API, ZoomTo - add 'getCenter' and 'setCenter' methods

[adube]

The Need

We need to be able to get and set the center of the map from external libraries. We also need to be able to add a marker on the center of the map and have the possibility to set and get its position from externals libraries as well.

Technical details

What we currently have

• an API widget used as a point of entry for external libraries to communicate with GeoPrisma.
• a GeoExtUX_ZoomTo widget that allows input of x y coordinates and projection to set the center of the map. It also supports adding the marker

To do

• API widgets :
  • new 'setcenter' event: fired by a new 'setCenter' API method, with an object as argument containing the center information (x, y, zoom, etc.)
  • new 'getCenter' method method that simply returns the same object the setCenter method would receive with infos about the current map extent
  • new 'centerchanged' event automatically fired on map 'moveend' event, which uses the 'getCenter' event to send the center infos
  • new 'centermarkermodified' event
  • new 'setmarkercenter' event

• ZoomTo :
  • add a ModifyFeature control to allow dragging the marker around. The layer should listen to the 'featuremodified' event to fire the API 'centermarkermodified' event
  • update the x and y coordinates of the popup when changed that way