Personally, i don't use any of google's custom overlay scripts and such. I made a custom php page which hold the iframe, where I can load custom css files, and also I create custom DIVs that go over top of the map, which are then repositioned while dragging when opened.
You can use the "Drag,Dragstart,Dragend" events to help you reposition elements that you have created.
If you have custom markers set onto you page you can get their pixel position with this function:
getPosition: function (marker) {
var map = this.map /* Your map, in my case is part of my controller object linked to this.map */;
var scale = Math.pow(2, map.getZoom());
var nw = new google.maps.LatLng(
map.getBounds().getNorthEast().lat(),
map.getBounds().getSouthWest().lng()
);
var worldCoordinateNW = map.getProjection().fromLatLngToPoint(nw);
var worldCoordinate = map.getProjection().fromLatLngToPoint(marker.getPosition());
var pixelOffset = new google.maps.Point(
Math.floor((worldCoordinate.x - worldCoordinateNW.x) * scale),
Math.floor((worldCoordinate.y - worldCoordinateNW.y) * scale)
);
return pixelOffset; /* Returns the top left pixel of the specified marker on the specified map */
}
And then I use a setPosition function which is used when the window is dragging, it sets your custom element's position to the marker's position.
The dragging event can be set in such manner:
google.maps.addEventListener(map,'drag',function () { setPosition(marker,element); });
The setPosition Function simply gathers the width,height of the element, and the pixel offset associated to the marker using the getPosition(marker) function:
setPosition: function (marker,element) {
var p = this.getPosition(marker),
s = {width:element.offsetWidth,height:element.offsetHeight},
markerOffset = {width:58,height:58};
element.style.left = p.x - (s.width/2) + (markerOffset.width/2) + "px"; /* We set the element's left position to the marker's position + half of our element's width + half of the marker's width's so it is centered */
element.style.top = p.y - s.height - (markerOffset.height) + 10 + "px"; /* We set the element's top position to the marker's position + our element's height + markers height so it is 10px above our marker vertically */
},
Sometimes you just have to think a bit outside the box