Only cache attachment items that include size.

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AttachmentRetrieverIntegrationTest.java

@@ -54,8 +54,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testSmallJpegImage() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getUrlInputStream(smallKitten);
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(msgId, item.getMessageId());
 		assertEquals(160, item.getWidth());
 		assertEquals(240, item.getHeight());
@@ -70,8 +70,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testBigJpegImage() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getUrlInputStream(originalKitten);
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(msgId, item.getMessageId());
 		assertEquals(1728, item.getWidth());
 		assertEquals(2592, item.getHeight());
@@ -86,8 +86,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testSmallPngImage() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/png");
 		InputStream is = getUrlInputStream(pngKitten);
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(msgId, item.getMessageId());
 		assertEquals(737, item.getWidth());
 		assertEquals(510, item.getHeight());
@@ -102,8 +102,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testUberGif() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getUrlInputStream(uberGif);
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(1, item.getWidth());
 		assertEquals(1, item.getHeight());
 		assertEquals(dimensions.minHeight, item.getThumbnailWidth());
@@ -117,8 +117,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testLottaPixels() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getUrlInputStream(lottaPixel);
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(64250, item.getWidth());
 		assertEquals(64250, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
@@ -132,8 +132,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testImageIoCrash() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getUrlInputStream(imageIoCrash);
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(1184, item.getWidth());
 		assertEquals(448, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
@@ -147,8 +147,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testGimpCrash() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getUrlInputStream(gimpCrash);
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(1, item.getWidth());
 		assertEquals(1, item.getHeight());
 		assertEquals(dimensions.minHeight, item.getThumbnailWidth());
@@ -162,8 +162,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testOptiPngAfl() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getUrlInputStream(optiPngAfl);
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(32, item.getWidth());
 		assertEquals(32, item.getHeight());
 		assertEquals(dimensions.minHeight, item.getThumbnailWidth());
@@ -177,8 +177,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testLibrawError() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getUrlInputStream(librawError);
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertTrue(item.hasError());
 	}
 
@@ -186,8 +186,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testSmallAnimatedGifMaxDimensions() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
 		InputStream is = getAssetInputStream("animated.gif");
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(65535, item.getWidth());
 		assertEquals(65535, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
@@ -201,8 +201,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testSmallAnimatedGifHugeDimensions() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
 		InputStream is = getAssetInputStream("animated2.gif");
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(10000, item.getWidth());
 		assertEquals(10000, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
@@ -216,8 +216,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testSmallGifLargeDimensions() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
 		InputStream is = getAssetInputStream("error_large.gif");
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(16384, item.getWidth());
 		assertEquals(16384, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
@@ -231,8 +231,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testHighError() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("error_high.jpg");
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(1, item.getWidth());
 		assertEquals(10000, item.getHeight());
 		assertEquals(dimensions.minWidth, item.getThumbnailWidth());
@@ -246,8 +246,8 @@ public class AttachmentRetrieverIntegrationTest {
 	public void testWideError() throws Exception {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("error_wide.jpg");
-		Attachment a = new Attachment(h, is);
+		Attachment a = new Attachment(is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.getAttachmentItem(h, a, true);
 		assertEquals(1920, item.getWidth());
 		assertEquals(1, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreationTask.java

@@ -1,22 +1,33 @@
 package org.briarproject.briar.android.attachment;
 
+import android.arch.lifecycle.LiveData;
+import android.arch.lifecycle.MutableLiveData;
+import android.arch.lifecycle.Observer;
 import android.content.ContentResolver;
 import android.net.Uri;
-import android.support.annotation.Nullable;
 
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.briar.api.messaging.Attachment;
 import org.briarproject.briar.api.messaging.AttachmentHeader;
 import org.briarproject.briar.api.messaging.MessagingManager;
 import org.jsoup.UnsupportedMimeTypeException;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
+
+import static java.util.Objects.requireNonNull;
+import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.IoUtils.tryToClose;
@@ -25,64 +36,97 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
 import static org.briarproject.briar.api.messaging.MessagingConstants.IMAGE_MIME_TYPES;
 
+@ThreadSafe
 @NotNullByDefault
 class AttachmentCreationTask {
 
 	private static Logger LOG =
 			getLogger(AttachmentCreationTask.class.getName());
 
+	private final Executor ioExecutor;
 	private final MessagingManager messagingManager;
 	private final ContentResolver contentResolver;
+	private final AttachmentRetriever retriever;
 	private final GroupId groupId;
 	private final Collection<Uri> uris;
 	private final boolean needsSize;
-	@Nullable
+	private final MutableLiveData<AttachmentResult> result;
-	private volatile AttachmentCreator attachmentCreator;
 
 	private volatile boolean canceled = false;
 
-	AttachmentCreationTask(MessagingManager messagingManager,
+	AttachmentCreationTask(Executor ioExecutor,
-			ContentResolver contentResolver,
+			MessagingManager messagingManager, ContentResolver contentResolver,
-			AttachmentCreator attachmentCreator, GroupId groupId,
+			AttachmentRetriever retriever, GroupId groupId,
 			Collection<Uri> uris, boolean needsSize) {
+		this.ioExecutor = ioExecutor;
 		this.messagingManager = messagingManager;
 		this.contentResolver = contentResolver;
+		this.retriever = retriever;
 		this.groupId = groupId;
 		this.uris = uris;
 		this.needsSize = needsSize;
-		this.attachmentCreator = attachmentCreator;
+		result = new MutableLiveData<>();
 	}
 
