10 files changed, 434 insertions, 151 deletions

diff --git a/src/eu/siacs/conversations/entities/Account.java b/src/eu/siacs/conversations/entities/Account.java
index eacd172c..80a9d62f 100644
--- a/src/eu/siacs/conversations/entities/Account.java
+++ b/src/eu/siacs/conversations/entities/Account.java
@@ -11,16 +11,14 @@ import net.java.otr4j.crypto.OtrCryptoException;
 import org.json.JSONException;
 import org.json.JSONObject;
 
+import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.crypto.OtrEngine;
-import eu.siacs.conversations.persistance.FileBackend;
 import eu.siacs.conversations.services.XmppConnectionService;
-import eu.siacs.conversations.utils.UIHelper;
 import eu.siacs.conversations.xmpp.XmppConnection;
 import android.content.ContentValues;
-import android.content.Context;
 import android.database.Cursor;
-import android.graphics.Bitmap;
+import android.os.SystemClock;
 
 public class Account extends AbstractEntity {
 
@@ -64,16 +62,14 @@ public class Account extends AbstractEntity {
 
 	protected boolean online = false;
 
-	transient OtrEngine otrEngine = null;
-	transient XmppConnection xmppConnection = null;
-	transient protected Presences presences = new Presences();
-
+	private OtrEngine otrEngine = null;
+	private XmppConnection xmppConnection = null;
+	private Presences presences = new Presences();
+	private long mEndGracePeriod = 0L;
 	private String otrFingerprint;
-
 	private Roster roster = null;
 
 	private List<Bookmark> bookmarks = new CopyOnWriteArrayList<Bookmark>();
-
 	public List<Conversation> pendingConferenceJoins = new CopyOnWriteArrayList<Conversation>();
 	public List<Conversation> pendingConferenceLeaves = new CopyOnWriteArrayList<Conversation>();
 
@@ -160,8 +156,12 @@ public class Account extends AbstractEntity {
 	}
 
 	public boolean hasErrorStatus() {
-		return getStatus() > STATUS_NO_INTERNET
-				&& (getXmppConnection().getAttempt() >= 2);
+		if (getXmppConnection() == null) {
+			return false;
+		} else {
+			return getStatus() > STATUS_NO_INTERNET
+					&& (getXmppConnection().getAttempt() >= 2);
+		}
 	}
 
 	public void setResource(String resource) {
@@ -341,20 +341,6 @@ public class Account extends AbstractEntity {
 		return false;
 	}
 
-	public Bitmap getImage(Context context, int size) {
-		if (this.avatar != null) {
-			Bitmap bm = FileBackend.getAvatar(this.avatar, size, context);
-			if (bm == null) {
-				return UIHelper.getContactPicture(getJid(), size, context,
-						false);
-			} else {
-				return bm;
-			}
-		} else {
-			return UIHelper.getContactPicture(getJid(), size, context, false);
-		}
-	}
-
 	public boolean setAvatar(String filename) {
 		if (this.avatar != null && this.avatar.equals(filename)) {
 			return false;
@@ -397,4 +383,17 @@ public class Account extends AbstractEntity {
 			return R.string.account_status_unknown;
 		}
 	}
+
+	public void activateGracePeriod() {
+		this.mEndGracePeriod = SystemClock.elapsedRealtime()
+				+ (Config.CARBON_GRACE_PERIOD * 1000);
+	}
+
+	public void deactivateGracePeriod() {
+		this.mEndGracePeriod = 0L;
+	}
+
+	public boolean inGracePeriod() {
+		return SystemClock.elapsedRealtime() < this.mEndGracePeriod;
+	}
 }
diff --git a/src/eu/siacs/conversations/entities/Bookmark.java b/src/eu/siacs/conversations/entities/Bookmark.java
index 722fb6d9..dd9e805c 100644
--- a/src/eu/siacs/conversations/entities/Bookmark.java
+++ b/src/eu/siacs/conversations/entities/Bookmark.java
@@ -2,9 +2,6 @@ package eu.siacs.conversations.entities;
 
 import java.util.Locale;
 
