Beginners July 2008

beginners@lists.squeakfoundation.org

62 participants
72 discussions

Speed up image loading
by Felix Dorner 09 Jul '08

09 Jul '08

Hi, I am trying to write a Photo Manager Application, to learn Morphic and Squeak. So far I have created a custom Thumbnail morph "LabeledThumbnail" that is capable of holding a form and a label: First I create forms like that: form := (ImageReadWriter formFromFileNamed:'/home/felix/DCIM/101HPIMG/HPIM1625.JPG') Thumbnails are then derived by (this is an instance method of LabeledThumbnail, not sure about the >> notation): LabeledThumbnail>>form: aForm thumbnail ifNotNil: [ self removeMorph: thumbnail]. thumbnail _ Thumbnail new. thumbnail maxWidth:150 minHeight:100. thumbnail makeThumbnailFromForm: aForm. self addMorph: thumbnail. Now I created a new Class "ThumbnailBar", that displays a collection of LabeledThumbnails: ThumbnailBar class>>newFromPhotoCollection: aPhotoCollection | tmp form | tmp _ self new. aPhotoCollection do: [ :entry | form _ ImageReadWriter formFromFileNamed: entry. tmp addMorph: (LabeledThumbnail newFromForm: form withLabel: entry) asMorph ]. ^ tmp PhotoCollection is a bare list of filenames. Obviously this is not complete, I want to add scrollbars etc. However, my current issue is speed. Doing a col := PhotoCollection newFromDirectory: '/home/felix/DCIM'. (ThumbnailBar newFromPhotoCollection: col) openInWorld takes about way too long (minutes range) until the Thumbnail bar shows up (there are about 200 hi-res jpegs in the collection). I guess that the most time is spent loading and scaling the images, so I'll probably cache the thumbs on disk. Another issue is easier and more intresting to me: I like to reduce the number of Morph objects. E.G. my "LabeledThumbnail" is a RectangleMorph that owns an ImageMorph and a StringMorph. I want to get rid of the submorphs and write my own drawing code. I have already seen how this is done, but am a little afraid of the redrawing/updating stuff. E.g. this confuses me already: ImageMorph>>image: anImage self changed. image := anImage depth = 1 ifTrue: [ColorForm mappingWhiteToTransparentFrom: anImage] ifFalse: [anImage]. super extent: image extent Intuitively the "changed" message should be send as the _last_ statement, not the first one. Can anyone explain? Thanks, Felix

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Re: [Newbies] more of a general smalltalk question
by Hanita Bte Abd Hamid 09 Jul '08

09 Jul '08

Can someone please remove me frrom this list ? ---------------------------------------- From: smith02243 <add_aaron_2_x(a)hotmail.com> Sent: Wednesday, July 09, 2008 8:52 AM To: beginners(a)lists.squeakfoundation.org Subject: Re: [Newbies] more of a general smalltalk question cdrick wrote: > > An idea: learning from source code could be documented too by small > "how-to". > > For instance to understand how sandstonedb works (which is already > well documented thanks to Ramon) we could imagine that: > > HOW-TO-LEARNING SDActiveRecord "file oodb persistency inspired by > ruby activerecord framework" > -restoring persistent objects > > "put a self halt in SDActiveRecord class>>warmUp" (wich is called at > startup for activerecord like objects, > "save and quit". then > "start again the image". > This opens a debugger that will help you understand how persistent > objects are restored... Debugger will open on Mock classes that exists > for test reasons. It will also open on all your active records > (subclasses of SDActiveRecord) > > etc etc... > > This is a small documentation effort that would be precious. We could > also illlustrate with videos which if we had standard tools could be > done without too much effort (I mean less than getting all done with > text only)... > > see: http://www.squeaksource.com/SandstoneDb/ > > My 2 cents ;) > > Cédrick > > _______________________________________________ > Beginners mailing list > Beginners(a)lists.squeakfoundation.org > http://lists.squeakfoundation.org/mailman/listinfo/beginners > > I strongly agree that the source code must be supplemented with something. GNU Smalltalk has excellent library documentation. Admittedly, in Squeak it's easier to browse the source-code thanks to Squeak's GUI, yet proper documentation would still be a huge boon to development, especially for neophytes. Furthermore, in Squeak by Example there's this quote by Alan Knight: Try not to care. Beginning Smalltalk programmers often have trouble because they think they need to understand all the details of how a thing works before they can use it. This means it takes quite a while before they can master Transcript show: 'Hello World'. One of the great leaps in OO is to be able to answer the question "How does this work?" with "I don't care". We cannot really take that advice seriously if we force users to browse source code whilst building their applications. This is especially detrimental to new users, who generally want to start building applications as soon as possible, and care little about implementation. If they're forced to care about implementation I would guess they'd prefer to use something else, something with better documentation and a rival set of libraries, Python for example. -- View this message in context: http://www.nabble.com/more-of-a-general-smalltalk-question-tp18288372p18352… Sent from the Squeak - Beginners mailing list archive at Nabble.com. _______________________________________________ Beginners mailing list Beginners(a)lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners

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more of a general smalltalk question
by Sean Allen 09 Jul '08

09 Jul '08

but i'm using squeak as my 'really learn smalltalk' einvironment so... can any suggest any good reading, books, websites, whatever for learning the ins and outs of how exceptions, signals etc work in smalltalk. i'm interested in both an 'end user' perspective as a start but getting into the nitty gritty of the why of the implementation as well.

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Re: [Newbies] Flushing Squeak Cache
by Marcin Tustin 09 Jul '08

09 Jul '08

I encountered a similar problem a few days ago, and asked about it. Discussion, but no particular answer was forthcoming, probably because I included the work around, which is: ClassName compileAll On 7/8/08, Dirk Leas <dirkleas(a)gmail.com> wrote: > > I'm running latest Squeak on OS X. I in the beginning of Section 2 of the > laser game walk through and I forgot to add the class method to > GridDirection. I run the test cases including my new GridDirectionTestCase > and it of course fails as it doesn't know what the symbol is. I go back and > add it (browse it again after adding it just to make sure I added it), and I > get the same error in the Test Runner. > > There have been several occasions where I add "something" (e.g. class, > method, instance variable, etc.), go back to do some rafactoring, and expect > the latest save to cascade through the VM so that my next test case runs the > latest code -- often it doesn't. I've seen this before in other environments > where the VM is cashing "stuff" and latest code isn't always getting run. > > TIA, > D > > > > On Tue, Jul 8, 2008 at 5:34 PM, Matthew Fulmer <tapplek(a)gmail.com> wrote: > >> On Tue, Jul 08, 2008 at 05:21:01PM -0400, Dirk Leas wrote: >> > I'm enjoying my stroll through the laser game walk through, but find >> the >> > VM caching scheme getting in the way with my test driven development >> (you >> > know, hack w/t regard, fix typos, test again ;-)). How do I flush it? >> >> I have no idea what you are talking about. I don't know of any >> VM caching scheme. Could you describe what problem you >> encountered, and what you were doing? >> >> -- >> Matthew Fulmer -- http://mtfulmer.wordpress.com/ >> _______________________________________________ >> Beginners mailing list >> Beginners(a)lists.squeakfoundation.org >> http://lists.squeakfoundation.org/mailman/listinfo/beginners >> > > > > -- > > Dirk Leas > South Orange, NJ > > Ergonomic Tip of the Day: Hug your spouse and kids! > _______________________________________________ > Beginners mailing list > Beginners(a)lists.squeakfoundation.org > http://lists.squeakfoundation.org/mailman/listinfo/beginners > >

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Flushing Squeak Cache
by Dirk Leas 09 Jul '08

