android: move wallet data to internal storage.

gui/kivy/Readme.txt

@@ -11,3 +11,8 @@ If something in included modules like kivy or any other module changes
 then you need to rebuild the distribution. To do so:
 
    `rm -rf electrum/.buildozer/android/platform/python-for-android/dist`
+
+
+Note:
+  python-for-android must be patched with:
+  git pull git@github.com:denys-duchier/python-for-android.git fix-recursive-delete

lib/blockchain.py

@@ -102,7 +102,7 @@ class Blockchain(util.PrintError):
         return hash_encode(Hash(self.serialize_header(header).decode('hex')))
 
     def path(self):
-        return os.path.join(self.config.path, 'blockchain_headers')
+        return util.get_headers_path(self.config)
 
     def init_headers_file(self):
         filename = self.path()

lib/util.py

@@ -196,6 +196,44 @@ def profiler(func):
     return lambda *args, **kw_args: do_profile(func, args, kw_args)
 
 
+def android_ext_dir():
+    import jnius
+    env = jnius.autoclass('android.os.Environment')
+    return env.getExternalStorageDirectory().getPath()
+
+def android_data_dir():
+    import jnius
+    PythonActivity = jnius.autoclass('org.renpy.android.PythonActivity')
+    return PythonActivity.mActivity.getFilesDir().getPath() + '/data'
+
+def android_headers_path():
+    path = android_ext_dir() + '/org.electrum.electrum/blockchain_headers'
+    d = os.path.dirname(path)
+    if not os.path.exists(d):
+        os.mkdir(d)
+    return path
+
+def android_check_data_dir():
+    """ if needed, move old directory to sandbox """
+    ext_dir = android_ext_dir()
+    data_dir = android_data_dir()
+    old_electrum_dir = ext_dir + '/electrum'
+    if not os.path.exists(data_dir) and os.path.exists(old_electrum_dir):
+        import shutil
+        new_headers_path = android_headers_path()
+        old_headers_path = old_electrum_dir + '/blockchain_headers'
+        if not os.path.exists(new_headers_path) and os.path.exists(old_headers_path):
+            print_error("Moving headers file to", new_headers_path)
+            shutil.move(old_headers_path, new_headers_path)
+        print_error("Moving data to", data_dir)
+        shutil.move(old_electrum_dir, data_dir)
+    return data_dir
+
+def get_headers_path(config):
+    if 'ANDROID_DATA' in os.environ:
+        return android_headers_path()
+    else:
+        return os.path.join(config.path, 'blockchain_headers')
 
 def user_dir():
     if "HOME" in os.environ:
@@ -205,14 +243,7 @@ def user_dir():
     elif "LOCALAPPDATA" in os.environ:
         return os.path.join(os.environ["LOCALAPPDATA"], "Electrum")
     elif 'ANDROID_DATA' in os.environ:
-        try:
+        return android_check_data_dir()
-            import jnius
-            env  = jnius.autoclass('android.os.Environment')
-            _dir =  env.getExternalStorageDirectory().getPath()
-            return _dir + '/electrum/'
-        except ImportError:
-            pass
-        return "/sdcard/electrum/"
     else:
         #raise Exception("No home directory found in environment variables.")
         return