World: r3wp

Gabriele, I do following:

copy-dir: func [from to][recursive copying function here]
copy-screen: layout [layout of screen code here]

forever [ if new drive is detected and contains particular directory, 
view copy-screen, which should start copy-dir function]


.... somehow can't get it working properly. View/new can't help me 
here imo ....

Gabriele - how could I do it with view/new? I can't start copying 
after it, because I want to update screen. I can show some elements, 
but e.g. buttons will not be active, unless do-events is being run. 
That is why I complicated my script by implementing "delayed" copying 
= view copy-screen, there is an 'init style with rate 1 and engage 
defined. I check if it is a first run, and if so, I set rate to none, 
call show, and that is the place from  where I call my copy-dir function 
.....

petr, if copy is running, events are not processed, no matter how 
many do-events you put there

you have to do view/new, then inside copy-dir you need to call wait 
0 every now and then (eg. every file you copy) if you need your buttons 
to work.

even if you call copy-dir from engage, events are not processed while 
inside copy-dir unless you call wait

ah, so wait 0 causes processing of events?

those that are pending, yes. you can wait a little more to allow 
more to be processed, if you don't care about slowing down your copy.

How are you detecting the the disk being inserted. Are you accessing 
the os. Also, would this work for flash disks?

yes, it works ...

it is very simple principle ... well, it is not even a detection. 
When my script runs in the background, it does:

root: %/
drives: read root

later on, I simply check:

forever [
  wait interval
    foreach disk difference read root drives [
    ]
]

... and difference on block will throw you new disk ....

That seems simple. I wanted to create an auto cd burner. That routine 
would help!

can I somehow have layout defined in the manner, that I can:


1) reinitialise it (I can imagine something like store-screen: [copy-dir-screen: 
layout []] do store-screen

2) how can I "unset" it, "uload" it, whatever, to be able to reset 
all its words?

like this?
window: func [param1 param2 param3 ..][
	layout compose/deep [btn "Exit" [unview face/parent-face]
]

Thanks, that might work, but not sure it is what I want. Maybe I 
don't need it, so here come further questions:

- I want to run infinite loop script
- I want small screen to be displayed during copy

- I want to keep memory low, so I want to "unload" all screen related 
objects from memory


Now - is that possible? With above wrapping function, by calling 
it, I can get new/fresh layout, so variables being reinitialised. 
But when the copying is done, can I remove objects defined by layout 
from memory? Unsetting 'window will just unset the function, but 
I am not sure it following would help?

window: does [copy-screen: center face layout []]
forever [
view/new window
copy-dir
unview copy-screen

unset 'copy-screen (and other VID defined words referring to styles)
recycle
]

?

hmm, above does not free any significant memory ....

Pekr;  This is in free-mem.r from the library by DocKimbel and Shadwolf...I 
haven't played with it, and I don't know if it's any better than 
unset with newer REBOLs
; the free mem function
free-mem: func ['word] [set :word make none! recycle]

unset in 2.7.5.4.2 frees memory,  1.3.2.4.2 unset does not but make 
none! 0 does lower system/stats on a recycle.   I think make none! 
2000'000'000 will work too, but that seems kinda funky.  :)

What would be the best strategy to take, to achieve following? Imagine 
app with say 20 forms. It is insane and unnecessary to keep everything 
in memory. We should have even option to prevent tabs from doing 
so.


So I am thinking of a method to load/unload screens (forms), but 
freeing a memory. Of course you want to remember the state of widgets. 
So - can I somehow save the form, state of its widgets, unload it 
from memory, and load and reinitialise it at will?

memory is cheap

:-)

That might be a solution :-)

what I am asking for though, is kind of cocneptual aproach to the 
topic, if you would think memory constrained environments for e.g. 
Just curious, what the possible aproach could be ....

other than that, I do agree with your argument :-)

how about defining the layouts and widget variables inside a function?

