Cancel notifications after rescheduling task

app/src/main/java/com/todoroo/astrid/activity/TaskListFragment.java

@@ -12,6 +12,7 @@ import static com.google.common.collect.Lists.newArrayList;
 import static com.todoroo.andlib.utility.AndroidUtilities.assertMainThread;
 import static org.tasks.activities.RemoteListPicker.newRemoteListSupportPicker;
 import static org.tasks.caldav.CaldavCalendarSettingsActivity.EXTRA_CALDAV_CALENDAR;
+import static org.tasks.date.DateTimeUtils.newDateTime;
 
 import android.app.Activity;
 import android.content.BroadcastReceiver;
@@ -99,6 +100,7 @@ import org.tasks.injection.ForActivity;
 import org.tasks.injection.FragmentComponent;
 import org.tasks.injection.InjectingFragment;
 import org.tasks.intents.TaskIntents;
+import org.tasks.notifications.NotificationManager;
 import org.tasks.preferences.Device;
 import org.tasks.preferences.Preferences;
 import org.tasks.sync.SyncAdapters;
@@ -158,6 +160,7 @@ public final class TaskListFragment extends InjectingFragment
   @Inject CaldavDao caldavDao;
   @Inject ThemeColor defaultThemeColor;
   @Inject ColorProvider colorProvider;
+  @Inject NotificationManager notificationManager;
 
   @BindView(R.id.swipe_layout)
   SwipeRefreshLayout swipeRefreshLayout;
@@ -643,6 +646,9 @@ public final class TaskListFragment extends InjectingFragment
           long taskId = data.getLongExtra(DateTimePicker.EXTRA_TASK, 0L);
           Task task = taskDao.fetch(taskId);
           long dueDate = data.getLongExtra(DateTimePicker.EXTRA_TIMESTAMP, 0L);
+          if (newDateTime(dueDate).isAfterNow()) {
+            notificationManager.cancel(task.getId());
+          }
           task.setDueDateAdjustingHideUntil(dueDate);
           taskDao.save(task);
         }

app/src/main/java/org/tasks/time/DateTime.java

@@ -7,6 +7,7 @@ import static java.util.Calendar.SUNDAY;
 import static java.util.Calendar.THURSDAY;
 import static java.util.Calendar.TUESDAY;
 import static java.util.Calendar.WEDNESDAY;
+import static org.tasks.time.DateTimeUtils.currentTimeMillis;
 
 import com.google.ical.values.DateTimeValue;
 import com.google.ical.values.DateValue;
@@ -65,7 +66,7 @@ public class DateTime {
   }
 
   public DateTime() {
-    this(DateTimeUtils.currentTimeMillis());
+    this(currentTimeMillis());
   }
 
   public DateTime(long timestamp) {
@@ -261,8 +262,16 @@ public class DateTime {
     return new DateTime(timestamp - millis, timeZone);
   }
 
+  public boolean isAfterNow() {
+    return isAfter(currentTimeMillis());
+  }
+
   public boolean isAfter(DateTime dateTime) {
-    return timestamp > dateTime.getMillis();
+    return isAfter(dateTime.getMillis());
+  }
+
+  public boolean isAfter(long timestamp) {
+    return this.timestamp > timestamp;
   }
 
   public boolean isBeforeNow() {