Question

I am developing an Android app to support both En/Ar. But I faced a problem that if the user changes from En to Ar the alignment of the user interface must turns from “left to right” to “right to left”.

Example: (TextView)(EditText) this is in En

But in Ar it should be: (EditText)(TextView).

Is there a way to do this without creating two different layouts or two different versions?

Answer 1

Why can’t this be done with two layouts (you never said why this is not desireable)? As described by the Android Developers documentation

A large part of localizing an application is providing alternative
text for different languages. In some cases you will also provide
alternative graphics, sounds, layouts, and other locale-specific
resources.

An application can specify many res// directories, each
with different qualifiers. To create an alternative resource for a
different locale, you use a qualifier that specifies a language or a
language-region combination.

Ref: http://developer.android.com/guide/topics/resources/localization.html

So in your case create res/layout-ar then copy your existing layout into this folder and then simply swap them round. Simple, follows best practices and is easy to do. This also makes any further localisation changes easier going forward without having to write more code.

If you were to write code you are going to need to find the default language of the device and then swap the Views based on this. You can get the language by:

Locale.getDefault().getDisplayLanguage();

See this question for more detail: Get the current language in device

On a final personal note: I think the former is a much better separation of concerns, as the code provides logic and the XML layouts actually control the layout (with Android selecting the right resources automagically for you without having to write any more code).