Hi I was wondering if anyone can help me.
I am looking to have a map where the user can select a location and a
marker will appear on it with a circle drawn round it. The circle will
have another marker with which the user can adjust the size of the
circle.
My problem. The whole thing works fine, I can place a marker on the
screen where I want it and can change the diameter of the circle (by
dragging the circle marker) and the polyline refreshes to the correct
size. You can even move the centre (by dragging the centre marker) of
the circle and the circle updates itself. The problem occurs when I
place the centre markers on the map for the first time.
I get the centre marker and the circle marker but no polyline. If I
move the circle marker, still no polyline. It is not until I move the
centre of the circle by the smallest amount that the whole thing
updates itself and the poygon draws and then after that the polyline
will update itself no matter what I do.
Can anyone help me get the polygon to draw as soon as the markers are
put on the map??
Thanks in advance
John
Here is some code I have
//this function places a marker at the centre of the circle and then a
marker
//a pre-set distance from the centre to be the boundary of the circle
//I can place more than one marker set onscreen
function placeMarkerAtPoint(lng, lat)
{
center[IconCount] = new GMarker(new GLatLng(lat,lng), {icon:icon,
draggable: true});
map.addOverlay(center[IconCount]);
center[IconCount].enableDragging();
GEvent.addListener(center[IconCount],'dragend',function()
{drawCircle()});
oldpoint = center[IconCount].getPoint();
radius[IconCount] = new GMarker(new GLatLng(lat,(lng-0.018)),
{icon:icon, draggable: true});
map.addOverlay(radius[IconCount]);
radius[IconCount].enableDragging();
GEvent.addListener(radius[IconCount],'dragend',function()
{drawCircle()});
IconCount++;
drawCircle();
}
//function which is called when one of the markers is dragged to a
new
//position and updates the screen. This should re-draw the polyline
circle
function drawCircle()
{
var point;
var lat;
var lng;
var p;
var x;
var y;
var Cradius;
var Ccolor = '#0000ff' ; // color blue
var Cwidth = 3 ; // width pixels
var d2r = Math.PI/180 ; // degrees to radians
var r2d = 180/Math.PI ; // radians to degrees
var Clat; // using 3963 as earth's radius
var Clng;
var Cx;
var Cy;
var loopcount;
for (loopcount=0; loopcount < IconCount; loopcount++)
{
point = center[loopcount].getPoint();
lat = point.lat();
lng = point.lng();
if ( center[loopcount].oldpoint ) // Move radius when center is moved
{
p = radius[loopcount].getPoint();
x = point.lat() - center[loopcount].oldpoint.lat();
y = point.lng() - center[loopcount].oldpoint.lng();
radius[loopcount].setPoint( new GLatLng( p.lat() + x, p.lng() + y) );
}
center[loopcount].oldpoint = point;
Cradius = point.distanceFrom(radius[loopcount].getPoint()) *
0.000621371192;
Clat = (Cradius/3963) * r2d; // using 3963 as earth's radius
Clng = Clat/Math.cos(lat*d2r);
var Cpoints=[];
for (var i = 0 ; i < 13 ; i++)
{
var theta = Math.PI * (i/6);
Cx = lng + (Clng * Math.cos(theta));
Cy = lat + (Clat * Math.sin(theta));
Cpoints.push(new GPoint(Cx,Cy));
}
// i think it is at this point here where the problem lies.
// I have found through some debugging that the points to plot
// the polyline are stored in Cpoints
// For some reason this part will only work then the centre point has
// been moved once
if ( circle[loopcount] )
{
map.removeOverlay(circle[loopcount]);
}
circle[loopcount] = new GPolyline(Cpoints,Ccolor,Cwidth);
map.addOverlay(circle[loopcount]);
}
}
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Google Maps API" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/Google-Maps-API?hl=en
-~----------~----~----~----~------~----~------~--~---
