OK, that makes sense. Will be interesting to hear more of how this works out with a browser-based database.
Cheers Adam On 23/11/2009, at 8:43 AM, Kris Geusebroek wrote: > Hi Adam, > > As Chris rightly point out there is already a canvas implementation > of the OpenLayers.Renderer which can be used instead of VML or SVG > renderer. > My changes for using canvas in OpenLayers are currently > concentrating on the other layer types like WMS or Grid layers. > > Cheers Kris > > > > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of Adam Ratcliffe > Sent: Saturday, November 21, 2009 1:54 AM > To: Kris Geusebroek > Cc: [email protected] > Subject: Re: [OpenLayers-Users] First try with html5 canvas for layers > > Hi Kris, > > I'm fairly new to OpenLayers and assumed that when creating a vector > layer for use with wfs-t that the layer features would be rendered > using either SVG or VML, thus allowing for the full range of mouse > interactions that other DOM elements support (click, mouseover, > mouseout etc). > > With the canvas implementation how do you support edting of a polygon > for instance? > > Cheers > Adam > > On Sat, Nov 21, 2009 at 1:32 PM, Kris Geusebroek <[email protected] > > wrote: >> Hi Adam, >> >> I think it doesn't make a difference in the current way OpenLayers >> works >> other then replacing a lot of div's by a single canvas. Nothing to do >> with interactivity I guess. >> >> The current div based vector layer can be used together with wfs-t or >> getfeatureinfo request to make it interactive. >> >> And together with the refresh strategy (in trunk) you can make it >> look >> like you are following the changes in data near real time. >> >> >> Perhaps I misunderstood your remark. If so feel free to contact me >> >> Cheers Kris >> >> -----Original Message----- >> From: [email protected] [mailto:[email protected] >> ] >> On Behalf Of Adam Ratcliffe >> Sent: Saturday, November 21, 2009 12:45 AM >> To: [email protected] >> Subject: Re: [OpenLayers-Users] First try with html5 canvas for >> layers >> >> Hi Kris, >> >> Am I correct in thinking this technique would be useful for >> displaying >> read-only vector data only? Or are you considering an approach such >> as overlaying a transparent image map to allow interactivity? >> >> Cheers >> Adam >> >> On Thu, Nov 19, 2009 at 8:58 PM, Kris Geusebroek <[email protected] >> > >> wrote: >>> Hi Eric, >>> >>> Indeed it's cool, thanks. >>> My goal was to write an application with open source technologies to >>> track cars driving around. >>> I wrote a prototype with geoserver and openlayers and this was >>> succesfull. The big problem was the memory consumption (especially >>> in >>> IE) because of the large amount of DOM manipulation that is done >>> when >>> panning and zooming and drawing vector's (the cars, with fills, >> stroke, >>> label etc.) >>> >>> Since using a plugin is out of the question here I began >>> investigating >>> the html5 canvas. >>> I know it's not supported in IE, but for me that was a good thing >>> because it gave me the opportunity to have the client choose a >> different >>> browser then IE. >>> >>> My plans for the future of the app is to also use workers and the >>> browser database (to be able to store historical responses >>> clientside >> to >>> draw a route the car has followed for the last 10 minutes or so) >>> >>> Also I think the canvas gives us the opportunity to create a print >>> control or a save map as, because in the end it's just an image. >>> (have >>> to combine the layer specific canvasses into one but that's >>> easy ;-)) >>> >>> If you have any other ideas or see different opportunities let me >> know, >>> my client is fundning me to experiment with html5 so I might be able >> to >>> spent some time on other's feature requests ;-) >>> >>> Cheers Kris >>> >>> >>> -----Original Message----- >>> From: Eric Lemoine [mailto:[email protected]] >>> Sent: Thursday, November 19, 2009 6:53 AM >>> To: Kris Geusebroek >>> Cc: OpenLayers Users >>> Subject: Re: [OpenLayers-Users] First try with html5 canvas for >>> layers >>> >>> On Wednesday, November 18, 2009, Kris Geusebroek >> <[email protected]> >>> wrote: >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> Hi All, >>>> >>>> >>>> >>>> I'm currently investigating the >>>> possibilities of integrating html5 functionality into openlayers. >>>> >>>> My first try is using canvas for a layer >>>> instead of div's >>>> >>>> >>>> >>>> I've setup a sandbox which you can >>>> use to have a look: >>> >> http://dev.openlayers.org/sandbox/krisgeus/openlayers/examples/tilecache >>> Canvas.html >>>> >>>> >>>> >>>> This is the first example to show it's >>>> possible ;-). Only features now are zoom and pan without the resize >>> transition effect. >>>> >>>> If anyone has remarks, ideas, feature >>>> requests, help offerings etc. Feel free to contact me. >>> >>> This is cool! >>> >>> May I ask what's your goal with displaying tiles using canvas? Is it >>> performance? I have never played with canvas so I'm interested to >>> know >>> and talk about what it can bring to OpenLayers. >>> >>> Thanks Kris, >>> >>> -- >>> Eric Lemoine >>> >>> Camptocamp France SAS >>> Savoie Technolac, BP 352 >>> 73377 Le Bourget du Lac, Cedex >>> >>> Tel : 00 33 4 79 44 44 96 >>> Mail : [email protected] >>> http://www.camptocamp.com >>> _______________________________________________ >>> Users mailing list >>> [email protected] >>> http://openlayers.org/mailman/listinfo/users >>> >> _______________________________________________ >> Users mailing list >> [email protected] >> http://openlayers.org/mailman/listinfo/users >> _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users
