yeah, I thought of that Vitali, but I thought what FastTree did was to pre-load the entire TreeItem dataset (i.e. fetch all data in one RPC operation) but then only actually draw visible tree layers, thus cutting down repeated RPC fetches on lazy tree node open but still only draw what is required on open clicks.
Which is no good for this situation because GWTFan has a flat tree structure, i.e. all 1000 items in same branch? On Mar 11, 12:18 pm, Vitali Lovich <[email protected]> wrote: > FastTree already takes care of all of this, so I'd recommend using it. > > http://collectionofdemos.appspot.com/demo/com.google.gwt.demos.fasttr... > > On Wed, Mar 11, 2009 at 7:37 AM, gregor <[email protected]>wrote: > > > > > I have never tried using StackPanel like that, but I did look at it's > > code once to enhance it and I think it is at least as "complicated" as > > Tree (in the sense it has many HTML "boxes") so I would guess it would > > probably be if anything worse than Tree in your situation. > > > The classic way to deal with large trees is to lazy load them by > > layer, but obviously that is not an option for you as you only have > > one layer. > > > I think you'll have to figure out a creative way to design a widget to > > deal with this edge case (1000 items). It's a bit difficult to suggest > > anything because we don't know either the contents of the tree nodes > > (what these 100 items are) or how they are used (presume user selects > > them?) > > > One idea that that immediately occurred to me was to use > > DisclosurePanels. This has a right pointing triangle when closed, and > > when clicked reveals the contents, rather like clicking the + on a > > Tree. I am assuming also that the problem is purely rendering and that > > there is no time problem fetching the 1000 items over RPC. You could > > make a Composite widget like so: > > > Choose a container, could be FlowPanel, VerticalPanel etc > > Keep a list of the items as a member of this class, and a cursor to > > keep an index against the list > > Set a maximum number to be rendered at any one time, say a few more > > than your happy days case of <=10 > > Iterate through the list making DisclosurePanels and adding them to > > the container as you go > > If the list size > your chosen max, add a button bar to the bottom > > giving forward/back options > > > Etc, I'm sure you get the idea. I think rendering 10 - 15 > > DiclosurePanels at a time will probably be quick enough. > > > On Mar 11, 5:49 am, GWTFan <[email protected]> wrote: > > > I read the threadhttp:// > > groups.google.com/group/Google-Web-Toolkit/browse_thread/threa... > > > on tree performance. > > > > We are having a similar issue with the tree, where most of the cases > > > it would have 1-10 items. However rarely it would have 500-1000 items, > > > which slows down IE badly. > > > > Ours is just one level hierarchy and I don't really need tree. Do you > > > think using a stack panel would be faster than tree? --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/Google-Web-Toolkit?hl=en -~----------~----~----~----~------~----~------~--~---
