FAQs

How do I center text in a rectangle?

I often find it necessary, especially in printouts, to center a string of text in a rectangle. The really great thing about this routine is that the text is drawn in the current mode. In other words, you may set the text mode (as in TextMode ( _srcOr) ) so that the text comes out transparent. In this way, any background will show through the printed items.

local fn getWdHt ( r as ^rect , @wdPtr& , @htPtr& )
 wdPtr&.nil& = r.right - r.left
 htPtr&.nil& = r.bottom - r.top
end fn

local fn centerText ( r as ^rect , s as str255)
 dim as long      @ wd , ht
 dim as long        xCenter , baseLine
 dim as fontInfo    fi
 fn getWdHt ( r , wd , ht )
 GetFontInfo ( fi )
 baseLine = ( ( ht  ) \\ 2 ) + ( ( fi.ascent + fi.descent ) \\ 2 ) + r.top - fi.descent
 xCenter  = ( ( wd ) \\ 2 ) - ( fn StringWidth ( s ) \\ 2 ) + r.left
 MoveTo ( xCenter , baseLine )
 TextMode ( _srcOr)
 DrawString ( s )
end fn

The function is called like this:

DIM as rect r
SetRect (r 10 , 10 , 200 , 200 )
fn centerText ( r , "This is centered text." )