JaGo: An Interactive Map

The Vertigo database group of the CEDRIC lab at CNAM, Paris, in collaboration with the Verso group of INRIA, Rocquencourt and the database group of Telecom, Paris, is interested in open architectures for GIS. More specifically, we are currently looking at different distribution platforms for geographical data and services.

This user interface allows you to display and modify maps obtained by database queries or stored in files (URL queries). A thematic map is obtained by an overlay of several layers, each of them representing a different theme (highways, rivers, equipments). The global framework and prototype architecture is described here.

ATTENTION:

The O2 database servers is not available. You cannot do spatial operations and you can only ask for stored maps in Postgres, miniSQL and files (URL queries).

The main interface is composed of three components:

• The first text area contains the name of the layer to be created.
• The second text area contains a query or an URL retrieving a layer.
• The buttons below are defined as follows:
• New Map allows you to select a map already created.
• Show Map displays the selected map.
• Send Query sends the query and creates a new layer in the selected area.
• Delete deletes the query.
• Next displays the next predefined query.
• Previous displays the previous predefined query.

Start with clicking on Next and Send Query. A new map will be displayed. In the drawing area, you can select objects (mouse down) and draw rectangles (shift mouse down). When you click on an object, its bounding rectangle and other useful information (identifier, graphic value, label, persistent root) are displayed. Each point and rectangle has a unique identifier ($i) and can be used in the queries (e.g. InWindow).

The buttons are defined as follows:

• Open Legend displays the legend of the map.
• Close Legend undisplays the legend of the map.
• Layers shows the different map layers. In order to create another layer on the same map, you have to select the map in the main window (button New Map) and send new queries to the database. In this window the buttons are defined as follows:
• Hide hides the corresponding layer.
• Labels shows the object labels (if there are any) in the corresponding layer.
• Top puts the corresponding layer on the top.
• Bottom puts the corresponding layer on the bottom.
• Hide Map hides the map (it can be redisplayed by being selected in the main window).
• Reset reinitializes the zooming factor and translation.
• Zoom zooms into the last rectangle drawn by the user.
• Center centers to the last point drawn by the user.
• Clear deletes all points and rectangles drawn by the user.
• +,-: zoom in/out.
• >,<,^,v: shift right/left/up/down.

---

Database Schema

---