Last update: 2021-1-17 version 1.52

Sourceforge: https://sourceforge.net/projects/tcl-flexmenu/

[bll] 2018-9-20: An alternative menu system.

2018-9-21: There seems to be a little interest in this.
I wrote it for a couple of rather minor reasons (one of which I'm not sure is valid). 
Though I do really like having real
checkbuttons and radiobuttons in the menu, 
and I like the -keepopen option.

[bll] 2019-12-7: In production as of 2019-11-25.

[flexmenu-ex1][flexmenu-ex2][flexmenu-ex3][flexmenu-ex4]

[flexmenu-ex5][flexmenu-ex6][flexmenu-ex7]

[flexmenu-ex8]

[flexmenu-flexfb-img]

<<discussion>>Version History
======none
   1.52  2021-1-17
       Mac OS: Fix menu colors for 8.6.11.
       Mac OS: Fix menu relief.
   1.51  2020-12-15
       Get menu -relief setting from standard menus.
   1.50  2020-10-26
       Fix another crash checking for -keepopen item.
   1.49  2020-10-24
       Fix a possible crash.
       Fix crash checking for -keepopen item.
   1.48  2020-9-25
       Added a -keepopen on a per item basis.
   1.47  2020-8-28
       Missing mousewheel binding for scrolling areas.
       Fixed scrollbar arrow buttons not working.
   1.46  2020-6-9
       allow index arithmetic
       add 'invoked' menu index to return invoked item.
   1.45  2020-5-1
       fix configure
   1.44  2020-4-30
       fix change of background color
   1.43  2020-4-9
       popup menus: fix bug: would immediately close after initial open.
   1.41  2020-2-25
       fix bugs with cascades introduced in 1.40
         (-precommand, -yalign, -xalign)
   1.40  2020-2-24
       popup menus: fix bug: would immediately close after initial open.
       styling issue: fix bug with non-unique styles.
       clone command is now working.
         The widget entry type cannot be cloned.
       Added tearoff entry type.
         It is a standard label, the text or image can be configured.
         The -tearoff option automatically adds a tearoff item
           (backwards compatibility).
         -tearoffcommand is available.
         -title is available.  Default title is empty.
         I expect this is not fully backwards compatible.
       tearoff command : create your own interface to tear off menus.
   1.39  2020-1-10
       Prevent a outofrange crash in updownhandler.
   1.38  2019-12-25
       Fixed a bug in the delete() method.
       Fixed a typo bug in _unpostMenu.
       Fixed a bug in invokeitem setting the wrong state.
   1.37  2019-12-3
       Add appearance/isdark call back in using a temporary toplevel.
   1.36  2019-10-31
       Remove appearance/isdark call.  Only works on existing windows.
   1.35  2019-10-17
       Fixed close check handling.
       Fixed combobox click completely outside of menu window.
       Added -clicktoopen option.
   1.34  2019-10-17
       Fixed mouse handling issues with overlapping menus.
   1.33  2019-10-15
       Fix a bug in delete.
   1.32  2019-9-29
       Fix a bug in deactivateitem, when the item is not present.
   1.31  2019-9-29
       Fix a bug win movement check when there was no prior movement.
   1.30  2019-9-25
       More MacOS color fixes.
       Fix color/styling issues.
   1.29  2019-9-18
       Change -relief default to always be raised.
       Fix bug deleting items when the layout is not set up.
       Fix per-menu configuration handling for
         -font, -background, -foreground.
       More MacOS color fixes.
       Protect grab calls.
   1.28  2019-9-16
       Fix gap on delete.
       Fix reconfigure on insert or delete.
   1.27  2019-9-16
       Fix column weight issues.
       MacOS: toplevels are ok for 10.14+
       MacOS: revert to old dark mode test for 10.14.
   1.26 2019-9-10
       Internal cleanup.
       Fix sizing issues.
   1.25
       Change color defaults for Mac OS.
   1.24
       Mac OS dark mode colors.
   1.23
       Fixed cascade unpost.
   1.22
       Handle change of item selection on insert/add/delete.
   1.21 2018-12-03
       Fix grab handling issue.
       Fix close check handling.
   1.20 2018-12-03
       Resolve issues with menu display and configuration.
   1.19 2018-12-02
       Added -bindaccelerators option.
       Added -stickycascade option.
       Fixed display when moving off of active item in certain cases.
       Fixed initial display of menu.
   1.18 2018-12-02
       Mac OS X: Force -mode frame, as toplevels cannot be supported
         at this time.
   1.17 2018-11-29
       Change manual invoke processing to work when the menu is inactive.
         This matches the original menu function.  May create some odd
         states if run on a sub-cascade.
       Fixed overlapping menu handling.
   1.16 2018-11-29
       Allow vertical separators in menubar.
       Add new -gap option for items.
   1.15 2018-10-25
       Fix mac os x: enter/leave processing does not work properly.
   1.14 2018-10-22
       Fix various bugs with user 'invoke' method.
   1.13 2018-10-22
       Turn off mouse activation of menus in the wait state so that
         overlapping menus work (changed in 1.12).
       -xalign and -yalign can have tag[+-]offset
       Fix menutop/menuleft display (call postprocess).
   1.12 2018-10-21
       Initialize styles once only.
       Fix x and y offsets.
       Fix borderwidth and relief on menubar/menuleft menus.
       Fix placement of active frame in scrolling window.
       Fix enter/leave handling.
       Fix accelerator keys.
       Fix F10.
       Fix left arrow item positioning.
   1.11 2018-10-1
       Fix mistake.
   1.10 2018-10-1
       Rewrite styling and active state handling (pass 1).
       Some option cleanup.
   1.9 2018-10-1
       Fix incorrect default for -borderwidth.
       Fix bad copy/paste in enterLeaveHandler.
       Fix column spans with -hidemargin.
       Fix non-global grab.
       Fix enter/leave handling.
       Fix press handler/menu.enter/grab.
       Fix column weighting with -hidemargin.
   1.8 2018-10-1
       Fix crash when window closed.
   1.7 2018-10-1
       Remove tailcall.
       Rewrite grab handling.
       Rewrite enter/leave handling.
       Fix invoke of item when -keepopen is false.
   1.6 2018-9-30
       Set menu colors from the current theme.
       Fix -font handling.
       Fix menus not closing on checkbutton select.
       Button press will activate the menu and item.
   1.5 2018-9-30
       Fixed -borderwidth and -relief options for items.
       Added -mode {toplevel|frame} option.
       Cleaned up some stacking order issues
         (fixes the activeframe covering menu items).
   1.4 2018-9-29
       Added -precommand for cascades.
       Added -yalign for cascades.
       Added -xalign for cascades.
       Fixed bug in entrycget.
       Fixed 'delete' operation to match 'menu'.
       Fixed bug where the width was lost on a redisplay.
       Fixed display when initial number of items did not exceed -maxheight.
       Fixed various bugs with empty menus.
   1.3 2018-9-22
       Fixed initialization to only execute on mac os x.
       Fixed incorrect state for menus after invoking an item.
       Brought state table documentation up to date.
   1.2 2018-9-21  (broken for non mac os x)
       Fixed -padx/-pady so they will work for the main menubar
       Set the -acceleratorprefix to \u2318 for Mac OS X.
         This is converted to 'Meta' (hope that's right).
       Changed default -acceleratorprefix to 'Alt-' (due to mac os x changes).
       Fixed the colors on mac os x.  Dark mode and graphite themes
         are supported.
       Documentation
   1.1 2018-9-20
       Fixed active highlight for scrolled menus
   1.0 2018-9-20
       initial release
======
<<enddiscussion>>

