Merge branch '1438-send-image-attachments-ui' into 'master'

Implement UX for sending image attachments

See merge request !1004

briar-android/build.gradle

@@ -105,6 +105,7 @@ dependencies {
 	implementation "com.android.support:cardview-v7:$supportVersion"
 	implementation "com.android.support:support-annotations:$supportVersion"
 	implementation "com.android.support:exifinterface:$supportVersion"
+	implementation "com.android.support:palette-v7:$supportVersion"
 	implementation 'com.android.support.constraint:constraint-layout:1.1.3'
 	implementation "android.arch.lifecycle:extensions:1.1.1"
 

briar-android/src/main/java/org/briarproject/briar/android/AndroidComponent.java

@@ -32,7 +32,7 @@ import org.briarproject.briar.BriarCoreModule;
 import org.briarproject.briar.android.conversation.glide.BriarModelLoader;
 import org.briarproject.briar.android.login.SignInReminderReceiver;
 import org.briarproject.briar.android.reporting.BriarReportSender;
-import org.briarproject.briar.android.view.TextInputView;
+import org.briarproject.briar.android.view.EmojiTextInputView;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.android.DozeWatchdog;
 import org.briarproject.briar.api.android.LockManager;
@@ -169,7 +169,7 @@ public interface AndroidComponent
 
 	void inject(NotificationCleanupService notificationCleanupService);
 
-	void inject(TextInputView textInputView);
+	void inject(EmojiTextInputView textInputView);
 
 	void inject(BriarModelLoader briarModelLoader);
 

briar-android/src/main/java/org/briarproject/briar/android/TestingConstants.java

@@ -30,4 +30,10 @@ public interface TestingConstants {
 	long EXPIRY_DATE = IS_DEBUG_BUILD || IS_BETA_BUILD ?
 			BuildConfig.BuildTimestamp + 90 * 24 * 60 * 60 * 1000L :
 			Long.MAX_VALUE;
+
+	/**
+	 * Feature flag for enabling image attachments.
+	 */
+	boolean FEATURE_FLAG_IMAGE_ATTACHMENTS = IS_DEBUG_BUILD;
+
 }

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

@@ -14,5 +14,6 @@ public interface RequestCodes {
 	int REQUEST_BLUETOOTH_DISCOVERABLE = 10;
 	int REQUEST_UNLOCK = 11;
 	int REQUEST_KEYGUARD_UNLOCK = 12;
+	int REQUEST_ATTACH_IMAGE = 13;
 
 }

briar-android/src/main/java/org/briarproject/briar/android/blog/ReblogFragment.java

 package org.briarproject.briar.android.blog;
 
+import android.net.Uri;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -18,7 +19,10 @@ import org.briarproject.briar.android.controller.handler.UiExceptionHandler;
 import org.briarproject.briar.android.controller.handler.UiResultExceptionHandler;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.view.TextInputView;
-import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.TextSendController;
+import org.briarproject.briar.android.view.TextSendController.SendListener;
+
+import java.util.List;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
@@ -29,10 +33,11 @@ import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.blog.BasePostFragment.POST_ID;
+import static org.briarproject.briar.api.blog.BlogConstants.MAX_BLOG_POST_TEXT_LENGTH;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class ReblogFragment extends BaseFragment implements TextInputListener {
+public class ReblogFragment extends BaseFragment implements SendListener {
 
 	public static final String TAG = ReblogFragment.class.getName();
 
@@ -77,7 +82,11 @@ public class ReblogFragment extends BaseFragment implements TextInputListener {
 		View v = inflater.inflate(R.layout.fragment_reblog, container, false);
 		ui = new ViewHolder(v);
 		ui.post.setTransitionName(postId);
-		ui.input.setSendButtonEnabled(false);
+		TextSendController sendController =
+				new TextSendController(ui.input, this, true);
+		ui.input.setSendController(sendController);
+		ui.input.setEnabled(false);
+		ui.input.setMaxTextLength(MAX_BLOG_POST_TEXT_LENGTH);
 		showProgressBar();
 
 		return v;
@@ -112,16 +121,14 @@ public class ReblogFragment extends BaseFragment implements TextInputListener {
 		ui.post.bindItem(item);
 		ui.post.hideReblogButton();
 
