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 wxWidgets Mnemonic FAQ
See also other tutorials.
List of questions in this category
An mnemonic is an underlined letter in a menu or labeled dialog control that
indicates to a user a quick, keyboard method of simulating a click on that
element. For example, an Apply button may have the letter A underlined. On
Windows and UNIX, pressing Alt+A is a convenient way to push that button. Mac
OS X does not support underlined mnemonics.
On Microsoft Windows 2000 and XP, the underlines only appear while ALT is
pressed. This makes the mnemonics difficult to debug. Especially in context
menus!
Windows can be instructed to automatically show underlines for accelerator
keys by checking the Show extra keyboard help in programs box in the
Keyboard pane of the Accessibility Options applet in the Windows
Control panel. Alternatively, right-click on the desktop background, go to
Properties -> Appearance -> Effects, and clear the
checkbox labeled Hide keyboard navigation indicators until I use the Alt
key.
An mnemonic can be added to a form control or menu item label by adding an
'&' before the letter.
- Avoid duplicates
- Don't use the same mnemonic letter is twice in the same
window.
- Be especially careful of drop down menus in the same
window. For example, for mail quick search controls, don't use
F, E, V, M, S, T, W or H (File, Edit,
View, Message, Spam, Tools,
Window,
Help).
- Help
wanted: it would be useful to have an automated tool to
check for duplicate and missing mnemonics in wxWindows-based
applications.
- Make it easy to see:
- Use letters at the beginning of the first or second word of
the label.
- Use a distinctive consonant or a vowel in the label.
- Use letters with wide widths, such as w, m, and capital
letters.
- Avoid letters with descenders, such as g, j, p, q, or
y.
- Avoid letters next to a letter with a descender.
- Avoid letters that are only one pixel wide, such as i or
l.
- Make it easy to remember
- Do the most important prompts first, so that they get the
best mnemonics.
- See if a similar prompt has an mnemonic elsewhere in
Windows, and use the same mnemonic. It's important to use
standard mnemonics, to take advantage of people's muscle
memory. For example: Properties, Rename,
Delete, Cut, Copy, Paste,
Open, Find, Find next, Save, Save
as, Print, Exit.
- If not, try the first letter of the first word in the
prompt.
- Next, try the first letter of another word in the
prompt.
- Finally, use any non-silent letter in an action word (do
these after the rest of the dialog has mnemonics chosen).
- Common elements that don't get mnemonics
- OK buttons.
- Cancel buttons.
- Close buttons.
- Tab panel labels.
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