general list:
- Window.SizeToFit() or WIndow.OptimalSize() (use: `Window.SetOptimalSize())`) for sizing a window to the control's interest
	- with the current code, will be a bit of a kludge, because preferredSize() assumes it's running on the main thread without locks
- Control.Show()/Control.Hide()
- Groupbox
- character-limited entry fields (not for passwords), numeric entry fields, multiline entry fields
	- possible rename of LineEdit?
		- especially for password fields - NewPasswordEntry()?
- padding and spacing in Stack
- allow Combobox to have initial settings
- Combobox and Listbox insertions and deletions should allow bulk (...string/...int)
- Combobox/Listbox.DeleteAll
- Combobox/Listbox.Select (with Listbox.Select allowing bulk)
	- Checkbox.Check or Checkbox.SetChecked
- Listbox.SelectAll
- Listbox/Combobox.Index(n)
	- Index(n) is the name used by reflect.Value; use a different one?
- figure out where to auto-place windows in Cocoa (also window coordinates are still not flipped properly so (0,0) on screen is the bottom-left)
	- also provide a method to center windows; Cocoa provides one for us but
		- GTK+ too: gtk_window_set_position(window, GTK_WIN_POS_CENTER) (via http://stackoverflow.com/questions/16832581/how-to-make-a-gtkwindow-background-transparent-on-linux)
- make Combobox and Listbox satisfy sort.Interface?
- should a noneditable Combobox be allowed to return to unselected mode by the user?
- provide a way for MouseEvent/KeyEvent to signal that the keypress caused the Area to gain/lose focus
	- provide an event for leaving focus so a focus rectangle can be drawn
- when adding menus:
	- provide automated About, Preferneces, and Quit that place these in the correct location
		- Quit should pulse AppQuit
- will probably want to bring back Event() as NewEvent() should that facility be necesary for menus, etc.

problem points:
- because the main event loop is not called if initialization fails, it is presently impossible for MsgBoxError() to work if UI initialization fails; this basically means we cannot allow initializiation to fail on Mac OS X if we want to be able to report UI init failures to the user with one (which would be desirable, maybe (would violate Windows HIG?))
- make sure GTK+ documentation version point differences (x in 4.3.x) don't matter
	- I found a GTK+ version number meaning page somewhere; have to find it again (TODO)

twists of fate:
- listboxes spanning the vertical height of the window don't always align with the bottom border of the edit control attached to the bottom of the window...
	- this specifically only happens when the window has an odd height; I don't think this can be fixed unless we explicitly ignore the extra pixel everywhere
- need a way to get ideal size for all controls on Windows, not just push buttons (Microsoft...)

style changes:
- make specific wording in documentation consistent (make/create, etc.)
	- document minor details like wha thappens on specific events so that they are guaranteed to work the same on all platforms (are there any left?)
		- what happens when the user clicks and drags on a listbox
			- I think this is a platform behavior...
	- should field descriptions in method comments include the receiver name? (for instance e.Held vs. Held) - see what Go's own documentation does
	- need to figure out exactly how to indicate that a struct{}{} is sent on an event channel (I use about six or so different wordings so far...)
	- "package ui", "the package"
		- also "library" both in docs and comments and code, etc.
- make passing of parameters and type conversions of parameters to uitask on Windows consistent: explicit _WPARAM(xxx)/_LPARAM(xxx)/uintptr(xxx), for example
	- do this for type signatures in exported functions: (err error) or just error?
	- do this for the names of GTK+ helper functions (gtkXXX or gXXX)
	- areaView -> goArea (or change the class name to be like the delegate name?) in area_darwin.go?

far off:
- localization
- strip unused constants from the Windows files
- combine more Windows files; rename some?
- tab stops
	- http://blogs.msdn.com/b/oldnewthing/archive/2003/10/21/55384.aspx
- rename Stack to Box?
- maybe change multiple selection lists to checkbox lists?
	- windows HIG refernece: http://msdn.microsoft.com/en-us/library/windows/desktop/aa511485.aspx - conflicting, confusing info
	- gtk+ HIG reference: https://developer.gnome.org/hig-book/3.4/controls-lists.html.en
	- mac HIG reference: ???
- go over the old new thing's scrollbar series to make sure I'm doing everything right with scrollbars in Windows Areas
- change the MsgBox() calls to encourage good alert dialog design??????? maybe? TODO

