World: r4wp

strange characters

: You need to set /line-list of your VID widget to show it correctly.

Line-list ? What is it ?

layout [x: text "test"]
;update x/text with a long text
x/line-list: none
show x

it is a internal field to store text in VID widgets (its about word 
wrap I think)

Here is some info:
http://www.rebol.com/docs/view-face-object.html


A block that holds text line information. This block is created, 
updated, and used by the system to optimize the updating of text. 
When you modify large areas of text (greater than 200 characters) 
you should set this variable to zero to force the system to recompute 
the positions of all lines. If you do not, you may see garbage characters 
appearing within the text.

Not enough memory !

Something wrong here.

Try to WRITE to a file the text you read from the web, it might be 
VERY long?

I have restarted REBOL. The error has gone

However I use RebDB to retrieve the text and it returns an empty 
string

When I update the widget with the empty string weird characters appear 
!

Its better to set line-list to none for every update.

When I update the widget with the empty string weird characters appear 
!

Garbage chars may appear if you don't. Read the above note.

Either way, you set some long text, or clear it when there was some 
long text.

Tomoorw I'll try. Thanks for your help. Now it is time to go to BED

Ciao !

For me too :) Bye!

What does PATH function?

It's internal, exported as a side effect of it being an action, used 
as part of path evaluation. Don't use it.

Next level !

Any suggestion about creating a dynamic built GUI ? I whish to create 
a GUI from a Block of data, each data is a button and each button 
has an action attached to it.
Could you please point me to some code to analize?
Thanks in advance

Giuseppe, you can experiment by creating your gui code as a block 
and then "do" it. Then view it.
a: [layout [button "hi" [print "hello"]]]
b: do a
view b

http://onlamp.com/pub/a/onlamp/2003/10/30/rebol.html

BrianH: Thanks for the info. It corrupts when I try it on objects. 
And wierd effects on blocks.. I've added "unset 'path" to my rebol.r 
file, so I won't be confused anymore.

Let us know whether you find that it's safe to unset 'path and reuse 
it for other stuff. There's no reason to think that the action! mechanism 
would call the function through its name (that's more of an R3 intrinsics 
thing), but any unpredictable behavior you find would be good to 
know.

Gregg, a little difficult for me but I'll try to lear.

Keep asking questions Giuseppe. Dynamic GUIs is a big subject, so 
if you ask more specific questions, that makes it easier to craft 
small answers and examples.

Perhaps it helps to learn about the mechanisms: There are several 
ways to generate a dynamic UI:


The LAYOUT function works by creating an object tree, a tree of faces 
that are simply ordinary objects. When passing this to the VIEW function, 
a layout is displayed. The layout function is part of VID and is 
as such a high level function. VIEW is a low level function to interpret 
the face tree.


The face tree consists of objects that contain other objects through 
the FACE/PANE word. If the FACE/PANE contains an object, that object 
is a single face, that is displayed inside the parent face. If the 
PANE contains a block, that block may contain multiple objects that 
are simply multiple faces. As such, a typical window is a face with 
a FACE/PANE that is a block that contains other objects.


Graphically, the face is represented by a region on the screen that 
has the size and offset, possibly an effect, such as coloring, blur 
or mirroring or a text attached to it, and image or other faces that 
are only visible inside that region.

A window is also a face.


To navigate to the parent face from a face, use the FACE&/PARENT-FACE 
word. Note that FACE/PARENT-FACE is many times not set by VID, which 
is sometimes problematic.


You can manipulate the face tree by adding removing objects dynamically 
and calling the SHOW function. You can also change values in existing 
face objects in the tree, such as for resizing or moving the faces 
and then calling SHOW again. You can also build a face tree entirely 
by hand, and this is usually the starting point for different layout 
engines, such as RebGUI, that simply build face trees in their own 
way.


The prototype face is FACE, which is a minimum requirement face for 
the View engine. The prototype face for a VID face, which contains 
a few more words, is SYSTEM/VIEW/VID/VID-FACE, which is the minimum 
requirement face for VID.


One condition for the face tree is to not use the same object in 
multiple locations. The VIEW or SHOW function will return an error 
if that is the case.


A simpler way is also to generate a new face tree every time you 
want to change the layout. Although this is slightly more computationally 
heavy, it allows you to manipulate the block that was passed to the 
LAYOUT function instead of manipulating the face tree directly. This 
technique is best used, when the face tree changes dramatically by 
each manipulation.


Another important concept is the DRAW engine which is a separate 
entity in REBOL2. It can be called to draw on an image bitmap, using 
the DRAW function or as in effect for a face object, by adding a 
parameter in the VID dialect block or by changing the FACE/EFFECT 
word. DRAW is used by calling a dialect. if you just want to use 
fields, buttons and simple user interface designs, you may not need 
to use DRAW.

