MrEd supports a number of preferences for global configuration. The MrEd preferences are stored in the common file reported by find-system-path for 'pref-file, and preference values can be retrieved and changed through get-preference and put-preferences. However, MrEd reads most preferences once at startup (all except the 'MrEd:playcmd preference).
The following are the (case-sensitive) preference names used by MrEd:
'MrEd:controlFontSize preference – sets the font size for control and menu labels (Windows, X); the font is the 'system font, which can be configured as described in Font Configuration.
'MrEd:defaultMenuPrefix preference – sets the prefix used by default for menu item shortcuts under X, one of 'ctl, 'meta, or 'alt. The default is 'ctl. When this preference is set to 'meta or 'alt, underlined mnemonics (introduced by & in menu labels) are suppressed.
'MrEd:hiliteColor preference – a string to sets the color for highlighting text, menus, and other GUI elements under X; the preference string should contain six hexadecimal digits, two for each component of the color. For example, set 'MrEd:hiliteColor preference to "0000A0" and set 'MrEd:hiliteMenuBorder preference to #t for a Bluecurve-like look.
'MrEd:wheelStep preference – sets the default mouse-wheel step size of editor-canvas% objects.
'MrEd:playcmd preference – used to format a sound-playing command; see play-sound for details.
'MrEd:selectionAsClipboard preference – under X, a true value causes the-clipboard to be an alias to the-x-selection-clipboard, which means that cut and paste operations use the X selection instead of the X clipboard. See also clipboard<%>.