big things:
- make sure every sysData function only performs a single invocation to uitask; see http://blogs.msdn.com/b/oldnewthing/archive/2005/10/10/479124.aspx#479182
	- windows: this requires major restructuring
	- gtk, mac: this just requires checking
- steamroll ALL errors, especially on windows
	- gtk: no way to catch errors
	- cocoa: discouraged
- make fully lock free
	- prerequisite is the above two
	- locks are used because of initial state; we can override by creating controls at construct time
		- cocoa, gtk: no real issues
		- windows: now required to specify no parent window at create time and set both the parent window AND the child window ID later
			- http://msdn.microsoft.com/en-us/library/windows/desktop/ms633541%28v=vs.85%29.aspx
				- don't worry about UI state messages yet; this is before opening the UI anyway (these might be needed when we add tab stops)
			- http://msdn.microsoft.com/en-us/library/windows/desktop/ms644898%28v=vs.85%29.aspx GWLP_ID

big dumb things:
- for our two custom window classes on Windows, we should allocate extra space in the window class's info structure and then use SetWindowLongPtrW() during WM_CREATE to store the sysData and not have to make a new window class each time; this might also fix the s != nil && s.hwnd != 0 special cases in the Area WndProc if done right
	- references: https://github.com/glfw/glfw/blob/master/src/win32_window.c#L182, http://www.catch22.net/tuts/custom-controls
	- this is a bit flakier as SetWindowLongPtr() can fail, and it can also succeed in such a way that the last error is unreliable
		- and doesn't exist on 32-bit windows; we will need special code for detecting 32-bit/64-bit (see http://bugs.winehq.org/show_bug.cgi?id=30556 and GerbilSoft in irc.badnik.net/#retro)
		- also CreateWindow() and CreateWindowEx() docs differ in indicating which messages are sent but ultimately send the same set; WM_GETMINMAXINFO is sent first so that throws a wrench in the whole point, AND we'll need a way to properly differentiate between custom classes and controls...
			- tl;dr what started as a somewhat quick change was really way too much effort for only potential/theoretical gain; approach if someone actually DOES hit Go's syscall.NewCallback() limit
			- theoretically I could just have a s != nil check in WM_GETMINMAXINFO only, but not too hot on the idea :/
				- raymond chen does it here: http://blogs.msdn.com/b/oldnewthing/archive/2005/04/22/410773.aspx (check the implementation of Window::s_WndProc())
				- ...and suggests we do it here http://blogs.msdn.com/b/oldnewthing/archive/2014/02/03/10496248.aspx (**NOTE THE DATE**) - the comments on this one provide some potential ideas, including IIntrospect's comment about HCBT_CREATEWND; later Raymond says we should not worry about SetWindowLongPtr() failing
				- and raymond suggests GWL_USERDATA here: http://blogs.msdn.com/b/oldnewthing/archive/2005/03/03/384285.aspx

specifics:

WINDOWS
- DateTime Picker
- ListView for Tables
- either Property Sheets or Tabs for Tabs
- either Rebar or Toolbar for Toolbars
- Status Bar
- Tooltip (should be a property of each control)
- Trackbar for Sliders
	- cannot automatically snap to custom step; need to do it manually
- Tree View
- Up-Down Control for Spinners
- maybe:
	- swap ComboBox for ComboBoxEx (probably only if requested enough)
	- IP Address control (iff GTK+ and Cocoa have it; maybe not necessary if we allow arbitrary target addresses?)
	- ListView for its Icon View?
	- something similar to Task Dialog might be useful to have as a convenience template later
- TODO
	- commcntl.h has stuff on a font control that isn't documented?
		- actually not a control, but localization support: http://msdn.microsoft.com/en-us/library/windows/desktop/bb775454%28v=vs.85%29.aspx
- notes to self:
	- groupbox is a mode of the BUTTON class (????)
	- OpenGL: http://msdn.microsoft.com/en-us/library/windows/desktop/dd374379%28v=vs.85%29.aspx
	- don't use ES_NUMBER for number-only text boxes, as "it is still possible to paste non-digits into the edit control." (though a commenter on MSDN says that's wrong?)
		- might want to just have spinners and not numeric text boxes???