-import android.content.Context;
-import android.graphics.Bitmap;
-import eu.siacs.conversations.utils.UIHelper;
 import eu.siacs.conversations.xml.Element;
 
 public class Bookmark extends Element implements ListItem {
@@ -120,21 +117,14 @@ public class Bookmark extends Element implements ListItem {
 		return this.account;
 	}
 
-	@Override
-	public Bitmap getImage(int dpSize, Context context) {
-		if (this.mJoinedConversation == null) {
-			return UIHelper.getContactPicture(getDisplayName(), dpSize,
-					context, false);
-		} else {
-			return UIHelper.getContactPicture(this.mJoinedConversation, dpSize,
-					context, false);
-		}
-	}
-
 	public void setConversation(Conversation conversation) {
 		this.mJoinedConversation = conversation;
 	}
 
+	public Conversation getConversation() {
+		return this.mJoinedConversation;
+	}
+
 	public String getName() {
 		return this.getAttribute("name");
 	}
diff --git a/src/eu/siacs/conversations/entities/Contact.java b/src/eu/siacs/conversations/entities/Contact.java
index b1ebe662..60c31a42 100644
--- a/src/eu/siacs/conversations/entities/Contact.java
+++ b/src/eu/siacs/conversations/entities/Contact.java
@@ -8,13 +8,9 @@ import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import eu.siacs.conversations.persistance.FileBackend;
-import eu.siacs.conversations.utils.UIHelper;
 import eu.siacs.conversations.xml.Element;
 import android.content.ContentValues;
-import android.content.Context;
 import android.database.Cursor;
-import android.graphics.Bitmap;
 
 public class Contact implements ListItem {
 	public static final String TABLENAME = "contacts";
@@ -330,20 +326,6 @@ public class Contact implements ListItem {
 		}
 	}
 
-	@Override
-	public Bitmap getImage(int size, Context context) {
-		if (this.avatar != null) {
-			Bitmap bm = FileBackend.getAvatar(avatar, size, context);
-			if (bm == null) {
-				return UIHelper.getContactPicture(this, size, context, false);
-			} else {
-				return bm;
-			}
-		} else {
-			return UIHelper.getContactPicture(this, size, context, false);
-		}
-	}
-
 	public boolean setAvatar(String filename) {
 		if (this.avatar != null && this.avatar.equals(filename)) {
 			return false;
@@ -353,6 +335,10 @@ public class Contact implements ListItem {
 		}
 	}
 
+	public String getAvatar() {
+		return this.avatar;
+	}
+
 	public boolean deleteOtrFingerprint(String fingerprint) {
 		boolean success = false;
 		try {
@@ -374,4 +360,8 @@ public class Contact implements ListItem {
 			return false;
 		}
 	}
+
+	public boolean trusted() {
+		return getOption(Options.FROM) && getOption(Options.TO);
+	}
 }
diff --git a/src/eu/siacs/conversations/entities/Conversation.java b/src/eu/siacs/conversations/entities/Conversation.java
index b4c99dc1..9d4c36db 100644
--- a/src/eu/siacs/conversations/entities/Conversation.java
+++ b/src/eu/siacs/conversations/entities/Conversation.java
@@ -1,14 +1,13 @@
 package eu.siacs.conversations.entities;
 
 import java.security.interfaces.DSAPublicKey;
+import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.CopyOnWriteArrayList;
 
 import org.json.JSONException;
 import org.json.JSONObject;
 
 import eu.siacs.conversations.services.XmppConnectionService;
-import eu.siacs.conversations.utils.UIHelper;
 
 import net.java.otr4j.OtrException;
 import net.java.otr4j.crypto.OtrCryptoEngineImpl;
@@ -17,9 +16,7 @@ import net.java.otr4j.session.SessionID;
 import net.java.otr4j.session.SessionImpl;
 import net.java.otr4j.session.SessionStatus;
 import android.content.ContentValues;
-import android.content.Context;
 import android.database.Cursor;
-import android.graphics.Bitmap;
 import android.os.SystemClock;
 
 public class Conversation extends AbstractEntity {
@@ -57,8 +54,8 @@ public class Conversation extends AbstractEntity {
 
 	private String nextPresence;
 