I do that a lot

Pekr: i normally create view objects by using a func - but GC doesnt 
handle things very well with multiple calls to the same func :(

If you're memory constrained, I wouldn't use VID!

That is my question in Core group - does function call, once finished, 
discard its context? If not, you will not save memory either. You 
would have to unset your func, recycle, and define it later once 
again ...

Graham - I am curious what will happen after R3 release. Theoretically, 
we should get VID more memory savy. I wonder if there will still 
be place for RebGUI (my opinion is - why not, right?)

If you are *really* constrained, create your UI with draw commands 
and manage events and everything yourself. Of course, you may end 
up with so much more code that it's a moot point, so it depends on 
what constraints you have. 


It reminds me of when VB1 came out, and people tried to use thousands 
of text boxes to create spreadsheets, which was slow, resource hungry, 
and limited in size, because you could only create so many windows. 
The common question was "How does Excel do it then?", and the answer 
was that Excel (v3 at the time I thnk) created only 3 (or so) actual 
GDI windows, everything else was rendered, and interaction handled, 
dynamically

If you are really, really constrained, use a wrapper around the native 
GUI controls for your platform, carefully. Only cell phones and other 
embedded platforms are that constrained though.

Thanks for your input guys. I am not constrained that much. Our kiosk 
PCs do have 256MB of memory, being older PCs, some Duron 1.2 or so, 
WinXP. It runs presentation in full mode, local Apache based. Plenty 
of photos, simply kiosk presenation, not ordinary web pages. Dunno 
how IE is memory hungry. My script, which will run in background, 
easily eats some 39MB memory. I did some unsets, recycles, so while 
in wait mode, script goes down to some 24MB. It is that I was just 
curious how to aproach that ...

Carl once said "View is miserly, saving pennies, while VID is like 
the government, spending millions".

Hi, I'm trying to visualize data I get from a network port within 
a view window. IIRC using wait within a view handler is greatly discouraged 
(and my first tests seem to show it: the window is updated for the 
first info, but the updates stop after the second, or so. )
So, how do I connect to a tcp port from within /View?

depending on your display needs you could set a rate in a view face 
for interval polling and catch the 'time event under engage - the 
application could then check a data pool/dump area that is being 
generated in a forever loop or something similar by a tcp watcher

Hi ICarii ... what do you mean? Having 2 rebol instances, one that 
listens on tcp and creates a file, which is then read by the other, 
and used for display?

data-i-want-to-display: [..............] ;probably a block
window: layout/tight [
	data-box: box 400x200 rate 0:00:0.001 feel [
		engage: func [f a e][

   if a = 'time [do-something-nifty data-i-want-to-display show f]
		]
	]
]
view/new center-face window
setup-port-listener
forever [
	check-my-port-and-update data-i-want-to-display

 ;add some window shutdown code to close ports etc after window closes..
]

but change the rate in the layout to whatever interval you desire 
for precision

make sure there is also some form of wait inside the forever loop 
or it will thrash about and not release any breathing room for view. 
 A wait of 0.001 typically takes processor usage from 100% to 1% 
as well.  Wait 0 inside a forever loop seems to stick at 100%.  Your 
mileage may vary ;)

Ahhh, thank you. I'll try that next. And thanks for the wait timings, 
I'll try it out.

Has anyone developed any code for a text field that can keep a history 
of previously entered values?

I have built an enhanced text field, that does not have this capability, 
but it would be nice to have it.

I know I saw that! I was thinking of just  using yours and adding 
that with the key action. BTW, the new List-View is great.

feel free to mess around with it. :-)

Well, I just saw list-view get updated with the mysql data. How cool.

the new list-view is great
? is there a new version available?

I just saw list-view get updated with the mysql data
? Is there some mysql interface now in list-view?

it supports object lists now. mysql views, I think he means that 
output from mysql-protocol.r fits in list-view.

I've been using list-view with mysql-protocol for a while but the 
method I use to move data back and forth between mysql data and the 
list-view is not very elegant. Are there any examples of how object 
lists..mysql views work with list-view?