****Disadvantages:****

   * Does not work with `.toplevel configure -menu .mymenu`.  Tk uses the internal menu API to attach menus.  flexmenu cannot work with the `-menu` option.  
   * Must use pack or grid (or place) to attach the menu.  Converting an existing program to use flexmenu could be quite painful.
   * The main menu must be created with either `-type menubar` or `-type menuleft`.
   * It has not been tested much.

****Advantages:****

   * Allows multiple menus to be active at the same time.  You can have a main menu, a couple of toolbars and a side menu active all at the same time.
   * Easier to create toolbars.

****Features:****

   * Checkbuttons and Radiobuttons are ttk widgets.
   * Supports left side menus (`-type menuleft`).
   * Scrolling menus (`-maxheight`).
   * Configure `-columnbreak <value>` at the menu level to automatically break every <value> items.
   * `-keepopen` option will leave the menu open after invoking an item.
   * `-acceleratorfont`, `-acceleratorforeground` and `-acceleratoractiveforeground` options.
   * `-activerelief` option.
   * `-hidearrows` option.
   * `-hideaccelerators` option.
   * `-acceleratorprefix` option to set the default accelerator prefix.
   * `-padx`, `-pady` options to change the padding for menu items.
   * `-bindaccelerators` option.
   * `-stickycascade` option.
   * `-clicktoopen` option.
   * `-mode` option to select the use of frames or toplevels.  (Mac OS X is forced to use `-mode frame` prior to version 10.14).
   * Is a little more dynamic than the standard `menu`.  Many things can be reconfigured and the changes will be picked up.
   * Cascades: -precommand option.  Useful for dynamic menu generation.

****Item Features:****

   * Any widget can be put into the menu (`.mymenu add widget -widget .mymenu.mycombobox`).
   * tearoff item type.  (The -tearoff 1 option will automatically add a tearoff item).  The tearoff item is a label and the text and image may be configured.
   * Margin images (`-marginimage`).  It is quite common nowadays to use small icons on the left margin of the menu as an aid for the user.
   * Accelerator labels are automatically generated based on either an `&` prefix in the label, the `-underline` option, or the `-accelerator` option.
   * Accelerator bindings are automatically generated.
   * -activerelief option.
   * -gap option.
   * -keepopen option.
   * Cascades: -yalign, -xalign options to change cascade alignment.

****Notes:****

   * Ignored: `-bitmap`, `-selectcolor`.
   * `-hidemargin` works properly on a per-entry basis. `menu` seems to treat it as a menu option even though it is specified per entry. I think `-hidemargin` would be better off as a menu option rather than an item option, but backwards compatibility is an issue. 
   * Mac OS X prior to 10.14: -mode toplevel is not supported.  Mac OS X is forced into -mode frame.

****Problems:****

   * May be overeager in generating accelerator labels.  The user may not want accelerator labels displayed for every item.
   * Has not been tested much.
   * At this time, flexmenu does not check to see if the entire menu is visible, and does not do any relocation of the menu.
   * Could use better documentation.

****Known Issues:****

'''Fixed in 1.18''': Mac OS X is not working at this time (2018-10-22).  Mac OS X works, but only with
-mode frame.  -mode frame is forced for Mac OS X (2018-11-02). (-mode toplevel works with Mojave).

'''Fixed in 1.1''': Active item highlighting for scrolling menus is not working right.

'''Fixed in 1.2''': The accelerator key prefix is set to `Alt`.  
This needs to be set correctly for Mac OS X, but I do not recall
which meta key the Mac sends.

'''Fixed in 1.41''': The `clone` command has only a very basic implementation.

Flicker with `-selectimage`.  Currently, the menu layout is reapplied when a `-image` is changed to a `-selectimage`.  This is
just in case the `-selectimage` is a different size.   If the assumption can be made that the image sizes are identical, this
redraw could be removed.