bpo-40468: Move IDLE helplist settings to extensions page of dialog. (GH-26593)

These are the settings that extend the help menu.  Moving them shortens the dialog and will help with it being too tall for small screens.
(cherry picked from commit ab36b9f)

Author: miss-islington

Lib/idlelib/configdialog.py

@@ -268,27 +268,28 @@ def create_page_extensions(self):
             set_extension_value: Set in userCfg['extensions'].
             save_all_changed_extensions: Call extension page Save().
         """
-        parent = self.parent
-        frame = Frame(self.note)
         self.ext_defaultCfg = idleConf.defaultCfg['extensions']
         self.ext_userCfg = idleConf.userCfg['extensions']
         self.is_int = self.register(is_int)
         self.load_extensions()
         # Create widgets - a listbox shows all available extensions, with the
         # controls for the extension selected in the listbox to the right.
         self.extension_names = StringVar(self)
-        frame.rowconfigure(0, weight=1)
-        frame.columnconfigure(2, weight=1)
-        self.extension_list = Listbox(frame, listvariable=self.extension_names,
+        frame = Frame(self.note)
+        frame_ext = LabelFrame(frame, borderwidth=2, relief=GROOVE,
+                               text=' Feature Extensions ')
+        frame_ext.rowconfigure(0, weight=1)
+        frame_ext.columnconfigure(2, weight=1)
+        self.extension_list = Listbox(frame_ext, listvariable=self.extension_names,
                                       selectmode='browse')
         self.extension_list.bind('<<ListboxSelect>>', self.extension_selected)
-        scroll = Scrollbar(frame, command=self.extension_list.yview)
+        scroll = Scrollbar(frame_ext, command=self.extension_list.yview)
         self.extension_list.yscrollcommand=scroll.set
-        self.details_frame = LabelFrame(frame, width=250, height=250)
+        self.details_frame = LabelFrame(frame_ext, width=250, height=250)
         self.extension_list.grid(column=0, row=0, sticky='nws')
         scroll.grid(column=1, row=0, sticky='ns')
         self.details_frame.grid(column=2, row=0, sticky='nsew', padx=[10, 0])
-        frame.configure(padding=10)
+        frame_ext.configure(padding=10)
         self.config_frame = {}
         self.current_extension = None
 
@@ -304,6 +305,13 @@ def create_page_extensions(self):
         self.extension_list.selection_set(0)
         self.extension_selected(None)
 
+
+        self.frame_help = HelpFrame(frame, borderwidth=2, relief=GROOVE,
+                                    text=' Help Menu Extensions ')
+        frame_ext.grid(row=0, column=0, sticky='nsew')
+        Label(frame).grid(row=1, column=0)
+        self.frame_help.grid(row=2, column=0, sticky='sew')
+
         return frame
 
     def load_extensions(self):
@@ -1854,14 +1862,6 @@ def create_page_general(self):
                 frame_auto_squeeze_min_lines: Frame
                     auto_squeeze_min_lines_title: Label
                     (*)auto_squeeze_min_lines_int: Entry - auto_squeeze_min_lines
-            frame_help: LabelFrame
-                frame_helplist: Frame
-                    frame_helplist_buttons: Frame
-                        (*)button_helplist_edit
-                        (*)button_helplist_add
-                        (*)button_helplist_remove
-                    (*)helplist: ListBox
-                    scroll_helplist: Scrollbar
         """
         # Integer values need StringVar because int('') raises.
         self.startup_edit = tracers.add(
@@ -1902,8 +1902,6 @@ def create_page_general(self):
                                   text=' Editor Preferences')
         frame_shell = LabelFrame(self, borderwidth=2, relief=GROOVE,
                                  text=' Shell Preferences')
-        frame_help = LabelFrame(self, borderwidth=2, relief=GROOVE,
-                                text=' Additional Help Sources ')
         # Frame_window.
         frame_run = Frame(frame_window, borderwidth=0)
         startup_title = Label(frame_run, text='At Startup')
@@ -1999,32 +1997,11 @@ def create_page_general(self):
                 validatecommand=self.digits_only, validate='key',
         )
 
-        # frame_help.
-        frame_helplist = Frame(frame_help)
-        frame_helplist_buttons = Frame(frame_helplist)
-        self.helplist = Listbox(
-                frame_helplist, height=5, takefocus=True,
-                exportselection=FALSE)
-        scroll_helplist = Scrollbar(frame_helplist)
-        scroll_helplist['command'] = self.helplist.yview
-        self.helplist['yscrollcommand'] = scroll_helplist.set
-        self.helplist.bind('<ButtonRelease-1>', self.help_source_selected)
-        self.button_helplist_edit = Button(
-                frame_helplist_buttons, text='Edit', state='disabled',
-                width=8, command=self.helplist_item_edit)
-        self.button_helplist_add = Button(
-                frame_helplist_buttons, text='Add',
-                width=8, command=self.helplist_item_add)
-        self.button_helplist_remove = Button(
-                frame_helplist_buttons, text='Remove', state='disabled',
-                width=8, command=self.helplist_item_remove)
-
         # Pack widgets:
         # Body.
         frame_window.pack(side=TOP, padx=5, pady=5, expand=TRUE, fill=BOTH)
         frame_editor.pack(side=TOP, padx=5, pady=5, expand=TRUE, fill=BOTH)
         frame_shell.pack(side=TOP, padx=5, pady=5, expand=TRUE, fill=BOTH)
-        frame_help.pack(side=TOP, padx=5, pady=5, expand=TRUE, fill=BOTH)
         # frame_run.
         frame_run.pack(side=TOP, padx=5, pady=0, fill=X)
         startup_title.pack(side=LEFT, anchor=W, padx=5, pady=5)
@@ -2077,17 +2054,12 @@ def create_page_general(self):
         auto_squeeze_min_lines_title.pack(side=LEFT, anchor=W, padx=5, pady=5)
         self.auto_squeeze_min_lines_int.pack(side=TOP, padx=5, pady=5)
 
