From 65ea6c17a0c1348aa9ef4e158102ddf173936882 Mon Sep 17 00:00:00 2001
From: Yuuta Liang <yuutaw@student.cs.ubc.ca>
Date: Thu, 23 Nov 2023 08:09:01 +0800
Subject: Add GUI

Signed-off-by: Yuuta Liang <yuutaw@student.cs.ubc.ca>
---
 src/main/ui/IssueDialog.java                | 110 +++++
 src/main/ui/Main.java                       |   4 +-
 src/main/ui/MainUI.form                     | 111 -----
 src/main/ui/MainUI.java                     | 690 +++++++++++++++++++++++++++-
 src/main/ui/RevokeDialog.java               | 186 ++++++++
 src/main/ui/TemplateEditDialog.java         |  82 ++++
 src/main/ui/widgets/CertEditDialog.java     | 108 +++++
 src/main/ui/widgets/CertTableModel.java     | 129 ++++++
 src/main/ui/widgets/GCBuilder.java          | 213 +++++++++
 src/main/ui/widgets/LogTableModel.java      |  79 ++++
 src/main/ui/widgets/TemplateTableModel.java | 105 +++++
 src/main/ui/widgets/UIUtils.java            | 168 +++++++
 12 files changed, 1857 insertions(+), 128 deletions(-)
 create mode 100644 src/main/ui/IssueDialog.java
 delete mode 100644 src/main/ui/MainUI.form
 create mode 100644 src/main/ui/RevokeDialog.java
 create mode 100644 src/main/ui/TemplateEditDialog.java
 create mode 100644 src/main/ui/widgets/CertEditDialog.java
 create mode 100644 src/main/ui/widgets/CertTableModel.java
 create mode 100644 src/main/ui/widgets/GCBuilder.java
 create mode 100644 src/main/ui/widgets/LogTableModel.java
 create mode 100644 src/main/ui/widgets/TemplateTableModel.java
 create mode 100644 src/main/ui/widgets/UIUtils.java

(limited to 'src/main/ui')

diff --git a/src/main/ui/IssueDialog.java b/src/main/ui/IssueDialog.java
new file mode 100644
index 0000000..905b8df
--- /dev/null
+++ b/src/main/ui/IssueDialog.java
@@ -0,0 +1,110 @@
+package ui;
+
+import model.asn1.exceptions.ParseException;
+import model.ca.Template;
+import model.csr.CertificationRequest;
+import model.x501.Name;
+import ui.widgets.CertEditDialog;
+
+import javax.swing.*;
+import java.awt.event.ActionEvent;
+import java.util.List;
+
+import static ui.widgets.UIUtils.alert;
+
+/**
+ * Dialog that allows user to choose a template and edit the incoming CSR properties to get it signed.
+ *        ┌───────────────────────────┐
+ *        │  Issue new certificate  X │
+ *        │                           │
+ *        │Template:       (Drop down)│
+ *        │Subject:         _________ │
+ *        │Validity (Days):  (Spinner)│
+ *        │                           │
+ *        │               Issue Cancel│
+ *        └───────────────────────────┘
+ */
+public class IssueDialog extends CertEditDialog<Template> {
+    /**
+     * The list of templates.
+     */
+    private final List<Template> templates;
+
+    /**
+     * The incoming CSR.
+     */
+    private final CertificationRequest csr;
+
+    /**
+     * Combo box to choose template.
+     */
+    private JComboBox<String> componentTemp;
+
+    /**
+     * The selected template, immutable.
+     */
+    private Template selectedTemplate;
+
+    /**
+     * EFFECTS: Init the dialog with CSR and templates.
+     * REQUIRES: csr must have a subject; templates must have at least one enabled.
+     */
+    public IssueDialog(CertificationRequest csr, List<Template> templates) {
+        super();
+        this.csr = csr;
+        this.templates = templates;
+
+        setTitle("Issue new certificate");
+        buttonOK.setText("Issue");
+        componentTemp.setModel(new DefaultComboBoxModel<>(templates.stream()
+                .filter(Template::isEnabled).map(Template::getName).toArray(String[]::new)));
+        componentTemp.addActionListener(this::onTemplateChange);
+
+        onTemplateChange(null);
+        pack();
+    }
+
+    /**
+     * EFFECTS: Create the templates combo box.
+     * MODIFIES: this
+     */
+    @Override
+    protected JComponent createTemplateComponent() {
+        return componentTemp = new JComboBox<>();
+    }
+
+    /**
+     * EFFECTS: Validate the form, compose a resulting template, close the dialog.
+     * MODIFIES: this
+     */
+    @Override
+    protected void onOK(ActionEvent ev) {
+        if (textFieldSubject.getText().isEmpty()) {
+            alert(this, getTitle(), "Subject must not be empty.");
+            return;
+        }
+        try {
+            res = new Template(selectedTemplate.getName(),
+                    true,
+                    Name.parseString(textFieldSubject.getText()),
+                    ((SpinnerNumberModel) spinnerValidity.getModel()).getNumber().longValue());
+            dispose();
+        } catch (ParseException e) {
+            alert(this, getTitle(), e);
+        }
+    }
+
+    /**
+     * EFFECTS: Handle template change, rewrite the form with the new template.
+     * MODIFIES: this
+     */
+    private void onTemplateChange(ActionEvent ae) {
+        selectedTemplate = templates.stream()
+                .filter(temp -> temp.getName().equals(componentTemp.getSelectedItem()))
+                .findFirst()
+                .get();
+        textFieldSubject.setText(selectedTemplate.getSubject() != null ? selectedTemplate.getSubject().toString() :
+                csr.getCertificationRequestInfo().getSubject().toString());
+        spinnerValidity.setValue(selectedTemplate.getValidity());
+    }
+}
diff --git a/src/main/ui/Main.java b/src/main/ui/Main.java
index 89a0fe3..e3d8d7d 100644
--- a/src/main/ui/Main.java
+++ b/src/main/ui/Main.java
@@ -7,6 +7,8 @@ import javax.swing.*;
 public class Main {
     public static void main(String[] args) throws Throwable {
         FlatIntelliJLaf.setup();
-        new MainUI().createWindow();
+        final JFrame frame = new MainUI();
+        frame.pack();
+        frame.setVisible(true);
     }
 }
diff --git a/src/main/ui/MainUI.form b/src/main/ui/MainUI.form
deleted file mode 100644
index 9ab1492..0000000
--- a/src/main/ui/MainUI.form
+++ /dev/null
@@ -1,111 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<form xmlns="http://www.intellij.com/uidesigner/form/" version="1" bind-to-class="ui.MainUI">
-  <grid id="27dc6" binding="rootPanel" layout-manager="GridLayoutManager" row-count="3" column-count="1" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
-    <margin top="0" left="0" bottom="0" right="0"/>
-    <constraints>
-      <xy x="20" y="20" width="500" height="400"/>
-    </constraints>
-    <properties/>
-    <border type="none"/>
-    <children>
-      <splitpane id="efbf3">
-        <constraints>
-          <grid row="1" column="0" row-span="1" col-span="1" vsize-policy="3" hsize-policy="3" anchor="0" fill="3" indent="0" use-parent-layout="false">
-            <preferred-size width="200" height="200"/>
-          </grid>
-        </constraints>
-        <properties>
-          <orientation value="0"/>
-        </properties>
-        <border type="none"/>
-        <children>
-          <tabbedpane id="4cbb0" binding="tabbedPane">
-            <constraints>
-              <splitpane position="left"/>
-            </constraints>
-            <properties/>
-            <border type="none"/>
-            <children>
-              <grid id="e83bf" layout-manager="GridLayoutManager" row-count="1" column-count="1" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
-                <margin top="0" left="0" bottom="0" right="0"/>
-                <constraints>
-                  <tabbedpane title="CA"/>
-                </constraints>
-                <properties/>
-                <border type="none"/>
-                <children/>
-              </grid>
-              <grid id="7d4f3" layout-manager="GridLayoutManager" row-count="1" column-count="1" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
-                <margin top="0" left="0" bottom="0" right="0"/>
-                <constraints>
-                  <tabbedpane title="Certificates"/>
-                </constraints>
-                <properties/>
-                <border type="none"/>
-                <children>
-                  <component id="d436b" class="javax.swing.JList" binding="listCertificates">
-                    <constraints>
-                      <grid row="0" column="0" row-span="1" col-span="1" vsize-policy="6" hsize-policy="2" anchor="0" fill="3" indent="0" use-parent-layout="false">
-                        <preferred-size width="150" height="50"/>
-                      </grid>
-                    </constraints>
-                    <properties/>
-                  </component>
-                </children>
-              </grid>
-              <grid id="5a23a" layout-manager="GridLayoutManager" row-count="1" column-count="1" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
-                <margin top="0" left="0" bottom="0" right="0"/>
-                <constraints>
-                  <tabbedpane title="Templates"/>
-                </constraints>
-                <properties/>
-                <border type="none"/>
-                <children>
-                  <component id="1f307" class="javax.swing.JList" binding="listTemplates">
-                    <constraints>
-                      <grid row="0" column="0" row-span="1" col-span="1" vsize-policy="6" hsize-policy="2" anchor="0" fill="3" indent="0" use-parent-layout="false">
-                        <preferred-size width="150" height="50"/>
-                      </grid>
-                    </constraints>
-                    <properties/>
-                  </component>
-                </children>
-              </grid>
-            </children>
-          </tabbedpane>
-          <component id="e63cf" class="javax.swing.JList" binding="listLogs">
-            <constraints>
-              <splitpane position="right"/>
-            </constraints>
-            <properties/>
-          </component>
-        </children>
-      </splitpane>
-      <toolbar id="a2d1e">
-        <constraints>
-          <grid row="0" column="0" row-span="1" col-span="1" vsize-policy="0" hsize-policy="6" anchor="0" fill="1" indent="0" use-parent-layout="false">
-            <preferred-size width="-1" height="20"/>
-          </grid>
-        </constraints>
-        <properties/>
-        <border type="none"/>
-        <children>
-          <component id="5ae86" class="javax.swing.JButton" binding="buttonSave">
-            <constraints/>
-            <properties>
-              <text value="Save"/>
-            </properties>
-          </component>
-        </children>
-      </toolbar>
-      <component id="54c37" class="javax.swing.JLabel" binding="labelStatus">
-        <constraints>
-          <grid row="2" column="0" row-span="1" col-span="1" vsize-policy="0" hsize-policy="0" anchor="0" fill="1" indent="0" use-parent-layout="false"/>
-        </constraints>
-        <properties>
-          <text value="Ready"/>
-        </properties>
-      </component>
-    </children>
-  </grid>
-</form>
diff --git a/src/main/ui/MainUI.java b/src/main/ui/MainUI.java
index ee35a53..4735c55 100644
--- a/src/main/ui/MainUI.java
+++ b/src/main/ui/MainUI.java
@@ -1,22 +1,680 @@
 package ui;
 
+import model.GroupObserver;
+import model.ObservedData;
+import model.Observer;
+import model.asn1.exceptions.InvalidCAException;
+import model.asn1.exceptions.InvalidDBException;
+import model.asn1.exceptions.ParseException;
+import model.asn1.parsing.BytesReader;
+import model.ca.AuditLogEntry;
+import model.ca.CertificationAuthority;
+import model.ca.Template;
+import model.csr.CertificationRequest;
+import model.pki.cert.Certificate;
+import model.pki.crl.CertificateList;
+import model.pki.crl.RevokedCertificate;
+import persistence.Decoder;
+import persistence.FS;
+import ui.widgets.*;
+
 import javax.swing.*;
+import javax.swing.event.ChangeEvent;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.security.SignatureException;
+import java.security.interfaces.RSAPublicKey;
+
+import static java.awt.GridBagConstraints.*;
+import static ui.widgets.UIUtils.*;
+
+/**
+ * The main GUI.
