Re: Developing for AWT/Swing and Android portability

Martin Gregorie <martin@address-in-sig.invalid> writes:


  The standard Android SDK contains an emulator (which can be
  somewhat slow).


  The emulator can execute Android software under Linux.

  Otherwise, Android applications (especially user interfaces,
  but also other parts) have to be structured differently than
  Swing applications from the beginning (from ground up), so a
  compatibility layer is difficult and one would have to forgo
  many features of Android or Swing using such a layer.

  However, one can split an application into two parts, which I
  here call the ?application-specific processing library?
  (ASPL) and the ?platform-specific application proper? (PSAP).

  The ASPL contains code for data storage (in containers, such
  as java.util.list) and data processing and uses solely the
  common subset of both Java implementations (i.e., of Android
  and of Java SE). It is a library written specifically for
  the use by the specific application (it might, however,
  itself delegate to other, more general, libraries).

  The two PSAPs contains everything that depends on the
  platform, including the methods ?main? or ?onCreate?,
  respectively.

  So, you have to write a new PSAP for every platform, but you
  do only have to write one ASPL. Start by writing the
  application for one platform first, building the PSAP and
  the ASPL at the same time. Try to move as much code as
  possible out of the PSAP and into the ASPL. You can even
  refactor an existing application this way, starting with an
  empty ASPL and the whole application being the PSAP, and
  then step-by-step moving parts into the ASPL. Then, write a
  new PSAP for the next platform, but now you can /reuse/ the
  same ASPL. (If the splitting was not done with both
  platforms already in mind, some changes to the ASPL might
  still become necessary, because the structure of the ASPL
  might impose some constraints on the PSAP that cannot be
  fulfilled on the other platform.)