-	private transient CopyOnWriteArrayList<Message> messages = null;
-	private transient Account account = null;
+	protected ArrayList<Message> messages = new ArrayList<Message>();
+	protected Account account = null;
 
 	private transient SessionImpl otrSession;
 
@@ -68,12 +65,10 @@ public class Conversation extends AbstractEntity {
 
 	private transient MucOptions mucOptions = null;
 
-	//private transient String latestMarkableMessageId;
+	// private transient String latestMarkableMessageId;
 
 	private byte[] symmetricKey;
 
-	private boolean otrSessionNeedsStarting = false;
-
 	private Bookmark bookmark;
 
 	public Conversation(String name, Account account, String contactJid,
@@ -106,17 +101,6 @@ public class Conversation extends AbstractEntity {
 	}
 
 	public List<Message> getMessages() {
-		if (messages == null) {
-			this.messages = new CopyOnWriteArrayList<Message>(); // prevent null
-																	// pointer
-		}
-
-		// populate with Conversation (this)
-
-		for (Message msg : messages) {
-			msg.setConversation(this);
-		}
-
 		return messages;
 	}
 
@@ -142,8 +126,9 @@ public class Conversation extends AbstractEntity {
 		if (this.messages == null) {
 			return null;
 		}
-		for(int i = this.messages.size() - 1; i >= 0; --i) {
-			if (this.messages.get(i).getStatus() <= Message.STATUS_RECEIVED && this.messages.get(i).markable) {
+		for (int i = this.messages.size() - 1; i >= 0; --i) {
+			if (this.messages.get(i).getStatus() <= Message.STATUS_RECEIVED
+					&& this.messages.get(i).markable) {
 				if (this.messages.get(i).isRead()) {
 					return null;
 				} else {
@@ -166,7 +151,7 @@ public class Conversation extends AbstractEntity {
 		}
 	}
 
-	public void setMessages(CopyOnWriteArrayList<Message> msgs) {
+	public void setMessages(ArrayList<Message> msgs) {
 		this.messages = msgs;
 	}
 
@@ -263,10 +248,7 @@ public class Conversation extends AbstractEntity {
 			try {
 				if (sendStart) {
 					this.otrSession.startSession();
-					this.otrSessionNeedsStarting = false;
 					return this.otrSession;
-				} else {
-					this.otrSessionNeedsStarting = true;
 				}
 				return this.otrSession;
 			} catch (OtrException e) {
@@ -282,12 +264,12 @@ public class Conversation extends AbstractEntity {
 
 	public void resetOtrSession() {
 		this.otrFingerprint = null;
-		this.otrSessionNeedsStarting = false;
 		this.otrSession = null;
 	}
 
 	public void startOtrIfNeeded() {
-		if (this.otrSession != null && this.otrSessionNeedsStarting) {
+		if (this.otrSession != null
+				&& this.otrSession.getSessionStatus() != SessionStatus.ENCRYPTED) {
 			try {
 				this.otrSession.startSession();
 			} catch (OtrException e) {
@@ -296,18 +278,23 @@ public class Conversation extends AbstractEntity {
 		}
 	}
 
-	public void endOtrIfNeeded() {
+	public boolean endOtrIfNeeded() {
 		if (this.otrSession != null) {
 			if (this.otrSession.getSessionStatus() == SessionStatus.ENCRYPTED) {
 				try {
 					this.otrSession.endSession();
 					this.resetOtrSession();
+					return true;
 				} catch (OtrException e) {
 					this.resetOtrSession();
+					return false;
 				}
 			} else {
 				this.resetOtrSession();
+				return false;
 			}
+		} else {
+			return false;
 		}
 	}
 
