November 2016 - Pharo-users

Looking for the library to sort object
by stepharo Nov. 7, 2016

Nov. 7, 2016

Hi I know that "steffen" did a nice library to sort objects and I know that this is a nice extension. But I cannot find it. Stef

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UK Smalltalk User Group Meeting - Monday, November 28th
by Giovanni Corriga Nov. 7, 2016

Nov. 7, 2016

Hi, The next meeting of the UK Smalltalk User Group Meeting will be on Monday, November 28th. We'll meet at our usual venue The Counting House ( http://www.the-counting-house.com/) at 7pm. If you'd like to join us, you can just show up at the pub. You can also sign up in advance at the meeting's Meetup page: https://www.meetup.com/ UKSTUG/events/233683252/ . Thanks, Giovanni

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Pharo Shared Memory with C++ executable
by Dimitris Chloupis Nov. 6, 2016

Nov. 6, 2016

Hey fellow Pharoers I have great news, I was able to finally !!!! understand how shared memory file works and actually do it Why is that great news you may ask. A shared memory file is a file that maps a specific area of memory, which means when you write to a specific part of the memory it writes directly to the file without you having to actually do this. Memory mapped files have the distinct characteristic of being able to share memory between processes. This actually is the fastest way to make two process communicate and exchange data. Its called Inter Process Communication or IPC for short , but is not technically communication because both executables share the memory. This means that its possible to make Pharo use C++ libraries from inside a C++ executable. Because basically the shared memory will allow Pharo and the C++ executables to share data, part of that data can be messages to execute specific functions. What is super cool about shared memory mapped files is not only that they are super fast(its what the OS uses to load shared libraries ie. DLLs) , its not that it automagically stores the shared memory to disk like a Pharo image (so we can store live data) but foremost that a great deal of programming languages can use Memory Mapped Files which basically means they have wrapped the mmap functions of the LibC library (C/C++ Standard Library). That means we can now use this to make Pharo able to use C++ libraries, python libraries and any library from any programming language. Its also a solution when you dont have access to a DLL or making one is very hard like in my case that I use Unreal Engine. As you can imagine this will replace/extend my socket bridge that I made for python. Of course all the above are no magic, you have to have some basic understanding of how C++ works and how memory mapped files work, funny thing is that shared memory is actually simpler to understand than C++. You also have to make the messaging system and manage the synchronisation. But those are details which I will implement anyway. So my challenge right now is to move this to Pharo. I have done it with C++, I made two different executables which share a string with the value "hello". I need two functions to do this one is open, which is the classic way to open files in C/C++ in my case is #define FILEPATH "mmapped.bin" fd = open(FILEPATH, O_RDWR | O_CREAT | O_TRUNC, (mode_t)0600); https://linux.die.net/man/3/open second one is lseek which expand the size of the file to a desired size result = lseek(fd, FILESIZE-1, SEEK_SET); http://man7.org/linux/man-pages/man2/lseek.2.html the third one is mmap which is doing the actually mapping of the shared memory map =(std::string*) mmap(0, FILESIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); http://man7.org/linux/man-pages/man2/mmap.2.html Now my challenges after reading the UFFI documentation are the following 1) How I can pass things like O_CREAT , MAP_SHARED 2) How I cast a void pointer (its what mmap returns) to a C++ string or C++ int In case you want to take a look at the code is part of a project I named Atlas which can be found here https://github.com/kilon/Atlas The file atlas-server.cpp creates the memory mapped file and writes to the shared memory the string "hello" The file atlas-client.cpp gains access to the shared memory and retrieves the "hello" string Atlas basically will be the library that will give Pharo full access to Unreal internals.

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How to consume the MOOC?
by Luke Gorrie Nov. 6, 2016

Nov. 6, 2016

Howdy! Just a question from a confused newbie: What is the easiest way to consume the Pharo MOOC content in English? I have tried to find the content a few times over the past few months but so far I have hit a registration page / short trailer video / video in French. (I keep hoping that a YouTube channel will appear that makes the videos easy to follow in sequence on any device.) Cheers! -Luke

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May I please be added as a contributor to the KevinLanvin/MaterialDesignLite repo on Sthub?
by PAUL DEBRUICKER Nov. 6, 2016

Nov. 6, 2016

This one: http://smalltalkhub.com/#!/~KevinLanvin/MaterialDesignLite/ my username is pdebruic

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Forgive me
by Robert Withers Nov. 6, 2016

Nov. 6, 2016

Forgive me for being such a huge unbearable fucking asshole.

