android: Add menu item to import VPN profile via Storage Access Framework

This is useful in case the proper MIME type was not set for a downloaded
profile.

src/frontends/android/app/src/main/java/org/strongswan/android/ui/MainActivity.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 Tobias Brunner
+ * Copyright (C) 2012-2017 Tobias Brunner
  * Copyright (C) 2012 Giuliano Grassi
  * Copyright (C) 2012 Ralf Sager
  * Hochschule fuer Technik Rapperswil
@@ -26,6 +26,7 @@ import android.content.Intent;
 import android.content.ServiceConnection;
 import android.net.VpnService;
 import android.os.AsyncTask;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.IBinder;
 import android.support.v4.app.Fragment;
@@ -140,11 +141,25 @@ public class MainActivity extends AppCompatActivity implements OnVpnProfileSelec
 		return true;
 	}
 
+	@Override
+	public boolean onPrepareOptionsMenu(Menu menu)
+	{
+		if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT)
+		{
+			menu.removeItem(R.id.menu_import_profile);
+		}
+		return true;
+	}
+
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item)
 	{
 		switch (item.getItemId())
 		{
+			case R.id.menu_import_profile:
+				Intent intent = new Intent(this, VpnProfileImportActivity.class);
+				startActivity(intent);
+				return true;
 			case R.id.menu_manage_certs:
 				Intent certIntent = new Intent(this, TrustedCertificatesActivity.class);
 				startActivity(certIntent);

src/frontends/android/app/src/main/java/org/strongswan/android/ui/VpnProfileImportActivity.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2016 Tobias Brunner
+ * Copyright (C) 2016-2017 Tobias Brunner
  * HSR Hochschule fuer Technik Rapperswil
  *
  * This program is free software; you can redistribute it and/or modify it
@@ -25,6 +25,7 @@ import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.Loader;
 import android.net.Uri;
+import android.os.Build;
 import android.os.Bundle;
 import android.security.KeyChain;
 import android.security.KeyChainAliasCallback;
@@ -75,7 +76,9 @@ import javax.net.ssl.SSLHandshakeException;
 public class VpnProfileImportActivity extends AppCompatActivity
 {
 	private static final String PKCS12_INSTALLED = "PKCS12_INSTALLED";
+	private static final String PROFILE_URI = "PROFILE_URI";
 	private static final int INSTALL_PKCS12 = 0;
+	private static final int OPEN_DOCUMENT = 1;
 	private static final int PROFILE_LOADER = 0;
 	private static final int USER_CERT_LOADER = 1;
 
@@ -107,7 +110,7 @@ public class VpnProfileImportActivity extends AppCompatActivity
 		@Override
 		public Loader<ProfileLoadResult> onCreateLoader(int id, Bundle args)
 		{
-			return new ProfileLoader(VpnProfileImportActivity.this, getIntent().getData());
+			return new ProfileLoader(VpnProfileImportActivity.this, (Uri)args.getParcelable(PROFILE_URI));
 		}
 
 		@Override
@@ -197,16 +200,13 @@ public class VpnProfileImportActivity extends AppCompatActivity
 		String action = intent.getAction();
 		if (Intent.ACTION_VIEW.equals(action))
 		{
-			mProgress = ProgressDialog.show(this, null, getString(R.string.loading),
-											true, true, new DialogInterface.OnCancelListener() {
-				@Override
-				public void onCancel(DialogInterface dialog)
-				{
-					finish();
-				}
-			});
-
-			getLoaderManager().initLoader(PROFILE_LOADER, null, mProfileLoaderCallbacks);
+			loadProfile(getIntent().getData());
+		}
+		else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT)
+		{
+			Intent openIntent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
+			openIntent.setType("*/*");
+			startActivityForResult(openIntent, OPEN_DOCUMENT);
 		}
 
 		if (savedInstanceState != null)
@@ -279,9 +279,34 @@ public class VpnProfileImportActivity extends AppCompatActivity
 					mImportUserCert.setEnabled(false);
 					mSelectUserCert.performClick();
 				}
+				break;
+			case OPEN_DOCUMENT:
+				if (resultCode == Activity.RESULT_OK && data != null)
+				{
+					loadProfile(data.getData());
+					return;
+				}
+				finish();
+				break;
 		}
 	}
 
+	private void loadProfile(Uri uri)
+	{
+		mProgress = ProgressDialog.show(this, null, getString(R.string.loading),
+				true, true, new DialogInterface.OnCancelListener() {
+					@Override
+					public void onCancel(DialogInterface dialog)
+					{
+						finish();
+					}
+				});
+
+		Bundle args = new Bundle();
+		args.putParcelable(PROFILE_URI, uri);
+		getLoaderManager().initLoader(PROFILE_LOADER, args, mProfileLoaderCallbacks);
+	}
+
 	public void handleProfile(ProfileLoadResult data)
 	{
 		mProgress.dismiss();

src/frontends/android/app/src/main/res/menu/main.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!--
-    Copyright (C) 2012-2014 Tobias Brunner
+    Copyright (C) 2012-2017 Tobias Brunner
     Hochschule fuer Technik Rapperswil
 
     This program is free software; you can redistribute it and/or modify it
@@ -16,6 +16,11 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
       xmlns:app="http://schemas.android.com/apk/res-auto">
 
+    <item
+        android:id="@+id/menu_import_profile"
+        android:title="@string/profile_import"
+        app:showAsAction="withText" />
+
     <item
         android:id="@+id/menu_manage_certs"
         android:title="@string/trusted_certs_title"