-	public void cancel() {
+	LiveData<AttachmentResult> getResult() {
+		return result;
+	}
+
+	/**
+	 * Cancels the task, asynchronously waits for it to finish, and deletes any
+	 * created attachments.
+	 */
+	void cancel() {
 		canceled = true;
-		attachmentCreator = null;
+		// Observe the task until it finishes (which may already have happened)
-	}
+		result.observeForever(new Observer<AttachmentResult>() {
-
+			@Override
-	@IoExecutor
+			public void onChanged(@Nullable AttachmentResult attachmentResult) {
-	public void storeAttachments() {
+				requireNonNull(attachmentResult);
-		for (Uri uri: uris) processUri(uri);
+				if (attachmentResult.isFinished()) {
-		AttachmentCreator attachmentCreator = this.attachmentCreator;
+					deleteUnsentAttachments(attachmentResult.getItemResults());
-		if (!canceled && attachmentCreator != null)
+					result.removeObserver(this);
-			attachmentCreator.onAttachmentCreationFinished();
+				}
-		this.attachmentCreator = null;
-	}
-
-	@IoExecutor
-	private void processUri(Uri uri) {
-		if (canceled) return;
-		try {
-			AttachmentHeader h = storeAttachment(uri);
-			AttachmentCreator attachmentCreator = this.attachmentCreator;
-			if (attachmentCreator != null) {
-				attachmentCreator.onAttachmentHeaderReceived(uri, h, needsSize);
 			}
+		});
+	}
+
+	/**
+	 * Asynchronously creates and stores the attachments.
+	 */
+	void storeAttachments() {
+		ioExecutor.execute(() -> {
+			if (LOG.isLoggable(INFO))
+				LOG.info("Storing " + uris.size() + " attachments");
+			List<AttachmentItemResult> results = new ArrayList<>();
+			for (Uri uri : uris) {
+				if (canceled) break;
+				results.add(processUri(uri));
+				result.postValue(new AttachmentResult(new ArrayList<>(results),
+						false, false));
+			}
+			result.postValue(new AttachmentResult(new ArrayList<>(results),
+					true, !canceled));
+		});
+	}
+
+	@IoExecutor
+	private AttachmentItemResult processUri(Uri uri) {
+		AttachmentHeader header = null;
+		try {
+			header = storeAttachment(uri);
+			Attachment a = retriever.getMessageAttachment(header);
+			AttachmentItem item =
+					retriever.getAttachmentItem(header, a, needsSize);
+			if (item.hasError()) throw new IOException();
+			if (needsSize) retriever.cachePut(item);
+			return new AttachmentItemResult(uri, item);
 		} catch (DbException | IOException e) {
 			logException(LOG, WARNING, e);
-			AttachmentCreator attachmentCreator = this.attachmentCreator;
+			// If the attachment was already stored, delete it
-			if (attachmentCreator != null) {
+			tryToRemove(header);
-				attachmentCreator.onAttachmentError(uri, e);
-			}
 			canceled = true;
+			return new AttachmentItemResult(uri, e);
 		}
 	}
 
@@ -113,4 +157,31 @@ class AttachmentCreationTask {
 		return false;
 	}
 
+	private void tryToRemove(@Nullable AttachmentHeader h) {
+		try {
+			if (h != null) messagingManager.removeAttachment(h);
+		} catch (DbException e1) {
+			logException(LOG, WARNING, e1);
+		}
+	}
+
+	private void deleteUnsentAttachments(
+			Collection<AttachmentItemResult> itemResults) {
+		List<AttachmentHeader> headers = new ArrayList<>(itemResults.size());
+		for (AttachmentItemResult itemResult : itemResults) {
+			AttachmentItem item = itemResult.getItem();
+			if (item != null) headers.add(item.getHeader());
+		}
+		if (LOG.isLoggable(INFO))
+			LOG.info("Deleting " + headers.size() + " unsent attachments");
+		ioExecutor.execute(() -> {
+			for (AttachmentHeader header : headers) {
+				try {
+					messagingManager.removeAttachment(header);
+				} catch (DbException e) {
+					logException(LOG, WARNING, e);
+				}
+			}
+		});
+	}
 }

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreator.java

@@ -1,56 +1,33 @@
 package org.briarproject.briar.android.attachment;
 
-
 import android.app.Application;
 import android.arch.lifecycle.LiveData;
-import android.arch.lifecycle.MutableLiveData;
 import android.net.Uri;
 import android.support.annotation.Nullable;
 import android.support.annotation.UiThread;
 
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.briar.R;
-import org.briarproject.briar.api.messaging.Attachment;
 import org.briarproject.briar.api.messaging.AttachmentHeader;
-import org.briarproject.briar.api.messaging.FileTooBigException;
 import org.briarproject.briar.api.messaging.MessagingManager;
-import org.jsoup.UnsupportedMimeTypeException;
 
-import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
-import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.Executor;
-import java.util.logging.Logger;
 
-import static java.util.logging.Level.WARNING;
+import static java.util.Collections.emptyList;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.util.LogUtils.logException;
-import static org.briarproject.briar.android.util.UiUtils.observeForeverOnce;
-import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_IMAGE_SIZE;
 
 @NotNullByDefault
 public class AttachmentCreator {
 
-	private static Logger LOG = getLogger(AttachmentCreator.class.getName());
-
 	private final Application app;
 	@IoExecutor
 	private final Executor ioExecutor;
 	private final MessagingManager messagingManager;
 	private final AttachmentRetriever retriever;
 
-	private final CopyOnWriteArrayList<Uri> uris = new CopyOnWriteArrayList<>();
-	private final CopyOnWriteArrayList<AttachmentItemResult> itemResults =
-			new CopyOnWriteArrayList<>();
-
-	private final MutableLiveData<AttachmentResult> result =
-			new MutableLiveData<>();
 	@Nullable
 	private AttachmentCreationTask task;
 
@@ -62,20 +39,19 @@ public class AttachmentCreator {
 		this.retriever = retriever;
 	}
 
+	/**
+	 * Starts a background task to create attachments from the given URIs and
+	 * returns a LiveData to monitor the progress of the task.
+	 */
 	@UiThread
-	public LiveData<AttachmentResult> storeAttachments(
+	public LiveData<AttachmentResult> storeAttachments(GroupId groupId,
-			LiveData<GroupId> groupId, Collection<Uri> newUris) {
+			Collection<Uri> uris) {
-		if (task != null || !uris.isEmpty())
+		if (task != null) throw new IllegalStateException();
-			throw new IllegalStateException();
+		boolean needsSize = uris.size() == 1;
-		uris.addAll(newUris);
+		task = new AttachmentCreationTask(ioExecutor, messagingManager,
-		observeForeverOnce(groupId, id -> {
+				app.getContentResolver(), retriever, groupId, uris, needsSize);
-			if (id == null) throw new IllegalStateException();
+		task.storeAttachments();
-			boolean needsSize = uris.size() == 1;
+		return task.getResult();
-			task = new AttachmentCreationTask(messagingManager,
-					app.getContentResolver(), this, id, uris, needsSize);
-			ioExecutor.execute(() -> task.storeAttachments());
-		});
-		return result;
 	}
 
