git-annex/doc/tips/android_sync_with_adb.mdwn

While git-annex can be [[installed_on_your_Android_device|/Android]],
it might be easier not to install it there, but run it on your computer
using `adb` to pull and push changes to the Android device.

A few reasons for going this route:

* Easier than installing git-annex on Android.
* Avoids needing to type commands into a terminal on Android.
* Avoids problems with putting a git-annex repository on Android's `/sdcard`,
  which is crippled by not supporting hard links etc.

All you should need is a USB cable (or adb over wifi), and the `adb`
command.

## setting it up

First, initialize your git-annex repository on your computer, if you haven't
already.

Then, in that repository, set up an adb special remote:

	initremote android type=adb androiddirectory=/sdcard encryption=none exporttree=yes importtree=yes

The above example syncs with the /sdcard directory of the
Android device. That can be a lot of files, so you may want a more
limited directory. See the sample workflows below for some more examples.

Next, configure how trees of files imported from it will be merged into your
git repository.

        git config remote.android.annex-tracking-branch master:android

Setting "master:android" makes the phone be treated as containing a branch
of the master branch, and makes all its files appear to be inside a
subdirectory named `android`. If you want its files to not be in a
subdirectory, set it to "master" instead.

Finally, you may want to configure a preferred content expression for the
remote. That will limit both what is exported to it, and what is imported
from it. If you want to fully sync all files, you don't need to do this.

For example, to limit the files that get imported and exported to sound files:

	git annex wanted android 'include=*.mp3 or include=*.ogg'

## syncing with it

	git annex sync --content android

This command does a bi-directional sync with the phone, first importing
new and changed files from it, merging that into the master branch,
and then exporting from the master branch back to the android device so any
modifications you have made get synced over to it.

See [[git-annex-import, [[git-annex-export]], and [[git-annex-sync]]
for more details, and bear in mind that you can also use commands like
these to only import from or export to the android device:

	git annex import master:android --from android
	git annex merge android/master
	git annex export master:android --to android

## sample workflows

### photos

Set up the remote to use the /sdcard/DCIM directory where the phone's
camera stores them.

	initremote android type=adb androiddirectory=/sdcard/DCIM encryption=none exporttree=yes importtree=yes
       
The annex-tracking-branch can be the same as before, to limit
the files that are synced to those in an android directory:

	git config remote.android.annex-tracking-branch master:android

If you don't want to keep old photos on your Android device, you can simply
`git mv` the files from the android directory to another directory, and
the next sync with the phone will delete them from the Android device:

	git mv android/* .
	git annex sync --content

### music and podcasts

You could set up the remote to use the /sdcard/Music directory.
But, I sometimes download music to other locations, and perhaps you do too.
Let's instead limit the remote to mp3 and ogg files:

	initremote android type=adb androiddirectory=/sdcard encryption=none exporttree=yes importtree=yes
	git annex wanted android 'include=*.mp3 or include=*.ogg'

The annex-tracking-branch can be the same as before, to limit
the files that are synced to those in an android directory:
	
	git config remote.android.annex-tracking-branch master:android

And then do an initial sync:

	git annex sync --content android

Now, you can copy music and podcasts you want to listen 
to over to the Android device, by first copying them to the android
directory of your git-annex repo:

	cp -a podcasts/LibreLounge/Episode_14__Secure_Scuttlebutt_with_Joey_Hess.ogg android/
	git annex add android
	git annex sync --content android

That will also import any new sound files from the Android device into 
your git-annex repo.

Once you're done with listening to something on the Android device, you can
simply delete it from the device, and the next time git-annex syncs, it
will get removed from the android directory. Or, you can delete it from the
android directory and the next sync will delete it from the Android device.