How-tos

New! Remote edition of a PostGIS DB via synchronization

The waypoints layer is stored in a small embedded database which can be synchronized via internet with a PostGIS database located in my house in Valencia (Spain).

You only have to do this:

  • Start the application.
  • Go to the settings tab and choose for example EPSG:3857 as the coordinate system.
  • Go to the layers tab and check the waypoints layer to make it visible. Also, choose your favorite raster background layer and push the button in the bottom-right corner, which will take you the map tab.
  • Go to the settings tab and push the synchro button. That should perform a first synchronization and you should see the POIs currently in the database (or nothing if the remote DB is empty).
  • Navigate to a place of interest with the zoom in, zoom out and pan tools.
  • Select the POI tool (a red circle) and click anywhere on the map. You will see a dialog where you can enter the waypoint info. Enter as many POIs as you want. If the GPS is active and has a coordinate, it’s unimportant where you click on the map because the application will use the last available coordinates from the GPS.
  • When you have added your POIs, go to the settings tab and push the synchro button again. That should perform the synchronization and you’ll see the public map updated (see below).
  • This is one PostGIS table for all! The data you add/remove is available to everyone who is using this application.

Current map (live!):

Current map (live!)

Of course you can access this map from a WMS client. The server URL is:

http://lucasdom.homelinux.org:5880/cgi-bin/mapserv.exe?map=D:/MAPSERVERCARTO/MAPFILES/wms005.map

The POIs layer is called Highways incident.

Other hints

  • The application main window is a finger-friendly tabbed pane. The first tab shows the map while others give access to layers, GPS and overall settings. The last tab shows credits.
  • The top-left corner shows the current map tool. If you push it, the following tool is activated.
  • The GPS tab also allows user to connect/disconnect the GPS device. When the GPS device is connected, a message will show (“GPS…”) until the first coordinate is received. The recenter option causes the map to be recentered on the current GPS position when the distance between the current GPS position and the center of the map exceeds 40% of the map width. Needles to say, this option must be used carefully to avoid too many map repaints. When the GPS device is connected, a message will show at the bottom of the map.
  • The layers tab shows current layers. The left-most checkbox indicates whether the layer is visible or not. Vector file layers shows layers loaded from local files. Currently, only the ESRI Shapefile format is supported. The left-most symbol is actually a button that can be pushed to enter a symbology dialog, where the user can choose border and fill color, border witdth and whether polygons will be filled or not.
  • The bottom combo box allows the user to set the background raster to be used in the map. Only layers matching the current coordinate system will be shown here (see settings tab). Available raster layers include Yahoo Maps Satellite layer and the three most popular OpenStreetMap layers (EPSG:3857). ArcIMS and WMS servers (tiled or not) are also supported. They are described in the file:[app_folder]/persistence/raster.properties
  • The settings tab allows the user to choose the current coordinate system and language (after changing the language, the app must be restarted). All coordinate systems in that drop-down box are known by the application, so the GPS arrow will be placed properly on the map, as long as the cartography matches the selected coordinate system. The cartography itself is never reprojected, so the user has to know its coordinate system before-hand. Each time a new coordinate system is selected, the raster layers in the layers tab is updated with the layers that match the new coordinate system, and the item [None] is selected by default.
  • The Quit button has currently no confirmation dialog. You push it – gvSIG Mobile vanishes.

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