World: r3wp

Is there a document that describes each feature in view and all the 
options etch please?  e.g. for slider

So far I can find tutorials that mention some aspects of slider, 
but nothing complete.

etch=etc.

First, there needs to be a distinction between VID and View. View 
is the basic display engine, faces, feel. (lower level). VID is the 
layout dialect, styles, etc. (higher level)

With that in mind:

http://www.rebol.com/docs/view-system.html

so slider is part of VID?

yes and no. it's a VID face, which is a more complicated version 
of a face. You would typically lay it out with VID and you would 
use and manipulate it with View functions.

ok

You could create and manage a layout with View alone, but it would 
be a lot harder, since you have to specify faces manually. That's 
why VID was created.

? face

will show you a basic face.

? system/view/vid/vid-face

will show you a VID face.

I have not quite understood what a face is yet.

I quite like learning by going through command descriptions, but 
it seems tricky to find them with Rebol.

Perhaps I should try & write the ones I need in the Wiki?  It seems 
strange that slider is not documented anywhere.

Then there is also DRAW, which is another engine used in conjunction 
with View. In REBOL 2 it works as a slap-on solution to more complex 
drawing with anti-aliasing, etc. It also has a separate font rendering 
engine, but DRAW is close to useless for layout. It's best for pretty 
drawings, that do very little.


REBOL 2 generally suffers here with multiple overlapping solutions 
for slightly different purposes, so it can be a bit confusing. View 
and VID is probably the most hacked part of REBOL.


In REBOL 3, DRAW is the only engine combined with the concept of 
GOBs: Light weight graphical objects. There are now 3 wholly separate 
parts and that concept is much less confusing.

VID (and slider) is not very well documented.

If you do:

? face


you'll see that a face is a simple object. If you do something like:

f: make face []

view f


It'll display a gray area in the upper left corner of your screen. 
View simply takes that object and converts it into graphics.

With the above example, you are using View alone without VID.

That's about as fundamental you can get. Now, a more complex layout 
consists of many faces and this works by grouping them in a tree 
of objects.


In the FACE object, there is an entry called PARENT-FACE, which is 
how faces are grouped together in a tree. PARENT-FACE can be another 
face object or a block of face objects.


This is fundamentally how a typical View layout works, and you can 
build a layout like this by hand, by creating each face, setting 
position and size, color, text, etc. for each face, and put them 
together in a tree and display them with View.

I see the grey square...  and I probed f too to see how the object 
is made..

I'm sure you can now figure out, that if you did something like:

f: make face [offset: 100x100 size: 200x200]

You can figure out what happens. :-)

I can guess, but I need to know how to know for sure.

I think I can work it out

? f shows offest    & ? f/offset shows F/OFFSET is a pair of value: 
479x202
I guess that is as much as I can find out about offset?

yes, offset is just a pair which positions the upper left corner 
of the face. nothing else.

so I suppose the slider must have some exposed face I could find 
if I keep hunting

it's jumping a little far, but essentially the face tree I talked 
about is where the slider would be.

if you make a layout with VID, a set-word! would allow you to reference 
a single face:

view layout [
	button
	field
	s: slider
]

escape to console

? s

brings up the slider face.

is there a list of documented featurs so I can try to avoid using 
the undocumented ones like Slider please?

Or is the graphics stuff really an experimental addon?

It's not experimental, but just not very well documented. I suggest 
you try the VID style tree in the REBOL desktop under REBOL/REBOL 
Tools.

It dosnt work.  it just says
missing file
http://www.codeconscious.com/rebsite/vid-ancestry.r

It works fine here in REBOL/View 2.7.6.

are you connected in the lower left corner?

REBOL/View 2.7.6.3.1

it says local.

Click the "local" text and it will connect and allow you to download 
the script.

In that script you can see the style tree, all styles available in 
VID. Click on the style will give you the source code for that style.

That is very good... I was wondering if there was a tree type view 
of some of the functions in Rebol.

After this, probably go to Demos and Easy VID, for a simple VID tutorial 
(unfortunately it was never completed, but it has good parts)

Thanks for your help again :-)  I can see I could spend hours looking 
at the tree view alone...

I had a quick look at the view top when I first instaleld it, but 
it was all too advance for me then, and then I forgot that it existed.

I have studied all the information about VID that I can find, for 
2 hours mostly trying to find out how to use a slider that is shown 
horizontaly, rather than verticaly but I cant find where this is 
described.  Have deliberatly not asked how I do this because I want 
to learn how to find the answers to these sorts of questions myself.. 
Without telling me the answer directly, can anyone suggest how I 
should learn to find this information for myself please?

there is another VID base doc, simpler, might help you start.

http://www.rebol.com/docs/view-guide.html

honestly, I literaly learned all of the VID tricks my doing this:

probe face

where face is any face you have setup in a layout.

ex: 

layout [
	my-btn: btn "ok"
]

probe my-btn

I still use this quite often.

I'd say learning to build new styles with the stylesheet system is 
the first big boost in productivity.  this will inevitably leed to 
you wondering how you can change this or that, and then by probing 
the face and looking at its code, you see that some values are being 
reset in the event handler... which is quite annoying.


the seconf big boost is to try and understand the event system.  
the view reference link that henrik gave you earlier is the best 
resource online.

and rebol, as a language is extremely easy to search on the net... 
you start any search on google with the word REBOL  and you'll end 
up with mailing list chats, altme pages, scripts on rebol.org, etc.

It seems too complex to get started... the examples seem to jump 
from childishly simple, right to very hard, with no middle ground.

did you look at the view guide?

(not the reference)

which one was that?  I am confused by so many sources of information.

http://www.rebol.com/docs/view-guide.html