David, Your advice is some of the best I've come across on these boards.
Would it be okay to ask you for any examples which include this clone technique you've discussed above? Also window scrolling versus iUI version of scrolling.. I'm a bit confused in that respect as to the differences between the two. Is there some documentation I can be pointed to explain how it's done in iUI and what the smoother way of doing it such as in the FB app? Thanks - sf On 1/24/08, davidroe <[EMAIL PROTECTED]> wrote: > > - YMMV with iui, if you use it out of the box, you can create a > generic application quickly, if you want to change how it works, you > have to continue from there onwards. animation is done by tweaking the > style and can lead to less-than-smooth transitions. even Joe changed > the technique in the FB app to use window scrolling instead > > - yes, it's a pain to clone data, just to put it side by side, but it > was necessary to get where I have got to. the DOM has a method for > cloning elements which works quickly. > > - the processor in today's iPhone is, if memory serves, a 400Mhz chip, > so anything you try to do with regards to Javascript is going to slow > your application down. my advice is, the less Javascript, the better - > render as much as HTML on the server and dish it up. > > - GWT is all about Javascript, or at least what I am doing with it > (google for "gwt feed reader" for a good example). I chose to generate > my UI completely in Javascript, which is necessary in some parts, but > otherwise is a choice I'm living with elsewhere. ultimately, it means > you have to tread carefully, not be too processor intensive, and build > things in the background wherever possible. > > - use an event model wherever possible. your UI will be unresponsive > while processing Javascript. split this up into chunks and implement a > command scheduler. > > /dave > > On Jan 18, 8:46am, "Steve Finkelstein" <[EMAIL PROTECTED]> wrote: > > Hi David, > > > > Thank you for the elaborate reply. It is quite annoying that the execution > > of JavaScript randomly does not occur. It's gotten to the point where I have > > to re-design/re-prototype my entire application because I couldn't figure > > out why it was happening. I'm going to try this time around with iUI, > > although I see you mentioned in your post it was an issue with iUI as well. > > The code GWT is producing seems to be more responsive on your application? > > Basically your solution sounds like making a double of every div that you > > plan on sliding in and out... ouch. That seems a bit bloated, even though it > > might work, I would really like to avoid that as it is a semantic headache. > > > > I'll be trying to re-create my application with iUI and see if anything > > happens. I really wish I did have some solid test cases to report to Apple > > about random javascript instances never being invoked by the browser. I > > cannot replicate any of these symptoms on desktop browsers, eg > > webkit,safari,ff. Only on mobile safari does this become an issue. > > > > Thanks for the reply, I'll see if I can come up with any other solution. > > > > - sf > > > > On 1/12/08, davidroe <[EMAIL PROTECTED]> wrote: > > > > > > > > > On Dec 28 2007, 8:09am, "Steve Finkelstein" <[EMAIL PROTECTED]> > > > wrote: > > > > > > It's almost as if the JavaScript never gets called. I slide a hidden div > > > into view, > > > > and make an XHR call to draw my HTML. I'd say 7 out of 10 times, it will > > > draw > > > > the rest of the div. At least 3 times no POST request is made. Really > > > > disappointing. :-( > > > > > I have spent a long time trying to get around some strange behaviour > > > regarding sliding and Javascript execution. To cut a long story short, > > > I would see perfect behaviour most of the time, but then sometimes the > > > Javascript interpreter would be unresponsive (although it would come > > > back to life if I scrolled the screen). > > > > > Chances are, the only thing our problems have in common is the levels > > > of frustration they are causing and the amount of hair-pulling, but > > > nevertheless, this is what I have finally decided is the cause of it > > > all - large amounts of off-screen content. > > > > > To further explain, you know when you scroll a long web page on Safari > > > on the iPhone/iPod Touch, you have to wait for parts of the display to > > > paint, I presume because the device only holds a certain part of the > > > rendered content in memory and otherwise has to go and build the rest > > > before being able to display it. Well, I think that problems arise > > > when you invoke the Javascript interpreter to scroll content around > > > the display, yet part of this content is buffered and part is not. I > > > don't exactly know what is going on here, but I've been messing around > > > with my particular problem for long enough, running different tests, > > > trying to make any sense of it, and this is the only thing that seems > > > to fit. > > > > > I'm able to say this because I have half a solution in place and am > > > unable to reproduce the problem - I can slide (in one direction, so > > > far) to my hearts content without seeing anything hang. I did this by > > > cloning the div currently displayed, cloning the div that is about to > > > slide in, put each one in a container div with height 480px, overflow > > > hidden, to ensure that displayed content is kept to a minimum, place > > > these two divs side by side and perform the slide, finally putting > > > everything back in place when it is done. And, to be a little more > > > specific, I am sliding using setScroll(), rather than manipulating the > > > div's left style, and am using GWT, not IUI, as my toolkit. > > > > > I hope this helps, in one way or another. I also hope I'm not posting > > > again tomorrow, saying that the problem has returned. I have already > > > wasted plenty of time on this, and I have already thought that the > > > problem had been solved, only to find it turn up again with different > > > content. > > > > > Good luck, > > > /dave > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "iPhoneWebDev" group. To post to this group, send email to iphonewebdev@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/iphonewebdev?hl=en -~----------~----~----~----~------~----~------~--~---
