Squeak-dev February 2002

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202 participants
665 discussions

transforming points from global to local coordinates
by Craig Latta 27 Feb '02

27 Feb '02

Hi-- I would expect (aMorph globalPointToLocal: aPointInGlobalCoordinates) to answer aPointInGlobalCoordinates as translated into the local coordinates of aMorph. This doesn't seem to be the case... should it? If not, what should I do instead, and how could I have learned this? thanks, -C *** "E.g., I would expect 25@25 from..." | morph | morph _ ( (Morph new) extent: 50@50; position: 300@300). morph globalPointToLocal: morph bounds center "...but I get 325@325 instead." -- Craig Latta composer and computer scientist craig.latta(a)netjam.org www.netjam.org crl(a)watson.ibm.com Smalltalkers do: [:it | All with: Class, (And love: it)]

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[BUG]Off-centerMorphs
by Jerome Peace 27 Feb '02

27 Feb '02

Fun with off-center morphs. Symptoms: flipped skectchMorphs lose the right or bottom row of pixels depending on whether they are vetically or horizontally flipped. Rectangles (I'm using rulerMorphs to debug) when rotated 90 degrees will lose the bottom (left rotation) or right (rotation) row of pixels Iff the rectangles extent is odd@even or even@odd. Some analysis: The inspectors show that the transformationMorph is using an offset of -xxx.5(a)-yyy.5 and the rulerMorph bound is usually -xx@-yy corner xx+1@yy or corner xx@yy+1. Where the extent is equally odd or even the problem isn't visible. So somewhere I believe the truncation of the offset squeeze a row or column out of the picture. Looking at the morph in a holder with the cursor indicating shows there are extra transparent pixels on the left or top and the final rows seem to be shifted out of the clipping box. Possible solutions: 1) the eight special cases (4 rotations including identity and there flipped counter parts) should be caught and handled specially. This has the great virtue of preserving your color form and form extent ( I'm assuming the special cases are handled by permuting the rectangle innerCorner quad before it is fed to warpBlt) 2)Since TransformMorph is padding the form anyway why not have it make pad the odd even extents so they are even@even or odd@odd. Odd@odd would have the same "center" as the odd even extents. 3)Thought about why this is occurring should be given. I believe it is actually a symptom of several off-by one errors in the drawing and transforming routines. **** Useful tests to see what's going on: I exported some rulerMorphs of various sizes as gifs and read them back in as sketch morphs. The problem when using rotation styles #vertical or #horizontal occurred regardless of the oddness/evenness of the height and width. I put the morphs in a holder and to my delight realized the holder surrounded the drawn morph form with its cursor. Generally the morph was being displayed with width and height increased by 2@2. And the form was getting the extra pixels on the left and top then clipping the significant pixels on the right and bottom. Further investigation showed that the off-centering was not confined to sketch morphs but applied to any transformed morph as well. Try rotating an ellipse in the holder and you will see how bad the accumulation of errors can get (at some 45 degree angles particularly). *** Yours in service, Jerome Peace _________________________________________________________________ Send and receive Hotmail on your mobile device: http://mobile.msn.com

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ARM GCC compiler issue
by Ohshima, Yoshiki 26 Feb '02

26 Feb '02

Hello, I'm trying to port Squeak to US version Zaurus (developer.sharpsec.com) and it is getting to work. I knew Tim mentioned couples of times about the GCC bug, but I was narrowly hoping that the bug is fixed in the toolchain which Sharp is providing. Unfortunately, it isn't fixed and I'm bitten by the bug. If I compile the VM without optimization, it (sort of) works on the PDA, but when I turn on the optimization, the process says "Illigal instruction" and quits. Virtually, there is no way for me to narrow down which function(s) in the VM causes the problem. So, does anyone have a program sniplet that triggers this compiler bug? I want to take a look at it and ultimately I want to let Sharp to fix it:-) Thank you, -- Yoshiki

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Re: SerialPort cross-platform question...
by Dan Ingalls 26 Feb '02

