Re: Large Fonts

"Jeff Johnson [MVP: VB]" <i.get@xxxxxxxxxxx> wrote in message news:%23aOopTsQGHA.4688@xxxxxxxxxxxxxxxxxxxxxxx

> [In response to] Changing the settings on the computers
> of our users is no option.

Too bad, because... http://www.divsoft.com/lfs

Yep. I've seen that before Jeff. It is a little bit contrived though, and there is a fair bit more to it than the author expresses. When I say "contrived" I don't mean that the author deliberately chose values that tended to prove his point, but simply that the values he happens to have used did that for him purely by chance.

The effects vary from one machine to the next of course, but generally in Windows all True Type fonts (including the Verdana 8 point he is using) are required to be "whole pixel" values, so that on most machines if you ask for 8 point Verdana you will actually get 8.25 points. With some fonts there are also other considerations, but the "whol pixel font size" one is always present. If you ask for 10 point Verdana (25 per cent bigger) you will probably get 9.75 points. So, the relationship between the fonts you actually get is not the same as the relationship between the fonts you asked for.

Similar considerations also come into effect when you switch between "Windows small fonts setting" (96 dpi) and "Windows large fonts setting" (120 dpi). So in the author's specific case (8 point Verdana) he would quite probably see the effect he described (the size of the "container" or button or whatever expanding by a larger percentage than the size of the font which it contains). If he had instead chosen 9 point Verdana then he might not have seen a difference at all, and for 10 point Verdana he would probably have experienced the opposite (where the font size increased by a larger percentage than its container). For example, on my own system I see something like the author himself describes when using 8 point Verdana. In my case the height of a Command Button increased by 25 per cent, as expected, when changing from 96 dpi to 120 dpi, but the height of the font increased by only 12 per cent (similar to the author's description), but at 9 points there was virtually no difference at all between the two, and at 10 point Verdana I had the opposite effect, where the height of the Command Button increased by 25 per cent but the height of the font increased by 33 per cent.

In fact, on one of my WinXP SP2 systems a standard Command Button using the standard 8 point MS Sans Serif changed the size of the Command Button by exactly 25 per cent when changing from 96 dpi to 120 dpi, and the size of the font changed by about 18 per cent (8.25 actual to 9.75 actual). This is what you would normally expect, and the Command Button's text would of course still fit onto the button. However, on my other WinXP SP2 system (using a different graphics card) the change from 96 dpi to 120 dpi refused to take effect at all as far as the size of Forms and Buttons (and other stuff) is concerned, so that the Command Button was the same size in both cases. This might not seem too bad at first, because you would expect that if the Form and Command Button sizes were not changed then the font sizes would not change either. This wasn't the case though, simply because at that dpi setting the 8 point (8.25 point) font size for MS Sans Serif became unavailable, and so the system had to choose the first available alternative, which was 10 point (9.75 point actual). This caused the Command Buttom to remain the same size at both the 96 dpi and the 120 dpi settings, but the font size to increase by about 20 per cent, sao that the text in my specifric case no longer fitted onto the button.

I do agree with the author on one point though, and that is I think there are better ways for people with poor eyesight to change their system than simply changing the dots per inch setting. However, it doesn't really matter what we say as programmers, it is a fact of life that some people, no matter how much you dislike it, will use a different Windows font size (by that I mean a different pixels per inch setting), and I think you should write your code to accommodate them. In fact, I know of people with perfectly good eyesight who use something other than the standard "96 dpi Windows small fonts setting". They do it because they use drawing or publication applications which do not allow then to choose any "display sizes" they wish. For example, an application might only allow the user to choose a "zoom" of page width, full page, 25 per cent, 50 per cent, 100 per cent, etc). Some applications do not allow you to use user specified magnifications of (say) 78.5 per cent, but virtually all of themn allow you to use 100 per cent. So, if those people want a document to be exactly the same size on the display as it is in real life (so they can hold a page up to the screen, for example) then they must choose 100 per cent (or some other fixed magnification). In such cases they can use the Windows "dots per inch" stuff in Control Panel to select a dots per inch setting where (on their specific monitor) a "page" shown at 100 per cent is exactly the same physical size (on the monitor) as a real piece of similarly sized paper held up against the screen. This helps some people. In fact if to facilitate this if you choose "custom size" Windows will present you with a ruler (I keep getting told off for calling a "rule" a "ruler"!) that you can simply "drag to different sizes" until it matches a real ruler held against the screen.

Anyway, what I'm really saying is that if you're writing a VB (or whatever) application then you shouldn't really expect your users to comply with your own rulings in these respects. You should instead allow them to do whatever they want to do and your application should modify itself accordingly. To do this you really need to add code that examines everything at run time to see what it is set to and then modifies its own screen output accordingly.

Life would be much simpler if there were no adjustable display settings in Windows, but sadly (at least sadly for VB6 programmers) that isn't the case. VB6 stores all of your settings (positions and sizes of controls, etc) using twips (in both the project and the form etc files and also in the exe files). It does this regardless of ther various ScaleModes you are using. In fact in the frm files, for example, it stores most settings using *both* your own Scale values and twips, but it uses the twips when it comes to draw your Form. You need to account for it. Other applications (Delphi, for example, and VB.net as far as I know) do not do this, but even they can be upset by the various things that can happen differently on different systems. So, I'd advise run time examination in all cases.

Mike








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