Decisions Decisions

Parted ways with Xamarin today. Reflecting on my time at Ximian and then Novell, I've enjoyed working closely, day-to-day, with the professionals on the Mono team, as well as our talented volunteer community. It's been a real treat for the past 8 years.

I believe in Mono and Gtk# and still think they're the best thing going on Linux and the Open Source universe. Looking at the amazing applications that have been written for the desktop using technologies I've helped to create, and the way we've managed to extend Mono's reach to mobile devices, I'm proud of what we've accomplished.

Nothing definite yet for where I go from here. I'm interested in serious opportunities for a skilled developer with expertise spanning the unmanaged C, Java, and Mono/.NET universes on Windows, Linux, OSX, Android, and iOS.

Scribbling 3.0 Style

Just a quick update. Got a little farther with the samples the last couple evenings. Fixed up a few bugs causing some issues with a couple of the ones that already build, like native-instantiation.exe. Then I tore into Scribble.cs.

It was originally ported from a gtk example back in the early days. It may have been before we really had much subclassing support in Gtk#. I decided to see if gtk+ was still shipping the sample, and just do a clean port of the current sample instead of trying a minimal update.

The majority of the work needed to port the old sample to 3.0 boiled down to a Gdk.Pixmap to Cairo.Surface port. The ExposeEvent to Drawn event transition was needed as well. This is starting to sound a bit like a broken record, though I would imagine many readers have never heard a broken record.

But I digress.

The finished port of the gtk+ sample is now in master, along with all the fixes to the stack to expose some needed API that wasn't getting generated. The list of non-working samples is getting shorter.

More Progress

Been slogging along with the process of auditing API and fixing samples to compile and not crash instantly. Things got a whole lot more stable in the last couple evenings. I pushed a bunch of updates today that allow the cairo drawing sample in the Gtk# samples to run cleanly.

The configure now requires the gtk+-3.0.0 release since it has hit the streets. There was a bit of API churn between 2.99.0 and 3.0.0, which accounted for one of the more insidious crashes to track down. Geoff Norton helped me figure that one out today, and when I reparsed for the 3.0 API a lot of things fell into place.

The size negotiation and drawing API changes are going to make for a little work when people start switching over. These are the most common trip-ups I'm experiencing in the samples. Any custom widgets which overloaded Widget.OnSizeRequested in 2.x will need to pick one or more of the new negotiation VMs and port to them. For example, in the PolarFixed sample, I made the existing OnSizeRequested method private and delegated to it from new overrides for OnGetPreferredWidth and OnGetPreferredHeight.

In CairoSample, the only substantial change required was converting the old OnExposeEvent override to a new OnDrawn method. The new method utilizes the new AllocatedWidth and AllocatedHeight properties to obtain sizing info to pass into the rendering methods. Of course, the code was already drawing to a Cairo.Context, so the logic was ready to go. A widget using the Gdk drawing API, or Style painting may have substantially more work to make the shift.

I'll try to blog more impressions of the porting effort as I move through the samples, and I encourage anyone who decides to dig in with their own apps to try to capture the knowledge, be it by sending a message to gtk-sharp-list, blogging, or adding them directly to the porting guide I've started on the wiki.

Signs of Life

With gtk+ closing in on their 3.0 release, many folks have been inquiring about Gtk# 3 lately. We've had a number of offers to help as well. I've been tied up with another project at the ol' day job, but I've been dedicating a fair amount of evening and weekend time toward 3.0 bindings since the holidays. It also looks like I'm going to be getting some more cycles to push the effort forward in the near future.

Over the past couple evenings, I've pushed a series of commits to github.com which update master to a 2.99.x API level. Several of the samples are still not being built because of 3.0 API breakage. Most of the samples which currently build also run cleanly, but there are some crashes there to address as well.

I've temporarily created a cairo-sharp.dll from the copy of Mono.Cairo we have been carrying in the tree, with a few updates to expose some of the new 1.10 API. This will likely get merged back into the mcs/class tree, but it's a convenient place for us to move fast with fleshing out the new bits.

The generated APIs are completely unaudited at this point. The improvements in the external Gio and Builder bindings since they spun off remain unmerged. There is plenty of work to go around if people would like to jump in and help. We are going to need migration docs, new API docs, the list goes on...

Since people are likely wondering, the module still starts from a C parse. I have experimented with starting from GIR format but feel at this point, given the current tooling state, that it will be quicker to get to 3.0 using the existing GAPI parser for gtk-sharp. Since this is getting long already, I'll expand on the reasons in another blog, plus talk about the approach I think we can take to begin incorporating GIR as a starting point in new bindings.