 	/**
@@ -85,134 +61,49 @@ public class AttachmentCreator {
 	 */
 	@UiThread
 	public LiveData<AttachmentResult> getLiveAttachments() {
-		if (task == null || uris.isEmpty())
+		if (task == null) throw new IllegalStateException();
-			throw new IllegalStateException();
 		// A task is already running. It will update the result LiveData.
 		// So nothing more to do here.
-		return result;
+		return task.getResult();
-	}
-
-	@IoExecutor
-	void onAttachmentHeaderReceived(Uri uri, AttachmentHeader h,
-			boolean needsSize) {
-		// get and cache AttachmentItem for ImagePreview
-		try {
-			Attachment a = retriever.getMessageAttachment(h);
-			AttachmentItem item = retriever.getAttachmentItem(a, needsSize);
-			if (item.hasError()) throw new IOException();
-			AttachmentItemResult itemResult =
-					new AttachmentItemResult(uri, item);
-			itemResults.add(itemResult);
-			result.postValue(getResult(false));
-		} catch (IOException | DbException e) {
-			logException(LOG, WARNING, e);
-			onAttachmentError(uri, e);
-		}
-	}
-
-	@IoExecutor
-	void onAttachmentError(Uri uri, Throwable t) {
-		// get error message
-		String errorMsg;
-		if (t instanceof UnsupportedMimeTypeException) {
-			String mimeType = ((UnsupportedMimeTypeException) t).getMimeType();
-			errorMsg = app.getString(
-					R.string.image_attach_error_invalid_mime_type, mimeType);
-		} else if (t instanceof FileTooBigException) {
-			int mb = MAX_IMAGE_SIZE / 1024 / 1024;
-			errorMsg = app.getString(R.string.image_attach_error_too_big, mb);
-		} else {
-			errorMsg = null; // generic error
-		}
-		AttachmentItemResult itemResult =
-				new AttachmentItemResult(uri, errorMsg);
-		itemResults.add(itemResult);
-		result.postValue(getResult(false));
-		// expect to receive a cancel from the UI
-	}
-
-	@IoExecutor
-	void onAttachmentCreationFinished() {
-		result.postValue(getResult(true));
 	}
 
+	/**
+	 * Returns the headers of any attachments created by
+	 * {@link #storeAttachments(GroupId, Collection)}, unless
+	 * {@link #onAttachmentsSent()} or {@link #cancel()} has been called.
+	 */
 	@UiThread
 	public List<AttachmentHeader> getAttachmentHeadersForSending() {
-		List<AttachmentHeader> headers = new ArrayList<>(itemResults.size());
+		if (task == null) return emptyList();
-		for (AttachmentItemResult itemResult : itemResults) {
+		AttachmentResult result = task.getResult().getValue();
-			// check if we are trying to send attachment items with errors
+		if (result == null) return emptyList();
-			if (itemResult.getItem() == null) throw new IllegalStateException();
+		List<AttachmentHeader> headers = new ArrayList<>();
-			headers.add(itemResult.getItem().getHeader());
+		for (AttachmentItemResult itemResult : result.getItemResults()) {
+			AttachmentItem item = itemResult.getItem();
+			if (item != null) headers.add(item.getHeader());
 		}
 		return headers;
 	}
 
 	/**
-	 * Marks the attachments as sent and adds the items to the cache for display
+	 * Informs the AttachmentCreator that the attachments created by
-	 *
+	 * {@link #storeAttachments(GroupId, Collection)} will be sent.
-	 * @param id The MessageId of the sent message.
 	 */
 	@UiThread
-	public void onAttachmentsSent(MessageId id) {
+	public void onAttachmentsSent() {
-		List<AttachmentItem> items = new ArrayList<>(itemResults.size());
+		task = null; // Prevent cancel() from cancelling the task
-		for (AttachmentItemResult itemResult : itemResults) {
-			// check if we are trying to send attachment items with errors
-			if (itemResult.getItem() == null) throw new IllegalStateException();
-			items.add(itemResult.getItem());
-		}
-		retriever.cachePut(id, items);
-		resetState();
 	}
 
 	/**
-	 * Needs to be called when created attachments will not be sent anymore.
+	 * Cancels the task started by
+	 * {@link #storeAttachments(GroupId, Collection)}, if any, unless
+	 * {@link #onAttachmentsSent()} has been called.
 	 */
 	@UiThread
 	public void cancel() {
-		if (task == null) throw new AssertionError();
+		if (task != null) {
-		task.cancel();
+			task.cancel();
-		deleteUnsentAttachments();
+			task = null;
-		resetState();
-	}
-
-	@UiThread
-	private void resetState() {
-		task = null;
-		uris.clear();
-		itemResults.clear();
-		result.setValue(null);
-	}
-
-	@UiThread
-	public void deleteUnsentAttachments() {
-		// Make a copy for the IoExecutor as we clear the itemResults soon
-		List<AttachmentHeader> headers = new ArrayList<>(itemResults.size());
-		for (AttachmentItemResult itemResult : itemResults) {
-			// check if we are trying to send attachment items with errors
-			if (itemResult.getItem() != null)
-				headers.add(itemResult.getItem().getHeader());
 		}
-		ioExecutor.execute(() -> {
-			for (AttachmentHeader header : headers) {
-				try {
-					messagingManager.removeAttachment(header);
-				} catch (DbException e) {
-					logException(LOG, WARNING, e);
-				}
-			}
-		});
 	}
-
-	private AttachmentResult getResult(boolean finished) {
-		// Make a copy of the list,
-		// because our copy will continue to change in the background.
-		// (As it's a CopyOnWriteArrayList,
-		//  the code that receives the result can safely do simple things
-		//  like iterating over the list,
-		//  but anything that involves calling more than one list method
-		//  is still unsafe.)
-		Collection<AttachmentItemResult> items = new ArrayList<>(itemResults);
-		return new AttachmentResult(items, finished);
-	}
-
 }

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentItem.java

@@ -68,7 +68,7 @@ public class AttachmentItem implements Parcelable {
 		header = new AttachmentHeader(messageId, mimeType);
 	}
 
-	public AttachmentHeader getHeader() {
+	AttachmentHeader getHeader() {
 		return header;
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentItemResult.java

@@ -15,18 +15,18 @@ public class AttachmentItemResult {
 	@Nullable
 	private final AttachmentItem item;
 	@Nullable
-	private final String errorMsg;
+	private final Exception exception;
 
 	AttachmentItemResult(Uri uri, AttachmentItem item) {
 		this.uri = uri;
 		this.item = item;
-		this.errorMsg = null;
+		this.exception = null;
 	}
 
-	AttachmentItemResult(Uri uri, @Nullable String errorMsg) {
+	AttachmentItemResult(Uri uri, Exception exception) {
 		this.uri = uri;
 		this.item = null;
-		this.errorMsg = errorMsg;
+		this.exception = exception;
 	}
 
 	public Uri getUri() {
@@ -43,8 +43,8 @@ public class AttachmentItemResult {
 	}
 
 	@Nullable
-	public String getErrorMsg() {
+	public Exception getException() {
-		return errorMsg;
+		return exception;
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentResult.java

@@ -12,11 +12,13 @@ public class AttachmentResult {
 
 	private final Collection<AttachmentItemResult> itemResults;
 	private final boolean finished;
+	private final boolean success;
 
-	public AttachmentResult(Collection<AttachmentItemResult> itemResults,
+	AttachmentResult(Collection<AttachmentItemResult> itemResults,
-			boolean finished) {
+			boolean finished, boolean success) {
 		this.itemResults = itemResults;
 		this.finished = finished;
+		this.success = success;
 	}
 
 	public Collection<AttachmentItemResult> getItemResults() {
@@ -27,4 +29,7 @@ public class AttachmentResult {
 		return finished;
 	}
 