-		ui.input.setListener(this);
-		ui.input.setSendButtonEnabled(true);
+		ui.input.setEnabled(true);
 		ui.scrollView.post(() -> ui.scrollView.fullScroll(FOCUS_DOWN));
 	}
 
 	@Override
-	public void onSendClick(String text) {
+	public void onSendClick(@Nullable String text, List<Uri> imageUris) {
 		ui.input.hideSoftKeyboard();
-		String comment = getComment();
-		feedController.repeatPost(item, comment,
+		feedController.repeatPost(item, text,
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
@@ -131,12 +138,6 @@ public class ReblogFragment extends BaseFragment implements TextInputListener {
 		finish();
 	}
 
-	@Nullable
-	private String getComment() {
-		if (ui.input.getText().length() == 0) return null;
-		return ui.input.getText().toString();
-	}
-
 	private void showProgressBar() {
 		ui.progressBar.setVisibility(VISIBLE);
 		ui.input.setVisibility(GONE);

briar-android/src/main/java/org/briarproject/briar/android/blog/WriteBlogPostActivity.java

 package org.briarproject.briar.android.blog;
 
 import android.content.Intent;
+import android.net.Uri;
 import android.os.Bundle;
-import android.text.Editable;
-import android.text.TextWatcher;
+import android.support.annotation.Nullable;
 import android.view.KeyEvent;
 import android.view.MenuItem;
 import android.widget.ProgressBar;
@@ -14,19 +14,22 @@ import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.identity.LocalAuthor;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.util.StringUtils;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
 import org.briarproject.briar.android.view.TextInputView;
-import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.TextSendController;
+import org.briarproject.briar.android.view.TextSendController.SendListener;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.blog.BlogManager;
 import org.briarproject.briar.api.blog.BlogPost;
 import org.briarproject.briar.api.blog.BlogPostFactory;
 
 import java.security.GeneralSecurityException;
+import java.util.List;
 import java.util.logging.Logger;
 
 import javax.inject.Inject;
@@ -35,10 +38,13 @@ import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 import static org.briarproject.briar.api.blog.BlogConstants.MAX_BLOG_POST_TEXT_LENGTH;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class WriteBlogPostActivity extends BriarActivity
-		implements OnEditorActionListener, TextInputListener {
+		implements OnEditorActionListener, SendListener {
 
 	private static final Logger LOG =
 			Logger.getLogger(WriteBlogPostActivity.class.getName());
@@ -58,9 +64,8 @@ public class WriteBlogPostActivity extends BriarActivity
 	@Inject
 	volatile BlogManager blogManager;
 
-	@SuppressWarnings("ConstantConditions")
 	@Override
-	public void onCreate(Bundle state) {
+	public void onCreate(@Nullable Bundle state) {
 		super.onCreate(state);
 
 		Intent i = getIntent();
@@ -71,24 +76,10 @@ public class WriteBlogPostActivity extends BriarActivity
 		setContentView(R.layout.activity_write_blog_post);
 
 		input = findViewById(R.id.textInput);
-		input.setSendButtonEnabled(false);
-		input.addTextChangedListener(new TextWatcher() {
-			@Override
-			public void beforeTextChanged(CharSequence s, int start, int count,
-					int after) {
-			}
-
-			@Override
-			public void onTextChanged(CharSequence s, int start, int before,
-					int count) {
-			}
-
-			@Override
-			public void afterTextChanged(Editable s) {
-				enableOrDisablePublishButton();
-			}
-		});
-		input.setListener(this);
+		TextSendController sendController =
+				new TextSendController(input, this, false);
+		input.setSendController(sendController);
+		input.setMaxTextLength(MAX_BLOG_POST_TEXT_LENGTH);
 
 		progressBar = findViewById(R.id.progressBar);
 	}
@@ -127,18 +118,15 @@ public class WriteBlogPostActivity extends BriarActivity
 		return true;
 	}
 
