Re: DocumentHeight Question

Author

Message

Mark DeMichele

Posted: 07/02/2002 17:41:25

Well, that kind of fixes it, but then you have a lot of extra space

underneath. In my application, I'm stacking RichViews, so the extra space

is ugly and will probably be not acceptable to my customer.

I've been looking into it and I discovered a few things.

1. When you call TRVScroll.UpdateScrollBars from

TRichViewRVData.SetDocumentAreaSize you pass in YS based on the the

DocumentHeight.

2. In side UpdateScrollBars the ScrollPage is calculated from ClientHeight

and ScrollMax is calculated from the Passed in YS value that was based on

DocumentHeight.

3. Windows hides the scrollbars whenever ScrollMax < ScrollPage and shows

them when ScrollMax >= ScrollPage (the way I understand it).

4. In my code I set the ClientHeight = DocumentHeight, but when you step

through the code, you can see that afterwards ClientHeight and

DocumentHeight are not the same. Which means that you're calculating

ScrollMax and ScrollPage base on different things.

5. One thing that I noticed that if I removed the "+1" from call to

UpdateScrollBars in TRichViewRVData.SetDocumentAreaSize, it helped.

However, as you resize the width there are cases when the scroll bar will

show.

My experience tells me that this is not caused by roundoff error. It has

something to do with the fact that I set ClientHeight to DocumentHeight, but

after that's done the ClientHeight is not equal to the DocumentHeight. It's

wierd.

Any help would be appreciated.

Thanks,

Mark DeMichele

If you want I can probably slap together a simple test from to demonstrate

the problem.

"Sergey Tkachenko" <[email protected]> wrote in message

news:[email protected]...

> It is because of rounding off error. Vertical scrollbar unit is larger

than

> pixel.

> Add VSmallStep to height:

> RichViewEdit1.ClientHeight :=

> RichViewEdit1.DocumentHeight+RichViewEdit1.VSmallStep;

> Or just hide vertical scrollbar (VScrollVisible)

> > It says in the help that DocumentHeight includes TopMargin and

> BottomMargin.

> > However, if I size the Height of my RichView control to DocumentHeight,

> > seems that I need to add TopMargin and BottomMargin for it not to have

> > scrollbars. Sometimes I even need to add a couple of pixels to stop it

> > from scrolling. Why, I don't know.

> >

> > Mark DeMichele

> >