Friday, April 01, 2016

Improving Inherently Important Internationalisation Issues

One of the lesser-known advantages of wxWidgets compared to many other libraries is that, using its API, you can centre a window on the screen and set its colour to grey without having to Americanise your programme. But, as natural as this behaviour is, and in spite of agreeing to wxWidgets licence (the very spelling of which should have been a sufficient hint), some users still expressed their surprise in their dialogue with us and refused our advice to accept using this flavour of the API. And so, to accommodate them, wxWidgets has traditionally provided alternatives such as Center() method, wxColor class and wxGRAY constant.

Admittedly, in practice this has been sufficient to avoid any problems for a long time while still remaining true to wxWidgets historically British roots. However, in addition to being British, wxWidgets was always mostly a European effort and, besides, knowing that it was actually born in Edinburgh, it might well end being exclusively European and not British at all in the near future (but don't worry, even if the worst happens, we plan to continue supporting British spelling for at least two more release cycles, in accordance with the general backwards compatibility policy). Considering this, it seems especially strange to have alternative American versions of the spelling, but no attention being paid to the other European languages.

And now, after releasing 3.1.0, it's finally time to do something about it as, clearly, there are few unresolved issues of comparable importance left. To begin with, I obviously had to add wxCouleur class which should undoubtedly help with wxWidgets adoption in francophone countries. But adding just the French variant would certainly be undiplomatic, so another pull request adds, in the grand European tradition of Franco-German alliance, wxFarbe, and both of them will be merged together to avoid any questions of precedence. Further, France and Germany notwithstanding, I certainly don't plan to discriminate against other countries but, in the usual spirit of Open Source, additions of wxColore, wxFarve, wxKleur etc will have to wait until the appropriate patches are submitted (luckily for them, Spanish users can, in the meanwhile, already reuse the American variant, just as they already do with many other words, e.g. burrito, for the classic American food).

Of course, nothing is ever as simple as planned and, while working on this, I quickly realized that Greek might present some practical difficulties as UTF-8 support is still, even in 2016, not perfect on some of the legacy platforms supported by wxWidgets, but it would be difficult to use wxΧρώμα without it. A compromise solution that we're currently discussing would be to introduce a wxChroma class right now and deprecate it by the time 3.2 is released as Unicode support should really be widely available everywhere by then (3.2 release is currently planned for the early 2030-ies).

I do hope you will enjoy these changes, but, let's be honest, this is just the beginning and we clearly still have a lot of work to do in this area. Fully supporting colour internationalization is important, but it's just the first step and we plan to go much further. Just imagine to be able to open a wxFenêtre and choose a wxStylo for drawing on it and then, perhaps if you live in Switzerland, create a wxKnopf as its child. The possibilities are endless! Unfortunately, the same can't be said about our resources, so we count on your help to make wxWidgets the best internationalized library of all time -- and we're looking forward to your contributions!

Monday, February 29, 2016

An unexpectedly expected release: 3.1.0 is available

Surprisingly, at least to me, we managed to make 3.1.0 release exactly as planned, i.e. today, without any delays. The price for this is that there are a couple of known problems in this release (see the errata on the release page), but we decided that it was not worth delaying the release for them.

This is not the most exciting release in wxWidgets project history, but it's still very much worth upgrading to as there has been a huge number of bug fixes in it, especially in wxGTK3 and wxOSX ports. Of course, as usual, there are a few new features as well, see the web site for a brief list and the change log for a fuller one and I'll try to find some time to write in more details about one of them, wxNativeWindow here in the near future.

The next goal is to release 3.0.3 to make at least some of the bug fixes, if not the new features, from 3.1.0 available to people using the system packages under Linux or just too cautious to start using the "development" releases (even although in my opinion this is not really justified as, on average, 3.1 branch has fewer, not more, bugs than 3.0.x one). As for 3.1.1, this will depend on how quickly the changes accumulate in the master, we'll see how it goes. In the meanwhile, we hope that you'll enjoy the new release!

Thursday, February 04, 2016

What g++ binaries for 3.1.0 release?

We plan to provide g++ binaries for the upcoming release, but we're not sure what are the versions and the build options that people would be interested in, so here is a quick poll to gather some information about this:

polls

Please select 1-3 options corresponding to the binaries that would be useful to you to allow us to make the best choice. Thanks in advance!

