OpenEuphoria

Re: Text scaling demo

• Posted by tone.skoda at gmx.net Jan 30, 2003
• 413 views

Thanks for this, I'll use it in my own project. I translated it to work
directly with HDCs.
I also thought of another, maybe faster way:
Measure difference of widths of strings which have fonts with different
heights (some random heights). Then measure also difference of font heights.
Then the desired font height should be:

desired_height = desired_width * (width1 - width2) / (height1 - height2)

This would work if width of string is linear to height of font. I don't know
if it is.

----- Original Message -----
From: <Patrick.Barnes at transgrid.com.au>
To: "EUforum" <EUforum at topica.com>
Sent: Tuesday, January 28, 2003 11:28 PM
Subject: Text scaling demo


>
> Got a text scaling demo working, thought I'd share it with y'all.
>
> It will fit the text perfectly inside a given rectangle, and it will
support strings with tab and newline characters, and automatically strip out
carriage return characters.
>
> =======================
> Patrick Barnes
> Information Systems Group
> 201 Elizabeth St, Sydney
> Patrick.Barnes at transgrid.com.au
> Ext: 91-3583
> Ph:(02) 9284-3583
> Mob: 0410 751 044
> =======================
> Below for those people without attachments.
> =======================
> ------------------------------------
> --Title: Automatic text sizing demo
> --Author: Patrick Barnes
> --Date: 28 / 1 / 2003
> ------------------------------------
> --This demo revolves around the
> --procedure drawText. It will
> --tokenize a given string into lines
> --and add tabs to it, then size it
> --to fit into a rectangle of given
> --size and position.
> ------------------------------------
> --Permission is freely granted for
> --anyone to use this library as they
> --see fit, save for misrepresenting
> --it's origin.
> ------------------------------------
> --Thanks to: Pete Lomax for his
> --binary search, Derek Parnell for
> --win32lib.
> ------------------------------------
>
>
> include win32lib.ew
> without warning
>
> constant win = create(Window, "Text scaling", 0, Default, Default, 400,
340, 0)
>
> constant text = "This is a test of the automatic\ntext sizing
system.\nChange this text in the source code."
> constant TABSIZE = 6
> constant TAB = 9
>
> atom dwin
>
> --returns a sequence with the x,y size of the lines of text submitted
> global function getMlTextExtent(integer win, sequence mtext)
> integer lnum, maxw
> lnum = length(mtext)
> maxw = 0
> for a = 1 to lnum do
> if getTextWidth(win, mtext[a]) > maxw then
> maxw = getTextWidth(win, mtext[a])
> end if
> end for
> return {maxw  , lnum*getTextHeight(win, "T")}
> end function
>
> --Will automatically size and draw the string itext (which may have '\n')
to the desired window.
> --It will scale and position to fit inside the rectangle defined by {ulx,
uly} -> {lrx, lry}
> --Font is a two-element sequence of the form { "Font name", Style }
> global procedure drawText(integer win, sequence itext, integer ulx,
integer uly, integer lrx, integer lry, sequence font )
> sequence text, tsize, wsize, pos
> integer bsize, ssize, fsize
> atom ctr
>
> --Tokenize the text into lines.
> --*****************************
> if not length(itext) then --if no text, then don't bother
> return
> elsif itext[length(itext)] = '\n' then --if the last char is a '\n' then
get rid of it.
> itext = itext[1..length(itext) - 1]
> end if
>
> text = {{}}
> ctr = 1
>
> for a = 1 to length(itext) do --step through every letter, building up the
lines
> if itext[a] = TAB then
> text[ctr] &= repeat(' ', remainder( TABSIZE * ( floor( length(text[ctr]) /
TABSIZE) + 1), length(text[ctr]) ) )
> elsif itext[a] = '\n' then
> text &= {{}}
> ctr += 1
> elsif itext[a] = '\r' then
> --ignore that character
> else text[ctr] &= itext[a]
> end if
> end for
> --Find the optimal font size for the window
> --*****************************************
> fsize = 8 --starting font size
> ssize = 1
> bsize = 0
> wsize = {lrx - ulx, lry - uly}
> while 1 do --Thanks to Pete Lomax for his binary search.
> --find the size of that text
> setFont(win, font[1], fsize, font[2])
> tsize = getMlTextExtent(win, text)
> --if it's bigger than the window...
> if tsize[1] >= wsize[1] or tsize[2] >= wsize[2] then
> bsize=fsize
> fsize=ssize+floor((fsize-ssize)/2)
> if fsize=ssize then
> exit
> end if
> else
> ssize=fsize
> if bsize=0 then
> fsize*=2
> else
> if fsize+1=bsize then exit end if
> fsize+=floor((bsize-fsize)/2)
> end if
> end if
> end while --At this point fsize is the optimal text size.
>
>
> --Draw the text to the window
> --***************************
> pos = {ulx, uly}
> --draw the text on the window.
>
> setFont(win, font[1], fsize, font[2])
> for a = 1 to length(text) do
> wPuts({win, pos[1], pos[2]}, text[a])
> pos[2] += getTextHeight(win, text[a])
> end for
> end procedure
> -------------------------------------------------------------------
> procedure display(integer ID, integer Event, sequence params)
> sequence sz
> sz = getClientRect(win)
> drawText(win, text, 50, 50, sz[3] - 50, sz[4] - 50, {"Times New Roman",
Normal} )
> drawRectangle(win, 0, 50, 50, sz[3] - 50, sz[4] - 50)
> end procedure
> setHandler(win, w32HPaint, routine_id("display") )
> -------------------------------------------------------------------
> procedure c(integer ID, integer Event, sequence params)
> sequence sz
> if params[1] != 27 then
> sz = getClientRect(win)
> setClientRect(win, sz[3]+5, sz[4]+5)
> else
> closeWindow(win)
> end if
> end procedure
> setHandler(win, w32HKeyDown, routine_id("c") )
> -------------------------------------------------------------------
> procedure resized(integer ID, integer Event, sequence params)
> repaintWindow(win)
> end procedure
> setHandler(win, w32HResize, routine_id("resized") )
> -------------------------------------------------------------------
> WinMain(win, Normal)
>  <<textscaletest.exw>>
>
>
> ***********************************************************************
>
>
> ***********************************************************************
>
>
>
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