+	public boolean isSuccess() {
+		return success;
+	}
 }

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentRetriever.java

@@ -9,6 +9,8 @@ import android.webkit.MimeTypeMap;
 
 import com.bumptech.glide.util.MarkEnforcingInputStream;
 
+import org.briarproject.bramble.api.Pair;
+import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
@@ -20,6 +22,7 @@ import org.briarproject.briar.api.messaging.MessagingManager;
 import java.io.BufferedInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -35,13 +38,16 @@ import static android.support.media.ExifInterface.TAG_ORIENTATION;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.IoUtils.tryToClose;
+import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.util.LogUtils.now;
 
 @NotNullByDefault
 public class AttachmentRetriever {
 
 	private static final Logger LOG =
 			getLogger(AttachmentRetriever.class.getName());
+
 	private static final int READ_LIMIT = 1024 * 8192;
 
 	private final MessagingManager messagingManager;
@@ -50,7 +56,7 @@ public class AttachmentRetriever {
 	private final int minWidth, maxWidth;
 	private final int minHeight, maxHeight;
 
-	private final Map<MessageId, List<AttachmentItem>> attachmentCache =
+	private final Map<MessageId, AttachmentItem> attachmentCache =
 			new ConcurrentHashMap<>();
 
 	@VisibleForTesting
@@ -88,27 +94,56 @@ public class AttachmentRetriever {
 		});
 	}
 
-	public void cachePut(MessageId messageId,
+	public void cachePut(AttachmentItem item) {
-			List<AttachmentItem> attachments) {
+		attachmentCache.put(item.getMessageId(), item);
-		attachmentCache.put(messageId, attachments);
 	}
 
 	@Nullable
-	public List<AttachmentItem> cacheGet(MessageId messageId) {
+	public AttachmentItem cacheGet(MessageId attachmentId) {
-		return attachmentCache.get(messageId);
+		return attachmentCache.get(attachmentId);
 	}
 
-	public Attachment getMessageAttachment(AttachmentHeader h)
+	@DatabaseExecutor
-			throws DbException {
+	public List<Pair<AttachmentHeader, Attachment>> getMessageAttachments(
-		return messagingManager.getAttachment(h);
+			List<AttachmentHeader> headers) throws DbException {
+		long start = now();
+		List<Pair<AttachmentHeader, Attachment>> attachments =
+				new ArrayList<>(headers.size());
+		for (AttachmentHeader h : headers) {
+			Attachment a = messagingManager.getAttachment(h.getMessageId());
+			attachments.add(new Pair<>(h, a));
+		}
+		logDuration(LOG, "Loading attachments", start);
+		return attachments;
+	}
+
+	Attachment getMessageAttachment(AttachmentHeader h) throws DbException {
+		return messagingManager.getAttachment(h.getMessageId());
+	}
+
+	/**
+	 * Creates {@link AttachmentItem}s from the passed headers and Attachments.
+	 * <p>
+	 * Note: This closes the {@link Attachment}'s {@link InputStream}.
+	 */
+	public List<AttachmentItem> getAttachmentItems(
+			List<Pair<AttachmentHeader, Attachment>> attachments) {
+		boolean needsSize = attachments.size() == 1;
+		List<AttachmentItem> items = new ArrayList<>(attachments.size());
+		for (Pair<AttachmentHeader, Attachment> a : attachments) {
+			AttachmentItem item =
+					getAttachmentItem(a.getFirst(), a.getSecond(), needsSize);
+			items.add(item);
+		}
+		return items;
 	}
 
 	/**
 	 * Creates an {@link AttachmentItem} from the {@link Attachment}'s
 	 * {@link InputStream} which will be closed when this method returns.
 	 */
-	public AttachmentItem getAttachmentItem(Attachment a, boolean needsSize) {
+	AttachmentItem getAttachmentItem(AttachmentHeader h, Attachment a,
-		AttachmentHeader h = a.getHeader();
+			boolean needsSize) {
 		if (!needsSize) {
 			String extension =
 					imageHelper.getExtensionFromMimeType(h.getContentType());

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

@@ -37,7 +37,6 @@ import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.NoSuchContactException;
-import org.briarproject.bramble.api.db.NoSuchMessageException;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventListener;
@@ -82,7 +81,6 @@ import org.briarproject.briar.api.messaging.Attachment;
 import org.briarproject.briar.api.messaging.AttachmentHeader;
 import org.briarproject.briar.api.messaging.MessagingManager;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
-import org.briarproject.briar.api.messaging.event.AttachmentReceivedEvent;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager;
 
 import java.util.ArrayList;
@@ -109,12 +107,10 @@ import static android.support.v7.util.SortedList.INVALID_POSITION;
 import static android.view.Gravity.RIGHT;
 import static android.widget.Toast.LENGTH_SHORT;
 import static java.util.Collections.emptyList;
-import static java.util.Collections.singletonList;
 import static java.util.Collections.sort;
 import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
@@ -142,7 +138,7 @@ public class ConversationActivity extends BriarActivity
 	public static final String CONTACT_ID = "briar.CONTACT_ID";
 
 	private static final Logger LOG =
-			getLogger(ConversationActivity.class.getName());
+			Logger.getLogger(ConversationActivity.class.getName());
 
 	private static final int TRANSITION_DURATION_MS = 500;
 	private static final int ONBOARDING_DELAY_MS = 250;
@@ -175,8 +171,6 @@ public class ConversationActivity extends BriarActivity
 	volatile GroupInvitationManager groupInvitationManager;
 
 	private final Map<MessageId, String> textCache = new ConcurrentHashMap<>();
-	private final Map<MessageId, PrivateMessageHeader> missingAttachments =
-			new ConcurrentHashMap<>();
 	private final Observer<String> contactNameObserver = name -> {
 		requireNonNull(name);
 		loadMessages();
@@ -440,40 +434,31 @@ public class ConversationActivity extends BriarActivity
 		});
 	}
 