Very nice Henrik.

I should add that it is possible for FACE/PANE also to be a function. 
This makes the face into an iterated face, where using a loop, you 
can "stamp" the face in various positions during a single SHOW, making 
it possible to use one face  with different texts, sizes and offsets 
to produce a grid or a table.

Henrik: With your permission I write your text to my blog. Also I'll 
study it later

A question: I create a layout wiich has two button. I whish to add 
more buttons dynamically updating the layout. How could I do this 
?

GiuseppeC: Go ahead.

You can do this by adding the buttons to a panel and update the contents 
of this panel.


view/new layout [p: panel 500x500 []] ; start with an empty panel. 
note that VID does not support scrolling panels out-of-the-box. For 
this you need the VID Extension Kit.

append p/pane make get-style 'button [] ; you will need to adjust 
for offset here, otherwise the new phase will be placed on top of 
the old one.

do in last p/pane 'init ; you will need to initialize the face, which 
is the FACE/INIT block that resides in the face style definition. 
once the init block has been run, the face will set itself up and 
then you can show it

show p

This is just a simple version of what can be done.

To clear it again:

clear p
show p


If you want to do more than this, I think you need to use the VID 
Extension Kit, because you will be spending a lot of time managing 
scrollbars and panels. It has styles that are meant for this purpose.

Thanks Henrik, I'll do one things at time. This is starting to be 
difficult.

You might now begin to experience the VID learning curve turning 
into a wall. Suddenly you need to know a lot about its internals 
to do fairly trivial things.

I wrote another simple example as a one-liner, not useful in a real-world 
app. but gives an idea:


view f: layout/size [btn "add" [append f/pane layout/tight/offset 
[backcolor random white btn random "abcdef"] 50x50 + random 300x300 
show f]] 400x400

It actually adds new faces to the main face's pane, not the new styles. 
So, not a useful example. 
;no need to backcolor.. shorter:


view f: layout/size [btn "add" [append f/pane layout/tight/offset 
[btn random "abcdef"] 50x50 + random 300x300 show f]] 400x400

how to use trim/auto? it says "auto indents relative to first line" 
but;

>> print trim/auto ajoin [tab tab "test" newline "line 2"]
test     ;no indentation?
line 2  ;no indentation?

It removes as much whitespace from consecutive lines as it removes 
from the first:


>> print trim/auto ajoin [tab tab "test" newline tab tab tab "line 
2"]
test
    line 2

To be precise: It removes up to as much whitespace.

I see, thank you. So it actually does not auto indent relative to 
the first line:


>> print trim/auto ajoin [tab "  test" newline tab tab "line 2" newline 
tab "line 3"]
test
  line 2
line 3

If it's inserting whitespace according to the first line I'm afraid 
there isn't such functionality available out-of-the-box. And if there 
was, TRIM wouldn't probably be a good name for it, then ;-)

Anyways, I'll have a go with:

indent: funct [string [string!]] [
    whitespace: charset "^- "
    indention: line-start: content: none
    parse/all string [
        copy indention any whitespace 

        any [thru "^/" line-start: any whitespace content: (insert remove/part 
        line-start content indention) :content]
    ]
    string
]

>> print indent ajoin [tab "  test" newline tab tab "line 2" newline 
tab "line 3"]
      test
      line 2
      line 3

Or what else is it what you're wanting to do?

hah! I wrote something similar:

indent: func [s /local x] [parse/all s [x: (insert x "^-") any [thru 
newline x: (insert x "^-")]] s]

It's simple but it solves my issue.

Hello, all. I am new to REBOL4 and while having followed Lava to 
REBOL and looked through tutorials every year once a year for more 
than 10 years I have only recently began making an actual REBOL script.

I hope it is not rude to leave a question here as opposed to be here 
for the disucssion live, ala IRC. Please forgive me if so, and if 
so I will ask again when others are present. I will break down my 
script into smaller part questions as time goes on. First thing, 
I am under the impression that if I can generate a random number 
between 1 and 1 billion and assign this result to an aribtray variable 
word like so

token: random/secure 1000000000


I want to email my newly generated random number to someone. So I 
thought of this:

send [person-:-example-:-com] "Thank you. Your number is token."


One second later I realized that will just the send the actial word 
token, not the number the variabkle word token represents.

Is the above a correct way to generate a random number?


How do I insert that random number into the body of the text of an 
email to send someone? (send [person-:-example-:-com] "Thank you. Your 
number is [token]" maybe?)


 Thanks for your help in advance, apologies for any breach of rules 
 or etiquette. 
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