Add "Turn off" action to demo mode snackbar (#1258)

Signed-off-by: mueller-ma <mueller-ma@users.noreply.github.com>

mobile/src/main/java/org/openhab/habdroid/ui/MainActivity.java

@@ -277,7 +277,7 @@ public class MainActivity extends AppCompatActivity implements
 
     private void handleConnectionChange() {
         if (mConnection instanceof DemoConnection) {
-            showSnackbar(R.string.info_demo_mode_short);
+            showDemoModeHintSnackbar();
         } else {
             boolean hasLocalAndRemote =
                     ConnectionFactory.getConnection(Connection.TYPE_LOCAL) != null
@@ -1033,6 +1033,18 @@ public class MainActivity extends AppCompatActivity implements
         mLastSnackbar.show();
     }
 
+    public void showDemoModeHintSnackbar() {
+        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
+        mLastSnackbar = Snackbar.make(findViewById(android.R.id.content),
+                R.string.info_demo_mode_short, Snackbar.LENGTH_LONG);
+        mLastSnackbar.setAction(R.string.turn_off, v -> {
+            prefs.edit()
+                    .putBoolean(Constants.PREFERENCE_DEMOMODE, false)
+                    .apply();
+        });
+        mLastSnackbar.show();
+    }
+
     private void showSnackbar(@StringRes int messageResId) {
         mLastSnackbar = Snackbar.make(findViewById(android.R.id.content),
                 messageResId, Snackbar.LENGTH_LONG);

mobile/src/main/res/values/strings.xml

@@ -79,6 +79,8 @@
     <string name="info_voice_input">openHAB, at your command!</string>
     <string name="info_voice_recognized_text">Recognized command: %1$s</string>
     <string name="info_demo_mode_short">Running in demo mode</string>
+    <!-- Please try to keep the string as short as possible -->
+    <string name="turn_off">Turn off</string>
     <string name="info_conn_url">Connecting to local URL</string>
     <string name="info_conn_rem_url">Connecting to remote URL</string>
     <string name="app_shortcut_diabled_habpanel">Your server doesn\'t have HABPanel installed</string>