JTable: Fix absence of horizontal scrollbar and add popup menu actions

This ensures horizontal scrollbar is displayed when contents of table too small to fit in view port.
In addition, it implements a contextual menu hosting some basic actions:
- Copy and Select All command (from the JTable action map)
- Delete selected rows command
- Resize command that enlarges column widths to largest cell in the column

Fixes #62

Author: tferr

src/main/java/org/scijava/ui/swing/viewer/table/SwingTableDisplayPanel.java

@@ -29,9 +29,25 @@
 
 package org.scijava.ui.swing.viewer.table;
 
+import java.awt.Component;
+import java.awt.Toolkit;
+import java.awt.event.ActionEvent;
+import java.awt.event.ComponentAdapter;
+import java.awt.event.ComponentEvent;
+import java.awt.event.KeyEvent;
+import java.util.Arrays;
+
+import javax.swing.AbstractAction;
+import javax.swing.Action;
+import javax.swing.JComponent;
+import javax.swing.JMenuItem;
+import javax.swing.JPopupMenu;
 import javax.swing.JScrollPane;
 import javax.swing.JTable;
+import javax.swing.KeyStroke;
 import javax.swing.table.AbstractTableModel;
+import javax.swing.table.TableCellRenderer;
+import javax.swing.table.TableColumn;
 
 import org.scijava.table.Table;
 import org.scijava.table.TableDisplay;
@@ -65,9 +81,25 @@ public SwingTableDisplayPanel(final TableDisplay display,
 		this.window = window;
 		nullModel = new NullTableModel();
 		table = makeTable();
+
 		table.setAutoCreateRowSorter(true);
+		table.setRowSelectionAllowed(true);
+		new TablePopupMenu().install();
+
+		//table.setPreferredScrollableViewportSize(getPreferredSize());
+		addComponentListener(new ComponentAdapter() {
+			@Override
+			public void componentResized(final ComponentEvent e) {
+				if (table.getPreferredSize().width < getWidth()) {
+					table.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS);
+				} else {
+					table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
+				}
+			}
+		});
 		setViewportView(table);
 		window.setContent(this);
+
 	}
 
 	// -- TableDisplayPanel methods --
@@ -133,6 +165,7 @@ private JTable makeTable() {
 
 	// -- Helper classes --
 
+	@SuppressWarnings("serial")
 	public static class NullTableModel extends AbstractTableModel {
 
 		@Override
@@ -209,6 +242,14 @@ public void setValueAt(final Object value, final int row, final int col) {
 			fireTableCellUpdated(row, col);
 		}
 
+		public void removeRows(int[] indices) {
+			Arrays.sort(indices);
+			for (int i = indices.length - 1; i >= 0; i--) {
+				tab.removeRow(indices[i]);
+				fireTableRowsDeleted(indices[i], indices[i]);
+			}
+		}
+
 		// -- Helper methods --
 
 		private <T> void set(final Table<?, T> table,
@@ -221,4 +262,91 @@ private <T> void set(final Table<?, T> table,
 
 	}
 
+	@SuppressWarnings("serial")
+	class TablePopupMenu extends JPopupMenu {
+		public TablePopupMenu() {
+			super();
+			JMenuItem mi;
+			mi= new JMenuItem(new ActionMapAction("Copy", table, "copy"));
+			final int MASK = Toolkit.getDefaultToolkit().getMenuShortcutKeyMask();
+			mi.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C, MASK));
+			add(mi);
+			mi = new JMenuItem(new ActionMapAction("Select All", table, "selectAll"));
+			mi.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_A, MASK));
+			add(mi);
+			addSeparator();
+			mi = new JMenuItem("Delete Selected Row(s)");
+			mi.addActionListener(e -> {
+				final int[] selectedRows = table.getSelectedRows();
+				if (selectedRows.length > 0)
+					((TableModel) table.getModel()).removeRows(selectedRows);
+			});
+			add(mi);
+			mi = new JMenuItem("Resize Column Widths");
+			mi.addActionListener(e -> resizeColumns());
+			add(mi);
+		}
+
+		private void resizeColumns() {
+			// https://stackoverflow.com/a/30355804
+			table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
+			table.getTableHeader();
+			for (int column = 0; column < table.getColumnCount(); column++) {
+				final TableColumn tableColumn = table.getColumnModel().getColumn(column);
+				int preferredWidth = Math.max(tableColumn.getMinWidth(), getColumnHeaderWidth(tableColumn, column));
+				final int maxWidth = tableColumn.getMaxWidth();
+				for (int row = 0; row < table.getRowCount(); row++) {
+					final TableCellRenderer cellRenderer = table.getCellRenderer(row, column);
+					final Component c = table.prepareRenderer(cellRenderer, row, column);
+					final int width = c.getPreferredSize().width + table.getIntercellSpacing().width;
+					preferredWidth = Math.max(preferredWidth, width);
+					if (preferredWidth >= maxWidth) {
+						preferredWidth = maxWidth;
+						break;
+					}
+				}
+				tableColumn.setPreferredWidth(preferredWidth);
+			}
+		}
+
+		private int getColumnHeaderWidth(final TableColumn tableColumn, final int column) {
+			final Object value = tableColumn.getHeaderValue();
+			TableCellRenderer renderer = tableColumn.getHeaderRenderer();
+			if (renderer == null) {
+				renderer = table.getTableHeader().getDefaultRenderer();
+			}
+			final Component c = renderer.getTableCellRendererComponent(table, value, false, false, -1, column);
+			return c.getPreferredSize().width;
+		}
+
+		void install() {
+			table.setComponentPopupMenu(this);
+			SwingTableDisplayPanel.this.setComponentPopupMenu(this);
+		}
+
+	}
+
+	@SuppressWarnings("serial")
+	private class ActionMapAction extends AbstractAction {
+
+		private final Action originalAction;
+		private final JComponent component;
+		private final String actionCommand = "";
+
+		ActionMapAction(final String name, final JComponent component, final String actionKey) {
+			super(name);
+			originalAction = component.getActionMap().get(actionKey);
+			if (originalAction == null) {
+				throw new IllegalArgumentException("No Action for action key: " + actionKey);
+			}
+			this.component = component;
+		}
+
+		@Override
+		public void actionPerformed(ActionEvent e) {
+			e = new ActionEvent(component, ActionEvent.ACTION_PERFORMED, actionCommand, e.getWhen(), e.getModifiers());
+			originalAction.actionPerformed(e);
+		}
+
+	}
 }