Category: Icetips Blog

Clarion uses dialog units as screen position measurement unit when designing windows. This is fixed and cannot be changed at design time, but it can be changed at runtime. For window design we can use PROP:Pixels and to change to pixels it is a simple matter of setting PROP:Pixels to true for the window object, like:

 WindowLabel {PROP:Pixels} = True

Or:

 0 {PROP:Pixels} = True

Since 0 (zero) always refers to the structure of the current target object. To set the window back to using dialog units, simply set PROP:Pixels to false:

 0 {PROP:Pixels} = False

It may not be immediately obvious, but you can also use a few other measurement units when dealing with windows at runtime. There are 3 more measurement units that can be used: PROP:Thous, PROP:mm and PROP:Points. If you set the properties to false Clarion goes back to dialog units. Normally we would only think of using PROP:Thous, PROP:mm and PROP:Points on reports, but they work equally well on windows!

The smallest unit you can use with PROP:Thous is 1 which equals 0.0254mm. Point is 1/72" equal to about 0.353mm. With millimeters, the smallest unit is 2 (or at least it used to be) or 100 times bigger than the smallest unit with PROP:Thous, which makes it pretty much useless for any precision placements. If I need to set sizes in metric units I convert to 1/1000" It may not always be perfect but for most things I think it is close enough.

If you have a control on a report, for example a fixed width textbox and you want the user of your software to be able to format the contents on a window so that it will look exactly as it will print, you can get the measurement from the report and use it to set the size of the textbox on a window. Let

Two months ago I implemented the Clarion PDF generation templates in a client project. I was pretty horrified by the results as characters were chopped and spaced very strangely. After posting about this on the Clarion newsgroups, Lee White suggested that this was because I was running Large Fonts on my system.

Since I have had to deal with Large Font issues before simply because I use high resolution and need to be able to seeB) I decided to take a closer look at this and see what was going on.

Sure enough the problem stems from code in the ABPRPDF.CLW file where the width of the characters is calculated. To fix this I made some changes to the files.

This involves adding a single method to the PDFGeneratorClass class in ABPRPDF.INC and ABPRPDF.CLW:

Add to class declaration in ABPRPDF.INC (I put it in at the top of the
method list, around line 195):

AdjustDPIValues   PROCEDURE(Long pValue),Long 
!! AB 2009-02-19  Adjusts DPI values

In the classfile, ABPRPDF.clw, I added this:

PDFGeneratorClass.AdjustDPIValues   PROCEDURE(Long pValue)!!,Long 
!! AB 2009-02-19  Adjusts DPI values
HDcScreen  UNSIGNED
IDPI       Long
R          Real
L          Long
 Code
 R = 1
 HDcScreen = GetDC(0)
 If HDcScreen <> 0
   IDPI = GetDeviceCaps(HDcScreen, 88)
   L = ReleaseDC(0, HDcScreen)
   R = IDPI/96
 End
 Return (pValue / R)

In PDFGeneratorClass.AddFontDescriptor method, you have code like this:

!SET the fonts Width
LOOP LOC:I=SELF.FontsNames.FirstChar TO SELF.FontsNames.LastChar
   LOC:CharToTest=CHR(LOC:I)
   IF GetTextExtentPoint32(LOC:DC,LOC:CharToTest, 1,LOC:CharSize)<>0 THEN
      IF LOC:Subclasing THEN
         IF SELF.FontsNames.CharWidth[LOC:I] THEN
            SELF.FontsNames.CharWidth[LOC:I] = LOC:CharSize.eW
         END
      ELSE
         SELF.FontsNames.CharWidth[LOC:I] = LOC:CharSize.eW
      END
   END
END

I changed both of the assignments to the CharWidth to:

SELF.FontsNames.CharWidth[LOC:I] = |
           SELF.AdjustDPIValues(LOC:CharSize.eW)

In PDFGeneratorClass.GetTextWidth method, you have code like this:

 IF SelectObject(LOC:DC, LOC:HFont) THEN
    RV = GetTextExtentPoint32(LOC:DC,pText, LEN(pText),LOC:CharSize)
    LOC:OLDMAPMODE=SetMapMode(LOC:DC,LOC:OLDMAPMODE)
    DeleteObject(LOC:HFont)
    RETURN LOC:CharSize.eW + (LOC:CharSize.eW/20)
 END

I changed the RETURN to adjust the value:

RETURN SELF.AdjustDPIValues(LOC:CharSize.eW + (LOC:CharSize.eW/20))

This takes care of the font sizing problem in any DPI combination that I
threw at it:)

Arnor Baldvinsson