VID questions

Best way to do it, in my opinion. :-)

To specifically find the words in the VID dialect: probe system/view/vid/vid-words

There are several methods that I've seen proposed. The one I use the most is simply perusing the source. If I recall, the way to peruse /View source is through a text printout like so: ;boot to the console mode of /view echo %view-vid-1.2.txt print mold system/view echo none This method was adapted from Larry Palmiter. Then read to your heart's delight. To specifically find text-list, search for that word. Some faces' words are sprinkled through-out, so searching for the case-constrained name is better, like TEXT for text face.

these VID

Almost too many to mention.;-) These are the two official ones: http://www.rebol.com/docs/easy-vid.html http://www.rebol.com/docs/view-guide.html

in the

I understand what you mean, kind of like the pack command in Tcl, etc. You may need to undergo a small paradigm shift. In this case, 'view is a function that displays the initial face layout. It kicks it off, so to speak. Later, after modifying faces in a layout, 'show allows *just* that face to be updated. It is more processing-efficient than going through 'view again.

Yes, actually there have been several, but I can't find any of them. If no one else answers this message thread, consider reasking this specific question again.

Here is one way: view layout [ across text "Name:" 100x24 right field "Your name" return text "Address:" 100x24 right field "Your address" return ] This was borrowed from one fof the references mentioned above. There are other ways, of course.

Robert Collect and submit: that's the "name of the game." Good luck, Robert. --Scott Jones

It's only the beginning for a browser. Anton.

/View

; This will list the styles extract system/view/vid/vid-styles 2

source for

text-list is for making a simple iterative list. More advanced lists can be made by use 'list with 'supply. (And for those who think supply is complicated, you obviously never used or don't remember the original method for creating an iterative pane function before we had 'List :-)

browser?

Jeff, has a visual object browser at http://www.cs.unm.edu/~whip/objview.r Cheers, Allen K

Am 24.05.01, 17:06:26, schrieb "GS Jones" <[gjones05--mail--orion--org]> zum Thema [REBOL] Re: VID questions:

heart's

[get-style 'text-list] gives the face, [get in get-style 'text-list 'facets] gives most of the differences to [get in get-style 'text-list 'type] wrap functions around :) also layout[ t1: area do[ probe t1/feel ;or other stuff probe first t1 ] ] helps

Hi, yep even it takes some time to gain development speed...

Yes, I have read them but these docs just mentioned the objects... that's it. Anyway, I'm seeking through all kind of postings and collecting knowledge from all the samples posted.

Hmm... why is the paradigm shifted? I think the difference between definitions/declarations and code which is actually executed is quite useful. I find it even more strange that I can't define Rebol variables inside the layout stuff: view layout [ myblock: make block! [] ] Won't work. So the pattern to use VID is to have the GUI collect all kind of data and transfer them to outer Rebol variables for later processing.

Yes, please post a link or a reference to a posting.

Ok, is there a way to have a right alignment for a group of text/labels etc. which will set the size to the longest text? Otherwise you have to find the optimal size yourselfe. Robert

From: Robert M. Muench

Until something more complete and definitive comes up, I guess that is the best approach. :-( Allen Kamp's Rebolforces.com site contains archived versions of documentation that is a little different than the current officially released documents. If you can tolerate some redundancy of information, it goes into a bit more detail about /View faces. For what its worth to you: http://www.rebolforces.com/archive/view099users.html

Yes. And this highlights the fact that VID is a dialect that requires a controlled vocabulary of VID words. If you would like to create some words/objects within the layout structure, you are allowed to include a 'do [] that runs on evaluation. For example: view layout [ button "click" button "don't click" do [ myblock: make block! [ my-var-a: 4 my-var-b: 2 ] ] ] This may be all that you are looking for. Dialects are neat and powerful, and I personally look forward to tapping into their rich potential, but it does require some re-thinking of how to achieve a programming goal.