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Re: [Pharo-users] Speed up JPG images loading
by Ben Coman Nov. 6, 2016

Nov. 6, 2016

What does the Time Profiler show? Can you link to a sample picture? cheers -ben On Sat, Nov 5, 2016 at 11:11 PM, Matteo via Pharo-users <pharo-users(a)lists.pharo.org> wrote: > > > ---------- Forwarded message ---------- > From: Matteo <matteob8(a)yahoo.it> > To: "Pharo is welcome (ML)" <pharo-users(a)lists.pharo.org> > Cc: > Date: Sat, 5 Nov 2016 16:10:45 +0100 > Subject: Speed up JPG images loading > Dears, > I'm loading a lot of pictures (70) through the method > "ImageReadWriter>>formFromFileNamed:". > The method is very slow, with images bigger than 5MB. > > Is there a way to improve the pictures speed loading? > > > Thanks > Matteo > >

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Speed up JPG images loading
by Matteo Nov. 5, 2016

Nov. 5, 2016

Dears, I'm loading a lot of pictures (70) through the method "ImageReadWriter>>formFromFileNamed:". The method is very slow, with images bigger than 5MB. Is there a way to improve the pictures speed loading? Thanks Matteo

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Re: [Pharo-users] Spec: Setting rows height of a pictures list
by Nicolai Hess Nov. 5, 2016

Nov. 5, 2016

2016-10-31 15:07 GMT+01:00 Matteo via Pharo-users < pharo-users(a)lists.pharo.org>: > > > ---------- Weitergeleitete Nachricht ---------- > From: Matteo <matteob8(a)yahoo.it> > To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> > Cc: > Date: Mon, 31 Oct 2016 15:06:27 +0100 > Subject: Re: [Pharo-users] Spec: Setting rows height of a pictures list > Thanks Nicolai, > > unfortunately, even using images of the same height I obtain a list > with thin rows. Maybe I'm typing something wrong. > > I'll try to figure out how to handle this. > Please let me know, if you have any further suggestion. > > Thanks, > Matteo > > For Images with the same height/width, you can use #buildWithSpecLayout: in the displayBlock and use a SpecTableLayout with the width/height of the image model image. But this doesn't really work, somehow the list widget can not handle the selection and scrolling (but the images are shown in full size) : imageModels := (1 to:10) collect:[:i | ImageModel new image: PolymorphSystemSettings pharoLogoForm]. listModel := ListModel new items: imageModels. listModel displayBlock:[:item | | layout | layout := SpecTableLayout row add:#yourself; height: item image height; width: item image width. item buildWithSpecLayout: layout]. listModel openWithSpec > > On 31/10/16 12:26, Nicolai Hess wrote: > > > > > > 2016-10-31 10:19 GMT+01:00 Matteo via Pharo-users > > <pharo-users(a)lists.pharo.org <mailto:pharo-users@lists.pharo.org>>: > > > > > > > > ---------- Weitergeleitete Nachricht ---------- > > From: Matteo <matteob8(a)yahoo.it <mailto:matteob8@yahoo.it>> > > To: "Pharo is welcome (ML)" <pharo-users(a)lists.pharo.org > > <mailto:pharo-users@lists.pharo.org>> > > Cc: > > Date: Mon, 31 Oct 2016 10:18:03 +0100 > > Subject: Spec: Setting rows height of a pictures list > > Hi, > > I've created a list of pictures, i.e. a widget based on > > ListModel where > > each item is a ImageModel. > > > > When the widget is displayed I get list window with very > > thin rows. > > > > Is there a way to control the ListModel rows height? > > > > > > Not if the images have different heights (you can, but it looks > > terrible, because the underlaying list morph does not work for list > > items with different heights). > > > > > > > > > > Thanks, > > Matteo > > > > > > > > >

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[ Article ] The code behind Google Authenticator
by Sven Van Caekenberghe Nov. 4, 2016

Nov. 4, 2016

I wrote another article in 'Concerning Pharo': The code behind Google Authenticator Implementing Time-base One-Time Passwords in Pharo https://medium.com/concerning-pharo/the-code-behind-google-authenticator-9c… I was curious how Google Authenticator, an iOS or Andriod mobile app used to implement two-factor authentication (2FA), really worked and how I could implement it myself. Since it is a lot of fun to experiment with and implement this kind of stuff in Pharo, I decided to give it a try. Note: fully documented source code with unit tests included. Sven -- Sven Van Caekenberghe Proudly supporting Pharo http://pharo.org http://association.pharo.org http://consortium.pharo.org

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