Added PrimaryScrollPane class with default scroll pane UI settings

src/main/java/envoy/client/ui/ChatWindow.java

@@ -1,6 +1,5 @@
 package envoy.client.ui;
 
-import java.awt.Color;
 import java.awt.ComponentOrientation;
 import java.awt.Font;
 import java.awt.GridBagConstraints;
@@ -20,7 +19,6 @@ import javax.swing.JFrame;
 import javax.swing.JList;
 import javax.swing.JOptionPane;
 import javax.swing.JPanel;
-import javax.swing.JScrollPane;
 import javax.swing.JTextPane;
 import javax.swing.ListSelectionModel;
 import javax.swing.SwingUtilities;
@@ -59,9 +57,7 @@ public class ChatWindow extends JFrame {
 	private JList<User>			userList				= new JList<>();
 	private Chat				currentChat;
 	private JList<Message>		messageList				= new JList<>();
-	private JScrollPane		scrollPane						= new JScrollPane();
+	private PrimaryScrollPane	scrollPane				= new PrimaryScrollPane();
-	private int				verticalScrollBarMaximumValue	= scrollPane.getVerticalScrollBar().getMaximum();
-	private boolean			chatOpened						= false;
 	private JTextPane			textPane				= new JTextPane();
 	private PrimaryButton		postButton				= new PrimaryButton("Post");
 	private PrimaryButton		settingsButton			= new PrimaryButton("Settings");
@@ -115,7 +111,6 @@ public class ChatWindow extends JFrame {
 		messageList.setBorder(new EmptyBorder(space, space, space, space));
 
 		scrollPane.setViewportView(messageList);
-		scrollPane.setBorder(null);
 
 		GridBagConstraints gbc_scrollPane = new GridBagConstraints();
 		gbc_scrollPane.fill			= GridBagConstraints.BOTH;
@@ -210,7 +205,7 @@ public class ChatWindow extends JFrame {
 				textPane.setText(currentChat.getRecipient().getName());
 
 				messageList.setModel(currentChat.getModel());
-				chatOpened = true;
+				scrollPane.setChatOpened(true);
 				contentPane.revalidate();
 			}
 		});
@@ -254,35 +249,7 @@ public class ChatWindow extends JFrame {
 		messageList.setForeground(theme.getMessageColorChat());
 		messageList.setBackground(theme.getCellColor());
 		// scrollPane
-		scrollPane.setForeground(theme.getBackgroundColor());
+		scrollPane.applyTheme(theme);
-		scrollPane.setBackground(theme.getCellColor());
-
-		// Scroll Bar Styling
-		scrollPane.getVerticalScrollBar().setBackground(theme.getCellColor());
-		scrollPane.getVerticalScrollBar()
-			.setUI(new PrimaryScrollBar(5, theme.getInteractableBackgroundColor(), new Color(theme.getInteractableBackgroundColor().getRGB() - 50),
-					new Color(theme.getInteractableBackgroundColor().getRGB() + 170), true));
-		scrollPane.getHorizontalScrollBar().setBackground(theme.getCellColor());
-		scrollPane.getHorizontalScrollBar()
-			.setUI(new PrimaryScrollBar(5, theme.getInteractableBackgroundColor(), new Color(theme.getInteractableBackgroundColor().getRGB() - 50),
-					new Color(theme.getInteractableBackgroundColor().getRGB() + 170), false));
-
-		// Autoscroll
-		scrollPane.getVerticalScrollBar().addAdjustmentListener(e -> {
-			if ((verticalScrollBarMaximumValue - e.getAdjustable().getMaximum()) == 0) { return; }
-
-			if (chatOpened == true) {
-				e.getAdjustable().setValue(e.getAdjustable().getMaximum());
-				verticalScrollBarMaximumValue	= scrollPane.getVerticalScrollBar().getMaximum();
-				chatOpened						= false;
-				return;
-			}
-			if (scrollPane.getVerticalScrollBar().getValue() + scrollPane.getVerticalScrollBar().getVisibleAmount()
-					+ 100 >= scrollPane.getVerticalScrollBar().getMaximum()) {
-				e.getAdjustable().setValue(e.getAdjustable().getMaximum());
-				verticalScrollBarMaximumValue = scrollPane.getVerticalScrollBar().getMaximum();
-			}
-		});
 
 		// messageEnterTextArea
 		messageEnterTextArea.setCaretColor(theme.getTypingMessageColor());

src/main/java/envoy/client/ui/PrimaryScrollBar.java

@@ -39,6 +39,11 @@ public class PrimaryScrollBar extends BasicScrollBarUI {
 		this.isVertical		= isVertical;
 	}
 
+	public PrimaryScrollBar(Theme theme, boolean isVertical) {
+		this(5, theme.getInteractableBackgroundColor(), new Color(theme.getInteractableBackgroundColor().getRGB() - 50),
+				new Color(theme.getInteractableBackgroundColor().getRGB() + 170), isVertical);
+	}
+
 	@Override
 	protected JButton createDecreaseButton(int orientation) {
 		JButton button = new JButton();

src/main/java/envoy/client/ui/PrimaryScrollPane.java

@@ -0,0 +1,48 @@
+package envoy.client.ui;
+
+import javax.swing.JScrollPane;
+
+/**
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>PrimaryScrollPane.java</strong><br>
+ * Created: <strong>15 Dec 2019</strong><br>
+ *
+ * @author Kai S. K. Engelbart
+ */
+public class PrimaryScrollPane extends JScrollPane {
+
+	private static final long serialVersionUID = -4786837444056228439L;
+
+	private int		verticalScrollBarMaximum	= getVerticalScrollBar().getMaximum();
+	private boolean	chatOpened					= false;
+
+	public PrimaryScrollPane() { setBorder(null); }
+
+	public void applyTheme(Theme theme) {
+		setForeground(theme.getBackgroundColor());
+		setBackground(theme.getCellColor());
+
+		getVerticalScrollBar().setBackground(theme.getCellColor());
+		getVerticalScrollBar().setUI(new PrimaryScrollBar(theme, true));
+		getHorizontalScrollBar().setBackground(theme.getCellColor());
+		getHorizontalScrollBar().setUI(new PrimaryScrollBar(theme, false));
+
+		// Automatic scrolling to the bottom
+		getVerticalScrollBar().addAdjustmentListener(e -> {
+			if (verticalScrollBarMaximum == e.getAdjustable().getMaximum()) return;
+
+			if (chatOpened) {
+				e.getAdjustable().setValue(e.getAdjustable().getMaximum());
+				verticalScrollBarMaximum	= getVerticalScrollBar().getMaximum();
+				chatOpened					= false;
+				return;
+			}
+			if (getVerticalScrollBar().getValue() + getVerticalScrollBar().getVisibleAmount() + 100 >= getVerticalScrollBar().getMaximum()) {
+				e.getAdjustable().setValue(e.getAdjustable().getMaximum());
+				verticalScrollBarMaximum = getVerticalScrollBar().getMaximum();
+			}
+		});
+	}
+
+	public void setChatOpened(boolean chatOpened) { this.chatOpened = chatOpened; }
+}