What does "This method is deprecated" mean for application developers

Question

I see quite a few good old useful methods or even entire classes being "deprecated and obsolete".

But code that used to call those methods continues to work. So, what does this mean to me, as an Android applications developer?

1. Continue using this method as long as I want, because newer SDKs will always remain backward compatible.
2. It will work as long as I build for older targets (e.g. API 8), but if I build from API 14 up, the compiler will refuse to complete the build.
3. Both (1) and (2)
4. Other?

This is especially confusing when no alternatives are provided, as in the case of WebView.PictureListener.html#onNewPicture.

Answer 1

It usually means that there's either a better way of doing things or that the deprecated functionality had some irreparable flaw and should be avoided. You can usually keep using deprecated methods, but you are advised to either switch to some new API (in the first case) or find some other way of doing what you want (in the second).

Regarding onNewPicture in particular, the entire PictureListener interface is deprecated. There's no sign of what, if anything, is supposed to replace it. A comment by @CommonsWare in this thread is food for thought:

It is conceivable that upstream changes in WebKit are driving the deprecation and that support for PictureListener might be totally lost in some future release.

Answer 2

I would go with 4:

It will basically tell you that the use of the method or class is discouraged; it is NOT 100% that they will keep backward compatibility (they can decide to not include that method in future releases), so you should try to use the replacement of the method or class. This is sometimes not possible to use the new methods (for instance, if you want to support devices running older versions).

Some other times it is actually possible. For instance, the showDialog method is now deprecated and they recommend to use DialogFragment class. You can achieve that even in older versions of Android by using the compatibility library.