topic Re: Off Center Zoom in ArcGIS JavaScript Maps SDK Questions

Off Center Zoom

WesAskew — Fri, 19 Dec 2014 15:42:35 GMT

I am trying to determine the best way to off center a zoom based on browser window size. I have a div container nested within my map div on the right side which takes up 20% of the screen. I would like to off center the map.centerAt() function 20% to the left to compensate for this taken space. Does anyone have an idea on the best way of going about this? Any suggestions are greatly appreciated. Thanks in advance.

Re: Off Center Zoom

HeikoHeijenga — Fri, 19 Dec 2014 16:17:27 GMT

Convert the point you want to center on to a screen point, this will give you the coordinates in pixel space. Then substract/add 0.2*map.width from the X value and convert the point back to map units and use that to center on. Makes sense?

Re: Off Center Zoom

HeikoHeijenga — Fri, 19 Dec 2014 17:16:22 GMT

You can also skip the unit conversion and use 0.2*map.extent.getWidth()...

Re: Off Center Zoom

WesAskew — Fri, 19 Dec 2014 17:29:27 GMT

Thanks, worked perfectly for my point features. Would a similar method be used for polygons?

Re: Off Center Zoom

HeikoHeijenga — Fri, 19 Dec 2014 17:32:49 GMT

to do what? map.centerAt only works with points...

Re: Off Center Zoom

WesAskew — Fri, 19 Dec 2014 19:02:02 GMT

I would like to off center my polygon features the same way. Currently I am using : map.setExtent(polygonFeatureLayer.geometry.getExtent().expand(1.1)); Would I simply do the same for the x coordinate for the polygon and recalculate the extent?

Re: Off Center Zoom

HeikoHeijenga — Fri, 19 Dec 2014 19:04:25 GMT

Yeah, you would do it the same way; loop over all vertices in the polygon and offset the X.