-	private void enableOrDisablePublishButton() {
-		input.setSendButtonEnabled(input.getText().length() > 0);
-	}
-
 	@Override
-	public void onSendClick(String text) {
+	public void onSendClick(@Nullable String text, List<Uri> imageUris) {
+		if (isNullOrEmpty(text)) throw new AssertionError();
+
 		// hide publish button, show progress bar
 		input.hideSoftKeyboard();
 		input.setVisibility(GONE);
 		progressBar.setVisibility(VISIBLE);
 
-		text = StringUtils.truncateUtf8(text, MAX_BLOG_POST_TEXT_LENGTH);
 		storePost(text);
 	}
 

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

@@ -6,6 +6,7 @@ import android.arch.lifecycle.ViewModelProvider;
 import android.arch.lifecycle.ViewModelProviders;
 import android.content.DialogInterface;
 import android.content.Intent;
+import android.net.Uri;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
 import android.support.annotation.UiThread;
@@ -52,7 +53,6 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.event.MessagesAckedEvent;
 import org.briarproject.bramble.api.sync.event.MessagesSentEvent;
-import org.briarproject.bramble.util.StringUtils;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
@@ -63,8 +63,12 @@ import org.briarproject.briar.android.forum.ForumActivity;
 import org.briarproject.briar.android.introduction.IntroductionActivity;
 import org.briarproject.briar.android.privategroup.conversation.GroupActivity;
 import org.briarproject.briar.android.view.BriarRecyclerView;
+import org.briarproject.briar.android.view.ImagePreview;
+import org.briarproject.briar.android.view.TextAttachmentController;
+import org.briarproject.briar.android.view.TextAttachmentController.AttachImageListener;
 import org.briarproject.briar.android.view.TextInputView;
-import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.TextSendController;
+import org.briarproject.briar.android.view.TextSendController.SendListener;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.blog.BlogSharingManager;
 import org.briarproject.briar.api.client.ProtocolStateException;
@@ -106,6 +110,7 @@ import static android.support.v4.app.ActivityOptionsCompat.makeSceneTransitionAn
 import static android.support.v4.view.ViewCompat.setTransitionName;
 import static android.support.v7.util.SortedList.INVALID_POSITION;
 import static android.view.Gravity.RIGHT;
+import static android.widget.Toast.LENGTH_LONG;
 import static android.widget.Toast.LENGTH_SHORT;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.sort;
@@ -115,6 +120,9 @@ import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
+import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
+import static org.briarproject.briar.android.TestingConstants.FEATURE_FLAG_IMAGE_ATTACHMENTS;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_ATTACH_IMAGE;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_INTRODUCTION;
 import static org.briarproject.briar.android.conversation.ImageActivity.ATTACHMENT;
 import static org.briarproject.briar.android.conversation.ImageActivity.DATE;
@@ -130,8 +138,8 @@ import static uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt.S
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class ConversationActivity extends BriarActivity
-		implements EventListener, ConversationListener, TextInputListener,
-		TextCache, AttachmentCache {
+		implements EventListener, ConversationListener, SendListener,
+		TextCache, AttachmentCache, AttachImageListener {
 
 	public static final String CONTACT_ID = "briar.CONTACT_ID";
 
@@ -161,6 +169,7 @@ public class ConversationActivity extends BriarActivity
 	private BriarRecyclerView list;
 	private LinearLayoutManager layoutManager;
 	private TextInputView textInputView;
+	private TextSendController sendController;
 
 	// Fields that are accessed from background threads must be volatile
 	@Inject
@@ -250,7 +259,16 @@ public class ConversationActivity extends BriarActivity
 		list.setEmptyText(getString(R.string.no_private_messages));
 
 		textInputView = findViewById(R.id.text_input_container);
-		textInputView.setListener(this);
+		if (FEATURE_FLAG_IMAGE_ATTACHMENTS) {
+			ImagePreview imagePreview = findViewById(R.id.imagePreview);
+			sendController = new TextAttachmentController(textInputView,
+					imagePreview, this, this);
+		} else {
+			sendController = new TextSendController(textInputView, this, false);
+		}
+		textInputView.setSendController(sendController);
+		textInputView.setMaxTextLength(MAX_PRIVATE_MESSAGE_TEXT_LENGTH);
+		textInputView.setEnabled(false);
 	}
 