-	private void eagerlyLoadMessageSize(PrivateMessageHeader h) {
+	private void eagerlyLoadMessageSize(PrivateMessageHeader h)
-		try {
+			throws DbException {
-			MessageId id = h.getId();
+		MessageId id = h.getId();
-			// If the message has text, load it
+		// If the message has text, load it
-			if (h.hasText()) {
+		if (h.hasText()) {
-				String text = textCache.get(id);
+			String text = textCache.get(id);
-				if (text == null) {
+			if (text == null) {
-					LOG.info("Eagerly loading text for latest message");
+				LOG.info("Eagerly loading text for latest message");
-					text = messagingManager.getMessageText(id);
+				text = messagingManager.getMessageText(id);
-					textCache.put(id, requireNonNull(text));
+				textCache.put(id, requireNonNull(text));
-				}
 			}
-			// If the message has a single image, load its size - for multiple
+		}
-			// images we use a grid so the size is fixed
+		// If the message has a single image, load its size - for multiple
-			List<AttachmentHeader> headers = h.getAttachmentHeaders();
+		// images we use a grid so the size is fixed
-			if (headers.size() == 1) {
+		List<AttachmentHeader> headers = h.getAttachmentHeaders();
-				List<AttachmentItem> items = attachmentRetriever.cacheGet(id);
+		if (headers.size() == 1) {
-				if (items == null) {
+			MessageId attachmentId = headers.get(0).getMessageId();
-					LOG.info("Eagerly loading image size for latest message");
+			AttachmentItem item = attachmentRetriever.cacheGet(attachmentId);
-					AttachmentHeader header = headers.get(0);
+			if (item == null) {
-					try {
+				LOG.info("Eagerly loading image size for latest message");
-						Attachment a = attachmentRetriever
+				item = attachmentRetriever.getAttachmentItems(
-								.getMessageAttachment(header);
+						attachmentRetriever.getMessageAttachments(headers))
-						AttachmentItem item =
+						.get(0);
-								attachmentRetriever.getAttachmentItem(a, true);
+				attachmentRetriever.cachePut(item);
-						attachmentRetriever.cachePut(id, singletonList(item));
-					} catch (NoSuchMessageException e) {
-						LOG.info("Attachment not received yet");
-						missingAttachments.put(header.getMessageId(), h);
-					}
-				}
 			}
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
 		}
 	}
 
@@ -551,30 +536,18 @@ public class ConversationActivity extends BriarActivity
 				&& adapter.isScrolledToBottom(layoutManager);
 	}
 
-	private void loadMessageAttachments(PrivateMessageHeader h) {
+	private void loadMessageAttachments(MessageId messageId,
-		// TODO: Use placeholders for missing/invalid attachments
+			List<AttachmentHeader> headers) {
 		runOnDbThread(() -> {
 			try {
+				List<Pair<AttachmentHeader, Attachment>> attachments =
+						attachmentRetriever.getMessageAttachments(headers);
 				// TODO move getting the items off to IoExecutor, if size == 1
-				List<AttachmentHeader> headers = h.getAttachmentHeaders();
+				List<AttachmentItem> items =
-				boolean needsSize = headers.size() == 1;
+						attachmentRetriever.getAttachmentItems(attachments);
-				List<AttachmentItem> items = new ArrayList<>(headers.size());
+				if (items.size() == 1)
-				for (AttachmentHeader header : headers) {
+					attachmentRetriever.cachePut(items.get(0));
-					try {
+				displayMessageAttachments(messageId, items);
-						Attachment a = attachmentRetriever
-								.getMessageAttachment(header);
-						AttachmentItem item = attachmentRetriever
-								.getAttachmentItem(a, needsSize);
-						items.add(item);
-					} catch (NoSuchMessageException e) {
-						LOG.info("Attachment not received yet");
-						missingAttachments.put(header.getMessageId(), h);
-						return;
-					}
-				}
-				// Don't cache items unless all are present and valid
-				attachmentRetriever.cachePut(h.getId(), items);
-				displayMessageAttachments(h.getId(), items);
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);
 			}
@@ -597,13 +570,6 @@ public class ConversationActivity extends BriarActivity
 
 	@Override
 	public void eventOccurred(Event e) {
-		if (e instanceof AttachmentReceivedEvent) {
-			AttachmentReceivedEvent a = (AttachmentReceivedEvent) e;
-			if (a.getContactId().equals(contactId)) {
-				LOG.info("Attachment received");
-				onAttachmentReceived(a.getMessageId());
-			}
-		}
 		if (e instanceof ContactRemovedEvent) {
 			ContactRemovedEvent c = (ContactRemovedEvent) e;
 			if (c.getContactId().equals(contactId)) {
@@ -654,15 +620,6 @@ public class ConversationActivity extends BriarActivity
 			scrollToBottom();
 	}
 
-	@UiThread
-	private void onAttachmentReceived(MessageId attachmentId) {
-		PrivateMessageHeader h = missingAttachments.remove(attachmentId);
-		if (h != null) {
-			LOG.info("Missing attachment received");
-			loadMessageAttachments(h);
-		}
-	}
-
 	@UiThread
 	private void onNewConversationMessage(ConversationMessageHeader h) {
 		if (h instanceof ConversationRequest ||
@@ -949,14 +906,19 @@ public class ConversationActivity extends BriarActivity
 	}
 
 	@Override
-	public List<AttachmentItem> getAttachmentItems(PrivateMessageHeader h) {
+	public List<AttachmentItem> getAttachmentItems(MessageId m,
-		List<AttachmentItem> attachments =
+			List<AttachmentHeader> headers) {
-				attachmentRetriever.cacheGet(h.getId());
+		List<AttachmentItem> items = new ArrayList<>(headers.size());
-		if (attachments == null) {
+		for (AttachmentHeader header : headers) {
-			loadMessageAttachments(h);
+			AttachmentItem item =
-			return emptyList();
+					attachmentRetriever.cacheGet(header.getMessageId());
+			if (item == null) {
+				loadMessageAttachments(m, headers);
+				return emptyList();
+			}
+			items.add(item);
 		}
-		return attachments;
+		return items;
 	}
 
 }

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

@@ -4,6 +4,7 @@ import android.app.Application;
 import android.arch.lifecycle.AndroidViewModel;
 import android.arch.lifecycle.LiveData;
 import android.arch.lifecycle.MutableLiveData;
+import android.arch.lifecycle.Observer;
 import android.arch.lifecycle.Transformations;
 import android.net.Uri;
 import android.support.annotation.Nullable;
@@ -124,7 +125,7 @@ public class ConversationViewModel extends AndroidViewModel
 	@Override
 	protected void onCleared() {
 		super.onCleared();
-		attachmentCreator.deleteUnsentAttachments();
+		attachmentCreator.cancel();
 	}
 
 	/**
@@ -200,12 +201,23 @@ public class ConversationViewModel extends AndroidViewModel
 	@UiThread
 	public LiveData<AttachmentResult> storeAttachments(Collection<Uri> uris,
 			boolean restart) {
-		if (restart) {
+		MutableLiveData<AttachmentResult> delegate = new MutableLiveData<>();
-			return attachmentCreator.getLiveAttachments();
+		// messagingGroupId is loaded with the contact
-		} else {
+		observeForeverOnce(messagingGroupId, groupId -> {
-			// messagingGroupId is loaded with the contact
+			requireNonNull(groupId);
-			return attachmentCreator.storeAttachments(messagingGroupId, uris);
+			LiveData<AttachmentResult> result;
-		}
+			if (restart) result = attachmentCreator.getLiveAttachments();
+			else result = attachmentCreator.storeAttachments(groupId, uris);
+			result.observeForever(new Observer<AttachmentResult>() {
+				@Override
+				public void onChanged(@Nullable AttachmentResult value) {
+					requireNonNull(value);
+					if (value.isFinished()) result.removeObserver(this);
+					delegate.setValue(value);
+				}
+			});
+		});
+		return delegate;
 	}
 