26 Feb '02

>On Monday 11 February 2002 03:05 am, Bergel Alexandre wrote: >> > Actually, the peculiar enumeration of the ports is a Mac-ism. On the >> > Windoze and Unix platforms, it would make more sense to supply a name. >> > > Why to supply a name ? 'COMx' belong to windows world... and Ned Konz <ned(a)bike-nomad.com> replied... >How would you know, portably, what the name of the serial port is in a Unix >system? Could be anything (including a symlink to an entry in /dev >somewhere). There are _no_ reliable standard names for serial ports in Unix. >I picked /dev/ttyS0 etc. because that worked on my system and common PC Linux >systems. But it's not going to work if (for instance) you have an intelligent >multiport serial card installed also and want to use one of those ports. > >For instance, /dev/ttyH0, /dev/ttyC0, /dev/ttyD0, /dev/ttyE0, /dev/ttySR0, >etc. are all typical names for a serial device. But these are only the >traditional names. And if someone linked /wherever/mySerialPort to one of >these (or made a node with that name), we should be able to use it as well. >This is why I said that names would help. > >On the Windows machines, there is no guarantee that there is any consecutive >number of the COMx ports. I have a Windows box whose COM ports start at COM4. > >> > And it's not clear how the ports are numbered on the Mac when you hang >> > USB serial ports on one (per Dan Ingalls). >> >> I use on my linux a usb->serial adaptor, and it is the same then a real >> port. I guess it should be the same for mac. > >So did we, but Dan hasn't been able to find a number that worked reliably. I've just learned a couple more useful facts. First of all, John McIntosh steered me toward a wonderful facility provided quite a while ago by John Maloney. At least on the Mac (I'm curious about other platforms), you can print, MidiPrimTester new getPortList to get a listing like the following (this Mac had a Belkin USB unit attached): MIDI Ports: 0: Infrared Port (in/out) 1: Internal Modem (in/out) 2: Printer Port USB (in/out) 3: Belkin Serial Port (in/out) 4: QuickTime MIDI (out) This immediately cleared up some questions I had about how the Belkin adapter (USB to 2 serial ports) worked. More importantly, it steered John Mc straight to a bug in the Mac serial primitive that prevents opening any port numbered higher than 1. He's preparing a fix even as I write. If the portCount and portName primitives used by this facility work on all platforms, then there is at least the promise of things being pretty civilized. - Dan

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Re: serialization and rematerialization of CompiledMethods, assistance needed!
by Chris Muller 26 Feb '02

26 Feb '02

Thank you Tim, Bob, John, Stephen and everyone else for your great responses. I feel a bit more informed about it, but still wondering a bit about: - In VisualAge, I'm able to store and retrieve CompiledMethods just fine because the literals and pointer variables are actually *instance variables* of the class CompiledMethod. If the CompiledMethod in Squeak only holds "references" to the literals (since it inherits from ByteArray, I presume this to be a memory-location-integer-reference to the String literal, and not the String itself), then how do the String literals themselves avoid being garbage collected? - How do the ReferenceStreams manage to rematerialize CompiledMethods? Do they instantiate and then go back through the literals and change them to point to the "real" literal? I'll have to check this out. - The next thing on my list is to get the BlockContexts going. They have a methodContext, so am I going to have similar challenges w/ blocks? - And finally, what is VI4? If it is going to make this easier then I may just wait for it.. You know, I think the Squeak community provides better "support" (in my experience) than a lot of high-priced corporate service contracts! Best regards, Chris PS - Bob, to answer your question about going the source route, it is still an option, but this is for a GemStone-like ODBMS and I want to be able to store objects as close to their "native" form as possible. Recompiling the source introduces some added complexity and probably lower performance but, as I said, it is a worthy option. Thank you.. The "semi-compiled" format that Stephen suggested is also being considered. I used to have "storage objects" for a couple of classes (which were simply a different representation of the object that made rematerailization feasible. For example, storing LargeIntegers > 64-bits into a wrapper of its printString). However, I have moved away from them in favor of custom buffer formats for various implementation complexity reasons.. __________________________________________________ Do You Yahoo!? Yahoo! Sports - Coverage of the 2002 Olympic Games http://sports.yahoo.com

