World: r3wp

I have a question WRT changing the text of a shown label. I use a 
way where the layout of my GUI is done at startup-time once. Now 
I need to change the text of some labels at run-time and I don't 
want to do the following:
	- name each label that needs to be updated.

 - write a function that changes the TEXT word and shows the widget


I would like to use a word in the initial context that keeps a reference 
to the text (or function returning the text) which gets reevaluated 
if a SHOW is used.


Do I have to write an own style that supports this or is there a 
simpler way?

an easy way is to keep all labels in a panel and then traverse the 
pane and set the label texts on a label.

if your panel consists of multiple different types of faces, you 
can filter on 'style

How about this:

data: ["hello" "there" "robert"]

spec: copy []
foreach string data [
	append spec compose [label 100 (string)]
]

view window: layout append spec [
	btn "change original strings" [
		insert clear data/1 "happy"
		insert clear data/2 "to be"
		insert clear data/3 "changed"
		show window
	]
]

You have to make sure the initial labels are large enough for your 
longest strings. Of course we can stylize label so that it resizes 
automatically, but maybe you don't need that.

Henrik's way can be helped using SET-FACE, I think. (I haven't used 
this feature yet.)
Have a look in svv/vid-styles/panel/access 'set-face*

Anton, ah the insert clear method... I missed this one. I think that's 
the way to go. I'll check this out. Thanks.

Hmm... one more. Let's I have:
	label-text: "The current value is ?"

and I know want to change the ? dynamically. After first replacement 
the ? is gone. So I need some way to keep the source version. Or 
first insert the source version, than replace and show.

Oh man... to many typos (I cut my right finger):
- Let's say I have
- know = now

; Something like this maybe?

REBOL []

texts: [
    EN [
       lbl-1 "Hello"
       lbl-2 "Goodbye"
    ]
    DE [
       lbl-1 "Hallo"
       lbl-2 "Aufwiedersehen"
    ]
]

lang: 'EN
res: func [id] [texts/:lang/:id]

good-ID?: func [id] [find texts/:lang id]

has-res-ID?: func [face] [
    all [
        find first face 'res-ID
        word? face/res-ID
        good-ID? face/res-ID
    ]
]

re-show: func [face] [
    foreach f face/pane [
        if has-res-ID? f [
            set-face f res f/res-ID
        ]    
    ]
    show face
] 


lay: layout [
    text 100 with [res-ID: 'lbl-1]
    text 100 with [res-ID: 'lbl-2]
    btn "English" [lang: 'EN  re-show lay]
    btn "Deutsch" [lang: 'DE  re-show lay]
]

re-show lay
view lay

tr "Rp/US$:" exchange-rate: field 270x24 feel [
            exchange-rate/text: exchange-rat
            show exchange-rate
        ]


The above code loads exchange-rat into exchange-rate/text when the 
script loads.  But after saving data it appears to be empty. How 
can exchange-rate/text be forced to persistently show its contents?

I changed it to this:

        tr "Rp/US$:" exchange-rate: field 270x24 

        feel [exchange-rate/text: exchange-rat: (read %exchange-rate.txt)
            show exchange-rate 
            (write %exchange-rate.txt exchange-rat) 
        ]

But it still doesn't work.

What I want is:


1. The exchange rate to be saved in a file, so that it will always 
be loaded upon start the script.

2. The exchange rate to remain in the field through each loop of 
view.

3. And, of course, I want to be able to change the exchange rate 
if needed.


Seems like it should be a common easy thing to do, but it eludes 
me.

Perhaps it would be clearer to say that I don't want to have to manually 
enter the exchange rate for each record.

Louis, I haven't been following this problem but if you want to just 
load a rate from a text file you could do something like this which 
handles loading before showing the face and allows saving an updated 
rate 

REBOL []

these-styles: stylize [
	lab: label  60x20 right bold middle font-size 11
    fld: field  60x20 font-size 11 middle edge [size: 1x1]
]

    rate-file: %/c/rate-file.txt
    if not exists? rate-file [write rate-file 1.000]    
    rate: load rate-file

view layout [
    across
    styles these-styles
    lab "Rate"    rate-field: fld bold (form rate) return
    btn "Save" #"^s" [save rate-file form rate-field/text]
]

If you want to keep the update function out of this script, it is 
simple to just use the REBOL editor to update the rate via 

btn "Editor" #"^e" [editor rate-file]

But make the rate field read only.

MikeL, thanks! I'm testing to see if this does what I need. I'll 
report back.

Robert, try this:

data: [
	"name: ?" "name: Robert" 
	"age: ?" "age: unknown" 
	"occupation: ?" "occupation: programmer"
]

spec: copy []
foreach [format string] data [
	append spec compose [label 100 (string)]
]

view window: layout append spec [
	btn "change original strings" [
		insert clear data/2 replace copy data/1 "?" "Anton"
		insert clear data/4 replace copy data/3 "?" "31"
		insert clear data/6 replace copy data/5 "?" "rebol surgeon"
		show window
	]
]

rebol []
either exists? %exchange-rate.txt [
    exchange-rat: load %exchange-rate.txt
][
    save %exchange-rate.txt 1
    exchange-rat: load %exchange-rate.txt
]
exchange-rate-style: stylize [
    exchange-rate-label: label  60x20 right bold middle
    exchange-rate-field: field  270x24 middle
]
view layout [
    styles exchange-rate-style

    exchange-rate-label "Rp/US$:" exchange-rate: exchange-rate-field 
    bold (form exchange-rat)
    button "Save" [
        save %exchange-rate.txt exchange-rate/text
    ]
]


The above code works in the above test script (mimics MikeL's script); 
but in my accounting script it yields and error message: 

** Script Error: val needs a value
** Where: forskip
** Near: forall args [
    val: first args
    switch/default type?/word val [
        pair! [append pairs val]
        integer...
>>

and = an

I just cut and pasted the code from my accounting script into the 
test script above.