 	@Override
@@ -294,7 +306,7 @@ public class ConversationViewModel extends AndroidViewModel
 	}
 
 	private void storeMessage(PrivateMessage m) {
-		attachmentCreator.onAttachmentsSent(m.getMessage().getId());
+		attachmentCreator.onAttachmentsSent();
 		dbExecutor.execute(() -> {
 			try {
 				long start = now();

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

@@ -15,6 +15,7 @@ import org.briarproject.briar.api.forum.ForumInvitationRequest;
 import org.briarproject.briar.api.forum.ForumInvitationResponse;
 import org.briarproject.briar.api.introduction.IntroductionRequest;
 import org.briarproject.briar.api.introduction.IntroductionResponse;
+import org.briarproject.briar.api.messaging.AttachmentHeader;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationRequest;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationResponse;
@@ -55,7 +56,8 @@ class ConversationVisitor implements
 		if (h.getAttachmentHeaders().isEmpty()) {
 			attachments = emptyList();
 		} else {
-			attachments = attachmentCache.getAttachmentItems(h);
+			attachments = attachmentCache
+					.getAttachmentItems(h.getId(), h.getAttachmentHeaders());
 		}
 		if (h.isLocal()) {
 			item = new ConversationMessageItem(
@@ -293,6 +295,7 @@ class ConversationVisitor implements
 	}
 
 	interface AttachmentCache {
-		List<AttachmentItem> getAttachmentItems(PrivateMessageHeader h);
+		List<AttachmentItem> getAttachmentItems(MessageId m,
+				List<AttachmentHeader> headers);
 	}
 }

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

@@ -12,6 +12,7 @@ import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.android.attachment.AttachmentItem;
 import org.briarproject.briar.android.viewmodel.LiveEvent;
 import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
@@ -134,10 +135,10 @@ public class ImageViewModel extends AndroidViewModel {
 
 	private void saveImage(AttachmentItem attachment, OutputStreamProvider osp,
 			@Nullable Runnable afterCopy) {
+		MessageId messageId = attachment.getMessageId();
 		dbExecutor.execute(() -> {
 			try {
-				Attachment a =
+				Attachment a = messagingManager.getAttachment(messageId);
-						messagingManager.getAttachment(attachment.getHeader());
 				copyImageFromDb(a, osp, afterCopy);
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);

briar-android/src/main/java/org/briarproject/briar/android/conversation/glide/BriarDataFetcher.java

@@ -9,8 +9,8 @@ import com.bumptech.glide.load.data.DataFetcher;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.android.attachment.AttachmentItem;
-import org.briarproject.briar.api.messaging.Attachment;
 import org.briarproject.briar.api.messaging.MessagingManager;
 
 import java.io.InputStream;
@@ -50,12 +50,11 @@ class BriarDataFetcher implements DataFetcher<InputStream> {
 	@Override
 	public void loadData(Priority priority,
 			DataCallback<? super InputStream> callback) {
+		MessageId id = attachment.getMessageId();
 		dbExecutor.execute(() -> {
 			if (cancel) return;
 			try {
-				Attachment a =
+				inputStream = messagingManager.getAttachment(id).getStream();
-						messagingManager.getAttachment(attachment.getHeader());
-				inputStream = a.getStream();
 				callback.onDataReady(inputStream);
 			} catch (DbException e) {
 				callback.onLoadFailed(e);

briar-android/src/main/java/org/briarproject/briar/android/view/TextAttachmentController.java

@@ -22,6 +22,8 @@ import org.briarproject.briar.android.attachment.AttachmentItemResult;
 import org.briarproject.briar.android.attachment.AttachmentManager;
 import org.briarproject.briar.android.attachment.AttachmentResult;
 import org.briarproject.briar.android.view.ImagePreview.ImagePreviewListener;
+import org.briarproject.briar.api.messaging.FileTooBigException;
+import org.jsoup.UnsupportedMimeTypeException;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -41,9 +43,11 @@ import static android.support.v4.content.ContextCompat.getColor;
 import static android.support.v4.view.AbsSavedState.EMPTY_STATE;
 import static android.view.View.GONE;
 import static android.widget.Toast.LENGTH_LONG;
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.util.UiUtils.resolveColorAttribute;
 import static org.briarproject.briar.api.messaging.MessagingConstants.IMAGE_MIME_TYPES;
 import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_ATTACHMENTS_PER_MESSAGE;
+import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_IMAGE_SIZE;
 import static uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt.STATE_DISMISSED;
 import static uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt.STATE_FINISHED;
 
@@ -186,18 +190,16 @@ public class TextAttachmentController extends TextSendController
 		result.observe(attachmentListener, new Observer<AttachmentResult>() {
 			@Override
 			public void onChanged(@Nullable AttachmentResult attachmentResult) {
-				if (attachmentResult == null) {
+				requireNonNull(attachmentResult);
-					// The fresh LiveData was deliberately set to null.
+				boolean finished = attachmentResult.isFinished();
-					// This means that we can stop observing it.
+				boolean success = attachmentResult.isSuccess();
+				if (finished) {
 					result.removeObserver(this);
-				} else {
+					if (!success) return;
-					boolean noError = onNewAttachmentItemResults(
-							attachmentResult.getItemResults());
-					if (noError && attachmentResult.isFinished()) {
-						onAllAttachmentsCreated();
-						result.removeObserver(this);
-					}
 				}
+				boolean noError = onNewAttachmentItemResults(
+						attachmentResult.getItemResults());
+				if (noError && success) onAllAttachmentsCreated();
 			}
 		});
 	}
@@ -207,7 +209,7 @@ public class TextAttachmentController extends TextSendController
 		if (!loadingUris) throw new AssertionError();
 		for (AttachmentItemResult result : itemResults) {
 			if (result.hasError()) {
-				onError(result.getErrorMsg());
+				onError(requireNonNull(result.getException()));
 				return false;
 			} else {
 				imagePreview.loadPreviewImage(result);
@@ -253,12 +255,20 @@ public class TextAttachmentController extends TextSendController
 	}
 