+ * ┌──────────────────────────────┐┌──────────────────────────────┐┌──────────────────────────────┐
+ * │  JCA                       X ││  JCA                       X ││  JCA                       X │
+ * ├──────────────────────────────┤├──────────────────────────────┤├──────────────────────────────┤
+ * │Load Save                  CSR││Load Save   Sign Revoke Export││Load Save      New Ena Dis Del│
+ * ├────┬───────┬───────────┬─────┤├────┬───────┬──────────┬──────┤├────┬───────┬─────────────────┤
+ * │ CA │ Certs │ Templates │     ││ CA │ Certs │ Templates│      ││ CA │ Certs │ Templates       │
+ * ├────┴───────┴───────────┴─────┤├─┬──┴─────┬─┴────┬─────┼──────┤├─┬──┴───┬───┴─────┬───────────┤
+ * │ Welcome to JCA               ││ │ Serial │ Subj │ Bef │ To   ││ │ Name │ Subj    │  Validity │
+ * │                              │├─┴────────┴──────┴─────┴──────┤├─┴──────┴─────────┴───────────┤
+ * │ CA certificate: Install CSR  ││      (Issued Certs)          ││      (All Templates)         │
+ * ├──────────────────────────────┤├──────────────────────────────┤├──────────────────────────────┤
+ * ├─────┼──────────┼─────────────┤├─────┼──────────┼─────────────┤├─────┼──────────┼─────────────┤
+ * │Time │ Operator │ Action      ││Time │ Operator │ Action      ││Time │ Operator │ Action      │
+ * ├─────┴──────────┴─────────────┤├─────┴──────────┴─────────────┤├─────┴──────────┴─────────────┤
+ * │  (Audit Logs)                ││  (Audit Logs)                ││  (Audit Logs)                │
+ * ├──────────────────────────────┤├──────────────────────────────┤├──────────────────────────────┤
+ * │ Ready: (Last operation)      ││ Unsaved: (Last operation)    ││ Ready: (Last Operation)      │
+ * └──────────────────────────────┘└──────────────────────────────┘└──────────────────────────────┘
+ */
+public class MainUI extends JFrame {
+    /**
+     * Default db file (./data/ca.json)
+     */
+    private static final Path PATH_DEFAULT = Path.of("data", "ca.json");
+
+    /**
+     * The root panel (Box layout).
+     */
+    private final JPanel rootPanel = new JPanel(new BoxLayout(rootPane, BoxLayout.PAGE_AXIS));
+
+    /**
+     * Common toolbar buttons
+     */
+    private final JButton buttonToolbarLoad = btn("Load", "open.png", this::onLoad);
+    private final JButton buttonToolbarSave = btn("Save", "saveall.png", this::onSave);
+
+    /**
+     * Toolbar that switches with the tab.
+     */
+    private final JPanel panelContextAwareToolbar = new JPanel(new CardLayout(0, 0));
+
+    /**
+     * Tab root.
+     */
+    private final JTabbedPane tabbedPane = new JTabbedPane();
+
+    /**
+     * CA tab
+     */
+    private final JLabel labelCACertificate = new JLabel();
+    private final JLabel labelPrivateKey = new JLabel();
+    private final JButton buttonGenPrivKey = btn("Generate", 'G', this::onGeneratePrivateKey);
+    private final JButton buttonInstallCA = btn("Install", 'I', this::onInstallCA);
+    private final JButton buttonGenCSR = btn("CSR", this::onSignCSR);
+    private final JToolBar toolbarCA = new JToolBar();
+    private final JButton buttonCAToolbarCRL = btn("CRL", "publisher.png", this::onCRL);
+
+    /**
+     * Certs tab
+     */
+    private JPanel panelCertsTab;
+    private final JTable tableCerts = new JTable();
+    private final CertTableModel modelCerts = new CertTableModel();
+    private final JToolBar toolbarCerts = new JToolBar();
+    private final JButton buttonCertsToolbarNew = btn("Sign", "new.png", this::onIssue);
+    private final JButton buttonCertsToolbarRevoke = btn("Revoke", "deletetest.png", this::onRevokeCert);
+    private final JButton buttonCertsToolbarExport = btn("Export", "export.png", this::onExportCert);
+
+    /**
+     * Templates tab
+     */
+    private JPanel panelTmpTab;
+    private final JTable tableTemplates = new JTable();
+    private final TemplateTableModel modelTemplates = new TemplateTableModel();
+    private final JToolBar toolbarTemplates = new JToolBar();
+    private final JButton buttonTemplatesToolbarNew = btn("New", "new.png", this::onNewTemplate);
+    private final JButton buttonTemplatesToolbarEnable = btn("Enable", "enable.png", this::onEnableTemplate);
+    private final JButton buttonTemplatesToolbarDisable = btn("Disable", "disable.png", this::onDisableTemplate);
+    private final JButton buttonTemplatesToolbarDelete = btn("Delete", "deletetest.png", this::onDeleteTemplate);
+
+    /**
+     * Logs region
+     */
+    private final JPanel panelLogs;
+    private final JTable tableAuditLogs = new JTable();
+    private final LogTableModel modelAuditLogs = new LogTableModel();
+
+    /**
+     * Status region
+     */
+    private final JLabel labelStatus = new JLabel();
+    private ObservedData<Boolean> unsaved = new ObservedData<>(false, this::acceptUnsaved);
+
+    /**
+     * CA and observers
+     */
+    private CertificationAuthority ca;
+
+    private final GroupObserver obs = new GroupObserver();
+
+    /**
+     * EFFECTS: Setup the CA and GUI.
+     */
+    public MainUI() {
+        setTitle("JCA");
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+        setContentPane(rootPanel);
+        rootPanel.setLayout(new BoxLayout(rootPanel, BoxLayout.PAGE_AXIS));
+
+        rootPanel.add(setupToolbar());
+        final JSplitPane splitPane = new JSplitPane(0);
+        rootPanel.add(splitPane);
+        splitPane.setLeftComponent(setupTabs());
+        rootPanel.getRootPane().setDefaultButton(buttonGenPrivKey);
+
+        splitPane.setRightComponent(panelLogs = defView(scrTbl(tableAuditLogs), "No audit logs"));
+        panelLogs.setPreferredSize(new Dimension(panelLogs.getPreferredSize().width,
+                panelLogs.getPreferredSize().height / 2));
+        panelLogs.setBackground(new Color(-1));
+
+        rootPanel.add(labelStatus);
+        labelStatus.setBorder(BorderFactory.createEmptyBorder(4, 8, 8, 8));
+
+        ca = new CertificationAuthority();
+
+        tableAuditLogs.setModel(modelAuditLogs);
+        tableCerts.setModel(modelCerts);
+        tableTemplates.setModel(modelTemplates);
+
+        tabbedPane.addChangeListener(this::onChangeTab);
+        setupObservers();
+
+        setCA(ca);
+    }
+
+    // -----BEGIN HELPER METHODS-----
+
+    /**
+     * EFFECTS: Rewind the CA and refresh all pages.
