I have been working with Virtual
Earth some more. I wrote recently about the tiles
that make up the map image and have made some new discoveries.
When you create a new map, the tiles collection has the tiles in the order of
their placement in the grid, by column, as opposed to by row, like a
<table> object builds a grid. So in a map of 12 tiles, map.tiles[0]
through map.tiles[11] are placed like this.
| 0 |
4 |
9 |
| 1 |
5 |
9 |
| 2 |
6 |
10 |
| 3 |
7 |
11 |
However as you pan (scroll) around the map
image, VE just keeps adding tiles to the end of the collection based on your
movement. Therefore, when you stop scrolling, the tiles will no longer be in any
order that you can count on, which is not good if you have code depending on the
above order.
To rectify this you can use two methods of the map control to
jiggle the tiles back into "proper order".
Capture the
onEndContinusPan event of the map and then use the
SetCenter method followed by the
_UpdateMap
method.
map.onEndContinuousPan =
function(e)
{
map.SetCenter(e.latitude,e.longitude);
map._UpdateMap();
}
I had originally tried to just create a new map when the panning ended,
but I was unable (by hook or by crook) to get the compass control, zooming
controls, etc to interact with the new map.
Thanks to ViaVirtualEarth for the lesson on how to
capture map events.
www.acehaid.org