05 Aug 09 PowerPointLaTeX Update

Because people complained to me about the formula feature in my PowerPointLaTeX add-in, which used a somewhat experimental approach to editing formula objects by adding an editing text shape that contained the formula code and that would be merged back into the formula as soon as you deselect it, I decided to rewrite it to use a standard modal dialog to edit formula objects:

The editor isn’t perfect (yet), but it certainly shouldn’t add any bugs to the add-in and solve some natural issues the old approach created.

Implementation Note

The idea was pretty straight-forward but the actual UI design was a PITA due me not knowning the panel/flow/table layout concepts very well and the code still has some annoying quirks with auto-scroll, so I need to fix that later.

I almost rewrote the whole cache system, because I’m using a background thread for updating the preview (if the text is changed, a 500 msec timer is started which triggers an update) and the update accesses the cache system, which in turn accesses PowerPoint to return some data, which in turn is busy because of the modal dialog -> dead-lock.

The solution to this is very simple but was not obvious to me at first (I actually began to rewrite the cache system with a feeling that there should be an easier solution):
The background thread needs an Invoke call to update the preview picture because the control has been created by a different thread (the main thread) and the code to get an updated picture can simply be moved into Invoke delegate function.

This solved all my problems and made 4 hours of previous work and thinking about a new cache system obsolete

Download the new build at: http://code.google.com/p/powerpointtools/downloads/list

Cheers,
Andreas

Tags: Formula Object, Invoke, LaTeX, PowerPoint

21 Jun 09 Extending Java and Javac

Today I want to write about something I’ve been working ages ago – specifically in March I wanted to see if I can extend a Java compiler to support LINQ´ expressions, too.

I probably spend more time on finding a good open-source compiler to experiment with than I later spent on trying things out, so let me share my preferred source with you: http://openjdk.java.net/ is a good address to start with.
More specifically http://openjdk.java.net/groups/compiler/ contains some valuable information about the way the compiler works.
A nice thing is that there is a branch that has added support for ANTLR which makes added language a tad bit easier since you get to change a grammar file instead of tweaking hand-written lexers and parsers. More info about it can be found at http://openjdk.java.net/projects/compiler-grammar/.
You can download the source code from http://hg.openjdk.java.net/ – don’t follow the link to http://hg.openjdk.java.net/compiler-grammar/compiler-grammar, that one will only allow you to download part of the branch´.

I didn’t come around to add support for LINQ in the end, but to get known to the compiler and the ANTLR grammer, I added support for the var keyword as known from C#, which allows for automatic type deduction and for anonymous objects (again using the C# syntax). Thus my changes allowed for the following to compile and execute correctly:

public class Test {
	public  static void main(String[] args) {
		// automatic type deduction
		var t = Math.atan(1);
		System.out.println( t );

		// anonymous type
		var i = new { Amount = 108, message = "hello" };
		System.out.println( i.Amount );
	}
}

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Tags: ANTLR, C#, Compiler, Java, JavaC, OpenJDK

03 Apr 09 PowerPoint Tools

I’ve finally managed to upload a version of my PowerPoint LaTeX add-in for PowerPoint 2007.

I’m just going to post a short Vimeo video here that shows how inline formulas work (the main feature):

http://www.vimeo.com/4442353

I’ve tried to work on the add-in during my spring vacation but somehow I have instead spent all my time watching four seasons of House M.D. (which was totally worth it though ).

There are still some features like support for MikeTeX, code clean-ups, small bugfixes and a preference window that I should work on, but I don’t plan on selling it, so I don’t really care if it’s still somewhat work in progress.
I’m going to continue working on it when I have to use PowerPoint again.

You can check it out (and another add-in dubbed Language Painter that I wrote to fix some annoyances when writing presentations in languages different from your keyboard layout) at http://code.google.com/p/powerpointtools/.

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Tags: AddIn, C#, LaTeX, MiKTeX, PowerPoint, TexPoint