+     * MODIFIES: ca (observer), this
+     */
+    private void setCA(CertificationAuthority ca) {
+        this.ca = ca;
+        ca.registerObserver(obs);
+
+        modelAuditLogs.setPtrData(ca.getLogs());
+        modelCerts.setPtrData(ca.getSigned());
+        modelCerts.setPtrRevokedData(ca.getRevoked());
+        modelTemplates.setPtrData(ca.getTemplates());
+
+        renderRefresh();
+    }
+
+    // -----END HELPER METHODS-----
+
+    // -----BEGIN DATA OBSERVERS-----
+
+    /**
+     * EFFECTS: Setup observers
+     * MODIFIES: this
+     */
+    private void setupObservers() {
+        obs.register(AuditLogEntry.class, this::acceptAuditLog);
+        obs.register(Certificate.class, this::acceptCertificate);
+        obs.register(RSAPublicKey.class, this::acceptPrivateKey);
+        obs.register(Template.class, this::acceptTemplate);
+    }
+
+    /**
+     * EFFECTS: Handle new audit log, hide default text, notify the model
+     * MODIFIES: this
+     * REQUIRES: direction == ADD, i >= 0
+     */
+    private void acceptAuditLog(AuditLogEntry auditLogEntry, int direction, int i) {
+        setContentVisible(panelLogs, true);
+        modelAuditLogs.fireTableRowsInserted(ca.getLogs().size() - 1, ca.getLogs().size() - 1);
+        acceptUnsaved(unsaved.get(), Observer.DIRECTION_CHANGE, Observer.INDEX_NOT_IN_LIST);
+    }
+
+    /**
+     * EFFECTS: Handle CA cert or new issued cert, notify CA page or model accordingly, hide certs default text
+     * MODIFIES: this
+     * REQUIRES: direction == CHANGE or ADD, i >= 0 or -1
+     */
+    private void acceptCertificate(Certificate cert, int direction, int i) {
+        if (i == Observer.INDEX_NOT_IN_LIST) {
+            renderCAPage();
+        } else {
+            setContentVisible(panelCertsTab, true);
+            modelCerts.fireTableRowsInserted(i, i);
+        }
+    }
+
+    /**
+     * EFFECTS: Handle added, changed, or deleted template; notify model, show / hide default text.
+     * MODIFIES: this
+     * REQUIRES: i >= 0.
+     */
+    private void acceptTemplate(Template template, int direction, int i) {
+        setContentVisible(panelTmpTab, !ca.getTemplates().isEmpty());
+        switch (direction) {
+            case Observer.DIRECTION_ADD:
+                modelTemplates.fireTableRowsInserted(i, i);
+                break;
+            case Observer.DIRECTION_CHANGE:
+                modelTemplates.fireTableRowsUpdated(i, i);
+                break;
+            case Observer.DIRECTION_REMOVE:
+                modelTemplates.fireTableRowsDeleted(i, i);
+                break;
+        }
+    }
+
+    /**
+     * EFFECTS: Handle added private key. Change buttons / labels accordingly.
+     * MODIFIES: this
+     */
+    private void acceptPrivateKey(RSAPublicKey pubKey, int direction, int i) {
+        renderCAPage();
+    }
+
+    /**
+     * EFFECTS: Handle status label change, set status to unsaved / saved + latest action.
+     * MODIFIES: this
+     */
+    private void acceptUnsaved(Boolean unsaved, int direction, int i) {
+        labelStatus.setText(unsaved ? "Unsaved" : "Ready");
+        if (!ca.getLogs().isEmpty()) {
+            labelStatus.setText(labelStatus.getText() + ": " + ca.getLogs().get(ca.getLogs().size() - 1).getAction());
+        }
+    }
+
+    // -----END DATA OBSERVERS----
+
+    // -----BEGIN RENDERERS-----
+
+    /**
+     * EFFECTS: Setup the toolbar.
+     * MODIFIES: this
+     */
+    private JToolBar setupToolbar() {
+        final JToolBar toolBar = new JToolBar();
+        toolBar.setAlignmentX(Component.LEFT_ALIGNMENT);
+        toolBar.setBorder(BorderFactory.createEmptyBorder(4, 8, 4, 8));
+
+        toolBar.add(buttonToolbarLoad);
+        toolBar.add(buttonToolbarSave);
+
+        toolBar.add(panelContextAwareToolbar);
+
+        panelContextAwareToolbar.add(toolbarTemplates, "CardToolbarTemplates");
+
+        toolbarTemplates.add(Box.createHorizontalGlue());
+        toolbarTemplates.add(buttonTemplatesToolbarNew);
+        toolbarTemplates.add(buttonTemplatesToolbarEnable);
+        toolbarTemplates.add(buttonTemplatesToolbarDisable);
+        toolbarTemplates.add(buttonTemplatesToolbarDelete);
+
+        panelContextAwareToolbar.add(toolbarCerts, "CardToolbarCerts");
+        toolbarCerts.add(Box.createHorizontalGlue());
+        toolbarCerts.add(buttonCertsToolbarNew);
+        toolbarCerts.add(buttonCertsToolbarRevoke);
+        toolbarCerts.add(buttonCertsToolbarExport);
+
+        panelContextAwareToolbar.add(toolbarCA, "CardToolbarCA");
+        toolbarCA.add(Box.createHorizontalGlue());
+        toolbarCA.add(buttonCAToolbarCRL);
+        return toolBar;
+    }
+
+    /**
+     * EFFECTS: Setup the tabs
+     * MODIFIES: this
+     */
+    private JTabbedPane setupTabs() {
+        tabbedPane.setAlignmentX(Component.LEFT_ALIGNMENT);
+        tabbedPane.setBorder(BorderFactory.createEmptyBorder(8, 8, 4, 8));
+
+        final JPanel panelTabCA = new JPanel();
+        panelTabCA.setLayout(new GridBagLayout());
+        tabbedPane.addTab("CA", panelTabCA);
+
+        panelTabCA.add(new JLabel("Welcome to JCA"), new GCBuilder().anchor(WEST).insectTop(8).build());
+        panelTabCA.add(labelPrivateKey, new GCBuilder().gridY(1).anchor(WEST).build());
+        panelTabCA.add(labelCACertificate, new GCBuilder().gridY(2).anchor(WEST).build());
+        panelTabCA.add(buttonGenPrivKey, new GCBuilder().gridXY(1, 1).fill(HORIZONTAL).build());
+        panelTabCA.add(buttonInstallCA, new GCBuilder().gridXY(1, 2).fill(HORIZONTAL).build());
+        panelTabCA.add(buttonGenCSR, new GCBuilder().gridXY(2, 2).fill(HORIZONTAL).build());
+        panelTabCA.add(new JPanel(), new GCBuilder().gridXY(3, 3).expandXY().fill(BOTH).build());
+        tabbedPane.addTab("Certs", panelCertsTab = defView(scrTbl(tableCerts), "No issued certs"));
+        tabbedPane.addTab("Templates", panelTmpTab = defView(scrTbl(tableTemplates), "No templates"));
+
+        return tabbedPane;
+    }
+
+    /**
+     * EFFECTS: Render public key and CA to the CA page and toolbar
+     * MODIFIES: this
+     */
+    private void renderCAPage() {
+        if (ca.getPublicKey() == null) {
+            labelPrivateKey.setText("Private key not installed");
+        } else {
+            labelPrivateKey.setText(String.format("%s key: %s ...",
+                    ca.getPublicKey().getAlgorithm(),
+                    ca.getPublicKey().getModulus().toString(16).substring(0, 16)));
+        }
+        if (ca.getCertificate() == null) {
+            labelCACertificate.setText("CA certificate not installed");
+        } else {
+            labelCACertificate.setText(String.format("<html>CA: %s<br>Issued by: %s</html>",
+                    ca.getCertificate().getCertificate().getSubject().toString(),
+                    ca.getCertificate().getCertificate().getIssuer().toString()));
+        }
+        buttonGenPrivKey.setEnabled(ca.getPublicKey() == null);
+        buttonInstallCA.setEnabled(ca.getPublicKey() != null && ca.getCertificate() == null);
+        buttonGenCSR.setEnabled(ca.getPublicKey() != null && ca.getCertificate() == null);
+        buttonCertsToolbarNew.setEnabled(ca.getPublicKey() != null && ca.getCertificate() != null);
+        buttonCAToolbarCRL.setEnabled(ca.getPublicKey() != null && ca.getCertificate() != null);
+    }
+
+    /**
+     * EFFECTS: Reset all GUI to initial state and render the CA again.
