On Wed, Apr 8, 2009 at 8:52 AM, Arthur Kalmenson <[email protected]>wrote:
> > Hey Jake, > > I've never used the SWT Canvas, but if it's anything like the <canvas> > tag, you might want to check out the GWTCanvas in the incubator: > > http://code.google.com/docreader/#p=google-web-toolkit-incubator&s=google-web-toolkit-incubator&t=GWTCanvas GWT 1.6 includes Canvas from what I recall off the top of my head (or is that only trunk?). > > > > Also, Vitali, there's a GWT library for accessing gears: > http://code.google.com/p/gwt-google-apis/ I never meant to imply that there wasn't - just that it's not part of GWT & probably never will be, especially given that HTML5 is an actual W3C standard that browsers have already started implementing. > > > Regards, > -- > Arthur Kalmenson > > > > On Tue, Apr 7, 2009 at 3:35 PM, Jake <[email protected]> wrote: > > > > Isaac, thank you for the informed response, I believe that was exactly > > what I was looking for. > > > > Best regards, > > > > Jake > > > > On Apr 7, 3:27 pm, Isaac Truett <[email protected]> wrote: > >> Jake, > >> > >> You would have to create a class org.eclipse.swt.widgets.Canvas such > >> that it is GWT-compatible. That means only using emulated JRE classes > >> (String, collections, etc.). Any class required for the Canvas class > >> API has to be implemented in a GWT-compatible manner as well. This > >> transitive dependency is what really kills you. If you get to a point > >> where you have to use a non-emulated JRE class (e.g., java.io.* > >> (almost)), you're hosed (I believe this was essentially Ian's point). > >> > >> Assuming you manage to implement the entire API, you create a module > >> file (gwt.xml) that includes the source you just wrote, inherit that > >> module in your GWT app, and enjoy. > >> > >> For more on JRE emulation, see: > >> > >> http://code.google.com/docreader/#p=google-web-toolkit-doc-1-5&s=goog. > .. > >> > >> - Isaac > >> > >> On Tue, Apr 7, 2009 at 3:14 PM, Jake <[email protected]> wrote: > >> > >> > I feel like I'm not expressing myself clearly. Let's just focus on the > >> > reduced case: > >> > >> > import org.eclipse.swt.widgets.Canvas; > >> > >> > public class foo { > >> > >> > } > >> > >> > Right now, if I try to run this through GWT, it will throw an error > >> > because it can't compile Canvas and all of its dependencies. This is > >> > to be expected. So what I would like is to roll my own Canvas class > >> > which extends GWT's Widget class, and have that be used instead, but > >> > in such a way that I don't have to touch the existing program's source > >> > code. > >> > >> > Ian, you seem to be suggesting that I need to hack this into the > >> > internals of GWT itself, and try to push it upstream. I feel like > >> > there should be a way to do this without having modify GWT internals, > >> > because this would allow certain applications (not all of them) that > >> > leverage native GUI toolkits to be compiled directly to a browser- > >> > based version, without having to port them to a GWT-friendly set of > >> > libraries. This would be a very powerful feature, but it may not > >> > exist. If I could just get confirmation on this, I would appreciate > >> > it. > >> > >> > Thanks, > >> > >> > Jake > >> > >> > On Apr 7, 2:38 pm, Ian Bambury <[email protected]> wrote: > >> >> GWT isn't Java. It just uses Java syntax so that Java books are > useful, and > >> >> things like Eclipse work for it. > >> >> GWT code becomes JavaScript. It is never at any point Java. > >> > >> >> A very simple compiler might recognise '"Window.alert(" and translate > it to > >> >> '"document.alert(" > >> > >> >> If you whole program consists of Window.alert("Hello"); then it will > be OK. > >> >> Anything else will fail. > >> > >> >> The Google team have emulated many other commands and structures, but > not > >> >> all of them: some are obscure and therefore not high enough up the > priority > >> >> list, and some are impossible because, like threading, JS just > doesn't do > >> >> that. > >> > >> >> It would be an impossible task to emulate every possible class in > every Java > >> >> library in existence. And would take for ever. > >> > >> >> So if it ain't emulated, it ain't gonna work because the compiler > will issue > >> >> a polite and rather technical version of 'WTF?' > >> > >> >> And just throwing any old java program into the GWT compiler is, > pretty > >> >> much, pointless. > >> > >> >> But if you really want to help Google and emulate > rg.eclipse.swt.widgets.Canvas > >> >> for GWT, then I'm sure they (and many others) will be eternally > grateful for > >> >> at least a week or two :-) > >> > >> >> If so, troll your little old lallies over to the very bonahttp:// > groups.google.com/group/Google-Web-Toolkit-Contributors > > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. 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