@@ -339,9 +326,8 @@ public class Conversation extends AbstractEntity {
 
 	public synchronized MucOptions getMucOptions() {
 		if (this.mucOptions == null) {
-			this.mucOptions = new MucOptions(this.getAccount());
+			this.mucOptions = new MucOptions(this);
 		}
-		this.mucOptions.setConversation(this);
 		return this.mucOptions;
 	}
 
@@ -438,14 +424,6 @@ public class Conversation extends AbstractEntity {
 		return this.bookmark;
 	}
 
-	public Bitmap getImage(Context context, int size) {
-		if (mode == MODE_SINGLE) {
-			return getContact().getImage(size, context);
-		} else {
-			return UIHelper.getContactPicture(this, size, context, false);
-		}
-	}
-
 	public boolean hasDuplicateMessage(Message message) {
 		for (int i = this.getMessages().size() - 1; i >= 0; --i) {
 			if (this.messages.get(i).equals(message)) {
@@ -506,4 +484,17 @@ public class Conversation extends AbstractEntity {
 			}
 		}
 	}
+
+	public void add(Message message) {
+		message.setConversation(this);
+		synchronized (this.messages) {
+			this.messages.add(message);
+		}
+	}
+
+	public void addAll(int index, List<Message> messages) {
+		synchronized (this.messages) {
+			this.messages.addAll(index, messages);
+		}
+	}
 }
diff --git a/src/eu/siacs/conversations/entities/Downloadable.java b/src/eu/siacs/conversations/entities/Downloadable.java
index 8fb4977e..70516b20 100644
--- a/src/eu/siacs/conversations/entities/Downloadable.java
+++ b/src/eu/siacs/conversations/entities/Downloadable.java
@@ -1,5 +1,21 @@
 package eu.siacs.conversations.entities;
 