Mono Visual Profiler

We're seeking the input of profiler users and other interested parties to help create a visual profiling tool for mono applications. Development is under way in the mono-tools module alongside the current command line decoder. The tool is a UI to interact with the built-in mono logging profiler and graphically display captured profile logs. The visualization capabilities of the tool are still fairly primitive, but it is already capable of creating and displaying log data for instrumented, allocation, and statistical profiles.

I have created a wiki page to track the feature capabilities and plans. There is also a "Visual Profiler" category for bug reporting and enhancement requests in the Mono:Tools bugzilla product. Discussion will occur on mono-devel-list.

Gtk# for .net

Forgot to blog about this when it happened, but since I've gotten a couple of questions lately...

In February, we released a new version of the Gtk# for .net installer. It packages Gtk# 2.12.8 and the associated gtk+ binaries, including the registry keys necessary to build projects with MSBuild and add references using the references dialog in VS.

This single installer combines the managed development functionality previously provided by both the SDK and Runtime installers in a significantly smaller download than the old SDK installer, since it no longer ships many of the C development files packaged in the old installers. This installer also works properly on XP and Vista, unlike previous versions.

In the near future, we will be announcing the availability of additional installers supporting the use of mono libraries like Mono.Posix, Mono.GetOptions, and Mono.Addins on .Net and maybe a new application installer or two as well. Stay tuned.

Gtk# for .Net installers

Today, by popular demand, we announced the availability of win32 installers for Gtk# version 2.12.6. Runtime and SDK installers for .Net similar to those provided in the past by Medsphere are now being provided from the Mono project downloads page.

Hack Week: 1WPF

For Novell Hack week, instead of hacking on exert as I did in the past, I chose to spend some time on a MonoDevelop Gtk designer restructuring project I've been considering: one widget per design file.

The current designer architecture is based on project-level design files, saved in a special hidden directory along with generated source files needed to compile the designs. This design decision builds upon the existing stetic project-based file format. It complicates several common operations, however, some of which have open bug reports.

One problem is the ability to either copy or move widgets between projects. Another, is the ability to add existing widgets to new projects as "external files" so that a single design can be reused by multiple projects. When the design of the widget is saved as a child element of a project-level xml document, all of the above operations are considerably more complicated than if the widget design is contained in a standalone file.

I'm implementing this redesign as a new addin in MonoDevelop, so that I won't have to pay as much attention to feature parity with the existing designer. The hope is that at some point we can just switch the default designer to the new addin, once it reaches maturity. Based on the amount of work remaining, this will clearly be post-2.0.

Thus far, I've ported the existing addin extension code and begun the rework of the stetic WidgetDesigner. Currently supported features include:

• SolutionPad display bindings and extensions
• Grouping of related source, design, and codebehind files.
• A CodeDom based project template to create Application projects in mulitple languages.
• Project Compilation extensions to generate codebehind files, capable of compiling template projects.
• CodeDom templates for ActionGroups, Dialogs, Widgets, and Windows.
• Toolbox provider and loader.
  
• WidgetEditor built on existing stetic wrappers and class descriptions, currently view-only.

Here's a screenshot of a template project in C#. The template also compiles already in VB.net.



Once I get the widget editor working, I'll probably go ahead and check in the addin for people to play around with. No current estimates on when that might be other than, "when it's ready."

GObject Property Registration

Christian Hoff submitted a nice patch to Gtk# supporting GObject property registration on managed subclasses. This is a feature request we've seen off and on for a while now, especially from people writing Custom CellRenderers. Until this patch, it was necessary to use a CellDataFunc with custom cell renderers instead of using the SetAttributes mechanism exposed by Gtk.

I committed a little sample along with the patch to demonstrate its use.

Standings and Exert Features

As of this evening, 5 quarters are finished. The prognostication standings:

Mike: 5
Maggie the Monkey and Jackson: 2

Been adding some new features to exert the last couple weekends. Last weekend, it was a couple new icons for swimming and cycling:



I also hacked EntryCategory editing and creation in the Preferences dialog. It supports editing of category names and icons, plus a "visible" checkbutton to indicate if you want the category shown in the Entry dialog combobox.

This weekend, I added a status tray icon and menu.



I've got a list of features I want to add, but I will probably kick out another release soon. The Garmin device support deserved a release months ago.

Hockey talk

Jackson took a group of us non-Canadians to a Bruins/Blackhawks game in Boston last fall, and rekindled my interest in the Blackhawks. Seeing as Jackson has posted his picks for the first round, I figured I would post my completely novice guesses just so I can belittle him if I happen to guess correctly.

