World: r3wp

I had another look at the scroller problem, and I'm beginning to 
see that it really does not work !
eg:

 == the scroll bar does not 'follow' the offset in the pane even when 
 its new position is calculated and set

        == does not seem to be anyway to adjust the size of the moving bar 
        itself. Unable to find any documentation.

 == even with calculating the length of the (sliding) form against 
 its (viewable) panel length, 
           the offset 'action' for TAB 

           is not consistent in that the last form field is not always viewable 
           by the tab action 

           -- seems to be dependent upon the relationship between form length 
           and panel size which you can adjust manually 

              but thats hardly a useful solution. When you add a field the whole 
              scroller stops working. ( Flaky !)
        == pretty disapointing really.


Whats needed is a scroller that can be defined to operate with any 
pane and automatically following the field tabbing
in that pane without coding required. "Follow the source --Luke!"

Heres the latest code effort !

;;======================================================
rebol ["cookbook-scroller-2-11.r"
       author "Brett Hallett 2008 "
	comment  { 

    Modified  cookbook-scroller.r program  to code automatic scrolling 
    of fields on TAB,

    allows the form to have fields off the viewable page and automatically 
    scroll up/down 
	   as the user leaves a field using TAB.

    -- display field position on TAB -- eg:  print  [ "f1 "  f1/offset] 
     ( for testing only !)

    -- scroll-panel-vert func modified with extra parameter  ( fields 
    y offset )

    -- compute offset value before calling scroll-panel-vert in out: 
    layout
	   -- move trace to func print-pos for easier modification
	  }
	 ]

 sub-panel: layout [  size 300x350
        across origin 0
        style label text bold right 60
        backcolor green
        h2 leaf "Scrolling Sub Panel" return

        label "Name:" f1: field       [ print-pos   "f1 " f1/offset   scroll-panel-vert 
        p1 s1 f1/offset/y ] return

        label "Email:" f2: field        [ print-pos   "f2 " f2/offset   scroll-panel-vert 
        p1 s1 f2/offset/y ] return

        label "Info:" f3: area 199x115 wrap  [ print-pos  "f3 " f3/offset 
          scroll-panel-vert p1 s1 f3/offset/y ] return
	

  label "More info: " f4: field   [ print-pos   "f4 " f4/offset   scroll-panel-vert 
  p1 s1 f4/offset/y ] return

 ;;  label "More info: " f41: field   [ print-pos   "f41 " f41/offset 
   scroll-panel-vert p1 s1 f41/offset/y ] return

  ;;label "More info: " f42: field   [ print-pos   "f42 " f42/offset 
    scroll-panel-vert p1 s1 f42/offset/y ] return

  label "Last  ;" f5: field [ print-pos   "f5 " f5/offset   scroll-panel-vert 
  p1 s1 0 
							print "write collected data"
							clear-fields sub-panel ] return 

 ;; notice how the  offset of zero is used to set the scroll position 
 to top of form on last field exit
	below
	pad 5
	below
    ]

btn-panel: layout [
        across
	 button "Submit" [ print "Press Submit "]
        button "Cancel" [ print "Quit" quit]
	]
	
main-form: layout [
        across
        h3 "Panel Scrolling Example" return
        space 0
        p1: box 	  300x250 coal frame black

        s1: scroller 16x250 [scroll-panel-vert p1 s1  ( s1/data * (max 0 
        p1/pane/size/y - p1/size/y))  ]
				;; compute offset value before calling scroll-panel-vert
        return
	  p2: box 300x50

    ]
 
print-pos: func [ fld pos ] [ print ["print-pos: "  fld  pos]]


;; scroll-panel-vert modified with extra parameter : fldoffset ( 
the y offset of the TAB'ded out of field )

scroll-panel-vert: func [pnl bar fldoffset][
	
	;; print [ "slider:" ( (max 0 p1/pane/size/y - pnl/size/y))]

        if fldoffset < ( (max 0 p1/pane/size/y - pnl/size/y))  [ pnl/pane/offset/y: 
        negate fldoffset ]
	
	;; print ["pnl-vert " pnl/pane/offset/y  fldoffset]
        show pnl

    ]

update-panel: func [pnl vbar  pnl2] [
        pnl/pane/offset: 0x0
        s1/data:  0
        vbar/redrag pnl/size/y / pnl/pane/size/y
        pnl2/pane/offset: 0x0
        show [pnl vbar pnl2]
    ]
   
    p1/pane: sub-panel
    p2/pane: btn-panel
   
    update-panel p1 s1  p2
  
    view main-form

;; ==========================

Hi guys. 

amacleod, I see the scroll-panel problem, will look into it shortly.

amacleod, the "selected text prevents scrolling in scroll-panel" 
problem is not the fault of scroll-panel.

demo-scroll-panel.r shows this problem because I didn't want to make 
it too complex, by including the necessary global event handler to 
handle scroll events on non-focused scrolling faces (such as scroll-panels). 
I do have a demo somewhere which has the necessary global event handler 
somewhere... at least style-gallery.r uses it.

