Paul wrote: "I would like to extend the Task class to support properties. Properties can be set by plug-ins on the task."
I wonder if we could use a Blackboard and PersistentBlackboardPlugIn to accomplish this? http://jump-pilot.sourceforge.net/javadoc/openjump_javadoc/com/vividsolutions/jump/workbench/ui/plugin/PersistentBlackboardPlugIn.html http://jump-pilot.sourceforge.net/javadoc/openjump_javadoc/com/vividsolutions/jump/util/Blackboard.html This would keep things a little simpler, as we'd be using classes that are already present in OpenJUMP. This is just a suggestion. If we support Objects, how will we represent their state when we write the data to the Task file? Will we just call toString on the object, or will there be another method? The Sunburned Surveyor On Sat, May 24, 2008 at 8:55 AM, Paul Austin <[EMAIL PROTECTED]> wrote: > Michael, > > The magic is new in JDK 1.5 generics. It's a generic method the <T> means > that at compile time it should deduce anywhere it sees T (T can be anything > you want) in the method based on the actual classes used. > > So in the below example we use T as the return type so the compiler can pick > this up from your assignment statement Integer i = task.getProperty(...) and > then use Integer where ever it sees T. > > public <T> T getProperty(QName name) { > return (T)properties.get(name); > } > > This just makes your code a lot easier to read as you don't have to cast in > your code > > http://java.sun.com/j2se/1.5/pdf/generics-tutorial.pdf section 5 generic > methods > > Paul > > > Michael Michaud wrote: > > Paul Austin a écrit : > > > I would like to extend the Task class to support properties. Properties > can be set by plug-ins on the task. An example of a property would be > the SRID for the whole task. This will allow us to support extended > metadata on tasks without having to add new methods each time or > subclassing. > > > > Seems to be a good idea to me. > > > I propose to use QName's as the key for the keys for the properties. > This would allow different namespaces for different applications. > > The change would include the following. > > private void Map<QName,Object> properties = new HashMap<QName,Object>(); > > public void setProperty(QName name, Object value) { > properties.put(name, value); > } > > /** > * This will auto cast so you can just type things like > * int value = getProperty(MY_KEY); > */ > public <T> T getProperty(QName name) { > return (T)properties.get(name); > } > > > > Hey, looks like magic code. > I cannot understand how the type T can be used in an object method if it > has not been declared in the class definition. > Can really the jvm know how to cast properties.get(KEY) while the object > associated with this key can be any Object value? > > Michaël > > > public Map<QName,Object> getProperties() { > } > > We'd also need to have it setup so this would be saved to the project file. > > Any suggestions/comments? > > Paul > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > > > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > > ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