-        # frame_help.
-        frame_helplist_buttons.pack(side=RIGHT, padx=5, pady=5, fill=Y)
-        frame_helplist.pack(side=TOP, padx=5, pady=5, expand=TRUE, fill=BOTH)
-        scroll_helplist.pack(side=RIGHT, anchor=W, fill=Y)
-        self.helplist.pack(side=LEFT, anchor=E, expand=TRUE, fill=BOTH)
-        self.button_helplist_edit.pack(side=TOP, anchor=W, pady=5)
-        self.button_helplist_add.pack(side=TOP, anchor=W)
-        self.button_helplist_remove.pack(side=TOP, anchor=W, pady=5)
-
     def load_general_cfg(self):
         "Load current configuration settings for the general options."
+        self.load_windows_cfg()
+        self.load_shelled_cfg()
+
+    def load_windows_cfg(self):
         # Set variables for all windows.
         self.startup_edit.set(idleConf.GetOption(
                 'main', 'General', 'editor-on-startup', type='bool'))
@@ -2106,6 +2078,7 @@ def load_general_cfg(self):
         self.paren_bell.set(idleConf.GetOption(
                 'extensions', 'ParenMatch', 'bell'))
 
+    def load_shelled_cfg(self):
         # Set variables for editor windows.
         self.autosave.set(idleConf.GetOption(
                 'main', 'General', 'autosave', default=0, type='bool'))
@@ -2120,12 +2093,63 @@ def load_general_cfg(self):
         self.auto_squeeze_min_lines.set(idleConf.GetOption(
                 'main', 'PyShell', 'auto-squeeze-min-lines', type='int'))
 
-        # Set additional help sources.
-        self.user_helplist = idleConf.GetAllExtraHelpSourcesList()
-        self.helplist.delete(0, 'end')
-        for help_item in self.user_helplist:
-            self.helplist.insert(END, help_item[0])
-        self.set_add_delete_state()
+
+class HelpFrame(LabelFrame):
+
+    def __init__(self, master, **cfg):
+        super().__init__(master, **cfg)
+        self.create_frame_help()
+        self.load_helplist()
+
+    def create_frame_help(self):
+        """Create LabelFrame for additional help menu sources.
+
+        load_helplist loads list user_helplist with
+        name, position pairs and copies names to listbox helplist.
+        Clicking a name invokes help_source selected. Clicking
+        button_helplist_name invokes helplist_item_name, which also
+        changes user_helplist.  These functions all call
+        set_add_delete_state. All but load call update_help_changes to
+        rewrite changes['main']['HelpFiles'].
+
+        Widgets for HelpFrame(LabelFrame):  (*) widgets bound to self
+            frame_helplist: Frame
+                (*)helplist: ListBox
+                scroll_helplist: Scrollbar
+            frame_buttons: Frame
+                (*)button_helplist_edit
+                (*)button_helplist_add
+                (*)button_helplist_remove
+        """
+        # self = frame_help in dialog (until ExtPage class).
+        frame_helplist = Frame(self)
+        self.helplist = Listbox(
+                frame_helplist, height=5, takefocus=True,
+                exportselection=FALSE)
+        scroll_helplist = Scrollbar(frame_helplist)
+        scroll_helplist['command'] = self.helplist.yview
+        self.helplist['yscrollcommand'] = scroll_helplist.set
+        self.helplist.bind('<ButtonRelease-1>', self.help_source_selected)
+
+        frame_buttons = Frame(self)
+        self.button_helplist_edit = Button(
+                frame_buttons, text='Edit', state='disabled',
+                width=8, command=self.helplist_item_edit)
+        self.button_helplist_add = Button(
+                frame_buttons, text='Add',
+                width=8, command=self.helplist_item_add)
+        self.button_helplist_remove = Button(
+                frame_buttons, text='Remove', state='disabled',
+                width=8, command=self.helplist_item_remove)
+
+        # Pack frame_help.
+        frame_helplist.pack(side=LEFT, padx=5, pady=5, expand=TRUE, fill=BOTH)
+        self.helplist.pack(side=LEFT, anchor=E, expand=TRUE, fill=BOTH)
+        scroll_helplist.pack(side=RIGHT, anchor=W, fill=Y)
+        frame_buttons.pack(side=RIGHT, padx=5, pady=5, fill=Y)
+        self.button_helplist_edit.pack(side=TOP, anchor=W, pady=5)
+        self.button_helplist_add.pack(side=TOP, anchor=W)
+        self.button_helplist_remove.pack(side=TOP, anchor=W, pady=5)
 
     def help_source_selected(self, event):
         "Handle event for selecting additional help."
@@ -2195,6 +2219,14 @@ def update_help_changes(self):
                     'main', 'HelpFiles', str(num),
                     ';'.join(self.user_helplist[num-1][:2]))
 
+    def load_helplist(self):
+        # Set additional help sources.
+        self.user_helplist = idleConf.GetAllExtraHelpSourcesList()
+        self.helplist.delete(0, 'end')
+        for help_item in self.user_helplist:
+            self.helplist.insert(END, help_item[0])
+        self.set_add_delete_state()
+
 
 class VarTrace:
     """Maintain Tk variables trace state."""