Hi Gabriele, You say your renderer is 150x80, yet the source images are 400x400 and up to 100KB.
Image loading is asynchronous, but bitmap rendering is not. If a 400x400 image has to be shrunk to 150x80, that will take a lot of CPU power. It would be better to have the images re-sampled before downloading. There will be less data and the bitmap renderer will not have to shrink images. As a test, chop a bunch of images to the right size and see if it performs better. -Alex ________________________________________ From: Gabriele Campi [[email protected]] Sent: Monday, June 30, 2014 8:11 AM To: [email protected] Subject: Re: list of images: poor performances My custom ItemRenderer is 150x80 I display 18 items at the same time Using an IconItemRenderer doesn't help ------------------------------------------------------------------------ Media Logic 20 Years *GABRIELE CAMPI* Graphical Department address: Via Maestri del Lavoro 10/L - 42122 Reggio Emilia - Italy phone: +39 0522 854058 <tel:+39%200522%20854058> fax: +39 0522 854313 <tel:+39%200522%20854313> email: [email protected] <mailto:[email protected]> web: www.medialogic.eu <http://www.medialogic.eu> skype: media.logic.eu <skipe:media.logic.eu?call> Le informazioni trasmesse sono destinate esclusivamente alla persona o alla società in indirizzo e sono da intendersi confidenziali e riservate. Ogni trasmissione, inoltro, diffusione o altro uso di queste informazioni a persone o società differenti dal destinatario é proibita. Se ricevete questa comunicazione per errore, contattate il mittente e cancellate le informazioni da ogni computer. /The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer./ Il 30/06/14 17:09, Gabriele Campi ha scritto: > 150 images > Size 10 to 100 KB > 400x400 pixel > > On iPad retina is almost ok. On iPad2/Mini is slow. On Android (galaxy > tab 2) the list is unusable. > Every new row of the list seems to freeze the ui while images are loading. > I don't understand, Isn't the load process of the images asynchronous? > > Gabri > > > > Il 30/06/14 16:49, Alex Harui ha scritto: >> How many images are we talking about? What pixel dimensions are the images >> in the list? What are some of the sizes in bytes of the images being >> downloaded? >> >> -Alex >> ________________________________________ >> From: Gabriele Campi [[email protected]] >> Sent: Monday, June 30, 2014 6:30 AM >> To: Javier Guerrero García; users >> Subject: Re: list of images: poor performances >> >> Nothing seems to work... performances are even worse with a timer or delay >> I cannot cache all the images because of memory consumption >> >> Il 28/06/14 10:44, Javier Guerrero García ha scritto: >>> Also adjust the opaqueBackground, don't set the image sources >>> inmediately but after a short timeout (so if you scroll down fast >>> skipping lets say 50 images you DON'T load 50 images before loading >>> the 51st), and use a contentCache loader with queueing >>> (http://corlan.org/2011/08/16/flex-mobile-development-caching-images-using-contentcache/) >>> >>> >>> P.S. you can use the ContentCache straight from MXML, not like the >>> sources in the link. Just declare it, set an ID and the rest of the >>> parameters, and set contentCache="{id}" in your itemRenderer. >>> >>> >>> On Sat, Jun 28, 2014 at 6:58 AM, Alex Harui <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> Make sure you are using a bitmap cache and that the images are not >>> being scaled down on the device. >>> Sent via the PANTECH Discover, an AT&T 4G LTE smartphone. >>> >>> Gabriele Campi <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> >>> Hi, >>> in a mobile app I need to display a list of 200 images. On the list I >>> use a tileLayout with virtualLayout=true and a custom itemRenderer >>> that >>> only contains a Spark Image. On the set value method of the >>> itemrenderer >>> I change the source of the image with the path to the new bitmap. >>> It works, but performances are poor and the list doesn't scroll >>> well. On >>> iPad it's almost acceptable, but on Android I have to scroll row >>> by row >>> and wait until every image of the row is loaded. >>> Any suggestions to improve the situation? >>> Thanks >>> >>> Gabriele >>> >>> >
