NetSurf Developer Workshop Redux

Once again the NetSurf developers congregated in Cambridge at the Collabora offices where we were made welcome in a nice environment for the event.

Five developers managed to attend from around the UK Rob Kendrick, Vincent Sanders, Daniel Silverstone, John-Mark Bell and Michael Drake. We also had Chris Young and François Revol providing some bug fixes remotely.

This was the first time we had all met since the previous event towards the end of 2012 and we took full advantage of this to discuss a pretty extensive agenda in addition to the practical programming tasks.

From Friday lunchtime through to Sunday evening we managed 30 hours of work consisting of over 70 commits to over 100 files.

Our main focus was working towards a 3.1 release which is scheduled for early April. Along with the source the release will have binary builds for RISC OS, AmigaOS, Windows and Mac OS X (x86 and ppc). Although the NetSurf project will not be directly releasing binaries for the GTK and Framebuffer frontends we will be ensuring the Debian packages are updated which is our prefered method of distribution for those targets.

We analysed the 3.0 release and formulated an improved process for the future. The 3.1 release will be generated automatically by the CI system ensuring constant results and removing the problems we encountered previously.

A set of release blocking issues was derived which we used as a task list during the workshop.The majority of these were completed including:

DOM based forms

Web forms are a feature Netsurf has supported for a long time and their implementation has not kept up with the rest of the browser. This is a long standing problem area which has resulted in numerous strange bugs with form submission. With this change the form system has been reworked to correctly operate directly from the DOM resulting in the squashing of a large number of bugs and a much improved user experience.

DOM based image loading

Up to now image fetching was performed only during the rendering of a page. With this change when the image link is placed into the DOM during the page parse it is scheduled to be fetched, this should give an improved user experience as images should be available earlier in a pages render.

Removal of MNG support

NetSurf has supported MNG since the 1.0 release, indeed the MNG library used to provide the PNG support too though we have long ago transitioned to libPNG. Alas the web has moved on and MNG has been largely forgotten, the libMNG library that performs the image decoding is old and generally unsupported specifically lacking security updates.

The build issues with libMNG (lack of pkg-config, reliance on libcms1 etc.) were causing maintenance issues in code nobody was actually using (there were crash bugs discovered during its removal!). Because of these issues it was decided to join the vast majority of browsers and remove support for this format.

The developers also addressed several issues with toolchain construction and a number of annoying usability bugs.

Plans for how to improve printing support we made. Initially we intend to fix the existing haru based pdf generation using this to print via pdf and in future have correct css styled page paginated printing render output.

The perennial issue of javascript was discussed however, while efforts to improve the existing support are ongoing, our usage of the spidermonkey library continues to raise various challenges including platform support and API changes between versions.

Due to these issues it has been suggested that we might add support for using the duktape JS engine instead, initial results are promising but given the size of the task of implementing an additional javascript engine binding further investigation is necessary before making a commitment.

Amongst the other discussions the group has also agreed that we will once again apply to be a GSoC organisation for a single student with some very focused projects:

• Improving our HTML5 parser (hubbub)
• Improving the DOM library implementing missing functionality.

While neither of these projects are as fashionable as some of our previous proposals they are well defined enough that as a group we believe we could offer enough support to the student to make their experience a pleasurable one and get the resulting code reviewed and merged promptly.

This event was very successful with a great deal achieved, the project is much more likely to be in a good shape to release 3.1 by April now and the meeting has given the developers a much welcomed boost.

I would like to extend the groups thanks to Robert McQueen for letting us use the Collabora offices, Dorée Carrier for organising all the administrative things and to Vivek Dasmohapatra for coming out on his Sunday afternoon to let us back in after locking ourselves out.

NetSurf Developer Workshop

Over the weekend we held the NetSurf developer workshop. The event was kindly hosted by Collabora at their Cambridge offices. The provided facilities were agreed to be excellent and contributed to the success of the event.

Five developers managed to attend from around the UK John-Mark Bell, Vincent Sanders, Michael Drake, Daniel Silverstone and Rob Kendrick. In addition James Shaw, one of the project founders, made a special appearance on Saturday.

Starting from Friday afternoon we each put in over 25 hours of actual useful work and made almost 170 commits changing over 350 files, added 10,000 new lines of code and altered another 18,000.

The main aim of the event was to make the transition from using libxml2 to our own libdom library for the browser DOM tree. This was done to improve the browsers performance and size when manipulating the DOM but also gives us the ability to extend the browsers features to include dynamic rendering and Javascript

We also took the opportunity to discuss and plan other issues including:

• User interface message handling and translation.
• User preference handling.
• Toolchain support.
• Disc caching.
• Javascript binding
• Electronic book content handler.

Rob tackled the first parts of the messages conversion from numerous separate files into a single easy to handle file which will in future allow for easier translation and reduce message proliferation.

We made decisions on the ongoing rework of user preference handling which will be implemented in future.

The decision on the toolchain was slightly changed to be that any core or library code (non frontend/toolkit specific parts) are required to conform to the C99 standard. Frontends are permitted to recommend and use whatever tools their maintainer selects but they cannot enforce those restrictions on core code. This issue is principly because the BeOS maintainer is compiling NetSurf with g++ 2.95 which is missing several important language features we wish to use.

The recurring issue of disc caching was raised again and we have come up with what we hope is a reasonably elegant solution to be implemented over the forthcoming months.

Now there is a suitable DOM to bind against, the existing Javascript engine support will be properly integrated and should result in basic script support before the 3.0 release. This support will remain a build time option so NetSurf can continue to be used on platforms where the interpreter is too resource intensive to be used.

A short discussion about the possibility of integrating a basic page based content handler for epub and mobi type documents was discussed and while the idea was well received no decisions on implementation were made.

Overall the event was a resounding success and we are left with only a small handful of regressions which appear straightforward to solve. We also have a clear set of decisions on what we need to do to improve the browser.