Yes, you are right, and no, I can't think of an easy, more efficient way right off hand. ALong the same line of how long a bit of text will be (after rendering), you will soon discover that if you reassign text or txt information that only the length of pixels of the original text will be rendered. Again, an example is worth a thousand words (two thousand of *my* words;-). Run the following: view layout [ t1: txt "Hi" button "Change Text" [t1/text: copy "Hello" show t1] ] Nice, uh? The current work-around I use is as distasteful as you issue with right aligning labels, namely: view layout [ t1: txt "Hi" 80x16 button "Change Text" [t1/text: copy "Hello" show t1] ] Ahhh, that's better ... sort of. What if one doesn't know how long a scrap of replacement text will be??? I've been wishing and asking of there is a way to calculate the rendered size of text so that this could be programmed dynamically. No answers so far... :-( If I run across a ggod example on the alignment problem, I'll certainly forward it. Happy /View-VID'ing. --Scott Jones

From: Robert M. Muench

Until something more complete and definitive comes up, I guess that is the best approach. :-( Allen Kamp's Rebolforces.com site contains archived versions of documentation that is a little different than the current officially released documents. If you can tolerate some redundancy of information, it goes into a bit more detail about /View faces. For what its worth to you: http://www.rebolforces.com/archive/view099users.html

Yes. And this highlights the fact that VID is a dialect that requires a controlled vocabulary of VID words. If you would like to create some words/objects within the layout structure, you are allowed to include a 'do [] that runs on evaluation. For example: view layout [ button "click" button "don't click" do [ myblock: make block! [ my-var-a: 4 my-var-b: 2 ] ] ] This may be all that you are looking for. Dialects are neat and powerful, and I personally look forward to tapping into their rich potential, but it does require some re-thinking of how to achieve a programming goal.

Yes, you are right, and no, I can't think of an easy, more efficient way right off hand. ALong the same line of how long a bit of text will be (after rendering), you will soon discover that if you reassign text or txt information that only the length of pixels of the original text will be rendered. Again, an example is worth a thousand words (two thousand of *my* words;-). Run the following: view layout [ t1: txt "Hi" button "Change Text" [t1/text: copy "Hello" show t1] ] Nice, uh? The current work-around I use is as distasteful as you issue with right aligning labels, namely: view layout [ t1: txt "Hi" 80x16 button "Change Text" [t1/text: copy "Hello" show t1] ] Ahhh, that's better ... sort of. What if one doesn't know how long a scrap of replacement text will be??? I've been wishing and asking of there is a way to calculate the rendered size of text so that this could be programmed dynamically. No answers so far... :-( If I run across a ggod example on the alignment problem, I'll certainly forward it. Happy /View-VID'ing. --Scott Jones

Scott, there is no need to set height in the above example Using just the width i.e t1: txt "Hi" 80 , allows the text to wrap at the width, very handy if you are laying out a paragraph and don't know how long it will be the height will autosize.

Scott here is an example for you, view lay: layout [ t1: text "Hi" black gray button "Change Text" [ ; temporarily set to the max width you wish to allow, ; this allows text to stretch out t1/size: lay/size t1/text: "Resize for Scott :-)" t1/line-list: none ; now set the label size back to the text size ; and add a bit to allow for margins & edge t1/size: 4x4 + size-text t1 ; finally show the result t1 show t1 ] ] ; Should I add this to my FAQ? Cheers, Allen K

Well it is not a great answer but here is a goofey solution: "size-text" view layout [ f1: field [t1/text: copy f1/text t1/size: 2000x2000 t1/size: ( add size-text t1 7x0) show t1] t1: txt "" black yellow ] but you probably knew that... Brett.

a

of

could

size-text

Actually, I did not. Never noticed/saw the size-text function. That should come in handy. Thanks! -_Scott Jones

issue

at the

long

If I knew that before, I had clearly forgotten. Thanks!!

could

certainly

Most definitely (add it to the FAQ). Your response and Brett's response have been very helpful to me. Now, for Robert's question on right aligning labels .... :-) I'll have to play with this newly learned functionality. I'll also be happy to start perusing your website, looking for possibly out-of-date /View beta stuff. It'll serve as a nice reminder on /View basics, too! Thanks. --Scott Jones

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from

Yes unfortunately the VID Doco needs more work.