09 Jul '08

I'm enjoying my stroll through the laser game walk through, but find the VM caching scheme getting in the way with my test driven development (you know, hack w/t regard, fix typos, test again ;-)). How do I flush it? TIA, D

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Morphic Widgets Overview with Screenshots
by Felix Dorner 08 Jul '08

08 Jul '08

Hi, I am bloody new to Squeak. I already read Squeak By Example and am currently reading Maloney's Morphic Introduction Paper - it is great. What I couldn't find so far was a document where all available Morphic Widgets are presented with Screenshots or so by the side, similar to this one for The Java/Swing libraries: http://java.sun.com/docs/books/tutorial/ui/features/components.html Dos something like this exist? If not, I think it would be great to create such a document. What I currently need is something that displays a List of Strings with a Top2Bottom Layout, similar to a Swing JList. Thanks, Felix

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[ANN] SqueakLightII Sunday News !!!
by Edgar J. De Cleene 06 Jul '08

06 Jul '08

To the huge multitude of SqueakLightII (3.11 unofficial) fans I got Spirograph 3.005.pr of Diego Gomez Deck (2004 originated) as you could see in the pict. Still need some polish for fool proof newbies, but is running . Also I have Aida / Scribo running on SqueakLightII. And put the loading script on the swiki page. So , is not vaporware and begins to show people could have a smaller , modular image and choices about how he/she wish grow. In the process I learning a lot about the art of put the worms again in the same can as they live some time ago :=) As example , for proper loading my in Ladrillos version EToys-edc.29.mcz needs load ScriptEditorMorph , TwoWayScrollPane and ZoomAndScrollControllerMorph before. My in the way 7189PackagesUniversesGlue.6.cs could "discover" this and intelligent load the classes from ftp. No panic, I only put four classes for show the idea of classes repository I have from 2005 is working. If I have authorization, could put all stuff I have in ftp://squeakros.atspace.com/squeakros.atspace.com/CompressedClasses/ "3.8" ftp://edgardec@squeakros.atspace.com/squeakros.atspace.com/3dot9 ftp://squeakros.atspace.com/squeakros.atspace.com/3dot11. But wait, some classes from past was very weird designed. See by example TileMorph initialize , you should have three morphs and run a commented out method... The only fast solution I see is made a EtoysReload.sar with all the stuff into. Edgar

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Totally dumbfounded!!
by Stephen Ng 06 Jul '08

06 Jul '08

Hi everyone, First off, I am really new to smalltalk. I have tons of experience with languages like C but have never made the move to OO type languages. Secondly, I've been reading up as much as I can on OO concepts and perhaps I can say that I feel comfortable with smalltalk syntax. My question is how does one start learning about the MVC or Morphic interfaces in order to use smalltalk in writing programs that make use of lots of windows with text fields etc like in traditional business systems? I cannot seem to find complete info on these topics. Many tutorials just spend lots of time painting pretty lines and patterns and fall short of showing someone like me how best to use the MVC, Graphics-* or Morphic-* class categories and their classes. I understand Morphic is the new wave as far as Squeak is concerned and I would be just as happy to use it. However, all the literature on the web is really disparate and does not approach the subject in a holistic way. I've even tried looking at the classes themselves in the Browser but the whole thing just gets very confusing. I'd appreciate it if anyone can provide some pointers, direction, literature (up to date with Squeak) etc. Thanks in advance. Stephen

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Learning Squeak [Was "Smart Paper"?]
by Rob Rothwell 06 Jul '08