Thanks Anton.

Are you developing specifically for Windows ? (I just found a bug 
in scroll-wheel-handler.r on linux.)

Just checked Style-Gallery.r. Yes, it scrols when high-lighted

For now!. Windows will surfice.

Ok, very good. :)

I thought I might try to analyse the Cyphre's tree + Anton's scroll-panel 
problem you spoke of before.
Did you just happen to make a minimal demo showing the problem ?

I got tree wiget to work but I had to include cypher's scroll panel 
as well. The problem with his slders not rendering I just realized 
was probably due to my not including his other stlyes he uses to 
raw the arrows etc.

Unless you mean to get tree widget to use your style it was just 
a nameing problem if i remembr correctly. 

I went with a different solution and I am no longer using tree widget 
for he app.

raw=draw

Ok, you've found another solution for now, but it's still interesting 
to me if there is a problem mixing styles from different authors. 
This 'should' (ought to) be possible without any conflict.

Anton, I'm looking at Style-Gallery...
Should I include "focus-on-down-event-handler.r" in my app? 

And what about "scroll-wheel-handler.r" Does this add functionality?

Yes and yes. They both bring benefits. Both are global handlers.

In style-gallery.r, if you go to Global Options / Handlers, you can 
enable / disable each of the global event handlers (by pressing a 
toggle button) to see the effect on the user interface dynamically.

I've just uploaded 
gui/demo-scroll-wheel-handler.r  and
gui/scroll-wheel-handler.r  is still there of course.

demo-scroll-wheel-handler.r  shows how to
- get and initialise the scroll-wheel-handler
- create and open your windows
- wait for events (VIEW does this)
- clean up the scroll-wheel-handler

do http://anton.wildit.net.au/rebol/gui/demo-scroll-wheel-handler.r

Anton, link to http://anton.wildit.net.au/rebol/gui/demo-scroll-area.r
is dead

I'm playing around with scroll-area. SET-FACE/NO-SHOW behaves like 
SET-FACE.

also no action block is available to run, as far as I can see.

is it possible to turn off the horizontal scroller?

Uploaded demo-scroll-area.r.

thanks

Let me check out horizontal scroller ...

I haven't programmed scrollers to be easily optional (though it's 
on to-do list).

ok. would it be possible to turn on wrap? for the area, so the scroller 
might ignore horizontal movement?

Have you tried setting wrap? already ?

I didn't yet study which face directly to set. I assume the text 
area is inside a pane?

Yes. (This is in scroll-area.r script header, at the top of the Notes..)

my-scroll-area/pane/1  or my-scroll-area/area/para/wrap?: true

Hmm.. it works, but there is an unwanted few pixels scroll when typing 
first line is wrapped.

Let me look why...

could it be made so that the hscroller is simply turned off for area/para/wrap? 
= true?

Hmm.. I just tried my-scroll-area/hscroll/show?: false, but as soon 
as you type, it is shown again... :)

it works nicely with BrianH's resizing system, BTW.

Good to hear.

I'm fixing the show code to respect face/show? for subfaces.

the blank area in the bottom right shows a default gray color. the 
color there should probably be none to respect the background.

Easy to change. (my-scroll-area/color: none)

I'll add it to todo... if it's not there already. There might be 
compositing errors visible when resizing or something... can't remember.

ok, thanks.

I'm going to resize the area to take advantage of space when any 
of the scrollers has show?: false

Bit complex... cogitation....

Updated scroll-area

load-thru/update http://anton.wildit.net.au/rebol/gui/scroll-area.r

do-thru/update http://anton.wildit.net.au/rebol/gui/demo-scroll-area.r

- scroll-area/color is now NONE by default to respect background.

- The horizontal/vertical scrollers are now optionally and dynamically 
visible/invisible.

  - New facets VSCROLL? and HSCROLL? have been added to facilitate 
  this.

  - When any scroller is not shown, the area resizes to take the extra 
  space.

anton i got a problem, it says user-prefs has no value

what is exactly user-prefs

hang on...

its in the demo