Adds support for up/down buttons to re-order a reorderable list. Needs images for the buttons?

Fixes issue 3569

Change-Id: Ia1cbe3151f5cc707c8afd97c5ac5a6276283b777
Reviewed-on: http://gerrit.dmdirc.com/718
Automatic-Compile: DMDirc Local Commits <dmdirc@googlemail.com>
Reviewed-by: Chris Smith <chris@dmdirc.com>

src/com/dmdirc/addons/nowplaying/ConfigPanel.java

@@ -22,6 +22,7 @@
 
 package com.dmdirc.addons.nowplaying;
 
+import com.dmdirc.addons.ui_swing.components.reorderablelist.ListReorderButtonPanel;
 import com.dmdirc.config.IdentityManager;
 import com.dmdirc.config.prefs.PreferencesInterface;
 import com.dmdirc.addons.ui_swing.components.text.TextLabel;
@@ -118,7 +119,8 @@ public class ConfigPanel extends JPanel implements PreferencesInterface,
         panel.setLayout(new MigLayout("fillx, ins 5"));
 
         panel.add(new JLabel("Drag and drop items to reorder"), "wrap");
-        panel.add(new JScrollPane(list), "growx");
+        panel.add(new JScrollPane(list), "growx, pushx");
+        panel.add(new ListReorderButtonPanel(list), "");
 
         add(panel, "growx, wrap");
 
@@ -136,8 +138,7 @@ public class ConfigPanel extends JPanel implements PreferencesInterface,
 
         add(new NowPlayingSubsitutionPanel(Arrays.asList(new String[]{"app",
                     "title", "artist", "album", "bitrate", "format", "length",
-                    "time",
-                    "state"})), "growx");
+                    "time", "state"})), "growx");
         schedulePreviewUpdate();
     }
 

src/com/dmdirc/addons/ui_swing/components/reorderablelist/ListReorderButtonPanel.java

@@ -0,0 +1,145 @@
+/*
+ * 
+ * Copyright (c) 2006-2010 Chris Smith, Shane Mc Cormack, Gregory Holmes
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.dmdirc.addons.ui_swing.components.reorderablelist;
+
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+import javax.swing.DefaultListModel;
+import javax.swing.JButton;
+import javax.swing.JList;
+import javax.swing.JPanel;
+import javax.swing.event.ListSelectionEvent;
+import javax.swing.event.ListSelectionListener;
+
+import net.miginfocom.swing.MigLayout;
+
+/**
+ * Simple panel to reorder a JList using buttons.
+ */
+public class ListReorderButtonPanel extends JPanel implements
+        ListSelectionListener, ActionListener {
+
+    /**
+     * A version number for this class. It should be changed whenever the class
+     * structure is changed (or anything else that would prevent serialized
+     * objects being unserialized with the new class).
+     */
+    private static final long serialVersionUID = 1;
+    /** List to reoder. */
+    private JList list;
+    /** Default list model. */
+    private DefaultListModel model;
+    /** Up button. */
+    private JButton up;
+    /** Down button. */
+    private JButton down;
+
+    /**
+     * Creates a panel to reoder a jlist.
+     * 
+     * @param list JList
+     */
+    public ListReorderButtonPanel(final ReorderableJList list) {
+        this.list = list;
+        this.model = list.getModel();
+
+        list.addListSelectionListener(this);
+        up = new JButton("/\\");
+        down = new JButton("\\/");
+
+        up.addActionListener(this);
+        down.addActionListener(this);
+
+        setLayout(new MigLayout("fill"));
+
+        add(up, "wrap");
+        add(down, "");
+
+        valueChanged(null);
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public void valueChanged(final ListSelectionEvent e) {
+        up.setEnabled(list.getSelectedIndex() != -1);
+        down.setEnabled(list.getSelectedIndex() != -1);
+    }
+
+    /**
+     * {@inheritDoc}
+     * 
+     * @param e Action event
+     */
+    @Override
+    public void actionPerformed(final ActionEvent e) {
+        final Object object = list.getSelectedValue();
+        final int currentIndex = list.getSelectedIndex();
+        if (e.getSource() == up) {
+            moveUp(object, currentIndex);
+        } else {
+            moveDown(object, currentIndex);
+        }
+    }
+
+    /**
+     * Moves an object up in the list.
+     *
+     * @param object Object to move
+     * @param currentIndex Current index
+     */
+    private void moveUp(final Object object, final int currentIndex) {
+        int newIndex = currentIndex - 1;
+        if (newIndex < 0) {
+            newIndex = model.getSize() - 1;
+        }
+        moveElement(object, newIndex);
+    }
+
+    /**
+     * Moves an object down in the list.
+     *
+     * @param object Object to move
+     * @param currentIndex Current index
+     */
+    private void moveDown(final Object object, final int currentIndex) {
+        int newIndex = currentIndex + 1;
+        if (newIndex > model.getSize() - 1) {
+            newIndex = 0;
+        }
+        moveElement(object, newIndex);
+    }
+
+    /**
+     * Moves an object from its current positition to a new position in a list.
+     *
+     * @param object Object to move
+     * @param newIndex Current index
+     */
+    private void moveElement(final Object object, final int newIndex) {
+        model.removeElement(object);
+        model.add(newIndex, object);
+        list.setSelectedIndex(newIndex);
+    }
+}