 	@Override
@@ -267,6 +285,9 @@ public class ConversationActivity extends BriarActivity
 					Snackbar.LENGTH_SHORT);
 			snackbar.getView().setBackgroundResource(R.color.briar_primary);
 			snackbar.show();
+		} else if (request == REQUEST_ATTACH_IMAGE && result == RESULT_OK) {
+			// remove cast when removing FEATURE_FLAG_IMAGE_ATTACHMENTS
+			((TextAttachmentController) sendController).onImageReceived(data);
 		}
 	}
 
@@ -405,7 +426,7 @@ public class ConversationActivity extends BriarActivity
 		runOnUiThreadUnlessDestroyed(() -> {
 			if (revision == adapter.getRevision()) {
 				adapter.incrementRevision();
-				textInputView.setSendButtonEnabled(true);
+				textInputView.setEnabled(true);
 				List<ConversationItem> items = createItems(headers);
 				adapter.addAll(items);
 				list.showData();
@@ -573,14 +594,23 @@ public class ConversationActivity extends BriarActivity
 	}
 
 	@Override
-	public void onSendClick(String text) {
-		if (text.isEmpty()) return;
-		text = StringUtils.truncateUtf8(text, MAX_PRIVATE_MESSAGE_TEXT_LENGTH);
+	public void onAttachImage(Intent intent) {
+		startActivityForResult(intent, REQUEST_ATTACH_IMAGE);
+	}
+
+	@Override
+	public void onSendClick(@Nullable String text, List<Uri> imageUris) {
+		if (!imageUris.isEmpty()) {
+			Toast.makeText(this, "Not yet implemented.", LENGTH_LONG).show();
+			textInputView.clearText();
+			return;
+		}
+		if (isNullOrEmpty(text)) throw new AssertionError();
 		long timestamp = System.currentTimeMillis();
 		timestamp = Math.max(timestamp, getMinTimestampForNewMessage());
 		if (messagingGroupId == null) loadGroupId(text, timestamp);
 		else createMessage(text, timestamp);
-		textInputView.setText("");
+		textInputView.clearText();
 	}
 
 	private long getMinTimestampForNewMessage() {

briar-android/src/main/java/org/briarproject/briar/android/introduction/IntroductionMessageFragment.java

 package org.briarproject.briar.android.introduction;
 
 import android.content.Context;
+import android.net.Uri;
 import android.os.Bundle;
-import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v7.app.ActionBar;
 import android.view.LayoutInflater;
@@ -17,14 +17,17 @@ import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.util.StringUtils;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.view.TextInputView;
-import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.TextSendController;
+import org.briarproject.briar.android.view.TextSendController.SendListener;
 import org.briarproject.briar.api.introduction.IntroductionManager;
 
+import java.util.List;
 import java.util.logging.Logger;
 
 import javax.inject.Inject;
@@ -41,8 +44,10 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.util.UiUtils.getContactDisplayName;
 import static org.briarproject.briar.api.introduction.IntroductionConstants.MAX_INTRODUCTION_TEXT_LENGTH;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class IntroductionMessageFragment extends BaseFragment
-		implements TextInputListener {
+		implements SendListener {
 
 	public static final String TAG =
 			IntroductionMessageFragment.class.getName();
@@ -84,8 +89,9 @@ public class IntroductionMessageFragment extends BaseFragment
 	}
 
 	@Override
-	public View onCreateView(@NonNull LayoutInflater inflater,
-			ViewGroup container, Bundle savedInstanceState) {
+	public View onCreateView(LayoutInflater inflater,
+			@Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
 