GTK+
- GtkCalendar for date selection (TODO doesn't handle times)
- GtkNotebook for Tabs
- GtkScale for Sliders
	- cannot automatically snap to INTEGERS (let alone to custom steps); need to do it manually
	- natural size is 0x0 for some reason
- GtkSpinButton for Spinners
- GtkStatusBar
- GtkToolbar
- maybe:
	- GtkFontButton would be nice but unless ComboBoxEx provides it Windows doesn't
		- same for GtkColorButton
	- GtkIconView
	- GtkSeparator (I think Windows makes this a mode of Static controls?)
- notes to self:
	- groupbox is GtkFrame
	- GtkTreeView can do tree views and Tables
	- OpenGL is done outside GTK+: https://projects.gnome.org/gtkglext/
		- only an issue if I want to provide OpenGL by default...
		- http://stackoverflow.com/questions/3815806/gtk-and-opengl-bindings suggest GtkGLArea is better but that seems to be a Mono thing? also indicates Clutter (with its Cogl) is not an option because it locks you out of using the OpenGL API directly
			- er no, the Mono thing is just the homepage... but it doesn't say if this targets GTK+ 2 or GTK+ 3, hm. (also it appears to not have been updated since Precise; in Ubuntu it's libgtkgl)
			- and gtkglext doesn't support GTK+ 3 officially anyway
			- and cairo doesn't seem to support OpenGL explicitly so it looks like I will need to communicate with glx directly: http://stackoverflow.com/questions/17628241/how-can-i-use-gtk3-and-opengl-together
				- except replace glx with EGL/GLES2 because of Wayland: http://wayland.freedesktop.org/faq.html#heading_toc_j_0 (assuming EGL/GLES2 can work on X11)

COCOA
- NSDatePicker for date/time selection
- NSOutlineView for tree views
- NSSlider for Sliders
- NSStatusBar
- NSStepper for Spinners
	- TODO does this require me to manually pair it with a single-line text entry field?
- NSTabView for Tabs
- NSTableView for Tables
- NSToolbar
- maybe:
	- NSBrowser seems nice...???
	- NSCollectionView for Icon View?
	- NSColorWell is the color button
	- NSOpenGLView for OpenGL; need to see how much OpenGL-specific stuff I need to expose
	- NSRuleEditor/NSPredicateEditor look nice too but
- notes to self:
	- groupbox is NSBox
	- don't look at NSForm; though it arranges in the ideal form layout, it only allows single-line text entry fields as controls
- TODO:
	- what does NSPathControl look like?

# Slider Capabilities
Capability | Windows | GTK+ | Cocoa
----- | ----- | ----- | -----
Data Type | int | float | float
Can Simulate ints? | yes | TODO | TODO
Mouse Step Snap | 1, fixed | something; likely 0.1 but not sure | yes (`setAllowsTickMarkValuesOnly:`); caveat: must specify an exact number of ticks (see below)
Keyboard Step Snap | configurable | configurable | TODO (same as mouse?)
Current Value Display | tooltip during drag | label, always visible | TODO
Tooltips? | TODO | TODO | TODO
Ticks | configurable display, configurable interval | TODO | configurable display; configurable COUNT (not interval!)
Can Catch Mouse Events to Snap? | I think this is how to do it | TODO | TODO
Preferred Size | given in UI guidelines | natural: 0x0; minimum: TODO | TODO

# Spinner Capabilities
Capability | Windows | GTK+ | Cocoa
----- | ----- | ----- | -----
Data Type | int | float | flaot
Can Simulate ints? | yes | yes | TODO
Mouse Step Snap | 1, fixed | configurable | configurable
Keyboard Step Snap | 1, fixed | configurable (uses same value as mouse) | TODO (same as mouse?)
Can Catch Events To Snap? | TODO | no need | TODO
Preferred Size | TODO | TODO | TODO


