Default browser (viewer) for CHM files

[MC Hammer]

Hi everyone
I produce some HTML Help files (CHM) and have been making sure that my XML/HTML (CSS) is compatible with most browsers (Internet Explorer has been causing me some grief). However I am not sure of what happens when our users open our CHM files ( ). If they have IE as default browser, there is no question, the CHMs will be viewed on IE. But if they have FF (or Opera, etc) as default browser, is the HTML Help viewer still IE or an IE component?
This is probably a fundamental question but unfortunately, I am not very clear on how things work.
Thank you.

[KevinDAmery]

It's a non-issue. CHMs are always viewed using the CHM viewer, which uses components that are common to Windows and IE to render the pages. It does not use other browsers for viewing, no matter what the default browser is.

Browser compatibility isn't an issue for CHMs. Just make sure that the CHM looks good in the fonts you choose, and you should be good on every other Windows system.

[MC Hammer]

Hi Kevin
That is what I suspected. Thanks for your valuable input.
I still want to make sure that my HTM files will look good no matter what the browser in case we upgrade our Help to WebHelp (which I am dying for).
So is the browser compatibility is only an issue with WebHelp then?

[KevinDAmery]

Yes, with WebHelp you do need to worry about browser compatibility. The other formats are self contained so it's not an issue for them.

[MC Hammer]

Thanks for your help (and prompt reply!)

[doc_guy]

"worry" is maybe a strong word. There are a few browser compatiblity issues, but unless you're doing some serious CSS tweaking and styling, then you probably won't notice any difference between browsers. There are minor display differences. However, if you're using a mostly standard layout, you'll probably not see tons of differences between browsers that you can't live with.

Maybe I'm not picky enough...

[LTinker68]

Some of the biggest differences will be in positioning and sizing. For instance, they have different default values for margins and padding on different tags. You might specify the width and height of a popup window and it'll look great in FF, but parts of it are cut off in IE because IE takes into account how much space the scrollbars might need, even if the content is too short to require scrollbars. So you then adjust the dimensions so that the popup looks fine in IE, but then you have extra spacing in the popup window in FF, but you decide it's better to have a bit too much padding than too little, so you live with the extra padding in FF.

[MC Hammer]

Thank you, Lisa, Kevin and Paul for your expert comments .
I have indeed noticed differences (mainly in positioning & sizing, as Lisa said), as well as image rendering differences (as far as transparency is concerned).
However, as Paul mentioned, most issues I can probably live with (Am I not picky enough too ??). It just requires being clever about things, for example using IE as a viewer to set up a popup window size (and know that there will probably be a bit too much padding in FF).
The thing that "annoys" me the most is the lack of support of IE6 towards PNG transparency. (I usually use GIFs but for some graphics, I would like a high res rendering and a nice Vista glossy effect, therefore I am using PNGs for these).

[KevinDAmery]

Hopefully by the time you need to migrate to webhelp IE6 will have gone the way of the 5.25" floppy.

[LTinker68]

The thing that "annoys" me the most is the lack of support of IE6 towards PNG transparency. (I usually use GIFs but for some graphics, I would like a high res rendering and a nice Vista glossy effect, therefore I am using PNGs for these).

The only way you're going to get that effect in IE6 is to not have a transparent PNG and save the image with a background color that matches your topic background color.