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RE: Modules and class... [ a off-topic question ?]
by goran.hultgren＠bluefish.se 26 Feb '02

26 Feb '02

"David Simmons" <David.Simmons(a)smallscript.com> wrote: [SNIP] > I think that it is mostly lack of experience in this space that is doing > the talking here amongst Squeak folks. Consider what happens when you It may very well be. On the other hand we do have some experienced guys too! :-) Like Les for example. So I don't think that is the only reason for our reactions to your view. Nevertheless I find your view very interesting and I am arguing because I want to understand it better. And I do, as many others have testified, very much value your input here - be sure of that. > need to define a new type of module. How will you package and deploy it > when nothing will understand it in base systems. It is very likely to > result in some kind of non-OO kludge mechanism... Ok, so your argument being that if a "module" can be defined using the same freedom as we define classes AND we also make sure our architecture for modules handles all that freedom then there will be much less limits to what future module "types" can be/do. Ok, I see what you mean. But... is it practical to give modules that much freedom? And just being a dumb average Smalltalker here: How do you compose your modules in Smallscript? How does a class "contain" other classes? Just curious - I could of course download and dissect but I have no time right now. > > But clearly, from David's examples, Smallscript is *not* a pure OO > > environment. Smallscript looks very cannibalized. > > Functions vs. methods vs. > > There is no versus. It sounds like you've not really understand what > classes are and how the MOP and behavior facilities support objects and > messaging. And, as a result, you do not understand the mechanisms by > which functions can be unified with an OO architecture. A function *is* > a class-method. Well. Trying to define "function" is kindof tricky. I always think of "functions" as having no state. On the other hand you could just view any state it does have access to as "parameters" and then, voila (hmmm, how do I get accents in Squeak on Linux? Strange. I just get Ž) it's a function! But given that a class method does have access to the state in the class object it is IMHO not a function. It's a class method. It can be inherited on the class side for example. Functions don't normally participate in inheritance, do they? And given all this, in Smallscript (I am guessing here), since a module is a class (and vice versa I guess) - a function in a module becomes just a class method (or vice versa). And you can of course have inheritance between modules since they are nothing else than classes. Now... what mechanisms have you added to the "class" concept to make it work as a "module concept" too? > Classes have shared/pool variables in classic Smalltalk. Therefore, > classes are already namespaces. Why retain SystemDictionary, or > non-class Pools, or introduce yet another namespace facility to confuse > everyone The Module system in 3.3alpha actually removed Pools. In the light of the Modules system they got redundant. > I agree completely. That is why it pains me to see some of the ideas > that have been implemented for namespaces in various Smalltalks. It is > also, what pains me as I see the work being done on modules, as I > project/foresee where it will put Squeak evolution a bit further down > the road. Could you state your prediction? Is it that the current system will not be able to handle more diversified "module" concepts? But honestly, do we really need so many different kind of modules? We have two different beasts today - Module and DeltaModule (the names of the classes in question). They together capture quite a lot of interesting functionality IMHO. And If we will need one or two more - fine, we should be able to squeeze that in without too much trouble. In short, in my opinion, which may be feebleminded since I am not even close to David Simmons in grasping all the meta-level questions here (and that was not meant as irony), I want a modules system which is understandable by everyone and still powerful ENOUGH. Emphasis on enough. The idea to give "module" the same freedom that "class" has feels weird to me. It would ALSO mean - and this is biggie - if we want to change the modules system we would ALSO change the class system and vice versa. I personally do not want them to be that tightly coupled. [SNIP] > > Let's not confuse Squeak. > > I am not trying to confuse or change Squeak -- to be honest it is > probably not even in my best interest to assist Squeak's evolution. It :-) :-) > is already changing, evolving, and maturing. I'm just trying to provide > some advice for the "child" (as you've characterized it) as it grows. > And, apparently, I'm doing a poor job of it. No, you are doing just fine I think. But you need to be prepared for some fire when you are so bold to say we are all doing it totally wrong. That hurts! :-) ;-) regards, Göran