 public interface Downloadable {
-	public void start();
+
+	public final String[] VALID_EXTENSIONS = { "webp", "jpeg", "jpg", "png" };
+	public final String[] VALID_CRYPTO_EXTENSIONS = { "pgp", "gpg", "otr" };
+
+	public static final int STATUS_UNKNOWN = 0x200;
+	public static final int STATUS_CHECKING = 0x201;
+	public static final int STATUS_FAILED = 0x202;
+	public static final int STATUS_OFFER = 0x203;
+	public static final int STATUS_DOWNLOADING = 0x204;
+	public static final int STATUS_DELETED = 0x205;
+	public static final int STATUS_OFFER_CHECK_FILESIZE = 0x206;
+
+	public boolean start();
+
+	public int getStatus();
+
+	public long getFileSize();
 }
diff --git a/src/eu/siacs/conversations/entities/DownloadableFile.java b/src/eu/siacs/conversations/entities/DownloadableFile.java
new file mode 100644
index 00000000..1605c75b
--- /dev/null
+++ b/src/eu/siacs/conversations/entities/DownloadableFile.java
@@ -0,0 +1,154 @@
+package eu.siacs.conversations.entities;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.Key;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.Cipher;
+import javax.crypto.CipherInputStream;
+import javax.crypto.CipherOutputStream;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+import eu.siacs.conversations.Config;
+import android.util.Log;
+
+public class DownloadableFile extends File {
+
+	private static final long serialVersionUID = 2247012619505115863L;
+
+	private long expectedSize = 0;
+	private String sha1sum;
+	private Key aeskey;
+
+	private byte[] iv = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+			0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0xf };
+
+	public DownloadableFile(String path) {
+		super(path);
+	}
+
+	public long getSize() {
+		return super.length();
+	}
+
+	public long getExpectedSize() {
+		if (this.aeskey != null) {
+			if (this.expectedSize == 0) {
+				return 0;
+			} else {
+				return (this.expectedSize / 16 + 1) * 16;
+			}
+		} else {
+			return this.expectedSize;
+		}
+	}
+
+	public void setExpectedSize(long size) {
+		this.expectedSize = size;
+	}
+
+	public String getSha1Sum() {
+		return this.sha1sum;
+	}
+
+	public void setSha1Sum(String sum) {
+		this.sha1sum = sum;
+	}
+
+	public void setKey(byte[] key) {
+		if (key.length == 48) {
+			byte[] secretKey = new byte[32];
+			byte[] iv = new byte[16];
+			System.arraycopy(key, 0, iv, 0, 16);
+			System.arraycopy(key, 16, secretKey, 0, 32);
+			this.aeskey = new SecretKeySpec(secretKey, "AES");
+			this.iv = iv;
+		} else if (key.length >= 32) {
+			byte[] secretKey = new byte[32];
+			System.arraycopy(key, 0, secretKey, 0, 32);
+			this.aeskey = new SecretKeySpec(secretKey, "AES");
+		} else if (key.length >= 16) {
+			byte[] secretKey = new byte[16];
+			System.arraycopy(key, 0, secretKey, 0, 16);
+			this.aeskey = new SecretKeySpec(secretKey, "AES");
+		}
+	}
+
+	public Key getKey() {
+		return this.aeskey;
+	}
+
+	public InputStream createInputStream() {
+		if (this.getKey() == null) {
+			try {
+				return new FileInputStream(this);
+			} catch (FileNotFoundException e) {
+				return null;
+			}
+		} else {
+			try {
+				IvParameterSpec ips = new IvParameterSpec(iv);
+				Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+				cipher.init(Cipher.ENCRYPT_MODE, this.getKey(), ips);
+				Log.d(Config.LOGTAG, "opening encrypted input stream");
+				return new CipherInputStream(new FileInputStream(this), cipher);
+			} catch (NoSuchAlgorithmException e) {
+				Log.d(Config.LOGTAG, "no such algo: " + e.getMessage());
+				return null;
+			} catch (NoSuchPaddingException e) {
+				Log.d(Config.LOGTAG, "no such padding: " + e.getMessage());
+				return null;
+			} catch (InvalidKeyException e) {
+				Log.d(Config.LOGTAG, "invalid key: " + e.getMessage());
+				return null;
+			} catch (InvalidAlgorithmParameterException e) {
+				Log.d(Config.LOGTAG, "invavid iv:" + e.getMessage());
+				return null;
+			} catch (FileNotFoundException e) {
+				return null;
+			}
+		}
+	}
+
+	public OutputStream createOutputStream() {
+		if (this.getKey() == null) {
+			try {
+				return new FileOutputStream(this);
+			} catch (FileNotFoundException e) {
+				return null;
+			}
+		} else {
+			try {
+				IvParameterSpec ips = new IvParameterSpec(this.iv);
+				Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+				cipher.init(Cipher.DECRYPT_MODE, this.getKey(), ips);
+				Log.d(Config.LOGTAG, "opening encrypted output stream");
+				return new CipherOutputStream(new FileOutputStream(this),
+						cipher);
+			} catch (NoSuchAlgorithmException e) {
+				Log.d(Config.LOGTAG, "no such algo: " + e.getMessage());
+				return null;
+			} catch (NoSuchPaddingException e) {
+				Log.d(Config.LOGTAG, "no such padding: " + e.getMessage());
+				return null;
+			} catch (InvalidKeyException e) {
+				Log.d(Config.LOGTAG, "invalid key: " + e.getMessage());
+				return null;
+			} catch (InvalidAlgorithmParameterException e) {
+				Log.d(Config.LOGTAG, "invavid iv:" + e.getMessage());
+				return null;
+			} catch (FileNotFoundException e) {
+				return null;
+			}
+		}
+	}
+}
diff --git a/src/eu/siacs/conversations/entities/ListItem.java b/src/eu/siacs/conversations/entities/ListItem.java
index 19089b28..a1872d2f 100644
--- a/src/eu/siacs/conversations/entities/ListItem.java
+++ b/src/eu/siacs/conversations/entities/ListItem.java
@@ -1,12 +1,7 @@
 package eu.siacs.conversations.entities;
 