+     * MODIFIES: this
+     */
+    private void renderRefresh() {
+        acceptUnsaved(false, Observer.DIRECTION_CHANGE, Observer.INDEX_NOT_IN_LIST);
+        onChangeTab(null);
+        renderCAPage();
+
+        modelAuditLogs.fireTableDataChanged();
+        setContentVisible(panelLogs, !ca.getLogs().isEmpty());
+
+        modelCerts.fireTableDataChanged();
+        setContentVisible(panelCertsTab, !ca.getSigned().isEmpty());
+
+        modelTemplates.fireTableDataChanged();
+        setContentVisible(panelTmpTab, !ca.getTemplates().isEmpty());
+    }
+
+    // -----END RENDERERS-----
+
+    // -----BEGIN ACTION LISTENERS-----
+
+    /**
+     * EFFECTS: Switch toolbar according to tab change.
+     * MODIFIES: this
+     */
+    private void onChangeTab(ChangeEvent ev) {
+        final CardLayout toolbarCardLayout = (CardLayout) panelContextAwareToolbar.getLayout();
+        switch (tabbedPane.getSelectedIndex()) {
+            case 0: {
+                toolbarCerts.setEnabled(false);
+                toolbarTemplates.setEnabled(false);
+                toolbarCardLayout.show(panelContextAwareToolbar, "CardToolbarCA");
+                break;
+            }
+            case 1: {
+                toolbarCerts.setEnabled(true);
+                toolbarTemplates.setEnabled(false);
+                toolbarCardLayout.show(panelContextAwareToolbar, "CardToolbarCerts");
+                break;
+            }
+            case 2: {
+                toolbarCerts.setEnabled(false);
+                toolbarTemplates.setEnabled(true);
+                toolbarCardLayout.show(panelContextAwareToolbar, "CardToolbarTemplates");
+                break;
+            }
+        }
+    }
+
+    /**
+     * EFFECTS: Generate private key.
+     * MODIFIES: this
+     * REQUIRES: No private key / CA is installed.
+     */
+    private void onGeneratePrivateKey(ActionEvent ev) {
+        try {
+            ca.generateKey();
+            unsaved.set(true);
+        } catch (NoSuchAlgorithmException e) {
+            alert(rootPanel, "Generate private key", e);
+        } finally {
+            renderCAPage();
+        }
+    }
+
+    /**
+     * EFFECTS: Sign a CSR and save to disk (in binary form).
+     * MODIFIES: this
+     * REQUIRES: Proper private key installed, no CA.
+     */
+    private void onSignCSR(ActionEvent ev) {
+        final Path p = chooseFile(rootPanel, "DER binary (*.csr)", "csr");
+        if (p == null) {
+            return;
+        }
+
+        try {
+            final OutputStream fd = Files.newOutputStream(p,
+                    StandardOpenOption.WRITE,
+                    StandardOpenOption.TRUNCATE_EXISTING,
+                    StandardOpenOption.CREATE);
+            final CertificationRequest csr = ca.signCSR();
+            fd.write(Utils.byteToByte(csr.encodeDER()));
+            fd.close();
+            unsaved.set(true);
+        } catch (IOException | ParseException | NoSuchAlgorithmException | SignatureException | InvalidKeyException e) {
+            alert(rootPanel, "Sign certification request", e);
+        }
+    }
+
+    /**
+     * EFFECTS: Pick a certificate and install.
+     * MODIFIES: this
+     * REQUIRES: Proper private key is installed, no CA.
+     */
+    private void onInstallCA(ActionEvent ev) {
+        final Path p = chooseFile(rootPanel, "DER X.509 certificate (*.crt, *.pem)", "crt", "pem");
+        if (p == null) {
+            return;
+        }
+
+        try {
+            final Certificate crt = new Certificate(new BytesReader(UIUtils.openDERorPEM(p, "CERTIFICATE")),
+                    false);
+            ca.installCertificate(crt);
+            unsaved.set(true);
+        } catch (IOException | ParseException | InvalidCAException e) {
+            alert(rootPanel, "Install CA", e);
+        } finally {
+            renderCAPage();
+        }
+    }
+
+    /**
+     * EFFECTS: Load the database and refresh.
+     * MODIFIES: this
+     */
+    private void onLoad(ActionEvent ev) {
+        if (unsaved.get()) {
+            alert(rootPanel, "Load database from filesystem",
+                    "Unable to load: current modifications are not saved.");
+            return;
+        }
+
+        try {
+            setCA(Decoder.decodeCA(FS.read(PATH_DEFAULT)));
+        } catch (NoSuchAlgorithmException | InvalidDBException e) {
+            alert(rootPanel, "Load database from filesystem", e);
+        }
+    }
+
+    /**
+     * EFFECTS: Save database.
+     * MODIFIES: this
+     */
+    private void onSave(ActionEvent ev) {
+        try {
+            FS.write(PATH_DEFAULT, Decoder.encodeCA(this.ca));
+            unsaved.set(false);
+        } catch (IOException e) {
+            alert(rootPanel, "Save database to filesystem", e);
+        }
+    }
+
+    /**
+     * EFFECTS: Enable a template.
+     * MODIFIES: this
+     */
+    private void onEnableTemplate(ActionEvent ev) {
+        if (tableTemplates.getSelectedRow() == -1) {
+            return;
+        }
+
+        final Template t = ca.getTemplates().get(tableTemplates.getSelectedRow());
+        if (t.isEnabled()) {
+            return;
+        }
+        ca.setTemplateEnable(t, true);
+        unsaved.set(true);
+    }
+
+    /**
+     * EFFECTS: Disable a template.
+     * MODIFIES: this
+     */
+    private void onDisableTemplate(ActionEvent ev) {
+        if (tableTemplates.getSelectedRow() == -1) {
+            return;
+        }
+
+        final Template t = ca.getTemplates().get(tableTemplates.getSelectedRow());
+        if (!t.isEnabled()) {
+            return;
+        }
+        ca.setTemplateEnable(t, false);
+        unsaved.set(true);
+    }
+
+    /**
+     * EFFECTS: Delete a template.
+     * MODIFIES: this
+     */
+    private void onDeleteTemplate(ActionEvent ev) {
+        if (tableTemplates.getSelectedRow() == -1) {
+            return;
+        }
+
+        final Template t = ca.getTemplates().get(tableTemplates.getSelectedRow());
+        ca.removeTemplate(t);
+        unsaved.set(true);
+    }
+
+    /**
+     * EFFECTS: Save the selected cert as a DER binary.
+     * MODIFIES: this
+     */
+    private void onExportCert(ActionEvent ev) {
+        if (tableCerts.getSelectedRow() == -1) {
+            return;
+        }
+
+        final Certificate c = ca.getSigned().get(tableCerts.getSelectedRow());
+        final Path p = chooseFile(rootPanel, "DER binary (*.crt)", "crt");
+        if (p == null) {
+            return;
+        }
+        try {
+            final OutputStream fd = Files.newOutputStream(p,
+                    StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.CREATE);
+            fd.write(Utils.byteToByte(c.encodeDER()));
+            fd.close();
+        } catch (IOException e) {
+            alert(rootPanel, "Export certificate", e);
+        }
+    }
+
+    /**
+     * EFFECTS: Show revocation dialog for the selected cert. Save enforced.
+     * MODIFIES: this
+     */
+    private void onRevokeCert(ActionEvent ev) {
+        if (tableCerts.getSelectedRow() == -1) {
+            return;
+        }
+
+        final Certificate c = ca.getSigned().get(tableCerts.getSelectedRow());
+        if (ca.getRevoked().stream().anyMatch(r ->
+                r.getSerialNumber().getLong() == c.getCertificate().getSerialNumber().getLong())) {
+            return;
+        }
+        final RevokeDialog diag = new RevokeDialog(c);
+        diag.pack();
+        diag.setLocationRelativeTo(this);
+        diag.setVisible(true);
+
+        final RevokedCertificate res = diag.getRes();
+        if (res == null) {
+            return;
+        }
+
+        ca.revoke(res);
+        onSave(null);
+    }
+
+    /**
+     * EFFECTS: Sign a CRL and save to disk. Save enforced.
+     * MODIFIES: this
+     * REQUIRES: Proper private key and CA cert installed.
+     */
+    private void onCRL(ActionEvent ev) {
+        final Path p = chooseFile(rootPanel, "DER CRL (*.crl)", "crl");
+        if (p == null) {
+            return;
+        }
+        try {
+            final OutputStream fd = Files.newOutputStream(p,
+                    StandardOpenOption.WRITE,
+                    StandardOpenOption.TRUNCATE_EXISTING,
+                    StandardOpenOption.CREATE);
+            final CertificateList crl = ca.signCRL();
+            fd.write(Utils.byteToByte(crl.encodeDER()));
+            fd.close();
+            onSave(null);
+        } catch (IOException | SignatureException | InvalidKeyException | NoSuchAlgorithmException e) {
+            alert(rootPanel, "Sign CRL", e);
+        }
+    }
+
+    /**
+     * EFFECTS: Pick a CSR, show issue dialog, sign cert. Save enforced.
+     * MODIFIES: this
+     * REQUIRES: Proper private key / CA is installed.
