Minor tidying around displayable events.

src/com/dmdirc/events/DisplayableEvent.java

      */
     <T> Optional<T> getDisplayProperty(DisplayProperty<T> property);
 
+    /**
+     * Determines whether this event has a display property.
+     *
+     * <p>Only use this method if the value of the property does not matter; otherwise use
+     * {@link #getDisplayProperty(DisplayProperty)} and use the appropriate {@link Optional}
+     * accessors.
+     *
+     * @param property The property to be checked.
+     * @return True if the property is present, false otherwise.
+     */
+    default boolean hasDisplayProperty(final DisplayProperty<?> property) {
+        return getDisplayProperty(property).isPresent();
+    }
+
     /**
      * Gets the map of all display properties.
      *

src/com/dmdirc/ui/messages/BackBuffer.java

 import com.dmdirc.interfaces.WindowModel;
 import com.dmdirc.util.EventUtils;
 
+import java.util.Arrays;
+
 import net.engio.mbassy.listener.Handler;
 
 /**
     @Handler(priority = EventUtils.PRIORITY_DISPLAYABLE_EVENT_HANDLER)
     private void handleDisplayableEvent(final DisplayableEvent event) {
         if (shouldDisplay(event)) {
-            formatter.format(event).map(s -> s.split("\n")).ifPresent(
-                    t -> {
-                        for (String line : t) {
-                            document.addText(event.getTimestamp(), event
-                                    .getDisplayProperties(), line);
-                        }
-                    });
+            formatter.format(event).map(s -> s.split("\n")).map(Arrays::stream).ifPresent(
+                    t -> t.forEach(line -> document.addText(
+                            event.getTimestamp(), event.getDisplayProperties(), line)));
         }
     }
 
      */
     private boolean shouldDisplay(final DisplayableEvent event) {
         return event.getSource().equals(owner)
-                && !event.getDisplayProperty(DisplayProperty.DO_NOT_DISPLAY).isPresent();
+                && !event.hasDisplayProperty(DisplayProperty.DO_NOT_DISPLAY);
     }
 
     public IRCDocument getDocument() {

src/com/dmdirc/ui/messages/EventFormatter.java

     public Optional<String> format(final DisplayableEvent event) {
         final Optional<EventFormat> format = formatProvider.getFormat(event.getClass());
 
-        if (!event.getDisplayProperty(DisplayProperty.FOREGROUND_COLOUR).isPresent()) {
+        if (!event.hasDisplayProperty(DisplayProperty.FOREGROUND_COLOUR)) {
             format.flatMap(EventFormat::getDefaultForegroundColour)
                     .ifPresent(c -> event.setDisplayProperty(DisplayProperty.FOREGROUND_COLOUR, c));
         }