-import android.content.Context;
-import android.graphics.Bitmap;
-
 public interface ListItem extends Comparable<ListItem> {
 	public String getDisplayName();
 
 	public String getJid();
-
-	public Bitmap getImage(int dpSize, Context context);
 }
diff --git a/src/eu/siacs/conversations/entities/Message.java b/src/eu/siacs/conversations/entities/Message.java
index 49482bbc..8a83c465 100644
--- a/src/eu/siacs/conversations/entities/Message.java
+++ b/src/eu/siacs/conversations/entities/Message.java
@@ -1,23 +1,21 @@
 package eu.siacs.conversations.entities;
 
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Arrays;
+
 import eu.siacs.conversations.Config;
-import eu.siacs.conversations.R;
 import android.content.ContentValues;
-import android.content.Context;
 import android.database.Cursor;
 
 public class Message extends AbstractEntity {
 
 	public static final String TABLENAME = "messages";
 
-	public static final int STATUS_RECEPTION_FAILED = -3;
-	public static final int STATUS_RECEIVED_OFFER = -2;
-	public static final int STATUS_RECEIVING = -1;
 	public static final int STATUS_RECEIVED = 0;
 	public static final int STATUS_UNSEND = 1;
 	public static final int STATUS_SEND = 2;
 	public static final int STATUS_SEND_FAILED = 3;
-	public static final int STATUS_SEND_REJECTED = 4;
 	public static final int STATUS_WAITING = 5;
 	public static final int STATUS_OFFERED = 6;
 	public static final int STATUS_SEND_RECEIVED = 7;
@@ -61,6 +59,9 @@ public class Message extends AbstractEntity {
 	protected Downloadable downloadable = null;
 	public boolean markable = false;
 
+	private Message mNextMessage = null;
+	private Message mPreviousMessage = null;
+
 	private Message() {
 
 	}
@@ -131,14 +132,8 @@ public class Message extends AbstractEntity {
 			if (this.trueCounterpart == null) {
 				return null;
 			} else {
-				Account account = this.conversation.getAccount();
-				Contact contact = account.getRoster().getContact(
-						this.trueCounterpart);
-				if (contact.showInRoster()) {
-					return contact;
-				} else {
-					return null;
-				}
+				return this.conversation.getAccount().getRoster()
+						.getContactFromRoster(this.trueCounterpart);
 			}
 		}
 	}
@@ -147,22 +142,6 @@ public class Message extends AbstractEntity {
 		return body;
 	}
 
-	public String getReadableBody(Context context) {
-		if ((encryption == ENCRYPTION_PGP) && (type == TYPE_TEXT)) {
-			return context.getText(R.string.encrypted_message_received)
-					.toString();
-		} else if ((encryption == ENCRYPTION_OTR) && (type == TYPE_IMAGE)) {
-			return context.getText(R.string.encrypted_image_received)
-					.toString();
-		} else if (encryption == ENCRYPTION_DECRYPTION_FAILED) {
-			return context.getText(R.string.decryption_failed).toString();
-		} else if (type == TYPE_IMAGE) {
-			return context.getText(R.string.image_file).toString();
-		} else {
-			return body.trim();
-		}
-	}
-
 	public long getTimeSent() {
 		return timeSent;
 	}
@@ -301,21 +280,34 @@ public class Message extends AbstractEntity {
 	}
 
 	public Message next() {
-		int index = this.conversation.getMessages().indexOf(this);
-		if (index < 0 || index >= this.conversation.getMessages().size() - 1) {
-			return null;
-		} else {
-			return this.conversation.getMessages().get(index + 1);
+		if (this.mNextMessage == null) {
+			synchronized (this.conversation.messages) {
+				int index = this.conversation.messages.indexOf(this);
+				if (index < 0
+						|| index >= this.conversation.getMessages().size() - 1) {
+					this.mNextMessage = null;
+				} else {
+					this.mNextMessage = this.conversation.messages
+							.get(index + 1);
+				}
+			}
 		}
+		return this.mNextMessage;
 	}
 