Monday, February 01, 2016

3.1.0 Is Coming

Although we've been talking about it since quite some time, this time we're really going to make a new release soon. To be even more precise, I firmly expect to make it this month. Of course, I did wait until January was over to announce it. On the other hand, I did not wait for the February to be over neither even though it's the shortest month of the year. On still another hand, we did wait an extra year for this release, presumably just to have one extra day to make it in February of this year, as opposed to the last one... In any case, barring something really catastrophic happening, we should have a pre-release on February 15 and the release some time after that.

Of course, deciding to make the release is not quite enough, there are other things to do too, such as applying at least the most urgent and long standing patches and fixing selected bugs. So this week-end I spent some time doing this and, as the result, instead of 49 3.1.0-critical bugs we now have only 20 of them which is not as good as I hoped, but better than I expected. Of course, some of these bugs were just postponed, while others turned out to be not bugs at all after all or to have been already fixed. Still, quite a few real bugs and, notably, a few regressions which really couldn't remain before the release, were fixed as well, so there is that. I hope to deal with the remaining bugs during the next week and maybe even apply some non 3.1.0-targetted patches too, but in the worst case we could just postpone all the remaining 3.1.0 tickets as there is nothing absolutely critical there (and only a couple I'd characterise as being moderately critical).

So things look cautiously good for 3.1.0 and if we make it according to the plan, thus proving that our new release scripts, updated after the switch to git, work, hopefully 3.0.3 will follow soon afterwards.

Thursday, January 21, 2016

Dropping Carbon support under OS X

We would like to remove the old Mac OS X port using Carbon in the upcoming 3.1.0 release because we think nobody should be using it any longer (and we definitely know that nobody building 64 bit applications does because Carbon just doesn't exist in 64 bits) and it would make things simpler for us. But "should" and "is" are different things and if there are more than a handful of people who are still using Carbon and can't migrate to wxOSX/Cocoa port (I'd like to know why!), but, at the same time, still plan to update to 3.2 in the observable future, we could reconsider this. So if you'd like Carbon to continue to be supported, please let us know, in the comments here or on the mailing list. Thanks!

Sunday, June 14, 2015

Build fixes for different gcc distributions under Windows

I've spent most of the day today fixing various compilation issues for the three most often used distributions of gcc under Windows: TDM-GCC, mingw-w64 and the "classic" MinGW trying to ensure that the upcoming 3.0.3 release (as well as the current master) builds out of the box with all of them using all the common build scenarios. TDM-GCC and mingw-w64 required just one minor fix for g++ 4.9.2 which started providing clang-like __has_include() except with different (and IMHO completely useless) semantics, so we just have to ensure that we don't use it with gcc even if it is available which was easy to do and actually had been already done on master.

However things were much more interesting with MinGW. The main problem with it was that it couldn't be used to build wxWidgets with -std=c++11 option (nor -std=c++98 one, but almost nobody ever used this one anyhow) nor, even worse, even use this option when compiling applications using wxWidgets as it broke compilation of wxWidgets headers. There always was a simple workaround of using -std=gnu++11 option instead, but it only was simple once you knew about it, which wasn't the case for most of first-time wxWidgets users who ran into it. So I finally decided to make -std=c++11 work as well and now it does, even though this wasn't simple nor pretty.

The summary is that now building with all 3 compilers with and without -std=c++11 works. And, as a side effect of this, I also fixed some (mostly harmless) warnings so that building with MinGW and mingw-w64 now doesn't give any -- at least in the configurations I tested. TDM-GCC is pickier (which is probably a good thing) and still gives quite a few warnings, so using -Wno-unused-value in CXXFLAGS with it is recommended: with this option only a couple of warnings in 3rd party code remain.

Of course, there are too many combinations for me to have tested all of them: 2 branches (3.0 and master), C++11 and C++98, static and shared, Unicode and ANSI, STL and not-STL already give 96 builds to test and there are other options too. So, before I spend too much time congratulating myself, it would be great if people could actually test the build configurations they use and are interested in and report if there are any (and especially any new) problems with them as I'm sure I must have also broken something with so many changes. I'm just not sure what, yet -- please let me know!

Tuesday, April 07, 2015

Validating XRC

Overview

If you write your XRC files
by hand (which is probably relatively rare as most people prefer to edit them visually, but it does happen), and if you are human (which is probably not so rare), you are bound to make mistakes in them. Some of these mistakes result in invalid XML which give errors when loading the XRC file, some of them are not a big deal and are just ignored by the XRC parser, but some others can result in the layout mysteriously not working as expected, which can be annoying. Validating XRC files, i.e. verifying that they conform to the scheme describing all the valid XRC elements, allows to avoid all these problems at once, so it is strongly recommended to do it -- and this post will explain how, in details.

