Great! I’m using version 2.12.
Thanks,
Rob Smart
From: Alexandre Dubé
Sent: Thursday, February 28, 2013 1:59 PM
Cc: openlayers-users@lists.osgeo.org
Subject: Re: [OpenLayers-Users] ModifyControl Select/Delete Vertex?
Sure, I'd be glad to help. What version do you use ?
Alexandre
On 13-02-27 12:36 PM, Robert Smart wrote:
Hi,
Thanks for a really in depth answer. It really explains it well.
Unfortunately my javascript skills are pretty basic at the moment, so a lot
of that went over my head!
I like the sound of the vertexselection event on the vector layer class.
Could you give me a few more hints about how this might work?
Or even better give me an example bit of code :)
We would need to be able to access the vertex index of the selected vertex,
and i guess there would have to be a method of removing the vertex from the
feature, which would trigger a redraw of the feature on the map.
We would have to also be able to define a style for that selected vertex too,
and i suppose add some error trap to ensure that we can't select a virtual
vertex?
Thanks again,
Rob
On 27 Feb 2013, at 13:51, "Alexandre Dubé" <ad...@mapgears.com> wrote:
Hi Rob,
This would indeed be a nice feature to have. Looking at the
ModifyFeature control, I think this could be easily accomplished with minor
modifications.
If we look at the ModifyFeature control, it creates a DragFeature control
to allow dragging the vertices around. When you "mouse hover" a vertex
feature, a callback function is triggered because it was defined here :
https://github.com/openlayers/openlayers/blob/master/lib/OpenLayers/Control/ModifyFeature.js#L267
That's the callbacks for the OpenLayers.Handler.Feature object the drag
control needs to interact with features on the map. The drag control defines
its callbacks method in the featureCallbacks object :
https://github.com/openlayers/openlayers/blob/master/lib/OpenLayers/Control/DragFeature.js#L119
and here's the list of callbacks you can set to a feature handler: click,
clickout, over, out, and dblclick.
https://github.com/openlayers/openlayers/blob/master/lib/OpenLayers/Handler/Feature.js#L30
So, back in the ModifyFeature control, you could add a 'click' callback
function just next to the 'over' one. Instead of coding what you want it to do
directly in the source, just define an abstract function that needs to be
overriden OR you could fire an new vector layer event : vertexselected (which
would need to be added to OpenLayer.Layer.Vector).
Whoa, sorry for the long reply :) In short, try to create a delegate
method or event we could register to to do whatever we wanted on vertex
selection.
Does that make sense ?
HTH,
Alexandre
On 13-02-26 11:42 AM, Robert Smart wrote:
Hi All,
I'm trying to port some existing functionality into open layers and have
managed to get most of it working. I'm just stuck on a seemingly simple
task.
The current code allows a user to highlight a polygon vertex by clicking
on
it (which changes its colour), so that the user can then press a delete
button to remove the vertex.
Using the modify control I'm able to display the vertices, and even
delete
them if I click on it and then press 'del' on my keyboard, but this is
not a
great solution as there is no visual clue as to what vertex has been
selected.
So is there a way to highlight or change the colour of a single vertex
the
user has clicked on? is there then a way to remove that vertex via code
and
have the polygon redraw on the screen to suit?
I think this would actually be quite useful as a standard feature as
there
are many cases where one might want to select an individual vertex.
Thanks,
Rob
_______________________________________________
Users mailing list
us...@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/openlayers-users
--
Alexandre Dubé
Mapgears
www.mapgears.com
_______________________________________________
Users mailing list
us...@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/openlayers-users
--
Alexandre Dubé
Mapgears
www.mapgears.com
--------------------------------------------------------------------------------
_______________________________________________
Users mailing list
us...@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/openlayers-users
_______________________________________________
Users mailing list
us...@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/openlayers-users
