Develop Reference

Differences and advantages of using libGDX or Android SDK?

Which are the main advantages of using libGDX? Is there some difference between libGDX and Android SDK, or libGDX is just like a framework that uses Android SDK? Which one you advise me to use?

First of all i want to say, that this question is a bit opinion based and so i think it will be closed soon. Anyway i want to point out an important thing:
Libgdx is a crossplattform framework. You can develop and test 99% of your game on desktop. Then add aview code lines and it runs on android to. The only difference between the android app and the desktop version are then the Sensors and the Touchscreen. You may also get problems with the Screen sizes, but for this there are solutions you should take a look at.
I never worked with the android sdk, but as much as i know you have to use the emulator or your phone for testing. So the testing process is really slow and annoying.
And also if you want to develop for Android phones only, why don't you spent 5 minutes in thinking about how to controll your game on desktop and add those few lines?
Thats the thing i wanted to point out. The rest is up to you.
Maybe you want to take a look at the video on this page.

Phonegap - cordova is laggy and slow on android and iOS devices

I just now started with my first PhoneGap project using zend studio. But, after i build and deploy it, the application is quite slow. Both on android and iOS. The scrolling is lagging, and if i press a button, it's slow to goto the next page. Is there any way to improve it's performance ? Thanks in advance

Since version 4.0.4, there is a known "bug" where if hardware acceleration is on, it will actually slow down screen redraw events. This is why scrolling is slow.
On the Samsung Galaxy III and IV, canvas would not render anything at all until we turned off hardware acceleration. Once we did canvas drawing performed well.
You can turn off hardware acceleration for your webview with this line of code in your app java file:
super.appView.setLayerType(WebView.LAYER_TYPE_SOFTWARE, null);
This may be fixed as of 4.4 (KitKat uses Chromeview rather than webview).

Yes,you can add fastclick.js file to your html file.
like:
<script src="../fastclick.js"></script>
& refer this documentation to improve your phonegap app.

Several reasons could be the root cause.
You should give more info to help you further.
Possible quick and simple solutions.
A) disable your page transitions and check the effect.
What kind of operations are you performing on your page?
Are you using additional libraries?
I am not familiar with Zen studio, but how are ypu building your UI?
The scroll could be slow or lagging if you are scrolling over a list or buttons or links and in each touch the page is triying to react to change to the hover state but it is not fast enough to match the scrolling speed. Once I had that problem and disable the hover state and the scroll speed improved a lot. Double check that in the meantime.

In Android KitKat you can use DevTools to debug performance of your application. This is a great video to get to grips with the tools: https://developers.google.com/live/shows/840309825
You should experiment with turning off hardware acceleration on the WebView, but would recommend experimenting on Pre-KitKat and KitKat seperately. The KitKatWebView is based on Chrome and as a result has very different performance characteristics.

as mentioned, use FastClick to remove the 300ms delay for clicks.
you can also use this code to speed up the page transition:
$(document).bind("mobileinit", function () {
$.mobile.defaultPageTransition = 'none';
});

PhoneGap - Bad Performance compared to Browser on Android

I developed an application for android using jquery mobile and phonegap.
I deployed the app to my device over usb. The performance of the app ist really bad, especially while scrolling a longer list.
The strange thing is: The whole app runs smooth if i just open up the browser on my phone and access the index.html directly. Same technology, same content. I do not use the phonegap native api or anything similar.
Tested with phonegap 1.5.0 and 1.7.0rc1, jquery mobile 1.1.0 on android 4.0.2.
Any ideas?

On honeycomb (3.0), Ice cream (4.0) and posterior devices, you can boost performance by adding the following in the < Application ... > tag:
android:hardwareAccelerated="true"
You could set the minSdk to 8 (Android 2.2) for compatibility and the targetSdk to 15 (Android 4.0) and that would make hardware acceleration work when its available on the device only.
I believe that with this flag the performance of my apps is equal to running them in the browser, so I guess its because the browser was coded with hardware acceleration :)

