BUI - restructuring, work on PyOpenGL frontend

Two weeks have gone since the last blog post. I took a tiny break from coding during X-mas but apart from that things have been going quite nicely. To summarize major work done, see following list:

• Restructured the source to reflect the architecture better. Now there are separate packages for frontend, backend, graphics, utils and tests. It should make more sense now even for people beyond me hopefully. :)
• Implemented basics of PyOpenGL frontend including window management (only one window at the moment) and a couple of elements (label and separator) for it.
• Implemented width: auto. This means that the object will scale its width to one of its parent automatically. If width is not set at all, it is considered auto. It is possible to constraint this setting using min_width and max_width. Note that auto setting has to be implemented for height still.
• Got rid of LayoutManager and replaced it with property based solution. This means updates to object properties (width/height for instance) cascade properly. So for instance if you alter the width of a HorizontalContainer its contents operate accordingly. This also separates the logic a bit better to smaller chunks.
  
• Converted elements to their own modules under element package. I am not still exactly convinced that this is the way to go (perhaps there needs to be alias for easier imports?) as in the end each module contains only one or a few classes. I might need to revert this decision at some point.
  
• Split up unserialize and clarified its structure.
• Got rid of Pyglet frontend. It might make sense to use pyglet in graphics package though as it has well optimized drawing methods available.
• Renamed Containers as Layouts. So instead of VerticalContainer there is VerticalLayout now. This reflects better the purpose of that specific class.
• Implemented FreeLayout. Children of FreeLayout have unconstrained coordinates. This means you can define the placement of the children freely using x, y (top left corner coordinates!), width and height.
• Cleared up attribute hierarchy of elements. There should not be any redundant attributes now. I also got rid of x_offset, y_offset and variable as they were pretty useless. I replaced variable using name. Name can be used to refer to certain element(s) internally. This meant I had to specify a way to determine the part visible to the user (think label!). To do this I followed the way used in PyGTK Glade and determined a label attribute.
• Implemented plenty of OpenGL based drawing functions in the graphics package. Probably quite a few have to be implemented still. :)

At the moment I am working on implementing timers for the PyOpenGL frontend. After this I will focus on the event system. It might take some sort of overhaul to make it work the way I want. GLUT seems to provide lot of needed stuff for me though.

Besides making event system work properly I have to further validate the current code, implement more elements for PyOpenGL frontend, add scrollbars, drag and drop, configuration system (determines default window size), serializer (save work), undo (session recording even?), proper layout system and perhaps something else I can't quite remember at the moment.

I hope to have the first test release done in a few weeks to get some initial user feedback. I am sure there are a lot of rough edges to polish.

I also found out that there is another project that uses the same acronym, BUI. Check it out at http://www.samskivert.com/code/jme-bui/ . Incidentally it seems to be pretty much Java equivalent of this project. Due to the same acronym I might have to rename BUI to something else.

Pytform is another interesting project I happened to stumble upon. Unlike BUI it's totally focused on game creation.