google maps

[Kyle Anderson]

I have developed an application in GWT which allows users to visualize a large graph.  The application has a few requirements:

1.) Display about 5000 nodes & edges

2.) add or delete nodes/edges from the graph

3.) click nodes/edges on the graph & execute a custom callback function

4.) Provide a blank overlay behind the markers so it is not obvious that this is a Google Map

I built this using gwt-maps-v2, but it performs very slugglishly.  Load time is slow, the elements take a while to reappear on pan/zoom, and the blank background flickers on pan/zoom.  I have seen solutions for this using javascript such as GMarker and MarkerLIght.  

Is there anything similar for GWT?

[Joseph Lust]

Provide a blank overlay behind the markers so it is not obvious that this is a Google Map 

If you don't want to show a map, on the map, then why use Google Maps? Why not just drop points on a canvas? It's easy to load an image of the world into the background of your canvas/div/etc to draw the points over.

Also, most browsers are going to be slow with 5K objects being tracked with events in the DOM. Consider drawing them on a canvas to cut down on that overhead. You can map click events on the canvas to a given point using a single event handler which will make things much faster.

Sincerely,

Joseph 

[Kyle Anderson]

I need to be able to pan and zoom, that's why I'm using Google Maps.

The solution I am thinking of is to prerender the map as a layer on the server,  The user can then add markers as needed.  Their delete operations, however, will not show up until they reload (not optimal, but I cannot think of any other way).

Kyle

[Joseph Lust]

Kyle,

Checkout the Google Maps Fusion Tables API. It is meant for working with very large amounts of data on the maps.

Sincerely,

Joseph

[Joseph Lust]

This example does what you mention, with thousands of markers rendered into the map tiles to prevent browser overhead.

Sincerely,

Joseph