Add simple draft actvity/fragment for conversation settings

briar-android/src/main/AndroidManifest.xml

@@ -141,6 +141,15 @@
 				android:value="org.briarproject.briar.android.conversation.ConversationActivity" />
 		</activity>
 
+		<activity
+			android:name=".android.conversation.ConversationSettingsActivity"
+			android:parentActivityName="org.briarproject.briar.android.conversation.ConversationActivity"
+			android:theme="@style/BriarTheme">
+			<meta-data
+				android:name="android.support.PARENT_ACTIVITY"
+				android:value="org.briarproject.briar.android.conversation.ConversationActivity" />
+		</activity>
+
 		<activity
 			android:name="org.briarproject.briar.android.privategroup.creation.CreateGroupActivity"
 			android:label="@string/groups_create_group_title"

briar-android/src/main/java/org/briarproject/briar/android/activity/ActivityComponent.java

@@ -28,6 +28,7 @@ import org.briarproject.briar.android.contact.add.remote.NicknameFragment;
 import org.briarproject.briar.android.contact.add.remote.PendingContactListActivity;
 import org.briarproject.briar.android.conversation.AliasDialogFragment;
 import org.briarproject.briar.android.conversation.ConversationActivity;
+import org.briarproject.briar.android.conversation.ConversationSettingsActivity;
 import org.briarproject.briar.android.conversation.ImageActivity;
 import org.briarproject.briar.android.conversation.ImageFragment;
 import org.briarproject.briar.android.forum.CreateForumActivity;
@@ -184,6 +185,8 @@ public interface ActivityComponent {
 
 	void inject(PendingContactListActivity activity);
 
+	void inject(ConversationSettingsActivity activity);
+
 	// Fragments
 
 	void inject(AuthorNameFragment fragment);

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationActivity.java

@@ -416,7 +416,10 @@ public class ConversationActivity extends BriarActivity
 				item.setChecked(enabled);
 				return true;
 			case R.id.action_conversation_settings:
-				// TODO: show settings
+				if (contactId == null) return false;
+				intent = new Intent(this, ConversationSettingsActivity.class);
+				intent.putExtra(CONTACT_ID, contactId.getInt());
+				startActivity(intent);
 				return true;
 			case R.id.action_delete_all_messages:
 				askToDeleteAllMessages();

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationSettingsActivity.java

@@ -0,0 +1,41 @@
+package org.briarproject.briar.android.conversation;
+
+import android.os.Bundle;
+import android.view.MenuItem;
+
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.activity.ActivityComponent;
+import org.briarproject.briar.android.activity.BriarActivity;
+
+import androidx.appcompat.app.ActionBar;
+
+public class ConversationSettingsActivity extends BriarActivity {
+
+	@Override
+	public void onCreate(Bundle bundle) {
+		super.onCreate(bundle);
+
+		ActionBar actionBar = getSupportActionBar();
+		if (actionBar != null) {
+			actionBar.setHomeButtonEnabled(true);
+			actionBar.setDisplayHomeAsUpEnabled(true);
+		}
+
+		setContentView(R.layout.activity_conversation_settings);
+	}
+
+	@Override
+	public void injectActivity(ActivityComponent component) {
+		component.inject(this);
+	}
+
+	@Override
+	public boolean onOptionsItemSelected(MenuItem item) {
+		if (item.getItemId() == android.R.id.home) {
+			onBackPressed();
+			return true;
+		}
+		return false;
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationSettingsFragment.java

@@ -0,0 +1,16 @@
+package org.briarproject.briar.android.conversation;
+
+import android.os.Bundle;
+
+import org.briarproject.briar.R;
+
+import androidx.preference.PreferenceFragmentCompat;
+
+public class ConversationSettingsFragment extends PreferenceFragmentCompat {
+
+	@Override
+	public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
+		addPreferencesFromResource(R.xml.conversation_settings);
+	}
+
+}

briar-android/src/main/res/layout/activity_conversation_settings.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+	android:layout_width="match_parent"
+	android:layout_height="match_parent">
+
+	<fragment
+		android:id="@+id/fragment"
+		android:name="org.briarproject.briar.android.conversation.ConversationSettingsFragment"
+		android:layout_width="match_parent"
+		android:layout_height="match_parent" />
+</FrameLayout>

briar-android/src/main/res/values/strings.xml

@@ -547,6 +547,12 @@
 	<string name="choose_ringtone_title">Choose ringtone</string>
 	<string name="cannot_load_ringtone">Cannot load ringtone</string>
 
+	<!-- Conversation Settings -->
+	<string name="disappearing_messages_title">Disappearing messages</string>
+	<string name="disappearing_messages_summary">Define a timeout after which messages self-destruct</string>
+	<string name="disappearing_messages_timeout_title">Self-destruct Timeout</string>
+	<string name="disappearing_messages_timeout_summary">7 days</string>
+
 	<!-- Settings Feedback -->
 	<string name="feedback_settings_title">Feedback</string>
 	<string name="send_feedback">Send feedback</string>

briar-android/src/main/res/xml/conversation_settings.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<PreferenceScreen
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:app="http://schemas.android.com/apk/res-auto">
+
+	<SwitchPreference
+		android:defaultValue="true"
+		android:key="pref_key_lock"
+		android:summary="@string/disappearing_messages_summary"
+		android:title="@string/disappearing_messages_title"
+		app:iconSpaceReserved="false"/>
+
+		<Preference
+			android:defaultValue="false"
+			android:enabled="false"
+			android:key="pref_key_purge"
+			android:summary="@string/disappearing_messages_timeout_summary"
+			android:title="@string/disappearing_messages_timeout_title"
+			app:iconSpaceReserved="false"/>
+
+</PreferenceScreen>