, True)
+
+    while True:             # Event Loop
+        event, values = window.read()
+        print(event, values)
+        if event == sg.WIN_CLOSED or event == 'Exit':
+            break
+        if event == 'Go':
+            window['-OUT-'].update(values['-IN-'])
+    window.close()
+
+if __name__ == '__main__':
+    main()