FlatLafの導入

build.gradle

@@ -37,6 +37,10 @@ dependencies {
   testImplementation 'org.mockito:mockito-core:4.7.0'
   testImplementation 'org.projectlombok:lombok:1.18.42'
 
+  // FlatLaf - Modern Look and Feel
+  implementation 'com.formdev:flatlaf:3.4.1'
+  implementation 'com.formdev:flatlaf-intellij-themes:3.4.1'
+
   implementation 'com.google.guava:guava:24.1-jre'
   implementation 'commons-codec:commons-codec:1.6'
   implementation 'commons-io:commons-io:2.4'

src/main/java/core/packetproxy/gui/CloseButtonTabbedPane.java

@@ -17,14 +17,17 @@
 
 import java.awt.Component;
 import java.awt.Dimension;
+import java.awt.Insets;
 import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
+import javax.swing.Box;
 import javax.swing.BoxLayout;
 import javax.swing.ImageIcon;
 import javax.swing.JButton;
 import javax.swing.JLabel;
 import javax.swing.JPanel;
 import javax.swing.JTabbedPane;
+import javax.swing.UIManager;
 
 public class CloseButtonTabbedPane extends JTabbedPane {
 
@@ -36,13 +39,15 @@ public CloseButtonTabbedPane() {
 		super();
 		icon = new ImageIcon(getClass().getResource("/gui/close.png"));
 		icon_mouseovered = new ImageIcon(getClass().getResource("/gui/close_mouseovered.png"));
+		UIManager.put("TabbedPane.tabInsets", new Insets(0, 7, 0, 7));
 	}
 
 	@Override
 	public void addTab(String title, Component content) {
 		JPanel main_panel = new JPanel();
 		main_panel.setLayout(new BoxLayout(main_panel, BoxLayout.X_AXIS));
 		main_panel.setOpaque(false);
+		main_panel.setBorder(javax.swing.BorderFactory.createEmptyBorder(0, 0, 0, 0));
 		JLabel label = new JLabel(title);
 		JButton button = new JButton(icon);
 		button.setPreferredSize(new Dimension(icon.getIconWidth() + 1, icon.getIconHeight() + 1));
@@ -66,6 +71,8 @@ public void mouseExited(MouseEvent e) {
 			}
 		});
 		main_panel.add(label);
+		// 数字とバツボタンの間に余白を追加
+		main_panel.add(Box.createHorizontalStrut(7));
 		main_panel.add(button);
 		super.addTab(null, content);
 		setTabComponentAt(getTabCount() - 1, main_panel);

src/main/java/core/packetproxy/gui/GUIBulkSenderTable.java

@@ -34,9 +34,12 @@
 import javax.swing.JMenuItem;
 import javax.swing.JPopupMenu;
 import javax.swing.JScrollPane;
+import javax.swing.BorderFactory;
 import javax.swing.JTable;
 import javax.swing.KeyStroke;
+import javax.swing.SwingConstants;
 import javax.swing.event.ListSelectionEvent;
+import javax.swing.table.DefaultTableCellRenderer;
 import javax.swing.table.TableCellRenderer;
 import packetproxy.common.Utils;
 import packetproxy.model.OneShotPacket;
@@ -131,6 +134,23 @@ public Component prepareRenderer(TableCellRenderer tcr, int row, int column) {
 
 			table.getColumn(columnNames[i]).setPreferredWidth(columnWidth[i]);
 		}
+		// Set header style with left alignment, border, and padding
+		DefaultTableCellRenderer headerRenderer = new DefaultTableCellRenderer() {
+			@Override
+			public Component getTableCellRendererComponent(JTable table, Object value,
+					boolean isSelected, boolean hasFocus, int row, int column) {
+				Component c = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
+				setBorder(BorderFactory.createCompoundBorder(
+						BorderFactory.createMatteBorder(0, 0, 1, 1, Color.LIGHT_GRAY),
+						BorderFactory.createEmptyBorder(2, 5, 2, 5)
+				));
+				return c;
+			}
+		};
+		headerRenderer.setHorizontalAlignment(SwingConstants.LEFT);
+		for (int i = 0; i < columnNames.length; i++) {
+			table.getColumnModel().getColumn(i).setHeaderRenderer(headerRenderer);
+		}
 
