AJAX viewer and IE - Images in tooltip

[Andy Morsell]

When images are referenced in the tooltip for a layer, the AJAX viewer with Internet Explorer can yield some very odd results. If it takes too long for the image to be returned, say more than 4 or 5 seconds, it's like it tries to call the image again and then this causes a loop which makes the tooltip to appear to blink. For an example that I just ran into, see ​http://mapguide.spatialgis.com/mapguide/spokanemaps/ and turn on the DOT Cameras layer. When you float your mouse over one of the camera symbols, a DOT traffic camera image should appear, but often times results in the above behavior. This works just fine in Firefox.

[chrisclaydon]

In Internet Explorer, under some circumstances, an onmousemove event is issued when the tooltip is displayed, even though the mouse has not actually moved. This causes the tooltip to be closed, and a new one is opened shortly afterwards. That causes a new onmousemove event, and the process repeats ad infinitum.

To fix the problem, a check can be added to the beginning of the OnMouseMove() method defined in ajaxmappane.templ to verify that the mouse position really has changed before proceeding. For the bogus onmousemove events generated by IE, the OnMouseMove() method will then return immediately, without closing the current tooltip. This solves the problem.

The change involves changing this piece of code:

function OnMouseMove(e)
{
    var x = e.clientX - mapPosX;
    var y = e.clientY;

    lastposx = x; lastposy = y;

to this:

function OnMouseMove(e)
{
    var x = e.clientX - mapPosX;
    var y = e.clientY;

    if(x == lastposx && y == lastposy)
    {
        return false;
    }
    lastposx = x; lastposy = y;

[chrisclaydon]

Fixed by an update to ajaxmappane.templ as described above.