The Main Skycat Window

Skycat defines subclasses of some rtd and cat classes and combines the image display features of the rtd with the catalog features of the cat package. The main window of the skycat application is inherited from rtd and adds only the Data-Servers menu, which is generated automatically based on the list of available catalogs. Skycat's top level window is implemented by the SkyCat(n) widget class, which is a subclass of the Rtd class. The SkyCat class adds the Data-Servers menu and defines an external proc interface, so that other Tcl applications can use the Tcl send command to send commands to skycat .

The SkyCatCtrl(n) widget defines the inner frame, containing the image and the upper panel. This is a subclass of the RtdImageCtrl class and adds methods for drawing plot symbols.

The Catalog Window

When a catalog is selected from the Data-Servers menu, the window that is displayed is a subclass of the catalog class cat::AstroCat called SkySearch(n).

The top level SkySearch widget class adds image and plotting support to the cat::AstroCat widget. It adds the Plot button and redefines the plot method to draw symbols in the image for each query result object.

Skycat redefines the internal widgets that make up the AstroCat widget here to deal with images and plotting.

The top widget, SkyQuery(n) , is a subclass of cat::AstroQuery and adds two buttons for setting the area of the image to search:

• " Select Area ", to interactively select a region of the image to search, and
• " Set From Image " to set the range to include the entire image.

The results of the query are displayed in a subclass of cat::QueryResult called SkyQueryResult(n) . This class redefines the methods for adding an object to a local catalog to include automatic selection of object coordinates using the RtdImagePick (pick object) widget.