 		// change toolbar text
 		ActionBar actionBar = introductionActivity.getSupportActionBar();
@@ -97,7 +103,11 @@ public class IntroductionMessageFragment extends BaseFragment
 		View v = inflater.inflate(R.layout.introduction_message, container,
 				false);
 		ui = new ViewHolder(v);
-		ui.message.setSendButtonEnabled(false);
+		TextSendController sendController =
+				new TextSendController(ui.message, this, true);
+		ui.message.setSendController(sendController);
+		ui.message.setMaxTextLength(MAX_INTRODUCTION_TEXT_LENGTH);
+		ui.message.setEnabled(false);
 
 		return v;
 	}
@@ -156,13 +166,10 @@ public class IntroductionMessageFragment extends BaseFragment
 			ui.progressBar.setVisibility(GONE);
 
 			if (possible) {
-				// set button action
-				ui.message.setListener(IntroductionMessageFragment.this);
-
 				// show views
 				ui.notPossible.setVisibility(GONE);
 				ui.message.setVisibility(VISIBLE);
-				ui.message.setSendButtonEnabled(true);
+				ui.message.setEnabled(true);
 				ui.message.showSoftKeyboard();
 			} else {
 				ui.notPossible.setVisibility(VISIBLE);
@@ -184,14 +191,11 @@ public class IntroductionMessageFragment extends BaseFragment
 	}
 
 	@Override
-	public void onSendClick(@NonNull String text) {
+	public void onSendClick(@Nullable String text, List<Uri> imageUris) {
 		// disable button to prevent accidental double invitations
-		ui.message.setSendButtonEnabled(false);
+		ui.message.setEnabled(false);
 
-		String txt = ui.message.getText().toString();
-		if (txt.isEmpty()) txt = null;
-		else txt = StringUtils.truncateUtf8(txt, MAX_INTRODUCTION_TEXT_LENGTH);
-		makeIntroduction(contact1, contact2, txt);
+		makeIntroduction(contact1, contact2, text);
 
 		// don't wait for the introduction to be made before finishing activity
 		introductionActivity.hideSoftKeyboard(ui.message);

briar-android/src/main/java/org/briarproject/briar/android/privategroup/conversation/GroupActivity.java

@@ -196,7 +196,7 @@ public class GroupActivity extends
 
 	private void setGroupEnabled(boolean enabled) {
 		isDissolved = !enabled;
-		textInput.setSendButtonEnabled(enabled);
+		textInput.setEnabled(enabled);
 		list.getRecyclerView().setAlpha(enabled ? 1f : 0.5f);
 
 		if (!enabled) {

briar-android/src/main/java/org/briarproject/briar/android/privategroup/creation/CreateGroupController.java

 package org.briarproject.briar.android.privategroup.creation;
 
+import android.support.annotation.Nullable;
+
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -18,6 +20,7 @@ public interface CreateGroupController
 			ResultExceptionHandler<GroupId, DbException> result);
 
 	void sendInvitation(GroupId g, Collection<ContactId> contacts,
-			String text, ResultExceptionHandler<Void, DbException> result);
+			@Nullable String text,
+			ResultExceptionHandler<Void, DbException> result);
 
 }

briar-android/src/main/java/org/briarproject/briar/android/privategroup/creation/CreateGroupControllerImpl.java

 package org.briarproject.briar.android.privategroup.creation;
 
+import android.support.annotation.Nullable;
+
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
@@ -123,7 +125,8 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 
 	@Override
 	public void sendInvitation(GroupId g, Collection<ContactId> contactIds,
-			String text, ResultExceptionHandler<Void, DbException> handler) {
+			@Nullable String text,
+			ResultExceptionHandler<Void, DbException> handler) {
 		runOnDbThread(() -> {
 			try {
 				LocalAuthor localAuthor = identityManager.getLocalAuthor();
@@ -144,7 +147,7 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 	}
 
 	private void signInvitations(GroupId g, LocalAuthor localAuthor,
-			Collection<Contact> contacts, String text,
+			Collection<Contact> contacts, @Nullable String text,
 			ResultExceptionHandler<Void, DbException> handler) {
 		cryptoExecutor.execute(() -> {
 			long timestamp = clock.currentTimeMillis();
@@ -160,15 +163,14 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 	}
 
 	private void sendInvitations(GroupId g,
-			Collection<InvitationContext> contexts, String text,
+			Collection<InvitationContext> contexts, @Nullable String text,
 			ResultExceptionHandler<Void, DbException> handler) {
 		runOnDbThread(() -> {
 			try {
-				String txt = text.isEmpty() ? null : text;
 				for (InvitationContext context : contexts) {
 					try {
 						groupInvitationManager.sendInvitation(g,
-								context.contactId, txt, context.timestamp,
+								context.contactId, text, context.timestamp,
 								context.signature);
 					} catch (NoSuchContactException e) {
 						// Continue

briar-android/src/main/java/org/briarproject/briar/android/privategroup/creation/GroupInviteActivity.java

