Add ability to collapse and expand notification groups

Closes #1

build.gradle

@@ -10,7 +10,7 @@ repositories {
 	mavenCentral()
 }
 
-def runeLiteVersion = '1.6.10.1'
+def runeLiteVersion = '1.6.19'
 
 dependencies {
 	compileOnly group: 'net.runelite', name:'client', version: runeLiteVersion
@@ -26,7 +26,7 @@ dependencies {
 }
 
 group = 'com.github.zakru.advancednotifications'
-version = '1.1'
+version = '1.1.1'
 sourceCompatibility = '1.8'
 
 tasks.withType(JavaCompile) {

src/main/java/com/github/zakru/advancednotifications/NotificationGroup.java

@@ -12,6 +12,9 @@ public class NotificationGroup extends Notification implements DraggableContaine
 	@Setter
 	private String name = "Group";
 	@Getter
+	@Setter
+	private boolean collapsed = false;
+	@Getter
 	private final List<Notification> notifications = new ArrayList<>();
 
 	public NotificationGroup(AdvancedNotificationsPlugin plugin)

src/main/java/com/github/zakru/advancednotifications/ui/NotificationGroupPanel.java

@@ -22,6 +22,11 @@ public class NotificationGroupPanel extends NotificationPanel<NotificationGroup>
 	private static final ImageIcon RENAME_ICON;
 	private static final ImageIcon RENAME_HOVER_ICON;
 
+	private static final ImageIcon COLLAPSE_ICON;
+	private static final ImageIcon COLLAPSE_HOVER_ICON;
+	private static final ImageIcon EXPAND_ICON;
+	private static final ImageIcon EXPAND_HOVER_ICON;
+
 	private final JTextField nameLabel;
 	private final JLabel rename;
 
@@ -36,6 +41,16 @@ public class NotificationGroupPanel extends NotificationPanel<NotificationGroup>
 			= ImageUtil.getResourceStreamFromClass(AdvancedNotificationsPlugin.class, "rename_icon.png");
 		RENAME_ICON = new ImageIcon(renameIcon);
 		RENAME_HOVER_ICON = new ImageIcon(ImageUtil.alphaOffset(renameIcon, 0.53f));
+
+		final BufferedImage collapseIcon
+			= ImageUtil.getResourceStreamFromClass(AdvancedNotificationsPlugin.class, "collapse_icon.png");
+		COLLAPSE_ICON = new ImageIcon(collapseIcon);
+		COLLAPSE_HOVER_ICON = new ImageIcon(ImageUtil.alphaOffset(collapseIcon, 0.53f));
+
+		final BufferedImage expandIcon
+			= ImageUtil.getResourceStreamFromClass(AdvancedNotificationsPlugin.class, "expand_icon.png");
+		EXPAND_ICON = new ImageIcon(expandIcon);
+		EXPAND_HOVER_ICON = new ImageIcon(ImageUtil.alphaOffset(expandIcon, 0.53f));
 	}
 
 	public NotificationGroupPanel(NotificationGroup notification, DraggableContainer container)
@@ -152,28 +167,57 @@ public void mouseExited(MouseEvent e)
 		actions.add(new EnabledButton(notification.getPlugin(), notification));
 		actions.add(deleteButton);
 
+		JLabel collapseOrExpand = new JLabel(notification.isCollapsed() ? EXPAND_ICON : COLLAPSE_ICON);
+		collapseOrExpand.addMouseListener(new MouseAdapter()
+		{
+			@Override
+			public void mousePressed(MouseEvent e)
+			{
+				notification.setCollapsed(!notification.isCollapsed());
+				notification.getPlugin().updateConfig();
+				notification.getPlugin().rebuildPluginPanel();
+			}
+
+			@Override
+			public void mouseEntered(MouseEvent e)
+			{
+				collapseOrExpand.setIcon(notification.isCollapsed() ? EXPAND_HOVER_ICON : COLLAPSE_HOVER_ICON);
+			}
+
+			@Override
+			public void mouseExited(MouseEvent e)
+			{
+				collapseOrExpand.setIcon(notification.isCollapsed() ? EXPAND_ICON : COLLAPSE_ICON);
+			}
+		});
+
+		northPanel.add(collapseOrExpand, BorderLayout.WEST);
 		northPanel.add(nameLabel, BorderLayout.CENTER);
 		northPanel.add(actions, BorderLayout.EAST);
 
-		JPanel notificationView = new JPanel();
-		notificationView.setLayout(new BoxLayout(notificationView, BoxLayout.Y_AXIS));
-		notificationView.setOpaque(false);
-		notificationView.setBorder(BorderFactory.createEmptyBorder(0, 10, 0, 0));
+		add(northPanel, BorderLayout.NORTH);
 
-		int index = 0;
-		notificationView.add(new DropSpace(plugin, notification, index++));
-		for (final Notification notif : notification.getNotifications())
+		if (!notification.isCollapsed())
 		{
-			NotificationPanel<?> panel = NotificationPanel.buildPanel(notification, notif);
-			if (panel != null)
+			JPanel notificationView = new JPanel();
+			notificationView.setLayout(new BoxLayout(notificationView, BoxLayout.Y_AXIS));
+			notificationView.setOpaque(false);
+			notificationView.setBorder(BorderFactory.createEmptyBorder(0, 10, 0, 0));
+
+			int index = 0;
+			notificationView.add(new DropSpace(plugin, notification, index++));
+			for (final Notification notif : notification.getNotifications())
 			{
-				notificationView.add(panel);
-				notificationView.add(new DropSpace(plugin, notification, index++));
+				NotificationPanel<?> panel = NotificationPanel.buildPanel(notification, notif);
+				if (panel != null)
+				{
+					notificationView.add(panel);
+					notificationView.add(new DropSpace(plugin, notification, index++));
+				}
 			}
-		}
 
-		add(northPanel, BorderLayout.NORTH);
-		add(notificationView, BorderLayout.CENTER);
+			add(notificationView, BorderLayout.CENTER);
+		}
 	}
 
 	public void resetScroll()