Sunday, June 04, 2006

Palm PCs

Getting back to programming, I am starting a small, but premiere project for Palm. These devices seem to be the work of the devil. The particular model I am programming for is something with a resolution of 240x320, with 64MB storage AND memory and with a 300Mhz processor.

Why?! When all computer screens are rectangular, with the width larger than the height, they make a device that is exactly the oposite. I mean, I understand they are meant to be hand held and all hand held devices are longer than they are wide, but it's still annoying.

Also, if I try to find a PC memory that is less than 256MB I would probably be forced to buy it second hand, yet they make a 64MB model? This also applies to the processor. Are they spending more money to make slower processors or is it just me seing things wrong?

Anyway, I found that working with DataSets in this environment is just awful. I started with a simple test project, 20000 rows in a 3.5MB XML file, loaded into a DataSet then displayed in a datagrid. First, the whole thing went out of memory and froze, then, when I fixed the memory problem by creating my own binary format and loading the file my way (oh yeah, I can see the roots of a XML sucks rant) the datagrid was very unwieldy.

Therefore I devised a ClusterGrid, something that shows clusters of rows in a datagrid and you just drill down and up on it. On my data, finding a customer in a 20000 rows table is 4 clicks away. First it shows 10 rows, representing clusters of 2000 people ordered alphabetically (ex: first cluster, from Alice to DeeDee). You click (or press with the finger, I have no idea how an actual Palm functions, I am using the emulator in Visual Studio 2003) on a cluster, you get another 10 clusters, with 200 people each. Then 20, then 2. Four clicks. Works like a charm. It seems a better deal than the scroll of the datagrid and I wonder why I haven't seen this before.

A small tip regarding the Palm Emulator. The default configuration is set on 32MB of memory+storage. If you want to at least have a functional program, increase it in the VS options, in the Mobile Devices tab. I couldn't make it larger than 64MB for whatever reason, but I never needed more and 32 is way too low.