 		table.addKeyListener(new KeyAdapter() {
 

src/main/java/core/packetproxy/gui/GUIFilterConfig.java

@@ -25,15 +25,12 @@
 import javax.swing.BoxLayout;
 import javax.swing.JButton;
 import javax.swing.JComponent;
-import javax.swing.JFileChooser;
 import javax.swing.JFrame;
 import javax.swing.JLabel;
 import javax.swing.JOptionPane;
 import javax.swing.JPanel;
 import javax.swing.JScrollPane;
 import javax.swing.JTable;
-import javax.swing.SwingUtilities;
-import javax.swing.filechooser.FileNameExtensionFilter;
 import javax.swing.table.DefaultTableCellRenderer;
 import javax.swing.table.DefaultTableModel;
 import javax.swing.table.TableCellRenderer;
@@ -262,12 +259,12 @@ public void mouseClicked(MouseEvent e) {
 			public void mouseClicked(MouseEvent e) {
 				try {
 
-					JFileChooser filechooser = new JFileChooser();
+					NativeFileChooser filechooser = new NativeFileChooser();
 					filechooser.setCurrentDirectory(new File(defaultDir));
-					filechooser.setFileFilter(new FileNameExtensionFilter("*.json", "json"));
-					filechooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
-					int selected = filechooser.showOpenDialog(SwingUtilities.getRoot(owner));
-					if (selected == JFileChooser.APPROVE_OPTION) {
+					filechooser.addChoosableFileFilter("*.json", "json");
+					filechooser.setAcceptAllFileFilterUsed(false);
+					int selected = filechooser.showOpenDialog(owner);
+					if (selected == NativeFileChooser.APPROVE_OPTION) {
 
 						File file = filechooser.getSelectedFile();
 						byte[] jbytes = Utils.readfile(file.getAbsolutePath());

src/main/java/core/packetproxy/gui/GUIHistory.java

@@ -47,6 +47,7 @@
 import java.util.Objects;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import javax.swing.BorderFactory;
 import javax.swing.BoxLayout;
 import javax.swing.ImageIcon;
 import javax.swing.JButton;
@@ -61,11 +62,13 @@
 import javax.swing.JTable;
 import javax.swing.JToggleButton;
 import javax.swing.KeyStroke;
+import javax.swing.SwingConstants;
 import javax.swing.SwingUtilities;
 import javax.swing.SwingWorker;
 import javax.swing.event.ListSelectionEvent;
 import javax.swing.event.TableModelEvent;
 import javax.swing.event.TableModelListener;
+import javax.swing.table.DefaultTableCellRenderer;
 import javax.swing.table.DefaultTableModel;
 import javax.swing.table.TableCellRenderer;
 import javax.swing.table.TableRowSorter;
@@ -204,7 +207,10 @@ public void focusGained(FocusEvent e) {
 		});
 
 		JButton filterConfigAdd = new JButton(new ImageIcon(getClass().getResource("/gui/plus.png")));
-		filterConfigAdd.setMaximumSize(new Dimension(15, gui_filter.getMaximumSize().height));
+		int buttonWidth = 35; // ボタンの横幅を広げる
+		filterConfigAdd.setPreferredSize(new Dimension(buttonWidth, gui_filter.getMaximumSize().height));
+		filterConfigAdd.setMaximumSize(new Dimension(buttonWidth, gui_filter.getMaximumSize().height));
+		filterConfigAdd.setMinimumSize(new Dimension(buttonWidth, gui_filter.getMaximumSize().height));
 		filterConfigAdd.setBackground(filterConfigAdd.getBackground());
 		filterConfigAdd.addActionListener(new ActionListener() {
 
@@ -222,8 +228,9 @@ public void actionPerformed(ActionEvent e) {
 		});
 
 		JToggleButton filterDropDown = new JToggleButton(new ImageIcon(getClass().getResource("/gui/arrow.png")));
-		filterDropDown.setMaximumSize(
-				new Dimension(filterConfigAdd.getMaximumSize().width, gui_filter.getMaximumSize().height));
+		filterDropDown.setPreferredSize(new Dimension(buttonWidth, gui_filter.getMaximumSize().height));
+		filterDropDown.setMaximumSize(new Dimension(buttonWidth, gui_filter.getMaximumSize().height));
+		filterDropDown.setMinimumSize(new Dimension(buttonWidth, gui_filter.getMaximumSize().height));
 		filterDropDown.setBackground(filterDropDown.getBackground());
 		filterDropDown.addMouseListener(new MouseAdapter() {
 
