1 files changed, 168 insertions, 0 deletions
diff --git a/src/main/ui/gui/widgets/UIUtils.java b/src/main/ui/gui/widgets/UIUtils.java
new file mode 100644
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+++ b/src/main/ui/gui/widgets/UIUtils.java
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+package ui.gui.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;
+    }
+}