+     */
+    private void onIssue(ActionEvent ev) {
+        if (ca.getTemplates().stream().noneMatch(Template::isEnabled)) {
+            alert(rootPanel, "Issue new certificate", "No enabled templates.");
+            return;
+        }
+        final Path p = chooseFile(rootPanel, "DER CSR (*.csr, *.pem)", "csr", "pem");
+        if (p == null) {
+            return;
+        }
+        try {
+            CertificationRequest csr = new CertificationRequest(new BytesReader(UIUtils.openDERorPEM(p,
+                    "CERTIFICATE REQUEST")), false);
+            final IssueDialog diag = new IssueDialog(csr, ca.getTemplates());
+            diag.setLocationRelativeTo(this);
+            diag.setVisible(true);
+            final Template res = diag.getRes();
+            if (res == null) {
+                return;
+            }
+            ca.signCert(csr.getCertificationRequestInfo(), res);
+            onSave(null);
+        } catch (IOException | ParseException | NoSuchAlgorithmException | SignatureException | InvalidKeyException e) {
+            alert(rootPanel, "Issue new certificate", e);
+        }
+    }
 
-public class MainUI {
-    private JTabbedPane tabbedPane;
-    private JPanel rootPanel;
-    private JList listTemplates;
-    private JList listCertificates;
-    private JList listLogs;
-    private JLabel labelStatus;
-    private JButton buttonSave;
-
-    public JFrame createWindow() {
-        final JFrame frame = new JFrame("JCA");
-        frame.setContentPane(this.rootPanel);
-        frame.setVisible(true);
-        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
-        frame.pack();
-        return frame;
+    /**
+     * EFFECTS: Show the new template dialog and add a template.
+     * MODIFIES: this
+     */
+    private void onNewTemplate(ActionEvent ev) {
+        final TemplateEditDialog diag = new TemplateEditDialog(temp ->
+                ca.getTemplates().stream().anyMatch(t -> t.getName().equals(temp)));
+        diag.pack();
+        diag.setLocationRelativeTo(this);
+        diag.setVisible(true);
+        final Template res = diag.getRes();
+        if (res == null) {
+            return;
+        }
+        ca.addTemplate(res);
+        unsaved.set(true);
     }
 }
diff --git a/src/main/ui/RevokeDialog.java b/src/main/ui/RevokeDialog.java
new file mode 100644
index 0000000..49c13d1
--- /dev/null
+++ b/src/main/ui/RevokeDialog.java
@@ -0,0 +1,186 @@
+package ui;
+
+import model.asn1.ASN1Object;
+import model.asn1.UtcTime;
+import model.pki.cert.Certificate;
+import model.pki.crl.Reason;
+import model.pki.crl.RevokedCertificate;
+import ui.widgets.GCBuilder;
+import ui.widgets.UIUtils;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.KeyEvent;
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
+import java.util.Arrays;
+
+import static java.awt.GridBagConstraints.HORIZONTAL;
+import static java.awt.GridBagConstraints.WEST;
+import static ui.widgets.UIUtils.alert;
+
+/**
+ * A dialog that presents user with cert info, revocation reason, and revocation time.
+ * ┌────────────────────────────┐
+ * │  Revoke Certificate        │
+ * │                            │
+ * │Revoking: CN=xyz (Serial: 1)│
+ * │Reason:   (Drop Down)       │
+ * │Time:     (ISO-8601 text)   │
+ * │                            │
+ * │               Revoke Cancel│
+ * └────────────────────────────┘
+ */
+public class RevokeDialog extends JDialog {
+    /**
+     * ISO8601
+     */
+    private static final DateTimeFormatter DATE_FORMAT = DateTimeFormatter.ISO_OFFSET_DATE_TIME;
+
+    /**
+     * The incoming certificate.
+     */
+    private final Certificate crt;
+
+    /**
+     * The result.
+     */
+    private RevokedCertificate res;
+
+
+    /**
+     * Root pane
+     */
+    private JPanel contentPane;
+
+    /**
+     * OK button
+     */
+    private JButton buttonOK;
+
+    /**
+     * Cancel button
+     */
+    private JButton buttonCancel;
+
+    /**
+     * Reason
+     */
+    private JComboBox<String> comboBoxReason;
+
+    /**
+     * Subject (not editable)
+     */
+    private JTextField textFieldSubject;
+
+    /**
+     * Time
+     */
+    private JFormattedTextField formattedTextFieldTime;
+
+    /**
+     * EFFECTS: Init GUI with the given cert.
+     */
+    public RevokeDialog(Certificate crt) {
+        this.crt = crt;
+
+        contentPane = new JPanel();
+        contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.PAGE_AXIS));
+        contentPane.setBorder(BorderFactory.createEmptyBorder(8, 8, 8, 8));
+        contentPane.add(renderForm());
+
+        contentPane.add(UIUtils.createActionsPane(buttonOK = new JButton("Revoke"),
+                        buttonCancel = new JButton("Cancel")));
+        buttonOK.addActionListener(this::onOK);
+        buttonCancel.addActionListener(this::onCancel);
+
+        setContentPane(contentPane);
+        setModal(true);
+        getRootPane().setDefaultButton(buttonOK);
+        setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
+
+        setTitle("Revoke certificate");
+
+        addWindowListener(new WindowAdapter() {
+            public void windowClosing(WindowEvent e) {
+                onCancel(null);
+            }
+        });
+
+        contentPane.registerKeyboardAction(this::onCancel,
+                KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0),
+                JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
+    }
+
+    /**
+     * EFFECTS: Init GUI.
+     * MODIFIES: this
+     */
+    private JPanel renderForm() {
+        final JPanel panelForm = new JPanel();
+        panelForm.setLayout(new GridBagLayout());
+
+        panelForm.add(new JLabel("Revoking: "), new GCBuilder().anchor(WEST).build());
+        panelForm.add(new JLabel("Reason: "), new GCBuilder().gridY(1).anchor(WEST).build());
+        panelForm.add(new JLabel("Time: "), new GCBuilder().gridY(2).anchor(WEST).build());
+
+        textFieldSubject = new JTextField(String.format("%s (Serial: %d)",
+                crt.getCertificate().getSubject().toString(), crt.getCertificate().getSerialNumber().getLong()));
+        textFieldSubject.setEditable(false);
+        panelForm.add(textFieldSubject, new GCBuilder().gridX(1).anchor(WEST).fill(HORIZONTAL).build());
+
+        comboBoxReason = new JComboBox<>(Arrays.stream(Reason.values()).map(Enum::toString).toArray(String[]::new));
+        panelForm.add(comboBoxReason, new GCBuilder().gridXY(1, 1).anchor(WEST).fill(HORIZONTAL).build());
+
+        formattedTextFieldTime = new JFormattedTextField(DATE_FORMAT.toFormat());
+        formattedTextFieldTime.setText(ZonedDateTime.now().format(DATE_FORMAT));
+        panelForm.add(formattedTextFieldTime, new GCBuilder().gridXY(1, 2).anchor(WEST).fill(HORIZONTAL).build());
+
+        panelForm.add(new JPanel(), new GCBuilder().gridXY(1, 3).expandXY().fill(HORIZONTAL).build());
+        return panelForm;
+    }
+
+    /**
+     * EFFECTS: Validate form, set result, and close dialog.
+     *          Time must be a valid ISO-8601 string with offset, and it will be converted into UTC.
+     *          Reason must be supported.
+     * MODIFIES: this
+     */
+    private void onOK(ActionEvent ev) {
+        try {
+            res = new RevokedCertificate(ASN1Object.TAG_SEQUENCE, null,
+                    crt.getCertificate().getSerialNumber(),
+                    new UtcTime(UtcTime.TAG, null,
+                            ZonedDateTime.parse(formattedTextFieldTime.getText(), DATE_FORMAT)
+                                    .withZoneSameInstant(ZoneId.of("UTC"))),
+                    Reason.valueOf(comboBoxReason.getSelectedItem().toString()));
+            dispose();
+        } catch (DateTimeParseException e) {
+            alert(rootPane, "Revoke certificate", "Invalid time: " + formattedTextFieldTime.getText()
+                    + ". It must be a valid ISO8601 time with offset, like '1919-08-10T11:45:14+09:00'.");
+        } catch (IllegalArgumentException e) {
+            alert(rootPane, "Revoke certificate", "Invalid reason.");
+        }
+    }
+
+    /**
+     * EFFECTS: Clear the result and close dialog.
+     * MODIFIES: this
+     */
+    private void onCancel(ActionEvent ev) {
+        res = null;
+        dispose();
+    }
+
+    /**
+     * EFFECTS: Get result.
+     */
+    public RevokedCertificate getRes() {
+        return res;
+    }
+}
diff --git a/src/main/ui/TemplateEditDialog.java b/src/main/ui/TemplateEditDialog.java
new file mode 100644
index 0000000..7c33af6
--- /dev/null
+++ b/src/main/ui/TemplateEditDialog.java
@@ -0,0 +1,82 @@
+package ui;
+
+import model.asn1.exceptions.ParseException;
+import model.ca.Template;
+import model.x501.Name;
+import ui.widgets.CertEditDialog;
+
+import javax.swing.*;
+import java.awt.event.ActionEvent;
+import java.util.function.Function;
+
+import static ui.widgets.UIUtils.alert;
+
+/**
+ * A dialog that allows users to input template name, subject, and validity.
+ * ┌───────────────────────────┐
+ * │  New Template             │
+ * │                           │
+ * │Template:         _________│
+ * │Subject:          _________│
+ * │Validity (Days):  (Spinner)│
+ * │                           │
+ * │                 Add Cancel│
+ * └───────────────────────────┘
+ */
+public class TemplateEditDialog extends CertEditDialog<Template> {
+    /**
+     * Callback function to check for name conflict.