West:
'Wings d Preds in 6. Ellis is gonna win 2.
Sharks d Flames in 4. Flames are going down hard.
Avs d Wild in 6. Wild are too boring to win.
Stars d Ducks in 7. Could go the other way in 7.

East:
Montreal d Boston in 5. Boston will win one at home.
Pittsburgh d Ottawa in 5. Crosby with 16 points.
Caps d Flyers in 6. Caps are gonna drop one at home, probably game 1.
Rangers d Devils in 7. Though I couldn't care less.

If you place any bets based on these picks, I will expect my usual commission.

gio-sharp

Been getting quite a few requests for libgio bindings. I whipped up a new module in mono svn to provide an unstable binding for people who want to experiment and help refine the API. It is my intention to eventually, most likely in gtk-sharp 2.14, merge this binding into gtk-sharp and eliminate the standalone package. Until then, it will install per the Mono Guidelines for Unstable Library Deployment outside the GAC.

For the extremely impatient and adventurous, you can find it at trunk/gio-sharp. You will need GAPI from trunk/gtk-sharp to build it. It still throws tons of generation warnings. I have made zero attempts to use it. It has no docs. If it melts your laptop, don't complain to me.

Feel free to file bug reports for anything out of order. I'll try to be responsive to any reports, and as always, patches are welcome.

Enjoy.

Hack Week II Exertion

This week was Hack Week 2 at Novell, and I decided to spend the week adding Garmin Forerunner import support to exert. I had hoped to maybe move on to some heart rate graphs and lap display, but time ran out.

All track, lap, and run data is importing correctly into the exert sqlite database, at least as far as I can tell from some sql querying. The visible entries are coming in cleanly and displayed properly, but there may still be some glitches in the lap summary and GPS track point data.

Here's a rather boring screenshot of the end result.



Current support is limited to the ForeRunner 305, but it should be easy enough to add other devices if people are interested. I just didn't feel like implementing the entire protocol up front.

The code is on svn at sourceforge. I will probably hold off on a release until I can display more of the data visually. I want to add heart rate graphs, route maps, and lap tables. Maybe next hack week...

IOChannels and Spawning

For the most part, we like to avoid wrapping as much of glib as possible, instead preferring the .Net framework capabilities. We hide as many GList and GHashtable parameters as possible, for example.

I've received several comments in the past that the .Net APIs for IO and process spawning didn't really match up to the glib API. Taking this feedback, I spent the last couple days wrapping, testing, and documenting a new glib-sharp binding for g_spawn_* and GIOChannel.

Here's an example usage from the docs:

using GLib;
using System;

public class SpawnTest  {

        public static void Main (string[] args)
        {
                new SpawnTest ();
        }

        MainLoop main_loop;
        IOChannel channel;

        public SpawnTest ()
        {
                main_loop = new MainLoop ();

                try {
                        Process proc;
                        int stdin = Process.IgnorePipe;
                        int stdout = Process.RequestPipe;
                        int stderr = Process.IgnorePipe;
                        GLib.Process.SpawnAsyncWithPipes (null, new string[] {"pwd"}, null,
                                                          SpawnFlags.SearchPath, null, 
                                                          out proc, ref stdin, ref stdout, 
                                                          ref stderr);
                        channel = new IOChannel (stdout);
                        channel.AddWatch (0, IOCondition.In | IOCondition.Hup, new IOFunc (ReadStdout));
                } catch (Exception e) {
                        Console.WriteLine ("Exception in Spawn: " + e);
                }

                main_loop.Run ();
        }

        bool ReadStdout (IOChannel source, IOCondition condition)
        {
                if ((condition & IOCondition.In) == IOCondition.In) {
                        string txt;
                        if (source.ReadToEnd (out txt) == IOStatus.Normal)
                                Console.WriteLine ("[SpawnTest output] " + txt);
                }
                if ((condition & IOCondition.Hup) == IOCondition.Hup) {
                        source.Dispose ();
                        main_loop.Quit ();
                        return true;
                }
                return true;
        }
}

I'd appreciate it if anyone who has been missing this functionality in Gtk# would try it out and let me know any issues you find, or places the API can be improved.

Exert 0.1

I've spent a little spare time hacking on exert recently and have reached the point where it has all the features I use from my online running log. I decided to switch over to using it for my log, so that means I need to maintain database compat from now on. I figured I might as well release it in case anyone else was interested in playing with it.

There's a source tarball available, and I used the opensuse build service to provide packages for 10.3 and fedora. Enjoy.