06 Jul '08

On Sat, Jul 5, 2008 at 2:13 PM, Steven Claflin <stevenclaflin(a)gmail.com> wrote: > Hi Rob, > > I wanted to thank you for your email to the list and your struggles. I > am just beginning to learn about Squeak and being an old procedural > programmer (PDP-11), OOP in general is kind of backwards to my way of > thinking, and so I can identify with your feeling as though you are just > not online all the way. The first programming that I did that was at all > object oriented was in Visual Basic many years ago, and I can remember > thinking; "Ok, these buttons and windows and textboxes can react to > actions, but how do you start the whole thing going?" It's kind of > laughable now, but at the time I was used to: first you have the > computer do one thing, then the next thing, and so on... So its like I > was sitting there waiting for the program to do something and the > program was sitting there waiting for me to do something. When I was a kid, all I ever wanted to learn was Assembly Language. I wanted to write my own OS, that was an interactive, lively, interpreted system. I only got as far as booting into protected mode with a keyboard, mouse, timer, and video driver which went straight into a split screen (text mode) debugger complete with disassembler. It actually still runs on x86 architecture, but, little did I know what was out there waiting...! I alway figure if I get far enough I would really enjoy the VM side of Smalltalk a lot. I, too, am heavily experienced in VB. Still use it a lot (VBA) at work, just because Excel and Access are hard to beat as a "Business Language." (Although my dream system is a combination Database Browsing/Query engine that returns recordsets into a Smalltalk driven spreadsheet with a built in statistical package and a "process oriented" calculation engine! But, I digress...). Coming from the VB angle, though, I really like events, and have become quite enamored with Announcements. Maybe too much so, but it is what I always wanted in VB! (How many times did you hack returning an OBJECT from a "dialog"). However, learning Smalltalk has made me and my co-worker much better VB programmers nonetheless. We tend to just start with a Class now, and write lots of really small, stupid methods. The "browser" makes it a little harder to work through the code, but we can each sort of pick up the others work if we need to now and figure out what is going on. We are working on transitioning more and more to Squeak, but it's hard to beat Access right now for a utility that runs lots of queries, etc... (hence, my dream system!) I am hoping that as I go through the material, ideas which aren't > immediately understandable will become so after getting more info. It's > hard to do that, because it makes me feel uncomfortable to feel as > though I'm not getting it. When I was going to school for my degree in > electronics there was a lot of that, and that turned out ok. I studied Physics long ago (Ohio University, 1990). I am NOT a physicist, but it taught me how to think, experiment, problem solve. But as an electronics guy, you might understand how when you get to quantum mechanics in Physics everyone waves their magic wand and says, "and from here we have demonstrated that you can derive all of Chemistry..." Smalltalk is more like Chemistry, it seems. Yes, you CAN "derive" it all from basic principles (messages), but it is just so...wonderfully...messy. Makes me wonder why I didn't like Chemistry... However, the best part of Physics (at least at OU), was that from the very beginning they said, "just believe what I tell you. It will make sense in the end." My last two quarters of Astrophysics were a blast! EVERYTHING came together... And so, I am in "belief" mode...just keep moving forward, asking questions, etc... You see, I have the upper hand in knowing that a slow learner like myself can see it all come together at an undetermined point in the future! Sounds like you have had a similar experience. > Good luck, hopefully we'll get it. :-) Thanks...you too. Let me know if I can help from a point of view that can understand what you are having a hard time with! I will rarely be much help to the guys who are building the tools we are using (except to get better about bug reporting), but I can likely help someone at a similar experience level. I am at the point now where my own classes make sense to me at least; trying to figure out what someone else did just isn't easy for me. Take care, Rob

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DLL api calls from Squeak v2
by Iulian Wande Radu 06 Jul '08

06 Jul '08

Hi, is there a way to make API calls to arbitrary DLLs from Squeak projects based on v2 sources ? I know that in v3 you can define a method which calls * <apicall: M module: 'D.dll'>, *where D is the dll, and M is the c-style definition of a method stored inside the DLL. (This kind of statement can access any DLL, so the DLL doesn't need to be defined to be a loadable Squeak module with proper primitives). I would like to do the same from v2, is it possible ? Thanks. PS: If there is a better place to search for this kind of info, please let me know also.

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Beginners July 2008