Using Fonts

You can specify fonts for user interface objects programmatically or through the User Interface Editor. These fonts are applied to features of the GUI such as panel titles, control text, and labels. You can use a predefined font or a predefined metafont. You can also choose a LabWindows/CVI-supplied metafont, a host font supplied on your system, or create your own metafont.

Note  When you change the font and point size of text, always set the font before setting the point size or style attributes.

The following table lists valid font values:

Predefined Fonts That Are Resident on the System

Predefined fonts contain typeface information only. Each value is an alias to an operating system font typeface. The computer operating system and user preferences determine this type of font appearance. Therefore, a predefined font can appear differently on two computers with the same screen resolution.

Predefined Metafonts That Are Resident on the System

The predefined metafonts contain typeface information, point size, and text styles such as bold, underline, italic, and strikeout. Each value is an alias to an operating system font. Therefore, the computer operating system and user preferences determine this font. If you distribute graphical user interfaces that use predefined metafonts, the control sizes and proportions can differ among computers with the same screen resolution. For example, a predefined metafont that is size 11 on one computer can be a size 13 font on a different computer that has the large fonts setting enabled. If you plan to distribute a user interface to a different computer, consider using host fonts.

Predefined metafonts are used in the LabWindows/CVI environment. The following values are predefined metafonts:

• VAL_MENU_META_FONT—Used for menu and menu item names.
• VAL_DIALOG_META_FONT—Used for labels in dialog boxes and function panels.
• VAL_EDITOR_META_FONT—A monospaced metafont used as the default font in Source windows.
• VAL_APP_META_FONT—Used as a smaller alternative to VAL_DIALOG_META_FONT.
• VAL_MESSAGE_BOX_META_FONT—Used for simple message boxes.

Metafonts Supplied by LabWindows/CVI

National Instruments ships LabWindows/CVI with two metafonts that use typefaces that are not native to the operating system:

• VAL_7SEG_META_FONT—Provides compatibility with LabWindows for DOS.
• VAL_SYSTEM_META_FONT—Provides compatibility with function panel help text and user interface panels from LabWindows for DOS that use extended IBM PC characters. Avoid using extended IBM PC characters because other fonts do not display them. Cut-and-paste operations with extended IBM PC characters fail across applications that use other fonts.

User-Defined Metafonts

You can create metafonts with CreateMetaFont, CreateMetaFontEx, or CreateMetaFontWithCharacterSet. Then you can apply the metafont to any control or panel attribute that takes a font value. When you apply a metafont, you set the typeface, point size, text styles, character set, and angle all at one time. Because metafonts contain character size information, strings that use metafonts are more likely to have the same width across platforms.

Note  Some LabWindows/CVI functions, such as PlotText and GetTextDisplaySize, require a metafont as an input parameter.

Host Fonts

In addition to fonts LabWindows/CVI provides and metafonts you create, you can use any host font supported on your system. For example, Arial, Courier New, and Times New Roman are available under Windows. Unlike metafonts, host fonts do not contain point size and text style information. You must specify this information.

If you are distributing an application across several computers, consider using common host fonts instead of predefined fonts. If you use a host font, a control will have the same size in pixels across computers with different user preferences.

Note   If you distribute an application that uses host fonts, these host fonts must be present on all machines to which you distribute the application.