@@ -271,8 +278,9 @@ public void mouseReleased(MouseEvent arg0) {
 
 		ImageIcon icon = new ImageIcon(getClass().getResource("/gui/config.png"));
 		JButton filterConfig = new JButton(icon);
-		filterConfig.setMaximumSize(
-				new Dimension(filterConfigAdd.getMaximumSize().width, gui_filter.getMaximumSize().height));
+		filterConfig.setPreferredSize(new Dimension(buttonWidth, gui_filter.getMaximumSize().height));
+		filterConfig.setMaximumSize(new Dimension(buttonWidth, gui_filter.getMaximumSize().height));
+		filterConfig.setMinimumSize(new Dimension(buttonWidth, gui_filter.getMaximumSize().height));
 		filterConfig.setBackground(filterConfig.getBackground());
 		filterConfig.addActionListener(new ActionListener() {
 
@@ -410,6 +418,23 @@ public Component prepareRenderer(TableCellRenderer tcr, int row, int column) {
 
 			table.getColumn(columnNames[i]).setPreferredWidth(columnWidth[i]);
 		}
+		// Set header alignment to left with border and padding
+		DefaultTableCellRenderer headerRenderer = new DefaultTableCellRenderer() {
+			@Override
+			public Component getTableCellRendererComponent(JTable table, Object value,
+					boolean isSelected, boolean hasFocus, int row, int column) {
+				Component c = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
+				setBorder(BorderFactory.createCompoundBorder(
+						BorderFactory.createMatteBorder(0, 0, 1, 1, Color.LIGHT_GRAY),
+						BorderFactory.createEmptyBorder(2, 5, 2, 5)  // top, left, bottom, right padding
+				));
+				return c;
+			}
+		};
+		headerRenderer.setHorizontalAlignment(SwingConstants.LEFT);
+		for (int i = 0; i < columnNames.length; i++) {
+			table.getColumnModel().getColumn(i).setHeaderRenderer(headerRenderer);
+		}
 		((JComponent) table.getDefaultRenderer(Boolean.class)).setOpaque(true);
 		table.getSelectionModel().addListSelectionListener(new javax.swing.event.ListSelectionListener() {
 

src/main/java/core/packetproxy/gui/GUIMain.java

@@ -26,6 +26,7 @@
 import java.beans.PropertyChangeListener;
 import javax.swing.*;
 import javax.swing.UIManager.LookAndFeelInfo;
+import com.formdev.flatlaf.FlatIntelliJLaf;
 import javax.swing.text.DefaultEditorKit;
 import javax.swing.text.JTextComponent;
 import javax.swing.text.Keymap;
@@ -117,6 +118,15 @@ private GUIMain(String title) {
 			gui_log = GUILog.getInstance();
 
 			tabbedpane = new JTabbedPane();
+
+			// タブの高さを数値で強制指定
+			UIManager.put("TabbedPane.tabHeight", 22);
+			// フォーカスが当たった時の枠線の太さを0にする
+			UIManager.put("TabbedPane.focusWidth", 0);
+			UIManager.put("TabbedPane.innerBorderInsets", new Insets(0, 0, 0, 0));
+			UIManager.put("TabbedPane.tabInsets", new Insets(0, 10, 0, 10));
+
+			SwingUtilities.updateComponentTreeUI(tabbedpane);
 			tabbedpane.addTab(getPaneString(Panes.HISTORY), gui_history.createPanel());
 			tabbedpane.addTab(getPaneString(Panes.INTERCEPT), gui_intercept.createPanel());
 			tabbedpane.addTab(getPaneString(Panes.RESENDER), gui_resender.createPanel());
@@ -161,12 +171,16 @@ private void setLookandFeel() throws Exception {
 			System.setProperty("swing.aatext", "true");
 		}
 
-		for (LookAndFeelInfo clInfo : UIManager.getInstalledLookAndFeels()) {
-
-			if ("Nimbus".equals(clInfo.getName())) {
-
-				UIManager.setLookAndFeel(clInfo.getClassName());
-				break;
+		// FlatLaf Modern Light Theme (IntelliJ)
+		try {
+			FlatIntelliJLaf.setup();
+		} catch (Exception e) {
+			// Fallback to Nimbus if FlatLaf fails
+			for (LookAndFeelInfo clInfo : UIManager.getInstalledLookAndFeels()) {
+				if ("Nimbus".equals(clInfo.getName())) {
+					UIManager.setLookAndFeel(clInfo.getClassName());
+					break;
+				}
 			}
 		}
 
@@ -178,6 +192,9 @@ private void setLookandFeel() throws Exception {
 		// OptionPaneのロケール
 		JOptionPane.setDefaultLocale(I18nString.getLocale());
 
