Add base interface for objects with display properties.

This will allow the formatter to check if strings coming from
(for example) users in channels should be formatted specially,
such as by colouring or linking them.

Issues #424 and DMDirc/Plugins#507

api/src/main/java/com/dmdirc/events/DisplayableEvent.java

@@ -22,52 +22,13 @@
 
 package com.dmdirc.events;
 
+import com.dmdirc.interfaces.Displayable;
 import java.time.LocalDateTime;
-import java.util.Optional;
 
 /**
  * Describes an event which is rendered in the client to the user.
  */
-public interface DisplayableEvent extends SourcedEvent {
-
-    /**
-     * Sets a property relating to how this event should be displayed.
-     *
-     * @param property The property to be set
-     * @param value The value of the property
-     * @param <T> The type of value that the property takes.
-     */
-    <T> void setDisplayProperty(DisplayProperty<T> property, T value);
-
-    /**
-     * Retrieves a property relating to how this event should be displayed.
-     *
-     * @param property The property to be retrieved.
-     * @param <T> The type of value that the property takes.
-     * @return An optional value for the property.
-     */
-    <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.
-     *
-     * @return The map of display properties.
-     */
-    DisplayPropertyMap getDisplayProperties();
+public interface DisplayableEvent extends SourcedEvent, Displayable {
 
     /**
      * Gets the times at which the event occurred.

api/src/main/java/com/dmdirc/interfaces/Displayable.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2006-2016 DMDirc Developers
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
+ * documentation files (the "Software"), to deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+ * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
+ * OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package com.dmdirc.interfaces;
+
+import com.dmdirc.events.DisplayProperty;
+import com.dmdirc.events.DisplayPropertyMap;
+import java.util.Optional;
+
+/**
+ * Common interface for objects which may be displayed, and are affected by {@link DisplayProperty}s.
+ */
+public interface Displayable {
+
+    /**
+     * Retrieves a property relating to how this object should be displayed.
+     *
+     * @param property The property to be retrieved.
+     * @param <T> The type of value that the property takes.
+     * @return An optional value for the property.
+     */
+    <T> Optional<T> getDisplayProperty(DisplayProperty<T> property);
+
+    /**
+     * Sets a property relating to how this object should be displayed.
+     *
+     * @param property The property to be set
+     * @param value The value of the property
+     * @param <T> The type of value that the property takes.
+     */
+    <T> void setDisplayProperty(DisplayProperty<T> property, T value);
+
+    /**
+     * Determines whether this object 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();
+    }
+
+    /**
+     * Removes a property relating to how this object should be displayed.
+     *
+     * @param property The property to be removed
+     */
+    default <T> void removeDisplayProperty(final DisplayProperty<T> property) {
+        getDisplayProperties().remove(property);
+    }
+
+    /**
+     * Gets the map of all display properties.
+     *
+     * @return The map of display properties.
+     */
+    DisplayPropertyMap getDisplayProperties();
+
+}

api/src/main/java/com/dmdirc/interfaces/GroupChatUser.java

@@ -22,16 +22,13 @@
 
 package com.dmdirc.interfaces;
 
-import com.dmdirc.events.DisplayProperty;
-import com.dmdirc.events.DisplayPropertyMap;
-
 import java.util.Comparator;
 import java.util.Optional;
 
 /**
  * Describes a {@link User} that is present on a {@link GroupChat}.
  */
-public interface GroupChatUser {
+public interface GroupChatUser extends Displayable {
 
     /**
      * Retrieves the {@link User} object which this object corresponds
@@ -107,33 +104,4 @@ public interface GroupChatUser {
      */
     Comparator<String> getModeComparator();
 
-    /**
-     * Sets a property relating to how this {@link GroupChatUser} should be displayed.
-     *
-     * @param property The property to be set
-     * @param value The value of the property
-     * @param <T> The type of value that the property takes.
-     */
-    <T> void setDisplayProperty(final DisplayProperty<T> property, final T value);
-
-    /**
-     * Retrieves a property relating to how this {@link GroupChatUser} should be displayed.
-     *
-     * @param property The property to be retrieved.
-     * @param <T> The type of value that the property takes.
-     * @return An optional value for the property.
-     */
-    <T> Optional<T> getDisplayProperty(final DisplayProperty<T> property);
-
-    /**
-     * Removes a property relating to how this {@link GroupChatUser} should be displayed.
-     */
-    <T> void removeDisplayProperty(final DisplayProperty<T> property);
-
-    /**
-     * Gets the map of all display properties for this {@link GroupChatUser}.
-     *
-     * @return The map of display properties.
-     */
-    DisplayPropertyMap getDisplayProperties();
 }