I had a similar problem: a page with a longer list of "medium complex" themed divs. The browser of HTC phone had no problems in displaying. But within the phonegap app rendering failed completely. I saw a kind of WSOD, which disappeared only after touching the display. After touching, the page was displayed correct.
The problem was not in place, when I shortened the div-list to one or two div-elements or when I reduced the sub elements within the divs and reduced the render effort caused by the css complexity.
The white screen looked like, if the whole body was invisible, since only the documents background-color was displayed (I added a light pink for this). So I guess, the rendering was the problem after reading this thread
I tried the various proposals I found in this thread to make the app work without the "WSOD". But nothing worked. Some of them made the app displaying really worse.
Finally, after a whole day of searching, I made it. I set within the tag (not the tag) of my AndroidManifest
<application android:hardwareAccelerated="false" ...
Now the app behaves in the same fast way as my webbrowser. Seems like, if hardware acceleration is not always the best feature...
My versions:
phonegap 3.5.0, Android 4.0.3, jQuery v2.1.0, HTC Sense 3.6

Found an answer here: http://groups.google.com/group/phonegap/browse_thread/thread/94da1cf881abe995/6d4f7aea7aeba523?lnk=gst&q=performance
There is probably a difference between the native browser and the webview in terms of javascript performance.

If you can confirm the browser performs better (that it's not something suboptimal in your code frustrating one but not the other), you could consider deploying as an html5 offline application so that you will actually run in the browser.

We bumped into performance issues while scrolling the same amount of list items with jquery mobile. The performance was so poor (we didn't even try in PhoneGap environment) that we rewrote the app using iScroll library... now the app scrolls really smoothly.
If you are at the beginning of the development, you could try to change the UI library.
After this situation we deploy our apps to test devices quite often to manage performance issues in time... this became a "policy" :)

Webb app performance android

I'm developing a webbapp for iOS and Android, primarily. The problem is that it tends to run slow on the android phone (testing made on Samsung Galaxy S2). I've tried a couple of different frameworks together with PhoneGap without any good result.
My experience this far (on android):
Dojo toolkit: (v1.7.1)
Pretty good but flickers alot when doing transitions between different views and the input forms performs badly.
Sencha Touch: (v1.1)
Not very responsive and flickers a bit during transitions. Changing orientation takes awfully long.
JQTouch: (beta 4)
Runs smooth but the layout is broken on android (back-buttons etc that uses CSS transform rotate and translate)
My question is:
Have any of you found a framework that works well on both iPhone and Android devices? or is the only solution to develop native?
On a side note I've noticed that Sencha touch 2.0 has focused on Android performance but there's only a developer preview available at this time and is not going to be release before Q2 2012.

What I have found is that many of the frameworks work just great but the root cause of the problems is earlier versions of Android's support for CSS3 style transitions. You are probably better off avoiding or disabling these transitions.

Is PhoneGap slow or it is a bug?

After I have compiled and deployed the demo application to my Samsung Galaxy S II I noticed that the Sample PhoneGap App which comes with PhoneGap was not very responsive when pressing buttons and scrolling.
I also made a little app using PhoneGap and jQuery Mobile, with 4 buttons everything was ok, but when I added more than 7 and my viewport needed to be scrolled, scrolling become to be very slow, the more buttons/widgets I had the slower the srolling was.
Is this a bug specific to my mobile device or it is just how PhoneGap works:
The fact that PhoneGap apps feel slow on my phone including the demo?
EDIT:
The same PhoneGap app served by an HTTP server from my laptop and launched in the standard Android browser works very smoothly

Try setting your targetSdkVersion higher. Changing mine from "8" (i.e. Android 2.2) to "14" (Android 4.0) dramatically improved PhoneGap performance on phones running newer versions of Android. Most likely this enables certain performance-enhancing features such as hardware graphics acceleration.
For more info see my other answer about this here: https://stackoverflow.com/a/12397768/233370

Since PhoneGap and the frameworks that is used with it (JQM,Sencha Touch etc) are just working in a WebKit browser they can be slow if there's too much to render.
There's actually no bug with your device or etc.It's just that PhoneGap and the frameworks are not so good if you want fast response and so on.You can try your app in other devices and can observe that they behave the same.

I had the same Problems, after Update to Android 4.0.4 my Phonegap (Cordova 2.0.0) & Sencha Touch 2 - APP was very very slow.
But after I insert
super.appView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
the APP works fine, as before the update.
http://developer.android.com/guide/topics/graphics/hardware-accel.html

For improved performance you may not need Phonegap.
If what you need is quick cross platform styling but fast native components try a tool like nativecss.com It keeps the styling in CSS, but uses native components for everything else - so no HTML rendering delays or clunky animations.