New Demo - Combo File Chooser with history and clear button.

DemoPrograms/Demo_Combo_Filechooser_With_History_And_Clear.py

@@ -0,0 +1,44 @@
+import PySimpleGUI as sg
+
+"""
+    Demo Combo File Chooser - with clearable history
+    
+    This is a design pattern that is very useful for programs that you run often that requires
+    a filename be entered.  You've got 4 options to use to get your filename with this pattern:
+    1. Copy and paste a filename into the combo element
+    2. Use the last used item which will be visible when you create the window
+    3. Choose an item from the list of previously used items
+    4. Browse for a new name
+    
+    To clear the list of previous entries, click the "Clear History" button.
+    
+    The history is stored in a json file using the PySimpleGUI User Settings APIs
+    
+    The code is as sparse as possible to enable easy integration into your code.
+
+    Copyright 2021 PySimpleGUI
+"""
+
+
+
+layout = [[sg.Combo(sg.user_settings_get_entry('-filenames-', []), default_value=sg.user_settings_get_entry('-last filename-', ''), size=(50, 1), key='-FILENAME-'), sg.FileBrowse(), sg.B('Clear History')],
+          [sg.Button('Ok'),  sg.Button('Cancel')]]
+
+window = sg.Window('Filename Chooser With History', layout)
+
+while True:
+    event, values = window.read()
+
+    if event in (sg.WIN_CLOSED, 'Cancel'):
+        break
+    if event == 'Ok':
+        # If OK, then need to add the filename to the list of files and also set as the last used filename
+        sg.user_settings_set_entry('-filenames-', list(set(sg.user_settings_get_entry('-filenames-', []) + [values['-FILENAME-'], ])))
+        sg.user_settings_set_entry('-last filename-', values['-FILENAME-'])
+        break
+    elif event == 'Clear History':
+        sg.user_settings_set_entry('-filenames-', [])
+        sg.user_settings_set_entry('-last filename-', '')
+        window['-FILENAME-'].update(values=[], value='')
+
+window.close()