+		// スクロールバーの幅を太くする
+		UIManager.put("ScrollBar.width", 15);
+
 		setIconForWindows();
 		addShortcutForWindows();
 		addShortcutForMac();
@@ -290,15 +307,16 @@ private void enableFullScreenForMac(Window window) throws Exception {
 	// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6939001
 	private void setInterceptHighLight() {
 		JLabel label = new JLabel(tabbedpane.getTitleAt(1));
-		label.setForeground(Color.ORANGE);
+		label.setForeground(new Color(255, 180, 0)); // Bright orange for dark theme
 		tabbedpane.setTabComponentAt(1, label);
 		tabbedpane.revalidate();
 		tabbedpane.repaint();
 	}
 
 	private void setInterceptDownLight() {
 		JLabel label = new JLabel(tabbedpane.getTitleAt(1));
-		label.setForeground(Color.BLACK);
+		// Use default foreground color from Look and Feel
+		label.setForeground(UIManager.getColor("TabbedPane.foreground"));
 		tabbedpane.setTabComponentAt(1, label);
 		tabbedpane.revalidate();
 		tabbedpane.repaint();

src/main/java/core/packetproxy/gui/GUIMenu.java

@@ -21,14 +21,11 @@
 import java.awt.event.ActionListener;
 import java.awt.event.KeyEvent;
 import java.io.File;
-import javax.swing.JFileChooser;
 import javax.swing.JFrame;
 import javax.swing.JMenu;
 import javax.swing.JMenuBar;
 import javax.swing.JMenuItem;
 import javax.swing.JOptionPane;
-import javax.swing.SwingUtilities;
-import javax.swing.filechooser.FileNameExtensionFilter;
 import packetproxy.common.ConfigIO;
 import packetproxy.common.I18nString;
 import packetproxy.common.RecentProjectsStore;
@@ -131,12 +128,12 @@ public void onError() {
 			public void actionPerformed(ActionEvent e) {
 				try {
 
-					JFileChooser filechooser = new JFileChooser();
+					NativeFileChooser filechooser = new NativeFileChooser();
 					filechooser.setCurrentDirectory(new File(defaultDir));
-					filechooser.setFileFilter(new FileNameExtensionFilter("*.sqlite3", "sqlite3"));
-					filechooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
-					int selected = filechooser.showOpenDialog(SwingUtilities.getRoot(self));
-					if (selected == JFileChooser.APPROVE_OPTION) {
+					filechooser.addChoosableFileFilter("*.sqlite3", "sqlite3");
+					filechooser.setAcceptAllFileFilterUsed(false);
+					int selected = filechooser.showOpenDialog(owner);
+					if (selected == NativeFileChooser.APPROVE_OPTION) {
 
 						File file = filechooser.getSelectedFile();
 						Database.getInstance().Load(file.getAbsolutePath());
@@ -261,12 +258,12 @@ public void actionPerformed(ActionEvent e) {
 			public void actionPerformed(ActionEvent e) {
 				try {
 
-					JFileChooser filechooser = new JFileChooser();
+					NativeFileChooser filechooser = new NativeFileChooser();
 					filechooser.setCurrentDirectory(new File(defaultDir));
-					filechooser.setFileFilter(new FileNameExtensionFilter("*.json", "json"));
-					filechooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
-					int selected = filechooser.showOpenDialog(SwingUtilities.getRoot(self));
-					if (selected == JFileChooser.APPROVE_OPTION) {
+					filechooser.addChoosableFileFilter("*.json", "json");
+					filechooser.setAcceptAllFileFilterUsed(false);
+					int selected = filechooser.showOpenDialog(owner);
+					if (selected == NativeFileChooser.APPROVE_OPTION) {
 
 						File file = filechooser.getSelectedFile();
 						byte[] jbytes = Utils.readfile(file.getAbsolutePath());

src/main/java/core/packetproxy/gui/GUIOption.java

@@ -79,7 +79,11 @@ private JComponent createElement(String title, String description) throws Except
 
 	private JComponent createSeparator() {
 		JSeparator line = new JSeparator();
-		line.setMaximumSize(new Dimension(Short.MAX_VALUE, line.getMinimumSize().height));
+		line.setForeground(Color.LIGHT_GRAY);
+		line.setBackground(Color.LIGHT_GRAY);
+		line.setOpaque(true);
+		line.setPreferredSize(new Dimension(0, 1));
+		line.setMaximumSize(new Dimension(Integer.MAX_VALUE, 1));
 		return line;
 	}