useful. I

layout

In Rebol, I'm not sure there is any such distinction between definitions/declarations and code which is actually executed. The only non-executable code in Rebol is unevaluated blocks if remember correctly. A VID specification is code that is interpreted. Interpreted differently from normal Rebol code. I say this to highlight that VID is a more concise way to achieve certain GUI goals - like layout. Regarding variables. set-words in VID are used to capture references to the face objects that are created. Eg. layout [text-face: text "I'm a text face"]. They become global unless you have pre-created them inside an object. You can also use the DO word to execute normal Rebol code - though it will DO it only once. Also remember that action blocks for various VID styles become functions. an-object: context [ text-face: none ; Pre-creating a variable to store a reference to a face. just-a-variable: 0 the-layout: layout [ text-face: text "I'm a text face" button "SetVar" [just-a-variable: add 1 just-a-variable] ] ] view an-object/the-layout print an-object/just-a-variable I want to include here some slightlyt edited stuff I wrote to myself while learning View. I don't guarantee correctness - just showing how I think about what I see (a programmer's viewpoint). ===Faces and VID The most fundamental graphical element of Rebol/View is the Face. Faces in Rebol are represented as objects and on the screen are represented by a rectangular visual image. One can manipulate the objects to achieve effects on the screen. Rebol View uses the model you create (an object model) to render the screen. The model also contains words and functions that react to various events. The VIEW function takes a face (which may comprise other faces - ie it is the a root of an object model) and renders it. VID is a dialect. The purpose of VID is to describe faces in a language which is easier to write than creating faces directly using object notation. The structure of VID and the machinery that supports it comprise an ingenious solution to this problem. Producing simple GUIs with VID is probably very important to the uptake of Rebol/View. For those that have not programmed before VID provides a very easy entry to building a GUI. The main interpreter of VID is the LAYOUT function. This function takes a VID specification and create the faces. It returns a face which encompasses all the faces created from the VID specification. ===Is understanding VID enough? While, I believe VID achieves the goal of creating screen representations easily, there comes a point where one wants to create a more complex user interface using VID. By complex I mean where there is a relationship between one "widget" on screen and another. Such relationships are common in user interfaces. For example, press a button and something becomes disabled, or move a slider and something scrolls. When programming at this level, I believe it helps to keep in mind what work VID is accomplishing for you - creating faces and adding them to an object model of faces. I also think that one should remember that Rebol/View interprets the face object model in order to create the screen representation (image) and to react to events. This concept helps when one encounters an unexpected behaviour. For example moving a slider and seeing the text on a different window scrolling. In this case one should remember how words and values are treated in Rebol. Consider strings, this code [a: "the cat" b: a clear b] - would result in the string referred to by a being empty. In the same way, faces are objects that point to all sorts of values. If a value is shared amongst different faces and one changes that value what is the effect? All faces sharing the same string value or object value, etc would be changed. This can be useful - it can also be very confusing when you have worked with other GUI development tools and you bring along a few habits of thought from those environments. So is understanding VID enough? Most definitely sometimes and perhaps not other times :) ... Regards, Brett

or

will

thousand

issue

From: "Paul Tretter"

Hi, Paul, I excerpted two code snippets. The first one should do what you observed, which was to only print as much text as was made visible by the original text "Hi". My point, which I evidently failed to make clear, is that one has to anticipate the longer text so that the longer text will print out correctly. The second example was meant to adjust for this VID "problem". As you will read later in the thread, Brett and Allen both suggested better ways of dealing with the "problem". Thanks for your feedback, and I hope I have clarified what I failed to make clear the first time. Have a nice weekend! --Scott Jones

Am 25.05.01, 14:51:41, schrieb "Allen Kamp" <[allenk--powerup--com--au]> zum Thema [REBOL] Re: VID questions:

<program snipped> This is *very* clever, Volker. There is a lot to learn from this example, not the least of which is how to right align a bunch of labels. Neat! Robert M. should also be pleased to have a more sophisticated way to dynamically lay out these types of elements. --Scott Jones

Am 25.05.01, 23:20:10, schrieb "GS Jones" <[gjones05--mail--orion--org]> zum Thema [REBOL] Re: VID questions:

labels.

Mmm! Thats goood :)

Oops. Again replyed to the wrong message?! ;-)

Volker ;-)

Hi, huh these are really just a few... nice.

Ok, I have done this. Results in a 300KB file. Is there a way to pretty-print it? Did someone created a pretty-printed version of it? Robert

Hi, I am! You guys post so fast, that it takes some time to read all the stuff, code my prototype and get some minutes of sleep ;-). Thanks a lot. Robert

From: "Volker Nitsch"

No, this was the correct one. Your meta-programing example has inspired me to expand on the database sample I sent to list/Petr theother day. --Scott Jones