@@ -55,7 +55,7 @@ public class GroupInviteActivity extends ContactSelectorActivity
 	}
 
 	@Override
-	public boolean onButtonClick(String text) {
+	public void onButtonClick(@Nullable String text) {
 		if (groupId == null)
 			throw new IllegalStateException("GroupId was not initialized");
 		controller.sendInvitation(groupId, contacts, text,
@@ -72,7 +72,6 @@ public class GroupInviteActivity extends ContactSelectorActivity
 						handleDbException(exception);
 					}
 				});
-		return true;
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/sharing/BaseMessageFragment.java

 package org.briarproject.briar.android.sharing;
 
 import android.content.Context;
+import android.net.Uri;
 import android.os.Bundle;
+import android.support.annotation.Nullable;
 import android.support.annotation.StringRes;
 import android.support.annotation.UiThread;
-import android.support.design.widget.Snackbar;
 import android.view.LayoutInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.view.LargeTextInputView;
-import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.TextSendController;
+import org.briarproject.briar.android.view.TextSendController.SendListener;
 
-import static android.support.design.widget.Snackbar.LENGTH_SHORT;
-import static org.briarproject.bramble.util.StringUtils.truncateUtf8;
-import static org.briarproject.bramble.util.StringUtils.utf8IsTooLong;
-import static org.briarproject.briar.api.sharing.SharingConstants.MAX_INVITATION_TEXT_LENGTH;
+import java.util.List;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public abstract class BaseMessageFragment extends BaseFragment
-		implements TextInputListener {
+		implements SendListener {
 
 	protected LargeTextInputView message;
 	private MessageFragmentListener listener;
@@ -34,16 +37,20 @@ public abstract class BaseMessageFragment extends BaseFragment
 	}
 
 	@Override
-	public View onCreateView(LayoutInflater inflater, ViewGroup container,
-			Bundle savedInstanceState) {
+	public View onCreateView(@Nullable LayoutInflater inflater,
+			@Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
 
 		// inflate view
 		View v = inflater.inflate(R.layout.fragment_message, container,
 				false);
 		message = v.findViewById(R.id.messageView);
+		TextSendController sendController =
+				new TextSendController(message, this, true);
+		message.setSendController(sendController);
+		message.setMaxTextLength(listener.getMaximumTextLength());
 		message.setButtonText(getString(getButtonText()));
 		message.setHint(getHintText());
-		message.setListener(this);
 
 		return v;
 	}
@@ -76,21 +83,12 @@ public abstract class BaseMessageFragment extends BaseFragment
 	}
 
 	@Override
-	public void onSendClick(String text) {
-		if (utf8IsTooLong(text, listener.getMaximumTextLength())) {
-			Snackbar.make(message, R.string.text_too_long, LENGTH_SHORT).show();
-			return;
-		}
-
+	public void onSendClick(@Nullable String text, List<Uri> imageUris) {
 		// disable button to prevent accidental double actions
-		message.setSendButtonEnabled(false);
+		message.setEnabled(false);
 		message.hideSoftKeyboard();
 
-		text = truncateUtf8(text, MAX_INVITATION_TEXT_LENGTH);
-		if(!listener.onButtonClick(text)) {
-			message.setSendButtonEnabled(true);
-			message.showSoftKeyboard();
-		}
+		listener.onButtonClick(text);
 	}
 
 	@UiThread
@@ -101,8 +99,7 @@ public abstract class BaseMessageFragment extends BaseFragment
 
 		void setTitle(@StringRes int titleRes);
 
-		/** Returns true when the button click has been consumed. */
-		boolean onButtonClick(String text);
+		void onButtonClick(@Nullable String text);
 
 		int getMaximumTextLength();