In my accounting script, however, some of the code is separated by 
other code. Could that be the problem?

By the way, thanks MikeL. This is what I am wanting.

Ok, I've traced the problem to 'clear-fields. How can I protect this 
particular field so that it is not cleared by 'clear-fields with 
all the rest of the fields upon save?

rebol []

either all [exists? %exchange-rate.txt "" <> read %exchange-rate.txt][
    exchange-rat: read %exchange-rate.txt
][
    write %exchange-rate.txt 1
    exchange-rat: read %exchange-rate.txt
]
exchange-rate-style: stylize [
    exchange-rate-label: label  60x20 
    exchange-rate-field: field  50x24
    note-label: label 55x20
    Note-field: field 55x55
]
test: layout [
    styles exchange-rate-style
    note-label "Notes:" notes: note-field bold 

    exchange-rate-label "Rp/US$:" exchange-rate: exchange-rate-field 
    bold (form exchange-rat)
    button "Save" [
        exchange-rat: exchange-rate/text
        write %exchange-rate.txt exchange-rate/text

        ;clear-fields test show test ;<=========<< UNCOMMENT THIS LINE TO 
        SEE THE PROBLEM.

        ;Needed: for the Notes field to clear on each save, but the exchange-rate 
        field to persist.
    ]
]
view/options  test [resize]

Please View experts come to my rescue!

You could replace the clear-fields line with this line:
Notes/text: copy "" show notes
Thus just clearing the notes field rather than all fields.

this includes a lot of redundant code

either all [exists? %exchange-rate.txt "" <> read %exchange-rate.txt][
    exchange-rat: read %exchange-rate.txt
][
    write %exchange-rate.txt 1
    exchange-rat: read %exchange-rate.txt
]

if not all [exists? %exchange-rate.txt "" <> exchange-rat: read %exchange-rate.txt][
    write %exchange-rate.txt "1"
    exchange-rat: "1"
]

if not all [exists? %exchange-rate.txt "" <> exchange-rat: read %exchange-rate.txt][
    write %exchange-rate.txt  exchange-rat: "1"
]

is a little shorter again

Sunanda and Graham, many thanks. Slowly but surely my script is better 
and better. The REBOL solution is almost always much easier than 
I thought. Thanks again!

Ok, I have 61 out of 63 fields to clear, so it would be a lot easier 
to deal with those two that don't have to be cleared than to deal 
with the 61 that must be. So I propose a modification to the clear-fields 
function: Here is the source:

clear-fields: func [
    "Clear all text fields faces of a layout."
    panel [object!]
][
    if not all [in panel 'type panel/type = 'face] [exit]
    unfocus
    foreach face panel/pane [
        if all [series? face/text flag-face? face field] [
            clear face/text
            face/line-list: none
        ]
    ]
]

I would just like to put the panes I don't want to be cleared into 
a block; all the rest would be cleared.

I think I can do this, but it would probably be better for you experts 
to come up with something really simple and elegant  that can be 
submitted to RT for Rebol 3.

It is just logical that this function has such a refinement.

Oh, the source above is what needs to be modified, not my modification. 
The only reason I posted it is to show how simple it is, and therefore 
how easy it should be to add a refinement to it.

It would be logical to call the refinement /except:

/except "Block of fields not to clear."

I''m working on this myself. My first question: How can evaluation 
be based on the name of a field, and thus not on the contents of 
the field? If the name of the field is this then do that.

Does this do what you want?

clear-fields: func [
    "Clear all text fields faces of a layout."
    panel [object!]
    /except exceptions [block!]
][
    if not all [in panel 'type panel/type = 'face] [exit]
    unfocus
    if not block? exceptions [exceptions: copy []]
    exceptions: reduce exceptions
    foreach face panel/pane [

       if all [series? face/text flag-face? face field not find exceptions 
       face] [
             clear face/text
             face/line-list: none
             show face
         ]
      
    ]
]

;; test/ example
l-o: layout [
     a: field "A" b: field "B" c: field "C"
     button "clear c" [
         clear-fields/except l-o [a b]
         ]
     button "clear a" [
         clear-fields/except l-o [b c]
         ]
     ]

unview/all
view l-o

Sunanda, thanks! That works perfectly. Your refinement made what 
would have been a big job into a minor task that took only a few 
seconds. In my opinion, this refinement definately needs to be in 
Rebol 3. I will make newbies much happier.

What is the best way to submit this to RT?

By the way, Allen Kamp sent me the same refinement code as Sunanda. 
Thanks to you also, Allen!

Louis, just catching up with your post back on Monday, I wanted to 
say that it's a bit odd to use the FEEL to do init code. It's not 
really intended for that. A way to do custom init code is like this:
	layout [
		field with [
			append init [
				; custom init code here
				text: exchange-rat
			]
		]
	]

and in the above case, just setting the text facet, it simplifies 
to:
	layout [
		field (exchange-rat)
	]

Thanks. I like things to be simple. By the way, I just  looked at 
your styles gallery. Very nice, and gives me examples to do things 
I need to do.

anton, the style gallery still doesn't work. I get the same include 
errors as yesterday.

http://www.lexicon.net/antonr/rebol/patch/ctx-text-next-field-patch.r
<--- link is dead

which is one of the first includes