3.2 Preferences
The preferences dialog consists of several panels.
3.2.1 Font
This panel controls the main font used by DrRacket.
3.2.2 Colors
The Colors panel has several sub-panels that let you configure the colors that DrRacket uses for the editor background, for highlighting matching parentheses, for the online coloring for Racket and Java modes, for Check Syntax, and for the colors of the text in the interactions window.
It also has two buttons, White on Black and Black on White, which set a number of defaults for the color preferences and change a few other aspects of DrRacket’s behavior to make DrRacket’s colors look nicer for those two modes.
3.2.3 Editing
The Editing panel consists of several sub-panels:
Indenting
This panel controls which keywords DrRacket recognizes for indenting, and how each keyword is treated.
Square bracket
This panel controls which keywords DrRacket uses to determine when to rewrite [ to (. For cond-like keywords, the number in parenthesis indicates how many sub-expressions are skipped before square brackets are started.
See Editing with Parentheses for details on how the entries in the columns behave.
General
Number of recent items – controls the length of the Open Recent menu (in the File menu).
Auto-save files – If checked, the editor generates autosave files (see Backup and Autosave Files) for files that have not been saved after five minutes.
Backup files – If checked, when saving a file for the first time in each editing session, the original copy of the file is copied to a backup file in the same directory. The backup files have the same name as the original, except that they end in either ".bak" or "~".
Map delete to backspace – If checked, the editor treats the Delete key like the Backspace key.
Show status-line – If checked, DrRacket shows a status line at the bottom of each window.
Count column numbers from one – If checked, the status line’s column counter counts from one. Otherwise, it counts from zero.
Display line numbers in buffer; not character offsets – If checked, the status line shows a ‹line›:‹column› display for the current selection rather than the character offset into the text.
Wrap words in editor buffers – If checked, DrRacket editors auto-wrap text lines by default. Changing this preference affects new windows only.
Use separate dialog for searching – If checked, then selecting the Find menu item opens a separate dialog for searching and replacing. Otherwise, selecting Find opens an interactive search-and-replace panel at the bottom of a DrRacket window.
Reuse existing frames when opening new files – If checked, new files are opened in the same DrRacket window, rather than creating a new DrRacket window for each new file.
Enable keybindings in menus – If checked, some DrRacket menu items have keybindings. Otherwise, no menu items have key bindings. This preference is designed for people who are comfortable editing in Emacs and find the standard menu keybindings interfere with the Emacs keybindings.
Color syntax interactively – If checked, DrRacket colors your syntax as you type.
Automatically print to PostScript file – If checked, printing will automatically save PostScript files. If not, printing will use the standard printing mechanisms for your computer.
Open files in separate tabs (not separate windows) – If checked, DrRacket will use tabs in the front-most window to open new files, rather than creating new windows for new files.
Automatically open interactions window when running a program – If checked, DrRacket shows the interactions window (if it is hidden) when a program is run.
Put the interactions window beside the definitions window – If checked, DrRacket puts the interactions window to the right of the definitions window. By default, the interactions window is below the definitions window.
Always show the #lang line in the Module language – If checked, the module language always shows the #lang line (even when it would ordinarily be scrolled off of the page), assuming that the #lang line is the first line in the file.
Racket
Highlight between matching parens – If checked, the editor marks the region between matching parenthesis with a gray background (in color) or a stipple pattern (in monochrome) when the blinking caret is next to a parenthesis.
Correct parens – If checked, the editor automatically converts a typed ) to ] to match [, or it converts a typed ] to ) to match (. Also, the editor changes typed [ to match the context (as explained in Editing with Parentheses).
Flash paren match – If checked, typing a closing parenthesis, square bracket, or quotation mark flashes the matching open parenthesis/bracket/quote.
3.2.4 Warnings
Ask before changing save format – If checked, DrRacket consults the user before saving a file in non-text format (see Program Files).
Verify exit – If checked, DrRacket consults the user before exiting.
Only warn once when executions and interactions are not synchronized – If checked, DrRacket warns the user on the first interaction after the definitions window, language, or teachpack is changed without a corresponding click on Run. Otherwise, the warning appears on every interaction.
Ask about clearing test coverage – If checked, when test coverage annotations are displayed DrRacket prompts about removing them. This setting only applies to the PLT languages. DrRacket never asks in the teaching languages.
Check for newer PLT Racket versions – If checked, DrRacket periodically polls a server to determine whether a newer version of DrRacket is available.
3.2.5 Profiling
This preference panel configures the profiling report. The band of color shows the range of colors that profiled functions take on. Colors near the right are used for code that is not invoked often and colors on the right are used for code that is invoked often.
If you are interested in more detail at the low end, choose the Square root check box. If you are interested in more detail at the upper end, choose the Square check box.
3.2.6 Browser
This preferences panel allows you to configure your HTTP proxy. Contact your system administrator for details.