I'm trying to optimize a Carousel component and I wanna have only one active item in DOM. It is easy to achieve simply by removing/adding components in the cardswitch event of carousel. But the problem is that my components load some ajax info from server before rendering and it takes time, so it's slow to rerender them on each cardswitch.
Is there any technique to cache created components but at the same time to not add them to DOM?
Actually there is no way to keep items otside the DOM and then put them back, so the only solution I found is to recreate items when the became active. It's actually the way Sencha suggests.
The other interesting technique is the one Sencha implemented in ST2. It actually keeps only 3 items in DOM event if carousel has 100000 items. Check the html in Chrome. Haven't seen this carefully yet, but it's cool and performance is great.
Related
I'm trying to implement jScrollPane on a playlist generated by jPlayer (with playlist) but it's not working. I think what is happening is that jPlayer builds the playlist dynamically after jScrollPane has been initialized on the playlist ul element.
The jPlayer and jPlayerPlaylist work fine; and I can see the element css added by jScrollPane, which shows it’s working, but the scrollbars are not visible. Possibly I'd need to call jScrollPane after the playlist has finished building? Does anybody have experience with these plugins?
Thanks!
The site is here: http://elricoshow.com
I finally figured it out, after a few tries… I think it was something with the css, maybe because I was trying to have a non-javascript version too, I'm not sure.
Anyways, I've managed to make some very nice scroll bars that blend well with the page, and that work better on a touchscreen (or with the mousewheel) than say a Carousel (because with the carousel you need to click for every advance).
I have a MVP type application where I will have a view that contains one or more buttons. The number of buttons is not known till run time and may vary each time the page is rendered. What is the best way to approach this apart from a simple loop that will just display 1 - n number of buttons that are passed to the view?
My suggestion: Add all the buttons on creation and use CSS to hide or show them dynamically. I think this will yield less DOM manipulations and still works the same, also it might produce a simpler code. I currently do it that way using SmartGwt.
I've done the prerequisite searching of stackoverflow and looking on the internet. I suspect that the answer is ' This can't be done. ' but I'm hoping someone here might have a solution.
My page loads fine, but many of my YUI components don't fully load before being displayed. For example, my DataTable will resize itself when displaying or my buttons will appear in their native form and then get YUI-fied.
Is there a way to delay the displaying of the page until all the Javascript is finished (i.e. all my YUI components are finished rendering)? I don't know how this would happen, as a lot of the JS depends on the DOM being present to manipulate it.
Is there a way to delay the displaying
of the page
If I understand correctly you would like to hide it until it's done?
If that's the case I have an idea:
add a wrapper around the element you
want to hide (or use
position:absolute to cover it)
give that div a background which use
the color of the surrounding with a
positive z-index
when all your javascript has loaded remove the
z-index or change the color of the background to transparent
Your javascript code would look like this:
do 1. and 2.
load your js
do 3.
Of course it needs to be synchrone.
As an alternative you could use visibility:hidden / visible on the element itself but I dunno for sure if it's well supported.
Try putting your Javascript in the head section of the page, as if it's near the end of the page, it'll load later (making the first elements load faster). OR, better yet, serve up your Javascript compressed and via a CDN, such as Amazon CloudFront so that it loads quickly.
I've yet another question. I'm working with GWT 2.0.4 and IE8 as well as FireFox (the latter only for comparison purpose). My application needs to load data and show it inside a table. There are about 60 columns and 150 rows to show.
Since the loading is dynamic - as soon as a dataset has been fetched, it's added to the table - I'm fine with slowdowns during loading process. However: when the table is completely loaded, I'd expect it to be pretty snappy and let me scroll it without much lag.
While the loaded table reacts in FireFox pretty good - it stays very responsive - Internet Explorer 8 is causing me a lot of headaches. In particular: as soon as the table finished loading and I try to scroll around or highlight a row, IE8 becomes VERY laggy and highlighting a row makes IE8 consume 50+% of CPU power.
I am not using any 3rd-party libraries and even displaying empty cells in a FlexTable still gives me the same issue.
I found some probably related issue here: SmartGWT ListGrid is slow, but only in Internet Explorer . Unfortunately neither the issue there, nor the supplied links for SmartGWT solved my problem as I am not using SmartGWT. I do believe though that the problem is related.
I'd be happy to try any suggestions.
If it's possible (and your description of the problem suggests so), use Grid instead:
A rectangular grid that can contain
text, html, or a child Widget within
its cells. It must be resized
explicitly to the desired number of
rows and columns.
Have a look at bulk table renderers # GWT Incubator for a comparison of these approaches (it's a little dated, but the point that FlexTable is slower than Grid still holds ;)). The "bulk rendered" tables from the incubator are also an option, however keep in mind that those widgets might not be maintained any more (and for example, contain bugs) - or are rapidly maintained :D But looking at the source might at least point you in the right direction, if you wanted to roll out your own solution to this problem.
highlighting a row makes IE8 consume 50+% of CPU power.
Maybe it's because you added mouse listeners to every row in your table. If so you could use :hover-pseudo-class in your css-files.
This article maybe helpful if you need to handle Events from a bunch of widgets in your table: http://code.google.com/intl/en/webtoolkit/doc/latest/FAQ_UI.html#As_the_application_grows,_event_handlers_seem_to_fire_more_slowl
I would like to arrange UIControls in WPF in a similar way to the applications on the iPhone. They should be positioned on a grid, but a user should be able to drag them somewhere else, after releasing the mouse button (or the finger in case of an iPhone) the selected UIControl should snap back to the next position in the grid. The other UIElements should be rearranged automatically.
Further the user should also be connect two elements with a line or something.
I'm not experienced with WPF. The first question is if there is a container which is suitable for something (System.Windows.Controls.Grid ?) or if I have to extend canvas or somethig else for this.
I would like to know which elements from the WPF framework can be used and which elements I have to write myself.
For people who do not own an iPhone: http://www.youtube.com/watch?v=3omhu2AUWC8
Update
I've looked at AnimatedTilePanel in the BangOTricks examples (see below), this one explains how to create your own Panel and how to let it arrange things there.. However I still need an idea how to implement drag and drop correctly in this example..
Unfortunately, you'll have to write a lot of things yourself, as WPF doesn't automatically do what you're looking for.
For positioning the controls, you can use either UniformGrid or Grid. Assuming it's much like the iPhone video you showed, you can just use the UniformGrid with 4 columns and however many rows you need.
For the dragging animation, layout-wise, you could start by manipulating the RenderTransform property on whatever is being dragged, but you'll have to set a handler to check once you've met whatever threshold necessary to move into the another "cell" -- and at that point, you'll have to changed the order of the items in the tree.
Take a look at AnimatedTilePanel from Kevin's Bag-o-Tricks at:
http://j832.com/bagotricks/
It doesn't do everything you want but it will show you how to write a panel that animates its children when changing size or order.
New input to this old post in 09. Earlier this year (2012) someone has wrote a FluidWrapPanel and open sourced it. I tried it and it works like a charm - just like that on the iPhone menu.
You can also apply to other UI Elements or UserControl.