Saturday, February 16, 2008

Chronoscope 0.8 Released / Upcoming Milestones

Major new features:
1) Internet Explorer/Flash Rendering support
2) Experimental Java2D renderer (servlet/applet)
3) Appendable Datasets / Dataset change listeners

4) many bug fixes
5) code aligned with GWT checkstyle

Internet explorer is supported by using a special Flash9 helper which emulates the WHATWG Canvas rather than using VML/ex-canvas as is traditionally done because performance and compatibility is not as good with VML. You can force flash rendering for all browsers by adding ?_force_flash to the URL of your app.

The Servlet/Applet support isn't transparent in the sense that you have to write different code to instantiate a servlet or applet graph. This will be rectified in the near future by harmonizing the chart factory to produce various types (Flash/Canvas, Servlet, Applet) depending on configuration parameters or browser detection, that is, if you lack both Flash9 and are running on IE, but have Java, then it can fall back to Java, and if you don't want Java, it can fall back to asking a servlet to assist.

Appendable datasets allow you to do streaming charts (finance, network sensors, etc) by appending new points to the end of a dataset. This are efficiently integrated into the internal multiresolution datastructure (log(N) ops), and the chart can now detect when the dataset has been mutated and automatically redraw itself.

Also, we are now committing to weekly releases, here are the planned upcoming milestones.

Next Week, 0.85 release
1) RangeMutableXYDataset - all features of Appendable datasets, plus
supports modifying Y values of already added points
2) Auto-precision/scaling of Axis labels

0.90+ releases (not prioritized yet)
1) IE GSS support (use CSS properties to style chart)
2) Shared Domain charts (two plots, sharing a single X axis,
vertically stacked, like Financial Price/Volume charts)
3) Generalized partition strategy for multiresolution algorithm
4) Restore bar chart to full functionality + control over span intervals (bar width)

Please file any bugs or RFEs in the issue tracker, which is available on the project page where you download the code at