topic Re: drawing graphic layer on client side in ArcGIS JavaScript Maps SDK Questions

drawing graphic layer on client side

Krystianp — Tue, 02 Oct 2012 11:39:58 GMT

hello,

I've got some problems with drawing graphics point on client side. The problem is, when I draw points by first time by JS api everything is OK. But when points exists and I try to realy fast pan my map window from left to right (for example) my graphic layer can't finish drawing before one pan is ended. After few this kind of operations I can see, that my graphics points aren't in the geographic position as they should be when I started to pan. My question is how can I block again pan untill my graphic is drawn properly. I think it is the only way to prevent described situation.
I would like to mention, that I'm using jQuery for this application and I tried many many tricks like setting flag and setting enableMapNaviagtion() after document ready, I have tried to setTimeout, but for now this doesnt works. Can anybody helps me?

Re: drawing graphic layer on client side

__Rich_ — Tue, 02 Oct 2012 11:46:25 GMT

How many graphics have you drawn?

There is a setting displayGraphicsOnPan:true that you can pass to the map constructor, but let's get the full picture before jumping to a 'silver bullet' 😉

Re: drawing graphic layer on client side

Krystianp — Tue, 02 Oct 2012 11:48:56 GMT

it's depends (scale, terrain etc.) but it's from 1 - 3000 graphics points per screen.

yeah... displayGraphicsOnPan:true is set, but my problem is that AFTER the pan is over points arent in the same geographic positions.

Re: drawing graphic layer on client side

__Rich_ — Tue, 02 Oct 2012 11:51:56 GMT

it's depends (scale, terrain etc.) but it's from 1 - 3000 graphics points per screen.

Which browser?

1 = fine
3000 = probably not fine

http://help.arcgis.com/en/webapi/javascript/arcgis/help/jshelp_start.htm#jshelp/limits_for_graphics.htm

http://forums.arcgis.com/threads/67027-QueryTask-error-in-IE9-when-loading-more-than-900-features-(IE8-FF-and-Chrome-works)

http://forums.arcgis.com/threads/65441-IE-Problems

Re: drawing graphic layer on client side

__Rich_ — Tue, 02 Oct 2012 11:59:16 GMT

yeah... displayGraphicsOnPan:true is set

That's the default, setting it to false might help performance.

but my problem is that AFTER the pan is over points arent in the same geographic positions

Does this happen when you only have a few graphics or only when you've got many?

Re: drawing graphic layer on client side

Krystianp — Tue, 02 Oct 2012 12:09:45 GMT

That's the default, setting it to false might help performance.
Does this happen when you only have a few graphics or only when you've got many?

I've read before all links that you sent. It's doesn't matter which browser, or how many graphics are there. I think that JS api can't help me (I really 'know by heart' arcgis JS api documentation 😉 ) from my debugging I can tell that problem is with SVG graphic, it takes some time to add graphics nodes to HTML file and untill this process is ended I should freeze pan option. But I dont know to which event handle this, becouse as I said before $(function(){}) (document.ready() ) not resolve the problem.

Re: drawing graphic layer on client side

__Rich_ — Tue, 02 Oct 2012 12:18:01 GMT

I've read before all links that you sent. It's doesn't matter which browser, or how many graphics are there. I think that JS api can't help me (I really 'know by heart' arcgis JS api documentation 😉 ) from my debugging I can tell that problem is with SVG graphic, it takes some time to add graphics nodes to HTML file and untill this process is ended I should freeze pan option. But I dont know to which event handle this, becouse as I said before $(function(){}) (document.ready() ) not resolve the problem.

So 1 graphic in Chrome causes a problem? 😛

I've got a few layers where I add hundreds of graphics and I haven't seen this problem, yep it can be laggy but the graphics are positioned correctly, so there must be something else going on. (I don't deploy layers like this to production though!)

I'm not surprised document.ready() doesn't help.

How/when are you adding the graphics?

Re: drawing graphic layer on client side

Krystianp — Sat, 11 Dec 2021 13:35:59 GMT

ok so below is my general concept of application

when application is started, user can pick the region to show points on the map. He picks something, then by AJAX my script is connecting to database which is returning X,Y coordinates for points, then I create json contains those coordinates and by addGraphics() points are on the map. Now, in event onPanStart I've got sequence:

  MAP.map.onPanStart = function() {
   MAP.map.disableMapNavigation();
  };

and onPanEnd:

  MAP.map.onPanEnd = function(extent, endPoint) {
   if(checkIfExtentContainsBoreholes()){

   if (MAP.points.length > 0) {
    MAP.drawPoints();
                        }

                 };
  };

and first if statement (checkIfExtentContainsBoreholes) checks if database contains points from my extent, and if its true, then it put points by the same function as is before (coordinates to json..)

so when onPanEnd drawing event has started I can pan map again, and if the graphics still are not on the map and I pan map to other place they appears badly(because the SVG graphic is drawing by relative coordinates to top-left corner of the map)

Re: drawing graphic layer on client side

JeffPace — Tue, 02 Oct 2012 13:08:27 GMT

would it be possible to

on pan start - hide graphicsLayer
on pan end - show graphicsLayer.

Re: drawing graphic layer on client side

Krystianp — Tue, 02 Oct 2012 13:12:20 GMT

would it be possible to

on pan start - hide graphicsLayer
on pan end - show graphicsLayer.

yes, I do this, but on pan start / end I've got really lots of code so I past only interesting parts of code. Now when I'm testing application I see, that this problem occuress only in google chrome (my. version is 22.0.1229.79 m) FF or IE is OK.

another observation

when I click mouse button and fast move map and in the end of panning I release mouse button but still move mouse the map is moving by the trace of my mouse (its only about for ~0.2 sec.) but if i move map very quickly I can pan a lot of area and then the postion-error can be saw exactly.

Re: drawing graphic layer on client side

__Rich_ — Tue, 02 Oct 2012 13:17:08 GMT

I don't suppose this application is on the web somewhere?

Sounds like a lot is going on and tracking down anything from snippets is going to be hard!

Re: drawing graphic layer on client side

Krystianp — Tue, 02 Oct 2012 14:03:12 GMT

OK. so I figured it out!!! 🙂

the problem was as I wrote before - when I release mouse button, but still moves mouse over the screen the map was moving with me. (only in google chrome) but when I changed event from onPanStart/Stop to onMouseDragStart/Stop everything works good, but I had to check if pan tool is active.

but still..3days went to hell! 😉

with greetings
Krystian.