+     */
+    private final Function<String, Boolean> dupDetector;
+
+    /**
+     * Text field for name.
+     */
+    private JTextField templateComponent;
+
+    /**
+     * EFFECTS: Init UI, title = New Template, OK button = Add, set dup detector.
+     */
+    public TemplateEditDialog(Function<String, Boolean> dupDetector) {
+        super();
+        this.dupDetector = dupDetector;
+        setTitle("New template");
+        buttonOK.setText("Add");
+    }
+
+    /**
+     * EFFECTS: Initialize the subject text field with JTextField.
+     * MODIFIES: this
+     */
+    @Override
+    protected JComponent createTemplateComponent() {
+        return templateComponent = new JTextField();
+    }
+
+    /**
+     * EFFECTS: Validate the form, set the result, and close the dialog.
+     *          Name must not be null; Name must not conflict; Subject must be valid.
+     * MODIFIES: this
+     */
+    @Override
+    protected void onOK(ActionEvent ev) {
+        if (templateComponent.getText().isEmpty()) {
+            alert(rootPane, getTitle(), "The template name must not be empty.");
+            return;
+        }
+        if (dupDetector.apply(templateComponent.getText())) {
+            alert(rootPane, getTitle(), "The template exists.");
+            return;
+        }
+
+        try {
+            res = new Template(templateComponent.getText(),
+                    false,
+                    textFieldSubject.getText().isBlank() ? null : Name.parseString(textFieldSubject.getText()),
+                    (Integer) spinnerValidity.getValue());
+            dispose();
+        } catch (ParseException e) {
+            alert(rootPane, getTitle(), e);
+        }
+    }
+}
diff --git a/src/main/ui/widgets/CertEditDialog.java b/src/main/ui/widgets/CertEditDialog.java
new file mode 100644
index 0000000..ea16b19
--- /dev/null
+++ b/src/main/ui/widgets/CertEditDialog.java
@@ -0,0 +1,108 @@
+package ui.widgets;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.KeyEvent;
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
+
+import static java.awt.GridBagConstraints.HORIZONTAL;
+import static java.awt.GridBagConstraints.WEST;
+import static ui.widgets.UIUtils.btn;
+
+/**
+ * A common dialog for cert / template editing. It will close upon Esc or Cancel.
+ *        ┌───────────────────────────┐
+ *        │  Dialog                 X │
+ *        │                           │
+ *        │Template:         (TBD)    │
+ *        │Subject:         _________ │
+ *        │Validity (Days):  (Spinner)│
+ *        │                           │
+ *        │              Button Cancel│
+ *        └───────────────────────────┘
+ */
+public abstract class CertEditDialog<T> extends JDialog {
+    /**
+     * The result.
+     */
+    protected T res;
+
+    /**
+     * Root pane.
+     */
+    protected JPanel contentPane = new JPanel();
+    protected JButton buttonOK = btn("", this::onOK);
+    protected JTextField textFieldSubject = new JTextField();
+    protected JSpinner spinnerValidity =
+            new JSpinner(new SpinnerNumberModel(60, 1, null, 0));
+
+    /**
+     * EFFECTS: Render the dialog, leaving title and OK button text blank.
+     */
+    public CertEditDialog() {
+        contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.PAGE_AXIS));
+        contentPane.setBorder(BorderFactory.createEmptyBorder(8, 8, 8, 8));
+        contentPane.add(renderForm());
+
+        contentPane.add(UIUtils.createActionsPane(buttonOK, btn("Cancel", this::onCancel)));
+
+        setContentPane(contentPane);
+        setModal(true);
+        getRootPane().setDefaultButton(buttonOK);
+        setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
+
+        addWindowListener(new WindowAdapter() {
+            public void windowClosing(WindowEvent e) {
+                onCancel(null);
+            }
+        });
+
+        contentPane.registerKeyboardAction(this::onCancel,
+                KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0),
+                JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
+    }
+
+    /**
+     * EFFECTS: Render the form.
+     */
+    private JPanel renderForm() {
+        final JPanel panelForm = new JPanel(new GridBagLayout());
+        panelForm.add(new JLabel("Template: "), new GCBuilder().anchor(WEST).build());
+        panelForm.add(new JLabel("Subject: "), new GCBuilder().gridY(1).anchor(WEST).build());
+        panelForm.add(new JLabel("Validity (Days): "), new GCBuilder().gridY(2).anchor(WEST).build());
+        panelForm.add(createTemplateComponent(), new GCBuilder().gridXY(1, 0).anchor(WEST)
+                .fill(HORIZONTAL).build());
+        panelForm.add(textFieldSubject, new GCBuilder().gridXY(1, 1).anchor(WEST).fill(HORIZONTAL).build());
+        panelForm.add(spinnerValidity, new GCBuilder().gridXY(1, 2).anchor(WEST).fill(HORIZONTAL).build());
+        panelForm.add(new JPanel(), new GCBuilder().gridXY(1, 3).expandXY().fill(HORIZONTAL).build());
+        return panelForm;
+    }
+
+    /**
+     * EFFECTS: Create the component for subject.
+     */
+    protected abstract JComponent createTemplateComponent();
+
+    /**
+     * EFFECTS: Handle OK.
+     */
+    protected abstract void onOK(ActionEvent ev);
+
+    /**
+     * EFFECTS: Handle cancel: clear result and close dialog.
+     * MODIFIES: this
+     */
+    private void onCancel(ActionEvent ev) {
+        res = null;
+        dispose();
+    }
+
+    /**
+     * EFFECTS: Get the result.
+     */
+    public T getRes() {
+        return res;
+    }
+}
diff --git a/src/main/ui/widgets/CertTableModel.java b/src/main/ui/widgets/CertTableModel.java
new file mode 100644
index 0000000..0259e1b
--- /dev/null
+++ b/src/main/ui/widgets/CertTableModel.java
@@ -0,0 +1,129 @@
+package ui.widgets;
+
+import model.ca.CertificationAuthority;
+import model.pki.cert.Certificate;
+import model.pki.crl.RevokedCertificate;
+
+import javax.swing.*;
+import javax.swing.table.AbstractTableModel;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+/**
+ * Table model that displays issued certificates.
+ */
+public class CertTableModel extends AbstractTableModel {
+    /**
+     * Valid certificate icon.
+     */
+    private static final ImageIcon ICON_OK =
+            new ImageIcon(CertTableModel.class.getResource("/verified.png"));
+
+    /**
+     * Revoked certificate icon (same as toolbar revoke icon).
+     */
+    private static final ImageIcon ICON_REVOKED =
+            new ImageIcon(CertTableModel.class.getResource("/deletetest.png"));
+
+    /**
+     * Columns
+     */
+    private static final String[] COLS = new String[] {
+            "", // Icon
+            "Serial",
+            "Subject",
+            "Signed",
+            "Expires"
+    };
+
+    /**
+     * Pointer to {@link CertificationAuthority#getSigned()}
+     */
+    private List<Certificate> ptrData;
+
+    /**
+     * Pointer to {@link CertificationAuthority#getRevoked()}
+     */
+    private List<RevokedCertificate> ptrRevokedData;
+
+    /**
+     * EFFECTS: Set pointer to certs
+     * MODIFIES: this
+     */
+    public void setPtrData(List<Certificate> ptrData) {
+        this.ptrData = ptrData;
+    }
+
+    /**
+     * EFFECTS: Set pointer to revoked
+     * MODIFIES: this
+     */
+    public void setPtrRevokedData(List<RevokedCertificate> ptrRevokedData) {
+        this.ptrRevokedData = ptrRevokedData;
+    }
+
+    /**
+     * EFFECTS: Count rows.
+     */
+    @Override
+    public int getRowCount() {
+        return ptrData == null ? 0 : ptrData.size();
+    }
+
+    /**
+     * EFFECTS: Count columns.
+     */
+    @Override
+    public int getColumnCount() {
+        return COLS.length;
+    }
+
+    /**
+     * EFFECTS: Get column name.
+     * REQUIRES: column in [9, getColumnCount())
+     */
+    @Override
+    public String getColumnName(int column) {
+        return COLS[column];
+    }
+
+    /**
+     * EFFECTS: Return the value for a cell:
+     *          ImageIcon (Valid / Revoked)
+     *          String (Serial number)
+     *          String (Subject)
+     *          String (NotBefore)
+     *          String (NotAfter)
+     *          Throws {@link IllegalArgumentException} if columnIndex is not in 0 ~ 4
+     * REQUIRES: rowIndex must in range.
+     */
+    @Override
+    public Object getValueAt(int rowIndex, int columnIndex) {
+        final Certificate e = ptrData.get(rowIndex);
+        switch (columnIndex) {
+            case 0: return ptrRevokedData.stream().anyMatch(r ->
+                    r.getSerialNumber().getLong() == e.getCertificate().getSerialNumber().getLong()
+            ) ? ICON_REVOKED : ICON_OK;
+            case 1: return e.getCertificate().getSerialNumber().getLong();
+            case 2: return e.getCertificate().getSubject().toString();
+            case 3:
+                return e.getCertificate().getValidity().getNotBefore().getTimestamp()
+                        .format(DateTimeFormatter.ISO_LOCAL_DATE_TIME);
+            case 4:
+                return e.getCertificate().getValidity().getNotAfter().getTimestamp()
+                        .format(DateTimeFormatter.ISO_LOCAL_DATE_TIME);
+            default: throw new IllegalArgumentException();
+        }
+    }
+
+    /**
+     * EFFECTS: Return ImageIcon for 0, String otherwise.