 	public Message prev() {
-		int index = this.conversation.getMessages().indexOf(this);
-		if (index <= 0 || index > this.conversation.getMessages().size()) {
-			return null;
-		} else {
-			return this.conversation.getMessages().get(index - 1);
+		if (this.mPreviousMessage == null) {
+			synchronized (this.conversation.messages) {
+				int index = this.conversation.messages.indexOf(this);
+				if (index <= 0 || index > this.conversation.messages.size()) {
+					this.mPreviousMessage = null;
+				} else {
+					this.mPreviousMessage = this.conversation.messages
+							.get(index - 1);
+				}
+			}
 		}
+		return this.mPreviousMessage;
 	}
 
 	public boolean mergable(Message message) {
@@ -323,6 +315,8 @@ public class Message extends AbstractEntity {
 			return false;
 		}
 		return (message.getType() == Message.TYPE_TEXT
+				&& this.getDownloadable() == null
+				&& message.getDownloadable() == null
 				&& message.getEncryption() != Message.ENCRYPTION_PGP
 				&& this.getType() == message.getType()
 				&& this.getEncryption() == message.getEncryption()
@@ -332,7 +326,9 @@ public class Message extends AbstractEntity {
 				.getStatus() == Message.STATUS_SEND_RECEIVED) && (message
 				.getStatus() == Message.STATUS_UNSEND
 				|| message.getStatus() == Message.STATUS_SEND || message
-					.getStatus() == Message.STATUS_SEND_DISPLAYED)))));
+					.getStatus() == Message.STATUS_SEND_DISPLAYED))))
+				&& !message.bodyContainsDownloadable()
+				&& !this.bodyContainsDownloadable());
 	}
 
 	public String getMergedBody() {
@@ -369,4 +365,148 @@ public class Message extends AbstractEntity {
 			return prev.mergable(this);
 		}
 	}
+	
+	public boolean trusted() {
+		Contact contact = this.getContact();
+		return (status > STATUS_RECEIVED || (contact != null && contact.trusted()));
+	}
+
+	public boolean bodyContainsDownloadable() {
+		try {
+			URL url = new URL(this.getBody());
+			if (!url.getProtocol().equalsIgnoreCase("http")
+					&& !url.getProtocol().equalsIgnoreCase("https")) {
+				return false;
+			}
+			if (url.getPath() == null) {
+				return false;
+			}
+			String[] pathParts = url.getPath().split("/");
+			String filename;
+			if (pathParts.length > 0) {
+				filename = pathParts[pathParts.length - 1];
+			} else {
+				filename = pathParts[0];
+			}
+			String[] extensionParts = filename.split("\\.");
+			if (extensionParts.length == 2
+					&& Arrays.asList(Downloadable.VALID_EXTENSIONS).contains(
+							extensionParts[extensionParts.length - 1])) {
+				return true;
+			} else if (extensionParts.length == 3
+					&& Arrays
+							.asList(Downloadable.VALID_CRYPTO_EXTENSIONS)
+							.contains(extensionParts[extensionParts.length - 1])
+					&& Arrays.asList(Downloadable.VALID_EXTENSIONS).contains(
+							extensionParts[extensionParts.length - 2])) {
+				return true;
+			} else {
+				return false;
+			}
+		} catch (MalformedURLException e) {
+			return false;
+		}
+	}
+
+	public ImageParams getImageParams() {
+		ImageParams params = getLegacyImageParams();
+		if (params!=null) {
+			return params;
+		}
+		params = new ImageParams();
+		if (this.downloadable != null) {
+			params.size = this.downloadable.getFileSize();
+		}
+		if (body == null) {
+			return params;
+		}
+		String parts[] = body.split("\\|");
+		if (parts.length == 1) {
+			try {
+				params.size = Long.parseLong(parts[0]);
+			} catch (NumberFormatException e) {
+				params.origin = parts[0];
+				try {
+					params.url = new URL(parts[0]);
+				} catch (MalformedURLException e1) {
+					params.url = null;
+				}
+			}
+		} else if (parts.length == 3) {
+			try {
+				params.size = Long.parseLong(parts[0]);
+			} catch (NumberFormatException e) {
+				params.size = 0;
+			}
+			try {
+				params.width = Integer.parseInt(parts[1]);
+			} catch (NumberFormatException e) {
+				params.width = 0;
+			}
+			try {
+				params.height = Integer.parseInt(parts[2]);
+			} catch (NumberFormatException e) {
+				params.height = 0;
+			}
+		} else if (parts.length == 4) {
+			params.origin = parts[0];
+			try {
+				params.url = new URL(parts[0]);
+			} catch (MalformedURLException e1) {
+				params.url = null;
+			}
+			try {
+				params.size = Long.parseLong(parts[1]);
+			} catch (NumberFormatException e) {
+				params.size = 0;
+			}
+			try {
+				params.width = Integer.parseInt(parts[2]);
+			} catch (NumberFormatException e) {
+				params.width = 0;
+			}
+			try {
+				params.height = Integer.parseInt(parts[3]);
+			} catch (NumberFormatException e) {
+				params.height = 0;
+			}
+		}
+		return params;
+	}
+	
+	public ImageParams getLegacyImageParams() {
+		ImageParams params = new ImageParams();
+		if (body == null) {
+			return params;
+		}
+		String parts[] = body.split(",");
+		if (parts.length == 3) {
+			try {
+				params.size = Long.parseLong(parts[0]);
+			} catch (NumberFormatException e) {
+				return null;
+			}
+			try {
+				params.width = Integer.parseInt(parts[1]);
+			} catch (NumberFormatException e) {
+				return null;
+			}
+			try {
+				params.height = Integer.parseInt(parts[2]);
+			} catch (NumberFormatException e) {
+				return null;
+			}
+			return params;
+		} else {
+			return null;
+		}
+	}
+
+	public class ImageParams {
+		public URL url;
+		public long size = 0;
+		public int width = 0;
+		public int height = 0;
+		public String origin;
+	}
 }
diff --git a/src/eu/siacs/conversations/entities/MucOptions.java b/src/eu/siacs/conversations/entities/MucOptions.java
index 12ea4e93..d7407cd5 100644
--- a/src/eu/siacs/conversations/entities/MucOptions.java
+++ b/src/eu/siacs/conversations/entities/MucOptions.java
@@ -102,6 +102,10 @@ public class MucOptions {
 		public long getPgpKeyId() {
 			return this.pgpKeyId;
 		}
+
+		public Contact getContact() {
+			return account.getRoster().getContactFromRoster(getJid());
+		}
 	}
 
