ws0n+@andrew.cmu.edu (Walter Ray Smith) (04/26/88)
> *Excerpts from: 22-Apr-88 Re: MultiFinder switch bug .. Alexander* > *Rosenberg@ucsc (1134)* > What's the deal with scroll bars? When they CDEF got updated to work with > the new control manager color support, why didn't it also get the variable > elevator sizing as found on the //gs and GEM? (sorry to say that, but it > has it and we don't...) How do you propose to do that?! Variable elevator sizing requires some idea of the size of the visible area relative to the view size--the scroll bar has to have four parameters. The Control Manager dictates that each control has a min, a max, and a value--three parameters. You could make a new control with some hack to get the elevator size into it, but I don't see how you could retrofit that functionality into CDEF 1. How would you get the applications to tell you how big to make the elevator? - Walt
alibaba@ucscb.UCSC.EDU (Alexander M. Rosenberg) (04/26/88)
This is really neat. Think of the following: ratioBits := (sBarTop.Y-sBarBot.Y)/ABS(sBarMax-sBarMin) value := ratioBits * (sBarTop.Y-sBarBot.Y) (This is all from memory, so I may be mesing it all up....) value is the height in pixels of a scroll bar "page". This is also the elevator height. QED. (Again, I think that this is wrong, but I don't got time now to look it up, ST:TNG is starting...) ------------------------------------------------------------------------------- - Alexander M. Rosenberg - INTERNET: alibaba@ucscb.ucsc.edu - Yoyodyne - - Crown College, UCSC - UUCP:...!ucbvax!ucscc!ucscb!alibaba- Propulsion - - Santa Cruz, CA 95064 - BITNET:alibaba%ucscb@ucscc.BITNET - Systems - - (408) 426-8869 - Disclaimer: Nobody is my employer - :-) - - - so nobody cares what I say. - -
ws0n+@andrew.cmu.edu (Walter Ray Smith) (04/28/88)
> *Excerpts from: 26-Apr-88 Re: Variable-sized elevators Alexander* > *Rosenberg@ucsc (881)* > ratioBits := (sBarTop.Y-sBarBot.Y)/ABS(sBarMax-sBarMin) > value := ratioBits * (sBarTop.Y-sBarBot.Y) You're assuming that the programmer is using view y-coordinates as the scroll bar limits. That's a bad assumption. It will work occasionally, but when it doesn't work, it will be awfully confusing. For example, it won't work in most word processing programs--if their scroll bars worked that way, they could only edit 80-page documents (65536 pixels long)... But go ahead and do it; it will be interesting, at least. You could paste it into applications where it worked, and leave the rest alone. - Walt
oster@dewey.soe.berkeley.edu (David Phillip Oster) (04/30/88)
Variable sized elevators can be built into any program you write, but they
will not work in general if you just make a new CDEF and paste it into
an arbitrary program.
Certainly, you can't expect it to work if you paste it into one of my text
editors:
1.) the scrollbar counts lines.
2.) because of multiple font sizes, the lines are variable widths
here is an example:
suppose that I have a file consisting of
1 line of 72 point font followed by
20 lines of 6 point font
if I scroll off the first line, then all the remaining lines fit in the
window, so my CtlMax is 1. But, that one line may keep 5 lines from
showing.
The part of the document that is visible if it is showing is
(72+15*6) / (72+20*6) = 0.8.. of the whole document
so I expect the elevator to show me
that. The CDEF has no idea that I am scrolling a collection of variable
sized objects, so it certainly can't know about my 0.8 unless I
tell it. In my own program, I can easily extend my controls to have more
data, and add a SetCtlThumbWidth() and GetCtlThumbWidth(), but in general,
anyone pasting into my programs is in for a surprise.
--- David Phillip Oster --When you asked me to live in sin with you
Arpa: oster@dewey.soe.berkeley.edu --I didn't know you meant sloth.
Uucp: {uwvax,decvax,ihnp4}!ucbvax!oster%dewey.soe.berkeley.edualibaba@ucscb.UCSC.EDU (Alexander M. Rosenberg) (05/01/88)
Yes, I did realize this later, as I thought about the Integer limit on the values. How is this for an idea: Either use a pair of procedures/functions to let the program do the calculation, or, use the RefCon value as a handle to a secondary record, containing settable values for the eleator height, and allow for future expansion? Also, I am thinking of writing a CDEF that looks like the new OPEN LOOK scroll bars. They are fantastic! The changes are logical, although deep consideration of certain elements must be made, as always. I have only seen them in like Infoworld or MacWeek, and not actually clicked on them, but I like the idea of a cluster that moves, instead of a seperate set of controls. (of course, the cluster should size to the page height, as I think all scroll bars should... If I make that improvement, do you think it is significantly different enough??? I would just use the cluster concept, which cannot possibbly be patented by now...) Ideas? Words of encouragment? A job? ------------------------------------------------------------------------------- - Alexander M. Rosenberg - INTERNET: alibaba@ucscb.ucsc.edu - Yoyodyne - - Crown College, UCSC - UUCP:...!ucbvax!ucscc!ucscb!alibaba- Propulsion - - Santa Cruz, CA 95064 - BITNET:alibaba%ucscb@ucscc.BITNET - Systems - - (408) 426-8869 - Disclaimer: Nobody is my employer - :-) - - - so nobody cares what I say. - -