If you are making a web mapping application using OpenLayers, etc. you could make a html based legend that changes based on openlayers events. In my case I have it changing depending on the base layer selected as all of the base layers are choropleth maps that require different legends. I've used a table to make mine so using prototype or jquery you can change just parts of the legend, such as the range of a class of data.
Matt, I'd love to find a way to do what you are doing with png with pdfs. The mapnik pdf output is great, I'd like to implement a print map button that would render a pdf map of the current extent with a proper legend! I've looked at http://pybrary.net/pyPdf/, looks like the merge function might work, for this. PIL doesn't open pdfs correct? ---- Jay ----- Original Message ----- From: "Matt Bartolome" <[email protected]> To: "Nop" <[email protected]> Cc: [email protected] Sent: Wednesday, January 14, 2009 10:08:43 AM GMT -08:00 US/Canada Pacific Subject: Re: [Mapnik-users] Creating map keys On Wed, Jan 14, 2009 at 9:51 AM, Nop <[email protected]> wrote: > > Hello! > > > The mapnik-rendered map I am working on is still lacking a map key. I am > a bit at a loss how to set up something for a map key efficnetly, > considering that it is likely that it will have to be re-rendered as the > map changes. > > Has any of you a recommendation, a trick or an example for this? > I've done something like this with PIL (python imaging library). This assumes a static legend saved as png but you could dynamically create it as well through pil (drawing text, colored boxes ect). It goes something like this: import Image legend = Image.open("legend.png") base = Image.open("base_map.png") base.paste(legend, (0,0), legend) image_file = "new_with_legend.png" base.save(image_file) I don't know if there is an easier way through mapnik but this is how I decided to do it. -matt > > thanks > Nop > _______________________________________________ > Mapnik-users mailing list > [email protected] > https://lists.berlios.de/mailman/listinfo/mapnik-users > _______________________________________________ Mapnik-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/mapnik-users _______________________________________________ Mapnik-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/mapnik-users