# Dialog box hijack
## Open/Save Dialogs
  | Windows | GTK+ | Cocoa
----- | ----- | ----- | -----
Directories | no (separate facility provided by the shell) | open and save | open only
Network vs. local only (URI vs. filename) | Network button enabled by default; can be switched off (**TODO** how are network filenames returned?) | yes (default local only; if local only, changing to, say, smb://127.0.0.1/ will pop up an error box; if nonlocal allowed, filename can be null) | xxx
Multiple selection | yes | yes | open only
Hidden files | user-specified; can be switched on in code (but is a no-op?) | hidden by default; can be switched on in code (but is a no-op?) and also by the user | xxx
Overwrite confirmation | available; must be explicitly enabled | available; must be explicitly enabled | xxx
New Folder button | xxx | optional (I think enabled by default? should do it explicitly to be safe, anyway) | optional
Preview widget | xxx | yes; optional, custom | xxx
Extra custom widget | xxx | yes; optional | yes; optional
File filters | Specified by "patterns" (consisting of filename characters and * but not space; I assume the only safe ones are *.ext and *.*); multiple patterns separated by semicolons; can have custom labels | Specified by MIME type (handles subtypes; has wildcards) or pattern ("shell-style glob", so I assume over whole basename) or by custom function; can have multiple of the above; can have custom labels; also has a shortcut to add all gdk-pixbuf-supported formats | Specified by "UTI"s or by individual filename extensions (format not documented but appears to be just the extension without embellishments); cannot have labels; 1:1 filter:extension mapping.
File filter list format | `"Label\0Filter-list\0Label\0Filter-list\0...Label\0FIlter-list\0\0"`; filter for all files is canonically `"All Files\0*.*\0\0"` in the docs (specifically this due to handling of shortcut links); also provides a way for users to write in their own filters | Add or remove individual GtkFileFIlter objects; can select one specified in the list to show by default; default behavior is all files; if selected one when none has been specified, filter selection disabled; filter for all files specified in docs under gtk_file_filter_new() (except doesn't set a name) | NSArray of filter strings, or nil for All Files. There is no provision to have an "all files" option: you either specify a set of filters or you don't. (See filename extension auto-append below.). All filters are applied at once; there is no way to select. We might need to introduce an accessory panel (extra widget) to fake the filtering rules of other platforms...
Default file name | settable | settable | settable (as the filename label)
Initial directory | complex rules that have changed over time; we can pass an absolute filename (the previous filename or a default filename) and have its path used (if we specify just a path it will either be used as the filename or the program will crash); or we can give it a directory; or Windows will remember for us for some time, or... | pass previous filename or URI to show; overrides default file name; intended only for saving files (so I don't know if it's possible to remember current directory for opening??????); effect of passing containing directory undocumented(???? in my tests the given folder itself is selected) | has some rules; there is a way to specify a custom one; seems to have the undocumented effect that it selects the file if a file is named
Confirmation and cancel buttons | xxx | GTK_STOCK_OPEN, GTK_STOCK_SAVE, GTK_STOCK_SAVE_AS / GTK_STOCK_CANCEL | cancel button predefined; confirmation button can be changed (setPrompt:) but **TODO** the docs imply prompt is actually a global property?
Returned filename rules | xxxx | memory provided by GTK+ itself (so no need to worry about size limits); can return a single filename or URI or a GSList of filenames or URIs | xxx
Window title | optional; defaults to either Open or Save As | required(?) | optional for save (defaults to Save); unknown (**TODO**) for Open
Prompt to create new files | available; must be explicitly enabled; seems to only apply to Open File dialogs (**TODO**) | xxx | xxx
Adds file to a Recent Documents list | available; must be explicitly disabled | xxx | xxx
Allows nonexistent files to be created in Open dialogs | yes; can be switched off | xxx | xxx
"Open as read-only"/"Save as read-only" checkbox | provided; default; can be switched off | xxx | xxx
Navigating changes the current working directory of the program | yes; can be switched off for Save dialogs only (????) | xxx | xxx
Link following | For .lnk files, enabled by default iff a filter is specified; the All Files filter above is listed as being necessary to follow links; can be shut off with a flag in all cases | xxx | For Finder aliases, setResolvesAliases:
Help button | Available; old-style dialog boxes need a parent window (Explorer-style ones don't; they just need a hook function) | xxx | xxx
Extension auto-appending | Optional; three-character maximum; doesn't seem to be available on a per-filter basis | xxx | **NOT OPTIONAL.** The only way to avoid this is to not specify any filters. You can't even circumvent this with a delegate. If the user specifies another extension, they are asked to choose one if setAllowsOtherFileTypes: is set. (**TODO** could we use nameFieldStringValue to circumvent?)
Other labels | xxx | xxx | field before filename entry can be changed; also can provide an additional optional message
Multiple selection allows empty selection | xxx | xxx | xxx

TODO
* Windows: OFN_NOTESTFILECREATE might be necessary
* Windows: OFN_NOVALIDATE - see what happens without a hook
* Windows: OFN_SHAREAWARE - this is a weird one but it's network related
* Windows: templates seem to be how to provide extra parameters, but their usage isn't documented on the OPENFILENAME struct help page; check the rest of MSDN
* Mac OS X: turn on both setExtensionHidden: and setCanSelectHiddenExtension: to show the extnesion in the dialog
* Mac OS X: turn on setTreatsFilePackagesAsDirectories: since file packages (bundles) are an OS X-specific concept