Re: [udig-devel] More questions about maps and projects

[Jesse Eichar <jeichar@xxxxxxxxxxxxxxx>]

I think I'll babble a little bit and maybe you'll be able to come up  
with some ideas or at least more questions.

Projects can contain anything that is a ProjectElement object so if  
your object is a ProjectElement (they are EObjects so beware) then  
you can add them to a project.  In order to open them in an editor  
you have to create a net.refractions.udig.project.ui.editorInputs  
extension that is responsible for converting the ProjectElement to a  
IEditorInput object.  Once you've done that you can use the normal  
eclipse editor extension point to define an editor for the IEditorInput.

There are "layers" call MapGraphics which can be used to draw  
anything you want onto the map.  The interface is basically just a  
paint method that is called each time the layer is rendered.  A  
commonly seen pattern is a mapgraphic that displays data that is on  
its blackboard or on the containing map's blackboard.  For example if  
someone wanted to make a drawing layer where some one can draw lines  
with out having to write to a shapefile or some other datastore, a  
Scribble map graphic (doesn't actually exist as of yet) could be  
added to that map and when the user selects the Scribble tool the  
scribble tool would add data to the MapGraphic's blackboard (see  
getProperties())  and trigger a refresh on that layer.  The  
MapGraphic would search its blackboard each time it renders and draws  
the data in some manner on the Graphics object.

> Is part of the problem the udig notion of "projects" not fitting in  
> very
> well with the user doing File... Open... and opening an outside EMF  
> file not
> directly connected with a project? Or is there a good way of making  
> all this
> fit together? Is it possible to use udig with no projects  
> whatsoever and
> just a single map display or is this unadvisable?

You could create a perspective that doesn't contain the  
ProjectExplorer so that the user doesn't even know about projects.   
The Startup extension point could check the existing projects to see  
if your map exists if it doesn't it can create "THE" map and open it  
(after adding all the layers to it).  You can add a WorkbenchPart  
listeners or maybe it is a page listener, that listens to all the  
opens, closes, activation of all the workbenchparts and if the map is  
closed maybe you can reopen it...  There may also be a way to make a  
map not be closeable... I've never researched that issue.

Jesse