TFont

Source: source/classes/font.prg

Standalone class (no inheritance)

TFont manages Windows GDI font objects. It encapsulates the creation, selection, and destruction of logical fonts, providing a high-level interface for typeface name, size, weight, style (bold, italic, underline, strikeout), character set, escapement, and orientation. TFont is used throughout the FiveWin framework by every control and window that renders text. Fonts must be explicitly released with End() when no longer needed to avoid GDI resource leaks.

Key DATA Members

DATA	Type	Description
`hFont`	Numeric (Handle)	Windows GDI font handle. Created by `New()`, used when activating onto a DC.
`cFaceName`	Character	Typeface name (e.g. "Arial", "Segoe UI", "Courier New").
`nInpHeight`	Numeric	Nominal font height in logical units. Negative values indicate character height (em-height); positive values indicate cell height.
`nInpWidth`	Numeric	Average character width. Zero lets Windows choose a proportional width.
`nWeight`	Numeric	Font weight: 0=default, 400=normal, 700=bold. Set automatically when `lBold` is `.T.`.
`nEscapement`	Numeric	Angle of the base text line in tenths of degrees (0 = horizontal, 900 = vertical upward).
`nOrientation`	Numeric	Angle of each character in tenths of degrees.
`nCharSet`	Numeric	Character set identifier: 0=ANSI, 1=DEFAULT, 204=RUSSIAN, 238=EASTEUROPE, 255=OEM.
`lBold`	Logical	If `.T.`, the font is created with bold weight (700).
`lItalic`	Logical	If `.T.`, the font is created with italic style.
`lUnderline`	Logical	If `.T.`, the font is created with underline.
`lStrikeOut`	Logical	If `.T.`, the font is created with strikeout.
`lSubstitute`	Logical	If `.T.`, the font name is substituted through the font substitution table (`FWFontSubst()`).
`lQuality`	Logical	If `.T.`, anti-aliased (CLEARTYPE) quality is requested when available.
`Cargo`	Any	General-purpose user data slot.

Methods

Method	Description
`New( cFace, nW, nH, lBold, lItalic, lUnder, lStrike, nEscap, nOrient, nWeight, nCharSet, lQuality, lSubst )`	Create a new font object. Negative `nH` specifies character height; positive specifies cell height. `nW` of 0 selects proportional width. The font handle `hFont` is created immediately.
`End()`	Release the GDI font handle (`DeleteObject( ::hFont )`) and free the object. Must be called when the font is no longer needed.
`Activate( hDC )`	Select the font into a device context. Returns the previous font handle. Use `DeActivate()` to restore.
`DeActivate( hDC, hOldFont )`	Restore the previous font handle into the device context. Call after `Activate()` to clean up.
`Modify( nH, lBold, lItalic, lUnder, lStrike, cFace, nW, nEscap, nOrient, nWeight, nCharSet, lQuality )`	Change font attributes and recreate the GDI font handle. The old handle is destroyed.
`Choose( nRGB )`	Open the standard Windows font selection dialog. The optional `nRGB` parameter presets the color. Returns the chosen RGB color or nil if cancelled. The font object is updated to the selection.
`Clone()`	Create an independent copy of the font with a new GDI handle. Useful when the same logical font is needed by different owners.
`nSize()`	Return the font height as a negative value (character height convention).
`Rotate( nDeg )`	Create a rotated version of the font. `nDeg` is the rotation angle in degrees (not tenths). Sets both escapement and orientation.
`Release()`	Alias for `End()`. Releases the GDI font handle.
`lChanged()`	Returns `.T.` if the font attributes have been modified since creation.

Commands: DEFINE FONT

FiveWin provides a preprocessor command for convenient font creation:

DEFINE FONT oFont ;
   NAME cFaceName ;
   SIZE nWidth, nHeight ;
   [ BOLD ] [ ITALIC ] [ UNDERLINE ] [ STRIKEOUT ] ;
   [ CHARSET nCharSet ] ;
   [ ESCAPEMENT nDeg ] ;
   [ ORIENTATION nDeg ] ;
   [ WEIGHT nWeight ] ;
   [ QUALITY ]

The SIZE clause takes width and height. Using a negative height (e.g. 0, -14) specifies character height in points; positive specifies cell height in logical units. Width of 0 lets Windows choose proportionally.

Example: Create Font and Use on a Device Context

#include "FiveWin.ch"

function Main()

   local oWnd, oFont, hOldFont, hDC

   DEFINE WINDOW oWnd TITLE "TFont Demo" SIZE 500, 300

   // Create a bold italic font
   DEFINE FONT oFont NAME "Arial" SIZE 0, -24 BOLD ITALIC

   ACTIVATE WINDOW oWnd CENTERED ;
      ON PAINT ( hDC := oWnd:GetDC(), ;
                 hOldFont := oFont:Activate( hDC ), ;
                 SayText( hDC, "Hello FiveWin!", 50, 50,, oFont:nInpHeight ), ;
                 oFont:DeActivate( hDC, hOldFont ), ;
                 oWnd:ReleaseDC( hDC ) )

   oFont:End()

return nil

Notes