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Re: [Q] Modules- just classes or more?
by Lex Spoon 26 Feb '02

26 Feb '02

> I wasn't sure about this for a while, but now I am of the opinion that > modules should only define the variables, and not their contents. > > Firstly, producing a Smalltalk expression to recreate the contents of a > variable (i.e. recreate in principle any possible object) is not a > well-defined and easily solvable problem. > > Secondly, modules define programs, i.e. in this case, define variables, but > not their contents. Compare to how in other languages you declare variables > in a declarations section, but initialize the contents inside the running > program. When languages allow you to declare and initialize a variable at > the same time, this is done within the running program. And modules just > define "dead" code, not running programs. > Programs aren't just code. Putting data in modules has some problems, but then so does putting ideas into code to begin with. :) I'm only curious why you only mention using *expressions* to initialize variables -- why not serialize the object? :) Really, the only problem seems to be what happens when a class in a different module changes its layout, and thus invalidates the stored object in your module file. Okay, it's a big problem, but, putting the values of the variables in there is also a very nice benefit.... Languages that don't have this built in, seem to end up with ways to serialize data in more ad hoc ways. -Lex

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Starting with PWS
by Gary McGovern 26 Feb '02

26 Feb '02

I'm trying to get PWS going for the first time and am looking for the error. If I write: PWS link'default' to: ServerAction new. PWS serverOnPort: 80 loggingTo: 'log.txt'. PWS initializeAll (this brings up a dialog The path to the Server folder is wrong. Please modify the following method... serverDirectory of class ServerAction). The path I used was 'C:\Windows\Desktop\Squeak\Server\' I used all permutations and none would work. Port 80 is correct in my instance. ComSwiki works fine on that port. Any tips ? Thanks! Gary

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Re: mac os-x -> Need multiple button mice with scroll wheel
by Bert Freudenberg 26 Feb '02

26 Feb '02

On Mon, 25 Feb 2002, Ned Konz wrote: > The wheel support I added to the Unix VM just gets button 4 or 5 events > from X and passes them up to the image as Up or Down keystroke events, > since there was no representation of mouse wheel actions in the image. Oops! You added that, too? In my version (that made it into Ian's code at some point) the wheel sends ctrl+up/down, not just up/down keystrokes, to distinguish them from normal key presses ... John: the keyboard events work well even in MVC, I'm not sure we really need to invent new events ... -- Bert

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Re: Convenient Reading
by Nevin Pratt 26 Feb '02

26 Feb '02

I've been silent on this thread, actually hoping (out of embarrassment) it would die, because as some have pointed out, it is trivial to configure Mozilla filters to do what I wanted. I then just go ahead and receive individual emails, and let Mozilla move the messages to a unique folder and thread them. Sorry to bother everybody. Nevin Yeoh Yiu wrote: > You can expect to have the option of an advertizing free > service for $100/year or so, RSN. > > I filter individual e-mails into a folder, and spend too > much on disk space at my ISP. > > YY > > Nevin Pratt <nevinpratt(a)earthlink.net> writes:a > > >>What's the most convenient method of reading the messages of this list? >> >>Reading them at http://groups.yahoo.com is very inconvenient. Yahoo >>groups puts too many popup ads up, plus the general response is >>sluggish reading them this way. >> >>Receiving emails is also inconvenient. I currently use Mozilla for >>email. If I specify individual emails, I get inundated with emails. >>If I specify daily summaries, it's not very convenient because I would >>prefer the messages to be threaded, like the usenet usegroups are. >> >>How do the rest of you do it? >> >>Nevin >> > >

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