On Fri, Feb 20, 2009 at 05:48:45PM +1100, Roald de Wit wrote: > Hi David and list, > > Today I looked a bit deeper into the matter and I think I know what is > going on. > In the function getMousePosition an event listener gets created that > will clear the mouse cache on a 'scroll' event. > My suspicion is that clearMouseCache gets called (by that listener) just > after this.element.scrolls = [] has been executed, causing > this.element.scrolls to be null directly after it got created! > > The easiest solution I've come up with is the following. Instead of: > this.element.scrolls = []; > this.element.scrolls[0] = (document.documentElement.scrollLeft > || document.body.scrollLeft); > this.element.scrolls[1] = (document.documentElement.scrollTop > || document.body.scrollTop); > > You do this: > this.element.scrolls = [ > (document.documentElement.scrollLeft > || document.body.scrollLeft), > (document.documentElement.scrollTop > || document.body.scrollTop) > ]; > > And to be on the safe side, we'd probably need to do that for the other > elements (lefttop and offsets) as well. > > If this would be an appropriate solution for inclusion in 2.8, I'm more > than happy to create a ticket and provide a patch for it.
Sounds like this is a simple fix, without much reason to suspect any problems: I'm happy to have this go into a patch and get reviewed. Thx. > Regards, Roald > > > David Martin wrote: > > Roald, > > > > No tidy solution - I have just left the try-catch solution in my production > > system and it seems to be working well. I do understand the problem and > > will work on it some more in due course. At the moment I am focused on many > > other projects however a major product update in one of my OpenLayers apps > > will be starting in about 4 weeks. I will get onto this error again then > > when I load up the latest build and start afresh. > > > > Do you need a copy of the mod? I installed it directly in the single file > > build and could copy out the lines if you need it. > > > > David > > > > -----Original Message----- > > From: Roald de Wit [mailto:roald.de...@lisasoft.com] > > Sent: Tuesday, 3 February 2009 1:23 PM > > To: David Martin > > Cc: users > > Subject: Re: [OpenLayers-Users] Javascript Error - ScrollWheel disabled - > > IE - scroll on map > > > > Hi David, > > > > Coincidentally, today I bumped into the same problem as you describe > > below. Did you manage to find a solution or did you stick to the > > workaround with the try-catch construction? > > > > Do you feel like creating an issue in Trac [1] (with a simplified > > example that can reproduce the error)? > > > > Kind regards, > > > > Roald > > > > [1] http://trac.openlayers.org/wiki/FilingTickets > > > > On Mon, 2008-12-22 at 11:50 +1030, David Martin wrote: > > > >> I have been having an on-going problem with OL (using 2.7 and same in > >> the trunk). The issue seems to only occur when using IE. If you > >> disable the zoomWheel in the Navigation control and then load a > >> Control.Click with an event script to capture clicks and mouse > >> positions in a map. Show this map in IE and then scroll with the wheel > >> over the map panel itself the browser throws a this.element.scrolls is > >> null or not an object. > >> > >> > >> > >> I looked at the event script and I believe that during the > >> getMousePosition function the evt is being destroyed with the > >> this.clearMouseCache event (caused be scrolling using the wheel over > >> the map). I know I am close because I wrapped the whole > >> getMousePosition function is a try { { catch{} and the error has gone > >> away. I would debug it further however I cannot use Firebug in IE as I > >> do in Firefox. I also find that IE does not launch my debuggers > >> correctly in this instance. > >> > >> > >> > >> I know it is killing the event (this) because if I comment out the > >> this.element.scrolls section lines 777 ??? 783 the error is reported > >> then against the this.element.lefttop. Is there a better solution? > >> > >> > >> > >> Regards > >> David Martin > >> Managing Director > >> I.T. Beyond Pty Ltd > >> > >> Postal: > >> > >> > >> PO BOX 967 > >> HILLARYS WA 6923 > >> > >> > >> Ph: > >> > >> > >> (08) 9403 3737 > >> > >> > >> Mobile: > >> > >> > >> 0417 677 275 > >> > >> > >> Fax: > >> > >> > >> (08) 9403 3738 > >> > >> > >> Skype: > >> > >> > >> itbeyond_david > >> > >> > >> > >> ______________________________________________________________________ > >> > >> Check out our websites: www.ExplorOz.com and www.itbeyond.com.au > >> > >> > >> ______________________________________________________________________ > >> > > -- > > Roald de Wit > > Software Engineer > > roald.de...@lisasoft.com > > > > Commercial Support for Open Source GIS Software > > http://lisasoft.com/LISAsoft/SupportedProducts/ > > > > > > The contents of this email are confidential and may be subject to legal or > > professional privilege and copyright. No representation is made that this > > email is free of viruses or other defects. If you have received this > > communication in error, you may not copy or distribute any part of it or > > otherwise disclose its contents to anyone. Please advise the sender of your > > incorrect receipt of this correspondence. > > > > > The contents of this email are confidential and may be subject to legal or > professional privilege and copyright. No representation is made that this > email is free of viruses or other defects. If you have received this > communication in error, you may not copy or distribute any part of it or > otherwise disclose its contents to anyone. Please advise the sender of your > incorrect receipt of this correspondence. > _______________________________________________ > Users mailing list > Users@openlayers.org > http://openlayers.org/mailman/listinfo/users -- Christopher Schmidt MetaCarta _______________________________________________ Users mailing list Users@openlayers.org http://openlayers.org/mailman/listinfo/users