+     */
+    @Override
+    public Class<?> getColumnClass(int columnIndex) {
+        switch (columnIndex) {
+            case 0: return ImageIcon.class;
+            default: return String.class;
+        }
+    }
+}
diff --git a/src/main/ui/widgets/GCBuilder.java b/src/main/ui/widgets/GCBuilder.java
new file mode 100644
index 0000000..0590cc1
--- /dev/null
+++ b/src/main/ui/widgets/GCBuilder.java
@@ -0,0 +1,213 @@
+package ui.widgets;
+
+import java.awt.*;
+
+/**
+ * A builder for {@link GridBagConstraints}.
+ */
+public class GCBuilder {
+    /**
+     * Grix X and Y, defaults to {@link GridBagConstraints#RELATIVE}
+     */
+    private int gridX = GridBagConstraints.RELATIVE;
+
+    private int gridY = GridBagConstraints.RELATIVE;
+
+    /**
+     * Weight X and Y, [0.0, 1.0], defaults to 0.0
+     */
+    private double weightX = 0.0;
+
+    private double weightY = 0.0;
+
+    /**
+     * Anchor, defaults to {@link GridBagConstraints#CENTER}
+     */
+    private int anchor = GridBagConstraints.CENTER;
+
+    /**
+     * How to stretch the component, defaults to {@link GridBagConstraints#NONE}
+     */
+    private int fill = GridBagConstraints.NONE;
+
+    /**
+     * Insects in pixels.
+     */
+    private int insectTop = 0;
+
+    private int insectLeft = 0;
+
+    private int insectRight = 0;
+
+    private int insectBottom = 0;
+
+    /**
+     * EFFECTS: Build the {@link GridBagConstraints} based on parameters.
+     * Grid width, grid height, ipad X, ipad Y will be 1, 1, 0, 0.
+     */
+    public GridBagConstraints build() {
+        return new GridBagConstraints(gridX, gridY,
+                1, 1,
+                weightX, weightY,
+                anchor, fill,
+                new Insets(insectTop, insectLeft, insectBottom, insectRight),
+                0, 0);
+    }
+
+    /**
+     * EFFECTS: Set grid X and Y.
+     * REQUIRES: > 0
+     * MODIFIES: this
+     */
+    public GCBuilder gridXY(int gridX, int gridY) {
+        return this.gridX(gridX).gridY(gridY);
+    }
+
+    /**
+     * EFFECTS: Set grid X.
+     * REQUIRES: > 0
+     * MODIFIES: this
+     */
+    public GCBuilder gridX(int gridX) {
+        this.gridX = gridX;
+        return this;
+    }
+
+    /**
+     * EFFECTS: Set grid Y.
+     * REQUIRES: > 0
+     * MODIFIES: this
+     */
+    public GCBuilder gridY(int gridY) {
+        this.gridY = gridY;
+        return this;
+    }
+
+    /**
+     * EFFECTS: Set weight X and Y.
+     * REQUIRES: [0.0, 1.0]
+     * MODIFIES: this
+     */
+    public GCBuilder weightXY(double weightX, double weightY) {
+        return this.weightX(weightX).weightY(weightY);
+    }
+
+    /**
+     * EFFECTS: Set weight X and Y to 1.0
+     * MODIFIES: this
+     */
+    public GCBuilder expandXY() {
+        return this.expandX().expandY();
+    }
+
+    /**
+     * EFFECTS: Set weight X to 1.0
+     * MODIFIES: this
+     */
+    public GCBuilder expandX() {
+        return this.weightX(1.0);
+    }
+
+    /**
+     * EFFECTS: Set weight X to 1.0
+     * MODIFIES: this
+     */
+    public GCBuilder weightX(double weightX) {
+        this.weightX = weightX;
+        return this;
+    }
+
+    /**
+     * EFFECTS: Set weight Y to 1.0
+     * MODIFIES: this
+     */
+    public GCBuilder expandY() {
+        return this.weightY(1.0);
+    }
+
+    /**
+     * EFFECTS: Set weight X to 1.0
+     * MODIFIES: this
+     */
+    public GCBuilder weightY(double weightY) {
+        this.weightY = weightY;
+        return this;
+    }
+
+    /**
+     * EFFECTS: Set anchor.
+     * REQUIRES: anchor in {@link GridBagConstraints} constants.
+     * MODIFIES: this
+     */
+    public GCBuilder anchor(int anchor) {
+        this.anchor = anchor;
+        return this;
+    }
+
+    /**
+     * EFFECTS: Set fill.
+     * REQUIRES: fill in {@link GridBagConstraints} constants.
+     * MODIFIES: this
+     */
+    public GCBuilder fill(int fill) {
+        this.fill = fill;
+        return this;
+    }
+
+    /**
+     * EFFECTS: Set insects to be 8, 8, 8, 8
+     * MODIFIES: this
+     */
+    public GCBuilder marginInsects() {
+        return this.insects(8, 8, 8, 8);
+    }
+
+    /**
+     * EFFECTS: Set insects.
+     * REQUIRES: >= 0
+     * MODIFIES: this
+     */
+    public GCBuilder insects(int top, int left, int bottom, int right) {
+        return this.insectTop(top).insectLeft(left).insectBottom(bottom).insectRight(right);
+    }
+
+    /**
+     * EFFECTS: Set top insect
+     * REQUIRES: >= 0
+     * MODIFIES: this
+     */
+    public GCBuilder insectTop(int insectTop) {
+        this.insectTop = insectTop;
+        return this;
+    }
+
+    /**
+     * EFFECTS: Set left insect
+     * REQUIRES: >= 0
+     * MODIFIES: this
+     */
+    public GCBuilder insectLeft(int insectLeft) {
+        this.insectLeft = insectLeft;
+        return this;
+    }
+
+    /**
+     * EFFECTS: Set right insect
+     * REQUIRES: >= 0
+     * MODIFIES: this
+     */
+    public GCBuilder insectRight(int insectRight) {
+        this.insectRight = insectRight;
+        return this;
+    }
+
+    /**
+     * EFFECTS: Set bottom insect
+     * REQUIRES: >= 0
+     * MODIFIES: this
+     */
+    public GCBuilder insectBottom(int insectBottom) {
+        this.insectBottom = insectBottom;
+        return this;
+    }
+}
diff --git a/src/main/ui/widgets/LogTableModel.java b/src/main/ui/widgets/LogTableModel.java
new file mode 100644
index 0000000..dc7dcbd
--- /dev/null
+++ b/src/main/ui/widgets/LogTableModel.java
@@ -0,0 +1,79 @@
+package ui.widgets;
+
+import model.ca.AuditLogEntry;
+import model.ca.CertificationAuthority;
+
+import javax.swing.table.AbstractTableModel;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+/**
+ * Table model that displays audit logs.
+ */
+public class LogTableModel extends AbstractTableModel {
+    /**
+     * Columns
+     */
+    private static final String[] COLS = new String[] {
+            "Time",
+            "Operator",
+            "Action"
+    };
+
+    /**
+     * Pointer to the {@link CertificationAuthority#getLogs()}.
+     */
+    private List<AuditLogEntry> ptrData;
+
+    /**
+     * EFFECTS: Set the pointer to templates
+     * MODIFIES: this
+     */
+    public void setPtrData(List<AuditLogEntry> ptrData) {
+        this.ptrData = ptrData;
+    }
+
+    /**
+     * EFFECT: Return number of rows.
+     */
+    @Override
+    public int getRowCount() {
+        return ptrData == null ? 0 : ptrData.size();
+    }
+
+    /**
+     * EFFECT: Return number of columns.
+     */
+    @Override
+    public int getColumnCount() {
+        return COLS.length;
+    }
+
+    /**
+     * EFFECTS: Get column name.
+     * REQUIRES: column in [9, getColumnCount())
+     */
+    @Override
+    public String getColumnName(int column) {
+        return COLS[column];
+    }
+
+    /**
+     * EFFECTS: Return the value for a cell:
+     *          String (Time)
+     *          String (Operator)
+     *          String (Action)
+     *          Throws {@link IllegalArgumentException} if columnIndex is not in 0 ~ 2
+     * REQUIRES: rowIndex must in range.
+     */
+    @Override
+    public Object getValueAt(int rowIndex, int columnIndex) {
+        final AuditLogEntry e = ptrData.get(rowIndex);
+        switch (columnIndex) {
+            case 0: return e.getTime().format(DateTimeFormatter.ISO_LOCAL_DATE_TIME);
+            case 1: return e.getUser();
+            case 2: return e.getAction();
+            default: throw new IllegalArgumentException();
+        }
+    }
+}
diff --git a/src/main/ui/widgets/TemplateTableModel.java b/src/main/ui/widgets/TemplateTableModel.java
new file mode 100644
index 0000000..da4557f
--- /dev/null
+++ b/src/main/ui/widgets/TemplateTableModel.java
@@ -0,0 +1,105 @@
+package ui.widgets;
+
+import model.ca.CertificationAuthority;
+import model.ca.Template;
+
+import javax.swing.*;
+import javax.swing.table.AbstractTableModel;
+import java.util.List;
+
+/**
+ * Table model that displays templates.