 	private Account account;
@@ -116,8 +120,9 @@ public class MucOptions {
 	private String joinnick;
 	private String password = null;
 
-	public MucOptions(Account account) {
-		this.account = account;
+	public MucOptions(Conversation conversation) {
+		this.account = conversation.getAccount();
+		this.conversation = conversation;
 	}
 
 	public void deleteUser(String name) {
@@ -253,10 +258,6 @@ public class MucOptions {
 		this.joinnick = nick;
 	}
 
-	public void setConversation(Conversation conversation) {
-		this.conversation = conversation;
-	}
-
 	public boolean online() {
 		return this.isOnline;
 	}
@@ -361,4 +362,8 @@ public class MucOptions {
 		conversation
 				.setAttribute(Conversation.ATTRIBUTE_MUC_PASSWORD, password);
 	}
+
+	public Conversation getConversation() {
+		return this.conversation;
+	}
 }
\ No newline at end of file
diff --git a/src/eu/siacs/conversations/entities/Roster.java b/src/eu/siacs/conversations/entities/Roster.java
index b6908793..3267b15a 100644
--- a/src/eu/siacs/conversations/entities/Roster.java
+++ b/src/eu/siacs/conversations/entities/Roster.java
@@ -14,7 +14,10 @@ public class Roster {
 		this.account = account;
 	}
 
-	public Contact getContactAsShownInRoster(String jid) {
+	public Contact getContactFromRoster(String jid) {
+		if (jid == null) {
+			return null;
+		}
 		String cleanJid = jid.split("/", 2)[0];
 		Contact contact = contacts.get(cleanJid);
 		if (contact != null && contact.showInRoster()) {