World: r3wp

Anton's made a version that has undo/redo, right?

You can copy the code from the default engage function, but you will 
fall into a trap; some of the words used in the default engage handler 
are bound to specific contexts. Your code will bind all the words 
in your context or global context. I'm talking about the words focal-face 
(which is in system/view), unlight-text, highlight-start, highlight-end 
and edit-text (which are in ctx-text).

So you should bind your code first to system/view, then to ctx-text, 
before making the function:

style my-field field feel [
	engage: func [face action event] bind bind [

		; your code which uses focal-face, unlight-text etc...

	] system/view ctx-text
]

Ok, just found some mention of ctx-text in the docs.

Henrik, unlimited undo/redo.

probably a good idea to learn about bindings first to know what it 
means :-)

My edit-panel style is actually based on PANEL style, but pretty 
much supplants AREA, if you're happy with monospace font. (I haven't 
supported a single-line FIELD-like style, but could be easily done 
I expect.)

See the Editors group to try out the edit-panel style.

One other funcionality I'm missing is to be able to set the tab order 
! They won't always be the presented order.
And wether CR should act a sTAB or not.

Aha... the built-in tab-cycling system is simplistic. I made my own 
but it still goes in pane order.

whether CR can act as tab can be determined with a face flag.

Ok thanks, Tab order might be cobbled by enlosing field in two or 
more vertical panels. Sorry missed the flag for CR.

layout [f: field] probe f/flags ; == [field return tabbed on-unfocus 
input]
view layout [f: field with [deflag-face self return]]

AREA does not have the 'return flag.
probe svv/vid-styles/area/flags ; == [tabbed on-unfocus input]

whats svv ?

You could also handle key events and trap the tab key, directing 
the focus to any face you like.

system/view/vid

A very handy shortcut.

ah thanks

view layout [field feel [insert body: second :engage bind [if all 
[act = 'key event/key = tab][focus f3 exit]] body/2] field f3: field 
"This is f3"]

I knew all this was possible, and I know a lot of people prefer things 
at this level to cover their own requirement.


But, returning to my original point. To make Rebol more general use 
- we need standard behaviour like this at a highr level?

absolutely. VID3 will not require this level of knowledge to produce 
something useful and complete.

I agree too.

Thanks Anton - what I was missing in my efforts last night was the 
'exit' that obviously releases the event. I was getting frustrated 
cos it just sits there doing nothing ;-)

Yeah I forgot it first time around too.

So with the 'all'  'exit' combination you are handling any events 
(keypresses) you like in a form of 'switch' ?

if all the following conditions are true:
	- the act (action, same 
as event/type) = 'key (and not 'down, 'up mouse presses etc.)
	- 
the event/key = tab (the tab character)
then:
	focus a face
	exit

I've inserted that at the top of the function body, so if we handle 
the tab char key event, then we exit and it doesn't have a chance 
to be handled by the rest of the default code (which actually calls 
upon the large edit-text function from ctx-text to handle key events).

With 'ALL' and 'ANY'  - in parse you also have 'SOME'.  If you do 
'exit' does it exit the event trap or can it move onto another event?

The parse dialect words 'all' and 'any' are not the same as normal 
rebol 'all' and 'any'. Don't get confused by that.

We're not using parse here.

Got it!

(Note that the above example where I set 'body is a bit "polluting". 
It sets the 'body word global. It's not strictly necessary, you can 
just replace body/2 with second second :engage. I just added it to 
make the meaning clearer.)

I wondered if the Rebol versions ended up becoming a lower-level 
parse.

Mmm.. I don't think so...

So, can we have one engage that can act upon more than one event? 
I think that's my question!

Of course. Which events ?

My example shows how to inject any code you like.

Ah, you wanted to filter out non-number characters, etc ?

yeah just exit when not find "0123456789" event/key

Yes, on a particular field I want to control what the user can and 
can't enter

On one field I want to trap and convert any chars to uppercase, but 
also stopthe user from antering more than say 5 chars !

either 5 > length? face/text [
	; allow event to pass through
][
	exit ; too many chars ! don't allow it !
]

or combining filter with length check:
if any [
	not find "0123...89" event/key
	5 <= length? face/text
][
	exit
]

Yeah I was trying to approach it with ( if chars < 6 allow it ) which 
got me in a mess.

I'm sorry for all these questions - It sounds like I want you to 
do my work for me! I don't maind having to figure some things out 
myself . But I was asked to present waht I found difficult from a 
newbie point of view.

you're lucky to have us around, otherwise some of this would take 
a long time to figure out. I was frustrated for a long time about 
many of these things.

Very True, hopefully I will be able give back - in time

particularly bindings can be baffling, because it looks like function 
names are pulled out of thin air. :-)