I’ve been noticing some oddities in how Visual Studio 2010 RC handles Custom ClassificationFormatDefinitions when multiple extensions are interacting together. It it hasn’t been fixed already, then I guess it’s already too late for it to matter, but I still wanted to bring it up just to know if it’s just me that’s been noticing this.

As some readers are aware, I’ve written a couple of VS2010 extensions for myself which I always install as soon as I setup a new VS2010 installation, and so far I’ve been very happy with the results and VS2010 extensibility in general. Both of these extensions define custom ClassificationFormatDefinition, whose format I then tweak on my current VS color scheme.

And this generally works great. That is, until I install another extension created by someone else. The first time I noticed this was when I installed the Visual Studio Color Theme Editor extension by Matthew Johnson. Everything worked fine, except that after using it a bit I realized that every time I changed the color theme for the whole IDE using Matthew’s extension, my custom ClassificationFormatDefinitions would revert back to the default formats specified in the original definitions in code, instead of the values I had assigned to them in my customized VS color scheme.

Re-importing the .vssettings file with my saved VS color scheme would get colors and formats right again, so, to be honest, I didn’t give it much thought at the moment.

Yesterday, however, I ran into this again while trying VsVim by Jared Parsons. As soon as I fired up VS2010 after installing VsVim, I noticed that custom formats for my own definitions reverted once again to the default values. I ran into a couple of issues with VsVim so decided to disable it for now while until I had time to look into it closer and imagine my surprise when right after restarting VS2010 my customized format definitions came up right away instead of the default values!

So my impression is that something (but not sure what) causes VS to ignore customized custom definition formats configuration (confusing, I know, sorry) when multiple VS extensions are running. Has anyone else run into this before?

Both Visual Studio 2008 and 2010 have a rather annoying issue relating to how XAML is highlighted in the Text Editor. I’ve complained in the past that the XAML designer team introduced a separate set of classifications (i.e. options in the Fonts and Colors dialog) to configure how XAML code would be highlighted by the editor, when in fact, it is just, for the most part XML and it would’ve been used if the XAML editor just used the same color definitions used by the XML editor.

However, this isn’t 100% true. It turns out that the XAML code editor uses the colors and font settings configured for String (e.g. like a C# string) to render raw text inside an XML element in the XAML code. Normally, this isn’t too much of a problem, until you create a color scheme that uses a custom background color to highlight strings. Then, this is what you end up with in XAML:

Notice how the different background is used to render even spaces used for indentation, which looks very, very ugly.

Now, there’s nothing I can do about VS2008, but at least with VS2010, I was able to write an extension that fixes this problem. Here’s how it looks with the extension enabled:

Much better, right?

Here’s basically all the code needed to fix this:

[Export(typeof(IWpfTextViewCreationListener))]
[ContentType("XAML")]
[Name("XAML Fix")]
[TextViewRole(PredefinedTextViewRoles.Document)]
public class XamlFixCreationListener : IWpfTextViewCreationListener {
   [Import]
      IClassificationTypeRegistryService registry = null;
   [Import]
      IClassificationFormatMapService mapService = null;

   public void TextViewCreated(IWpfTextView textView) {
      var formatMap = mapService.GetClassificationFormatMap(textView);
      var textClassification = registry.GetClassificationType("text");
      var stringClassification = registry.GetClassificationType("string");
      var props = formatMap.GetExplicitTextProperties(textClassification);
      formatMap.SetExplicitTextProperties(stringClassification, props);
   }
}

As usual, you can get the code for the extension from github. Enjoy!

Following the release of Visual Studio 2010 Release Candidate, I installed it on one of my laptops. I ran into some minor issues with the Silverlight dev tools SDK, but I hear they’ve been resolved for RTM. Other than that, it seems to be working fine.

I’ve already updated my Current Line Highlighting and Keyword Classifier extensions for the RC, so they should be ready to go if you build them from source.