 	@UiThread
-	private void onError(@Nullable String errorMsg) {
+	private void onError(Exception e) {
-		if (errorMsg == null) {
+		String errorMsg;
-			errorMsg = imagePreview.getContext()
+		Context ctx = imagePreview.getContext();
-					.getString(R.string.image_attach_error);
+		if (e instanceof UnsupportedMimeTypeException) {
+			String mimeType = ((UnsupportedMimeTypeException) e).getMimeType();
+			errorMsg = ctx.getString(
+					R.string.image_attach_error_invalid_mime_type, mimeType);
+		} else if (e instanceof FileTooBigException) {
+			int mb = MAX_IMAGE_SIZE / 1024 / 1024;
+			errorMsg = ctx.getString(R.string.image_attach_error_too_big, mb);
+		} else {
+			errorMsg = ctx.getString(R.string.image_attach_error);
 		}
-		Toast.makeText(textInput.getContext(), errorMsg, LENGTH_LONG).show();
+		Toast.makeText(ctx, errorMsg, LENGTH_LONG).show();
 		onCancel();
 	}
 

briar-android/src/test/java/org/briarproject/briar/android/attachment/AttachmentRetrieverTest.java

@@ -9,6 +9,7 @@ import org.briarproject.briar.api.messaging.MessagingManager;
 import org.jmock.Expectations;
 import org.junit.Test;
 
+import java.io.BufferedInputStream;
 import java.io.ByteArrayInputStream;
 import java.io.InputStream;
 
@@ -24,26 +25,32 @@ public class AttachmentRetrieverTest extends BrambleMockTestCase {
 			100, 50, 200, 75, 300
 	);
 	private final MessageId msgId = new MessageId(getRandomId());
+	private final Attachment attachment = new Attachment(
+			new BufferedInputStream(
+					new ByteArrayInputStream(getRandomBytes(42))));
+
 	private final MessagingManager messagingManager =
 			context.mock(MessagingManager.class);
 	private final ImageHelper imageHelper = context.mock(ImageHelper.class);
-	private final AttachmentRetriever retriever = new AttachmentRetriever(
+	private final AttachmentRetriever controller =
-			messagingManager,
+			new AttachmentRetriever(
-			dimensions,
+					messagingManager,
-			imageHelper
+					dimensions,
-	);
+					imageHelper
+			);
 
 	@Test
 	public void testNoSize() {
 		String mimeType = "image/jpeg";
-		Attachment attachment = getAttachment(mimeType);
+		AttachmentHeader h = getAttachmentHeader(mimeType);
 
 		context.checking(new Expectations() {{
 			oneOf(imageHelper).getExtensionFromMimeType(mimeType);
 			will(returnValue("jpg"));
 		}});
 
-		AttachmentItem item = retriever.getAttachmentItem(attachment, false);
+		AttachmentItem item =
+				controller.getAttachmentItem(h, attachment, false);
 		assertEquals(mimeType, item.getMimeType());
 		assertEquals("jpg", item.getExtension());
 		assertFalse(item.hasError());
@@ -52,21 +59,22 @@ public class AttachmentRetrieverTest extends BrambleMockTestCase {
 	@Test
 	public void testNoSizeWrongMimeTypeProducesError() {
 		String mimeType = "application/octet-stream";
-		Attachment attachment = getAttachment(mimeType);
+		AttachmentHeader h = getAttachmentHeader(mimeType);
 
 		context.checking(new Expectations() {{
 			oneOf(imageHelper).getExtensionFromMimeType(mimeType);
 			will(returnValue(null));
 		}});
 
-		AttachmentItem item = retriever.getAttachmentItem(attachment, false);
+		AttachmentItem item =
+				controller.getAttachmentItem(h, attachment, false);
 		assertTrue(item.hasError());
 	}
 
 	@Test
 	public void testSmallJpegImage() {
 		String mimeType = "image/jpeg";
-		Attachment attachment = getAttachment(mimeType);
+		AttachmentHeader h = getAttachmentHeader(mimeType);
 
 		context.checking(new Expectations() {{
 			oneOf(imageHelper).decodeStream(with(any(InputStream.class)));
@@ -75,7 +83,7 @@ public class AttachmentRetrieverTest extends BrambleMockTestCase {
 			will(returnValue("jpg"));
 		}});
 
-		AttachmentItem item = retriever.getAttachmentItem(attachment, true);
+		AttachmentItem item = controller.getAttachmentItem(h, attachment, true);
 		assertEquals(msgId, item.getMessageId());
 		assertEquals(160, item.getWidth());
 		assertEquals(240, item.getHeight());
@@ -89,7 +97,7 @@ public class AttachmentRetrieverTest extends BrambleMockTestCase {
 	@Test
 	public void testBigJpegImage() {
 		String mimeType = "image/jpeg";
-		Attachment attachment = getAttachment(mimeType);
+		AttachmentHeader h = getAttachmentHeader(mimeType);
 
 		context.checking(new Expectations() {{
 			oneOf(imageHelper).decodeStream(with(any(InputStream.class)));
@@ -98,7 +106,7 @@ public class AttachmentRetrieverTest extends BrambleMockTestCase {
 			will(returnValue("jpg"));
 		}});
 
-		AttachmentItem item = retriever.getAttachmentItem(attachment, true);
+		AttachmentItem item = controller.getAttachmentItem(h, attachment, true);
 		assertEquals(1728, item.getWidth());
 		assertEquals(2592, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
@@ -108,7 +116,7 @@ public class AttachmentRetrieverTest extends BrambleMockTestCase {
 
 	@Test
 	public void testMalformedError() {
-		Attachment attachment = getAttachment("image/jpeg");
+		AttachmentHeader h = getAttachmentHeader("image/jpeg");
 
 		context.checking(new Expectations() {{
 			oneOf(imageHelper).decodeStream(with(any(InputStream.class)));
@@ -117,13 +125,12 @@ public class AttachmentRetrieverTest extends BrambleMockTestCase {
 			will(returnValue(null));
 		}});
 
-		AttachmentItem item = retriever.getAttachmentItem(attachment, true);
+		AttachmentItem item = controller.getAttachmentItem(h, attachment, true);
 		assertTrue(item.hasError());
 	}
 
-	private Attachment getAttachment(String contentType) {
+	private AttachmentHeader getAttachmentHeader(String contentType) {
-		AttachmentHeader header = new AttachmentHeader(msgId, contentType);
+		return new AttachmentHeader(msgId, contentType);
-		InputStream in = new ByteArrayInputStream(getRandomBytes(42));
-		return new Attachment(header, in);
 	}
+
 }

briar-api/src/main/java/org/briarproject/briar/api/messaging/Attachment.java

@@ -1,27 +1,15 @@
 package org.briarproject.briar.api.messaging;
 
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
 import java.io.InputStream;
 
-import javax.annotation.concurrent.Immutable;
-
-@Immutable
-@NotNullByDefault
 public class Attachment {
 
-	private final AttachmentHeader header;
 	private final InputStream stream;
 
-	public Attachment(AttachmentHeader header, InputStream stream) {
+	public Attachment(InputStream stream) {
-		this.header = header;
 		this.stream = stream;
 	}
 
-	public AttachmentHeader getHeader() {
-		return header;
-	}
-
 	public InputStream getStream() {
 		return stream;
 	}

briar-api/src/main/java/org/briarproject/briar/api/messaging/FileTooBigException.java