+ */
+public class TemplateTableModel extends AbstractTableModel {
+    /**
+     * Template enabled icon, same as toolbar enable icon.
+     */
+    private static final ImageIcon ICON_ENABLED =
+            new ImageIcon(TemplateTableModel.class.getResource("/enable.png"));
+
+    /**
+     * Template disbled icon, same as toolbar enable icon.
+     */
+    private static final ImageIcon ICON_DISABLED =
+            new ImageIcon(TemplateTableModel.class.getResource("/disable.png"));
+
+    /**
+     * Columns
+     */
+    private static final String[] COLS = new String[] {
+            "", // Icon
+            "Name",
+            "Subject",
+            "Validity"
+    };
+
+    /**
+     * Pointer to the {@link CertificationAuthority#getTemplates()}.
+     */
+    private List<Template> ptrData;
+
+    /**
+     * EFFECTS: Set the pointer to templates
+     * MODIFIES: this
+     */
+    public void setPtrData(List<Template> ptrData) {
+        this.ptrData = ptrData;
+    }
+
+    /**
+     * EFFECT: Return number of rows.
+     * REQUIRES: column in [9, getColumnCount())
+     */
+    @Override
+    public int getRowCount() {
+        return ptrData == null ? 0 : ptrData.size();
+    }
+
+    /**
+     * EFFECT: Return number of rows.
+     */
+    @Override
+    public int getColumnCount() {
+        return COLS.length;
+    }
+
+    /**
+     * EFFECTS: Get column name.
+     */
+    @Override
+    public String getColumnName(int column) {
+        return COLS[column];
+    }
+
+    /**
+     * EFFECTS: Return the value for a cell:
+     *          ImageIcon (Enabled / Disabled)
+     *          String (Name)
+     *          String (Subject or Not Set)
+     *          String (xx days)
+     *          Throws {@link IllegalArgumentException} if columnIndex is not in 0 ~ 3
+     * REQUIRES: rowIndex must in range.
+     */
+    @Override
+    public Object getValueAt(int rowIndex, int columnIndex) {
+        final Template e = ptrData.get(rowIndex);
+        switch (columnIndex) {
+            case 0: return e.isEnabled() ? ICON_ENABLED : ICON_DISABLED;
+            case 1: return e.getName();
+            case 2: return e.getSubject() == null ? "<Not Set>" : e.getSubject().toString();
+            case 3: return String.format("%d days", e.getValidity());
+            default: throw new IllegalArgumentException();
+        }
+    }
+
+    /**
+     * EFFECTS: Return ImageIcon for 0, String otherwise.
+     */
+    @Override
+    public Class<?> getColumnClass(int columnIndex) {
+        switch (columnIndex) {
+            case 0: return ImageIcon.class;
+            default: return String.class;
+        }
+    }
+}
diff --git a/src/main/ui/widgets/UIUtils.java b/src/main/ui/widgets/UIUtils.java
new file mode 100644
index 0000000..4442be3
--- /dev/null
+++ b/src/main/ui/widgets/UIUtils.java
@@ -0,0 +1,168 @@
+package ui.widgets;
+
+import model.asn1.exceptions.ParseException;
+import ui.Utils;
+
+import javax.swing.*;
+import javax.swing.filechooser.FileNameExtensionFilter;
+import java.awt.*;
+import java.awt.event.ActionListener;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardOpenOption;
+import java.util.stream.IntStream;
+
+import static java.awt.GridBagConstraints.BOTH;
+import static java.awt.GridBagConstraints.HORIZONTAL;
+import static javax.swing.JOptionPane.*;
+
+/**
+ * Useful utilities for building GUI.
+ */
+public class UIUtils {
+    /**
+     * EFFECTS: Create a horizontal actions pane:
+     * -----------------------------------------------------------
+     * |                 | Button1 | Button2 | Button3 | ButtonN |
+     * -----------------------------------------------------------
+     * REQUIRES: buttons != null
+     */
+    public static JPanel createActionsPane(JButton... buttons) {
+        final JPanel panelAct = new JPanel();
+        panelAct.setLayout(new GridBagLayout());
+        IntStream.range(0, buttons.length)
+                .forEach(i -> panelAct.add(buttons[i],
+                        new GCBuilder().gridXY(i + 1, 1).fill(HORIZONTAL).build()));
+        panelAct.add(new JPanel(), new GCBuilder().expandXY().fill(BOTH).build());
+        return panelAct;
+    }
+
+    /**
+     * EFFECTS: Show / hide default text for a card layout container.
+     * MODIFIES: cardLayoutPanel
+     * REQUIRES: cardLayoutPanel must have a card layout; it must have CardContent and CardDefault cards.
+     */
+    public static void setContentVisible(Container cardLayoutPanel, boolean showContent) {
+        switchTo(cardLayoutPanel, showContent ? "CardContent" : "CardDefault");
+    }
+
+    /**
+     * EFFECTS: Switch to the card for a card layout panel.
+     * MODIFIES: cardLayoutPanel
+     * REQUIRES: cardLayoutPanel must have a card layout; it must have "card" card.
+     */
+    public static void switchTo(Container cardLayoutPanel, String card) {
+        ((CardLayout) cardLayoutPanel.getLayout()).show(cardLayoutPanel, card);
+    }
+
+    /**
+     * EFFECTS: Show an error message based on {@link Throwable#getMessage()}
+     * REQUIRES: component must have a frame.
+     */
+    public static void alert(Component component, String title, Throwable e) {
+        alert(component, title, e.getMessage());
+    }
+
+    /**
+     * EFFECTS: Show an error message.
+     * REQUIRES: component must have a frame.
+     */
+    public static void alert(Component component, String title, String message) {
+        showMessageDialog(getFrameForComponent(component),
+                message,
+                title,
+                ERROR_MESSAGE);
+    }
+
+    /**
+     * EFFECTS: Show a file chooser with the given filter title and list of extensions. Starting from cwd.
+     * Return null if cancelled.
+     */
+    public static Path chooseFile(Component component, String filterTitle, String... extensions) {
+        final JFileChooser fc = new JFileChooser();
+        fc.setFileFilter(new FileNameExtensionFilter(filterTitle, extensions));
+        fc.setCurrentDirectory(Paths.get("").toAbsolutePath().toFile());
+        if (fc.showOpenDialog(getFrameForComponent(component)) == JFileChooser.APPROVE_OPTION) {
+            return fc.getSelectedFile().toPath();
+        }
+        return null;
+    }
+
+    /**
+     * EFFECTS: Create a JPanel with CardLayout that has CardDefault set to component and CardContent set to a JLabel
+     * with the default text.
+     */
+    public static JPanel defView(Component component, String defaultText) {
+        final JPanel panel = new JPanel();
+        panel.setLayout(new CardLayout(0, 0));
+
+        JLabel labelDefault = new JLabel(defaultText);
+        labelDefault.setHorizontalAlignment(0);
+        panel.add(labelDefault, "CardDefault");
+        panel.add(component, "CardContent");
+
+        return panel;
+    }
+
+    /**
+     * EFFECTS: Create a JScrollPane-wrapped JTable.
+     * MODIFIES: table
+     */
+    public static JScrollPane scrTbl(JTable table) {
+        final JScrollPane scrollPane = new JScrollPane();
+        table.setFillsViewportHeight(true);
+        scrollPane.setViewportView(table);
+        return scrollPane;
+    }
+
+    /**
+     * EFFECTS: Parse the given path and automatically determine if it is a DER binary or a PEM. Automatically decode
+     * PEM.
+     *      Throws {@link IOException} if it cannot be read.
+     *      Throws {@link ParseException} if the PEM is invalid.
+     */
+    public static Byte[] openDERorPEM(Path path, String tag) throws IOException, ParseException {
+        final InputStream fd = Files.newInputStream(path, StandardOpenOption.READ);
+        Byte[] bs = Utils.byteToByte(fd.readAllBytes());
+        fd.close();
+        if (bs.length < 1) {
+            throw new ParseException("Invalid file: too short");
+        }
+        if (bs[0] == '-') {
+            bs = Utils.parsePEM(bs, tag);
+        }
+        return bs;
+    }
+
+    /**
+     * EFFECTS: Create a button with the given label and click listener.
+     */
+    public static JButton btn(String string, ActionListener onClick) {
+        final JButton btn = new JButton(string);
+        btn.addActionListener(onClick);
+        return btn;
+    }
+
+    /**
+     * EFFECTS: Create a button with the given label, mnemonic, and click listener.
+     */
+    public static JButton btn(String string, char m, ActionListener onClick) {
+        final JButton btn = new JButton(string);
+        btn.setMnemonic(m);
+        btn.setDisplayedMnemonicIndex(0);
+        btn.addActionListener(onClick);
+        return btn;
+    }
+
+    /**
+     * EFFECTS: Create a button with the given label, mnemonic, icon, and click listener.
+     */
+    public static JButton btn(String string, String icon, ActionListener onClick) {
+        final JButton btn = new JButton(string, new ImageIcon(UIUtils.class.getResource("/" + icon)));
+        btn.addActionListener(onClick);
+        return btn;
+    }
+}
-- 
cgit v1.2.3