Setup

To validate them you need two things: a schema and a tool using it. The schema exists in our repository since October 2013 and is also available at the public URL http://www.wxwidgets.org/wxxrc. As for the tools, anything supporting compact RELAX NG schema syntax can work, but in practice this seems to limit the choices either to the online validator at validator.nu (Edit: this validator can't be used for validating XRC currently as RELAX NG support seems to be broken) or the original command-line validator, written by James Clark, one of the persons behind RELAX NG, called Jing, and the offline version is, unsurprisingly, much more useful as it can be integrated into the build process or used as part of pre-commit hook checks easily, so this is the one we are going to look at.
The latest Jing release is available from Google Code, but as the entire site will be closing soon, it might not work any longer by the time you are reading this, so here is the smaller and more up-to-date version. It is completely standalone and requires just a working Java installation, you can put the JAR file anywhere you want and simply run
$ java -jar /full/path/to/jing/jar
(in spite of the dollar sign indicating the Unix prompt, this works under Windows, too). The basic Jing command line syntax is just the schema file followed by any number of files to validate, however XRC schema uses the compact syntax which has to be explicitly selected by its -c option, so in the simplest case the full command line would look like
$ java -jar jing.jar -c $WXWIN/misc/schema/xrc_schema.rnc myfile.xrc
where WXWIN environment variable is supposed to contain the full path of your wxWidgets installation.
As an aside, it is also possible to avoid hard coding the path to the XRC schema, which may be important to make the validation step work on different machines. The natural way to do it would be to just use the canonical URI instead of the path to the schema, i.e. http://www.wxwidgets.org/wxxrc but currently this doesn't work, seemingly because of a bug in Jing handling HTTP-to-HTTPS redirections. The following command does work:
$ java -jar jing.jar -c https://www.wxwidgets.org/wxxrc myfile.xrc
but still has two problems: first, the URI is, formally speaking, wrong as it should be using "http" schema. Second, and probably more importantly in practice, it can be slow as the file needs to be downloaded from network every time. To fix this problem, an XML catalog mapping the canonical URI to a local file can be used. I won't pretend to know much about XML catalogs (because I don't), but here is a minimal one that can be used to set up the correct redirection:
If you save the above file as catalog.xml and adjust the value of the uri attribute to contain the correct path to xrc_schema.rnc on your machine (notice that triple slashes are needed), you should be able to use
$ java -jar jing.jar -C catalog.xml -c http://www.wxwidgets.org/wxxrc myfile.xrc

Using (or not) Custom XRC Elements

After the setup describe above you can use the standard schema xrc_schema.rnc to validate the contents of all the standard XRC elements, such as <sizeritem> or <object class="wxButton">. However any custom elements are simply ignored by default because the standard schema has no knowledge of them. Of course, you might not have any custom XRC elements at all. In this case, you should use xrc_schema_builtin_only.rnc, located in the same $WXWIN/misc/schema directory of your wxWidgets installation, to forbid any of them from appearing. There is no canonical URI for it, so you should simply pass full path to it on Jing command line.
The more interesting case is when you do define some custom XRC handlers. In this case using xrc_schema_builtin_only.rnc would result in errors about invalid value of attribute "class" for all your custom elements, so you need to define a custom schema describing just them. An example of doing it is shown in misc/schema/README, but here is an even simpler custom schema:
This schema allows appearance of a custom Frobnicator window-like (because of stdWindowProperties inclusion) element which can have one specific (but optional, because of the trailing *) num_times attribute, i.e. would validate the following XRC fragment: if you issue
$ java -jar jing.jar -C catalog.xml -c frob.rnc frob.xrc
command. Of course, the same fragment would also be accepted by the standard schema, the real benefit of using a custom one is that typos in either "Frobnicator" or "num_times" would be detected only by the latter.

TL;DR Summary

Your easy guide to XRC validation:
  1. Download jing.jar
  2. For one-time validation of only standard XRC elements just run
    $ java -jar jing.jar -c https://www.wxwidgets.org/wxxrc myfile.xrc
  3. For repeated use, download XML catalog, edit the file path in it and run
    $ java -jar jing.jar -C catalog.xml -c http://www.wxwidgets.org/wxxrc myfile.xrc
  4. If you use custom XRC elements, consider defining a schema for them too, it is simple to do.