Save drafts for recipients without an existing thread

- Save drafts without thread in draft database
- Clear drafts when deleting conversation(s), otherwise
  the drafts stay in the database and will reappear when a thread
  with the same threadId is created

Closes #1510

src/org/thoughtcrime/securesms/ConversationActivity.java

@@ -23,8 +23,6 @@ import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.IntentFilter;
-import android.graphics.Bitmap;
-import android.graphics.drawable.BitmapDrawable;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Build;
@@ -92,7 +90,6 @@ import org.thoughtcrime.securesms.sms.OutgoingEncryptedMessage;
 import org.thoughtcrime.securesms.sms.OutgoingEndSessionMessage;
 import org.thoughtcrime.securesms.sms.OutgoingTextMessage;
 import org.thoughtcrime.securesms.util.BitmapDecodingException;
-import org.thoughtcrime.securesms.util.BitmapUtil;
 import org.thoughtcrime.securesms.util.CharacterCalculator;
 import org.thoughtcrime.securesms.util.Dialogs;
 import org.thoughtcrime.securesms.util.DirectoryHelper;
@@ -538,6 +535,7 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
       public void onClick(DialogInterface dialog, int which) {
         if (threadId > 0) {
           DatabaseFactory.getThreadDatabase(ConversationActivity.this).deleteConversation(threadId);
+          threadId = -1;
           finish();
         }
       }
@@ -919,28 +917,34 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
   }
 
   private void saveDraft() {
-    if (this.threadId <= 0 || this.recipients == null || this.recipients.isEmpty())
+    if (this.recipients == null || this.recipients.isEmpty())
       return;
 
-    final Drafts       drafts           = getDraftsForCurrentState();
-    final long         thisThreadId     = this.threadId;
-    final MasterSecret thisMasterSecret = this.masterSecret.parcelClone();
+    final Drafts       drafts               = getDraftsForCurrentState();
+    final long         thisThreadId         = this.threadId;
+    final MasterSecret thisMasterSecret     = this.masterSecret.parcelClone();
+    final int          thisDistributionType = this.distributionType;
 
-    new AsyncTask<Void, Void, Void>() {
+    new AsyncTask<Long, Void, Void>() {
       @Override
-      protected Void doInBackground(Void... params) {
-        MasterCipher masterCipher = new MasterCipher(thisMasterSecret);
-        DatabaseFactory.getDraftDatabase(ConversationActivity.this).insertDrafts(masterCipher, thisThreadId, drafts);
+      protected Void doInBackground(Long... params) {
         ThreadDatabase threadDatabase = DatabaseFactory.getThreadDatabase(ConversationActivity.this);
+        DraftDatabase  draftDatabase  = DatabaseFactory.getDraftDatabase(ConversationActivity.this);
+        long           threadId       = params[0];
+
         if (drafts.size() > 0) {
-          threadDatabase.updateSnippet(thisThreadId, drafts.getSnippet(ConversationActivity.this), Types.BASE_DRAFT_TYPE);
-        } else {
-          threadDatabase.update(thisThreadId);
+          if (threadId == -1) threadId = threadDatabase.getThreadIdFor(getRecipients(), thisDistributionType);
+
+          draftDatabase.insertDrafts(new MasterCipher(thisMasterSecret), threadId, drafts);
+          threadDatabase.updateSnippet(threadId, drafts.getSnippet(ConversationActivity.this), Types.BASE_DRAFT_TYPE);
+        } else if (threadId > 0) {
+          threadDatabase.update(threadId);
         }
+
         MemoryCleaner.clean(thisMasterSecret);
         return null;
       }
-    }.execute();
+    }.execute(thisThreadId);
   }
 
   private void calculateCharactersRemaining() {

src/org/thoughtcrime/securesms/database/DraftDatabase.java

@@ -13,6 +13,7 @@ import org.thoughtcrime.securesms.crypto.MasterCipher;
 
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Set;
 
 public class DraftDatabase extends Database {
 
@@ -51,6 +52,27 @@ public class DraftDatabase extends Database {
     db.delete(TABLE_NAME, THREAD_ID + " = ?", new String[] {threadId+""});
   }
 
+  public void clearDrafts(Set<Long> threadIds) {
+    SQLiteDatabase db        = databaseHelper.getWritableDatabase();
+    StringBuilder  where     = new StringBuilder();
+    List<String>   arguments = new LinkedList<>();
+
+    for (long threadId : threadIds) {
+      where.append(" OR ")
+           .append(THREAD_ID)
+           .append(" = ?");
+
+      arguments.add(String.valueOf(threadId));
+    }
+
+    db.delete(TABLE_NAME, where.toString().substring(4), arguments.toArray(new String[0]));
+  }
+
+  public void clearAllDrafts() {
+    SQLiteDatabase db = databaseHelper.getWritableDatabase();
+    db.delete(TABLE_NAME, null, null);
+  }
+
   public List<Draft> getDrafts(MasterCipher masterCipher, long threadId) {
     SQLiteDatabase db   = databaseHelper.getReadableDatabase();
     List<Draft> results = new LinkedList<Draft>();

src/org/thoughtcrime/securesms/database/ThreadDatabase.java

@@ -290,6 +290,7 @@ public class ThreadDatabase extends Database {
   public void deleteConversation(long threadId) {
     DatabaseFactory.getSmsDatabase(context).deleteThread(threadId);
     DatabaseFactory.getMmsDatabase(context).deleteThread(threadId);
+    DatabaseFactory.getDraftDatabase(context).clearDrafts(threadId);
     deleteThread(threadId);
     notifyConversationListeners(threadId);
     notifyConversationListListeners();
@@ -299,6 +300,7 @@ public class ThreadDatabase extends Database {
   public void deleteConversations(Set<Long> selectedConversations) {
     DatabaseFactory.getSmsDatabase(context).deleteThreads(selectedConversations);
     DatabaseFactory.getMmsDatabase(context).deleteThreads(selectedConversations);
+    DatabaseFactory.getDraftDatabase(context).clearDrafts(selectedConversations);
     deleteThreads(selectedConversations);
     notifyConversationListeners(selectedConversations);
     notifyConversationListListeners();
@@ -307,6 +309,7 @@ public class ThreadDatabase extends Database {
   public void deleteAllConversations() {
     DatabaseFactory.getSmsDatabase(context).deleteAllThreads();
     DatabaseFactory.getMmsDatabase(context).deleteAllThreads();
+    DatabaseFactory.getDraftDatabase(context).clearAllDrafts();
     deleteAllThreads();
   }