Subject: Re: Scrolling a Card?

[Ken Norris]

Hi Klaus,

> Date: Sat, 21 Feb 2004 11:57:44 +0100
> From: Klaus Major <klaus at major-k.de>
> Subject: Re: Scrolling a Card?

> Let me see if i get you right...
> 
> You are faking a group with separate scrollbar-objects?
-----------
Nope. The group has normal scrollbars (checked in Inspector for the group).
I'm faking a 'grab' of the content of the group by setting hScroll/vScroll
relative to mouseMove coordinates in a max/min bounding expression. You hold
down the mouse inside the card and 'grab' it (the fake, because a real grab
in Rev can't pass messages nor bound itself, and would end  up moving the
entire group, scrollbars and all, which is no good), move it in any
direction you want, but when it reaches the scroll limits, it wont go any
further in that direction. Since I'm setting hScroll/vScroll via mouseMove,
the scrollbars react like their supposed to, but that's not the
problem...read on.
---------
> Why does a goup with its v- and hscrollbar set to true does not work
> for you?
----------
It does...see above.
----------
> (I am still presuming a group as high/wide as a card...)
----------
The stack window, yes.

My expression moves the group and the scrollbars react OK, but it's causing
the contents to "scroll" like the scrollbars do, i.e., opposite the
direction you move the mouse instead of "grabbing" it and moving with the
mouse.

Does that help you to understand?

I can send you a SC project offlist that shows exactly what I want to do. SC
'grab' command allows message passing and rect bounds, very simple scripts
(I wish Rev had this feature).

I want to fine scroll an aerial photograph enlargement by grabbing it, but I
also want it to have scrollbars that react properly with the grab, which I
can do very easily in SC. I want a Windows method to do the same thing.

It's a normal thing with large maps. These aerials will have accompanying
object and property-line graphics which can be examined with the aerial in
multiple ways, i.e. measure distances from ground-truth controls, locate
underground utilities, scale grids, variable tints between certain objects
(making them stand out on the aerial), clickable objects which display
relevent ground photos (closeups) and accompanying data.

The state has closed a couple of their aerial photo departments due to
budget cuts. I figure I might be able to inch my way into a niche of that
market if I hurry. If I can come up with a couple demos county users and
private parties can run on their machines, maybe I can put together a
proposal to get $$ for modern data acquisition equipment and an appropriate
bird for the aerial platform.

Like this Leica system you might have heard of:
<http://www.lh-systems.com/products/aerial_cameras.html>

Ken N.