OpenEuphoria

Re: Win32Lib: any way to GET the font size?

• Posted by CChris <christian.cuvier at agriculture.gouv.fr> Mar 23, 2007
• 566 views

Dan Moyer wrote:
> 
> don cole wrote:
> > 
> > Dan Moyer wrote:
> > > 
> > > don cole wrote:
> > > > 
> > > > 
> > > > Dan Moyer wrote:
> > > > > 
> > > > > Is there some way to get the font SIZE?  I don't mean the height or
> > > > > width
> </font></i>
> > > > > extents of CHARACTERS, I mean the value that would be used to SET the
> > > > > font
> > > > > to a particular size. 
> > > > > 
> > > > > I want to be able to center various text within columns, by changing
> > > > > the
> > > > > size of the font as needed, but that text could
> > > > > be in different sized fonts to begin with, so my routine needs to
> > > > > change
> > > > > the font size *from* whatever original size it was, so I need to be
> > > > > able
> to</font></i>
> > > > > *find out* what size it happens to be initially.
> > > > > 
> > > > > Dan Moyer
> > > > 
> > > > Hello Dan,
> > > > 
> > > > Try getFontDialog()
> > > > 
> > > > Don Cole
> > > 
> > > Don,
> > > 
> > > I'm not looking for a *dialog*, wherein a user *selects* a font/size,
> > > but rather a way for my *program* to ascertain what font size is currently
> > > in force for a window.  I want my program to GET the font size first, then
> > > it will decrement it as necessary, then return to original after using 
> > > smaller size as needed to fit space allotted.
> > > 
> > > Dan
> > 
> > Hello Dan,
> > 
> >   I was just reading from index.html the desciption of 
> > 
> >    getFontDialog ( window )
> > 
> >    that says 
> > 
> >    Returns: { font name, points, style flags, color } or -1 if cancelled.
> > 
> >   I have never used this. However I have a program that I think does what
> >   you
> > want. It starts out with a randon (large) font size. Then it keeps reducing
> > it until all the columns fit on the paper. This print preview program is
> > lengthy
> > and I have never posted it in the archives. If you are interested I coulde
> > e-mail
> > it to you.
> > 
> > Don Cole
> 
> Don,
> 
> Thanks, I can do it myself once I know the font size (which I'll work around
> by making sure that I keep track of it whenever it gets changed), but I'm
> always interested in how others code a similar problem, so if you will,
> go ahead & email it to me.
> 
> Actually I'm just concerned with fitting things onto the *screen* right now,
> but as soon as I get that working I will want
> to do the exact same thing for printer, also.
> 
> Dan

The following appears to work. It reverses what convPointsToLogical() does.

include win32lib.ew
constant
   Err_ECFSAVEDCFAIL = {"ezCreateFont:SaveDC failed.", 491},
   Err_ECFRESTOREDC = {"ezCreateFont:RestoreDC failed.", 486},
xGetCurrentObject=registerw32Function(gdi32,"GetCurrentObject",{C_POINTER,C_LONG},C_POINTER),
xLPtoDP=registerw32Function(gdi32,"LPtoDP",{C_POINTER,C_POINTER,C_LONG},C_LONG)

global function getFontPointSize(object pDC)
    integer pointSize
    atom lDC
    atom lSavedDC,currentFont
    atom lDpiY
    atom lPoint,logFont

    -- save the current device context because I'm about to
    -- possibly mess it up.

    if atom(pDC) then
        -- Then a control ID was passed
        lDC = getDC(pDC)
    elsif length(pDC)>1 then
        -- Then a raw window handle is at position 1
        lDC=w32Func(xGetDC,{pDC[1]})
    else
        -- Else a real dc was passed
        lDC = pDC[1]
    end if

    lSavedDC = w32Func( xSaveDC, {lDC} )
    if lSavedDC = 0 then
        abortErr( Err_ECFSAVEDCFAIL )
    end if

    -- these are NT specific. they should have no effect in Win95
    VOID = w32Func( xSetGraphicsMode, {lDC, GM_ADVANCED} )
    VOID = w32Func( xModifyWorldTransform, {lDC, NULL, MWT_IDENTITY} )

    VOID = w32Func( xSetViewportOrgEx, {lDC, 0, 0, NULL} )
    VOID = w32Func( xSetWindowOrgEx,   {lDC, 0, 0, NULL} )

    lDpiY = w32Func( xGetDeviceCaps, {lDC, LOGPIXELSY} )

    -- w32allot
    lPoint = w32acquire_mem( 0, SIZEOF_POINT )
    currentFont = w32Func(xGetCurrentObject,{lDC,6}) -- OBJ_FONT
    logFont = w32acquire_mem(0,SIZEOF_LOGFONT)
    VOID = w32Func(xGetObject,{currentFont,SIZEOF_LOGFONT,logFont})
    w32store( lPoint,ptY, peek4u(logFont))
    VOID = w32Func( xLPtoDP, {lDC, lPoint, 1} )
    pointSize = w32fetch( lPoint,ptY )
    w32release_mem(lPoint)
    w32release_mem(logFont)
    pointSize = floor(pointSize*(72.0/lDpiY)+0.5)

    -- restore the device context
    if not w32Func( xRestoreDC, {lDC, lSavedDC} ) then
        abortErr( Err_ECFRESTOREDC )
    end if

    if atom(pDC) then
        releaseDC( pDC )
    end if

    return pointSize

end function

constant w=create(Window,"taaaa",0,50,50,50,50,0)
procedure p(integer id,integer event,sequence data)
?getFontPointSize(w)
end procedure -- prints 12 here, and the floor() isn't really needed

setHandler(w,w32HActivate,routine_id("p"))

WinMain(w,Normal)

CChris

PS: you can avoid calling GetCurrentObject() by sending the control the
 WM_GETFONT message. However, if you only have a DC, you'll have to retrieve
 the control handle using WindowFromDC().