@@ -2,5 +2,8 @@ package org.briarproject.briar.api.messaging;
 
 import java.io.IOException;
 
+/**
+ * An exception that is thrown when a file is too big to attach to a message.
+ */
 public class FileTooBigException extends IOException {
 }

briar-api/src/main/java/org/briarproject/briar/api/messaging/InvalidAttachmentException.java

@@ -1,14 +0,0 @@
-package org.briarproject.briar.api.messaging;
-
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-/**
- * An exception that is thrown when an {@link AttachmentHeader} is used to
- * load an {@link Attachment}, and the header refers to a message that is not
- * an attachment, or to an attachment that does not have the expected content
- * type.
- */
-@NotNullByDefault
-public class InvalidAttachmentException extends DbException {
-}

briar-api/src/main/java/org/briarproject/briar/api/messaging/MessagingManager.java

@@ -40,7 +40,7 @@ public interface MessagingManager extends ConversationClient {
 	/**
 	 * Stores a local attachment message.
 	 *
-	 * @throws FileTooBigException If the attachment is too big
+	 * @throws FileTooBigException
 	 */
 	AttachmentHeader addLocalAttachment(GroupId groupId, long timestamp,
 			String contentType, InputStream is) throws DbException, IOException;
@@ -68,13 +68,9 @@ public interface MessagingManager extends ConversationClient {
 	String getMessageText(MessageId m) throws DbException;
 
 	/**
-	 * Returns the attachment with the given message ID and content type.
+	 * Returns the attachment with the given ID.
-	 *
-	 * @throws InvalidAttachmentException If the header refers to a message
-	 * that is not an attachment, or to an attachment that does not have the
-	 * expected content type
 	 */
-	Attachment getAttachment(AttachmentHeader h) throws DbException;
+	Attachment getAttachment(MessageId m) throws DbException;
 
 	/**
 	 * Returns true if the contact with the given {@link ContactId} does support

briar-core/src/main/java/org/briarproject/briar/messaging/MessagingManagerImpl.java

@@ -23,7 +23,6 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.validation.IncomingMessageHook;
-import org.briarproject.bramble.api.system.Scheduler;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager.ClientVersioningHook;
 import org.briarproject.briar.api.client.MessageTracker;
@@ -33,7 +32,6 @@ import org.briarproject.briar.api.conversation.ConversationMessageHeader;
 import org.briarproject.briar.api.messaging.Attachment;
 import org.briarproject.briar.api.messaging.AttachmentHeader;
 import org.briarproject.briar.api.messaging.FileTooBigException;
-import org.briarproject.briar.api.messaging.InvalidAttachmentException;
 import org.briarproject.briar.api.messaging.MessagingManager;
 import org.briarproject.briar.api.messaging.PrivateMessage;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
@@ -48,19 +46,13 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.logging.Logger;
 
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 import static java.util.Collections.emptyList;
-import static java.util.concurrent.TimeUnit.SECONDS;
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
 import static org.briarproject.bramble.util.IoUtils.copyAndClose;
-import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.client.MessageTrackerConstants.MSG_KEY_READ;
 import static org.briarproject.briar.messaging.MessageTypes.ATTACHMENT;
 import static org.briarproject.briar.messaging.MessageTypes.PRIVATE_MESSAGE;
@@ -79,10 +71,6 @@ class MessagingManagerImpl implements MessagingManager, IncomingMessageHook,
 		ConversationClient, OpenDatabaseHook, ContactHook,
 		ClientVersioningHook {
 
-	private static final Logger LOG =
-			getLogger(MessagingManagerImpl.class.getName());
-
-	private final ScheduledExecutorService scheduler;
 	private final DatabaseComponent db;
 	private final ClientHelper clientHelper;
 	private final MetadataParser metadataParser;
@@ -91,12 +79,10 @@ class MessagingManagerImpl implements MessagingManager, IncomingMessageHook,
 	private final ContactGroupFactory contactGroupFactory;
 
 	@Inject
-	MessagingManagerImpl(@Scheduler ScheduledExecutorService scheduler,
+	MessagingManagerImpl(DatabaseComponent db, ClientHelper clientHelper,
-			DatabaseComponent db, ClientHelper clientHelper,
 			ClientVersioningManager clientVersioningManager,
 			MetadataParser metadataParser, MessageTracker messageTracker,
 			ContactGroupFactory contactGroupFactory) {
-		this.scheduler = scheduler;
 		this.db = db;
 		this.clientHelper = clientHelper;
 		this.metadataParser = metadataParser;
@@ -252,20 +238,9 @@ class MessagingManagerImpl implements MessagingManager, IncomingMessageHook,
 				meta.put(MSG_KEY_ATTACHMENT_HEADERS, headers);
 			}
 			// Mark attachments as shared and permanent now we're ready to send
-			// FIXME: Revert
-			int i = 15;
 			for (AttachmentHeader a : m.getAttachmentHeaders()) {
-				scheduler.schedule(() -> {
+				db.setMessageShared(txn, a.getMessageId());
-					try {
+				db.setMessagePermanent(txn, a.getMessageId());
-						db.transaction(false, txn1 -> {
-							db.setMessageShared(txn1, a.getMessageId());
-							db.setMessagePermanent(txn1, a.getMessageId());
-						});
-					} catch (DbException e) {
-						logException(LOG, WARNING, e);
-					}
-				}, i, SECONDS);
-				i *= 2;
 			}
 			clientHelper.addLocalMessage(txn, m.getMessage(), meta, true,
 					false);
@@ -399,20 +374,13 @@ class MessagingManagerImpl implements MessagingManager, IncomingMessageHook,
 	}
 
 	@Override
-	public Attachment getAttachment(AttachmentHeader h) throws DbException {
+	public Attachment getAttachment(MessageId m) throws DbException {
 		// TODO: Support large messages
-		MessageId m = h.getMessageId();
 		byte[] body = clientHelper.getMessage(m).getBody();
 		try {
 			BdfDictionary meta = clientHelper.getMessageMetadataAsDictionary(m);
-			Long messageType = meta.getOptionalLong(MSG_KEY_MSG_TYPE);
-			if (messageType == null || messageType != ATTACHMENT)
-				throw new InvalidAttachmentException();
-			String contentType = meta.getString(MSG_KEY_CONTENT_TYPE);
-			if (!contentType.equals(h.getContentType()))
-				throw new InvalidAttachmentException();
 			int offset = meta.getLong(MSG_KEY_DESCRIPTOR_LENGTH).intValue();
-			return new Attachment(h, new ByteArrayInputStream(body, offset,
+			return new Attachment(new ByteArrayInputStream(body, offset,
 					body.length - offset));
 		} catch (FormatException e) {
 			throw new DbException(e);