Moko Bindings

One of the comments on my last blog entry suggested a libmokoui binding. Since it was a nice small target, I went ahead and whipped up a binding for it this afternoon. It took me longer to write the tutorial I added to the wiki than it did to produce the binding.

Granted this was a very simple binding, since it is small and the source code was written perfectly for the GAPI parser's consumption. It also has no auto* magic. The tarball contains generated sources which could be copied into your project and compiled and installed as a private assembly. There is really no point to GAC magic for an assembly with no guarantees.

Bind this...

We are looking to add to the already impressive list of libraries accessible from mono. If you have any special requests of the latest and greatest libraries which you like to access from the sexy managed language of your choice, please let us know your needs so we can prioritize our efforts.

You can make your wishes known by commenting on this blog entry, mailing gtk-sharp-list@lists.ximian.com, filing a bug report, or writing on a cocktail napkin and mailing it to us, if you can figure out where we live.

GInterface Implementation

Finally "finished" the framework for GInterface registration in Gtk# this week. I wrote up a small tutorial and API description. It points to the small test application I wrote to demonstrate TreeModel implementation, which is the most common reason people have requested GInterface registration for the past few years.

Here's a screenshot of the sample which uses reflection to display the assemblies, types, and members in the application's AppDomain.

Reflection: a Cautionary Tale

Back in the day, I needed a mechanism to execute a method for a class for each new subclass of that type. Class constructors were not sufficient, because they are only run once per type, not once for every subclass of that type.

I decided to annotate the init method with an attribute and use reflection to lookup the method. When we register a new GType, we scan the class hierarchy for private static methods with a GLib.ClassInitializerAttribute and invoke any that exist. We use a similar mechanism to hook overridden virtual methods into the GObject class vtables for signal default handlers using the GLib.DefaultSignalHandlerAttribute.

This strategy works, but it turns out to be pretty suboptimal, especially from a memory usage standpoint. In order to find the methods with [ClassInitializer] defined, we had to load all the private static methods in the type hierarchy, and then iterate over them to look for the attribute. This caused a pretty substantial memory spike for types like Gtk.Widget which have a ton of static method delegate implementations for signal marshaling.

The root of the error was in not recognizing that the Class init problem is a one-to-one relationship of class to method, where the signal delegate problem I borrowed from is a one-to-many scenario. There is a [DefaultSignalHandler] method for each signal defined by a class.

To improve the mechanism, I added a GLib.TypeInitializerAttribute which takes a type and method name argument. With this attribute applied to a type declaration, we can lookup the specific methods by name and avoid loading all the static methods in the entire class hierarchy. This feature is now committed to trunk and the branch svn.

Since we have released the GLib.ClassInitializerAttribute as public API in a stable release, I couldn't just remove the reflection for it, even though it is unlikely that anyone out there really discovered the feature and is using it. In order to make it possible for subclass authors to avoid the reflection step, I also added the GLib.IgnoreClassInitializersAttribute which can be applied to any assemblies which contain GLib.Object subclass declarations. Svn trunk and branch add this attribute to all the gtk-sharp and gnome-sharp assemblies, so that all the types defined by the packages avoid this reflection overhead. The internal usage of [ClassInitializer] has been ported to [TypeInitializer] as well.

Thanks to Lluis for identifying the issue and Paolo for his usual insightful feedback in alternative approaches to the functionality. Lluis also helped refine the implementation of the [ClassInitializer] back-compat mechanism. My understanding is that the recent changes reduced MonoDevelop startup memory usage by about a MB.

Change change change

After living with 4 German Shepherds for over 10 years, the past year has held a lot of painful if not unexpected changes for Sherry and I. We lost OD last fall at ten and a half. This summer was particularly bad, losing our 11 year old JR just two weeks after 13 year old Maggie.

Sherry, Qman, and I have sort of been moping around the house for the last month. It's amazing how empty a house can feel.

That all changed Wednesday night.



It's equally amazing how quickly a 3 month old puppy can fill up a house. Her name is Beebee. We haven't had a puppy in the house in over 11 years. The frantic dashes to the back yard during housebreaking. The brief periods of high-energy romping separated by hours of food-induced comas.

Qman has not been all that interested in playing her little puppy games, but has been very tolerant of her. At times, it seems like he's just laying there rolling his eyes at her. She has a pretty amazing personality. Extremely friendly and confident, and the shepherd drive to please is already evident. We are really looking forward to watching her develop and anticipating the fun we'll have earning obedience, agility, and tracking titles.

Oops, time to take her out back again!