Add Tables.wrap method for Map as 1-column table

Author: ctrueden

src/main/java/org/scijava/table/Tables.java

@@ -34,6 +34,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 /**
  * Utility methods for constructing tables.
@@ -46,6 +47,61 @@ private Tables() {
 		// NB: Prevent instantiation of utility class.
 	}
 
+	/**
+	 * Creates a single-column table wrapping a map. Each entry is one row of the
+	 * table.
+	 * 
+	 * @param data The data to wrap. Each map entry is a row.
+	 * @param colHeader Header to use for the table's sole column. Pass null for
+	 *          no column header.
+	 * @param <T> The type of data in each cell of the table.
+	 * @return A {@link Table} object wrapping the data structure.
+	 */
+	public static <T> Table<Column<T>, T> wrap(final Map<?, T> data,
+		final String colHeader)
+	{
+		final List<String> rowHeaders = data.keySet().stream() //
+			.map(k -> k == null ? null : k.toString()) //
+			.collect(Collectors.toList());
+
+		return new ReadOnlyTable<T>() {
+
+			@Override
+			public int getRowCount() {
+				return data.size();
+			}
+
+			@Override
+			public String getRowHeader(final int row) {
+				return rowHeaders.get(row);
+			}
+
+			@Override
+			public int size() {
+				return 1;
+			}
+
+			@Override
+			public Column<T> get(final int col) {
+				if (col != 0) //
+					throw new IllegalArgumentException("Column out of range: " + col);
+
+				return new ColumnAccessor<T>(data, colHeader) {
+
+					@Override
+					public int size() {
+						return data.size();
+					}
+
+					@Override
+					public T get(final int index) {
+						return data.get(rowHeaders.get(index));
+					}
+				};
+			}
+		};
+	}
+
 	/**
 	 * Creates a single-column table wrapping a list. Each element is one row of
 	 * the table.

src/test/java/org/scijava/table/TablesTest.java

@@ -46,6 +46,41 @@
  */
 public class TablesTest {
 
+	@Test
+	public void testWrapMap() {
+		final Map<?, ?> info = map( //
+			"Name", "Barack Obama", //
+			"Birth date", "August 4, 1961", //
+			"Birth place", "Honolulu, Hawaii" //
+		);
+		final String colHeader = "Stat";
+		final Table<?, ?> table = Tables.wrap(info, colHeader);
+
+		// check table dimensions
+		assertEquals(1, table.size());
+		assertEquals(1, table.getColumnCount());
+		assertEquals(info.size(), table.getRowCount());
+
+		// check row headers
+		assertEquals("Name", table.getRowHeader(0));
+		assertEquals("Birth date", table.getRowHeader(1));
+		assertEquals("Birth place", table.getRowHeader(2));
+
+		// check direct data access
+		assertEquals("Barack Obama", table.get(0, 0));
+		assertEquals("August 4, 1961", table.get(0, 1));
+		assertEquals("Honolulu, Hawaii", table.get(0, 2));
+
+		// check first column
+		assertEquals("Stat", table.getColumnHeader(0));
+		final Column<?> statColumn = table.get("Stat");
+		assertEquals(3, statColumn.size());
+		assertEquals("Barack Obama", statColumn.get(0));
+		assertEquals("August 4, 1961", statColumn.get(1));
+		assertEquals("Honolulu, Hawaii", statColumn.get(2));
+		assertEquals(statColumn, table.get(0));
+	}
+
 	@Test
 	public void testWrapList() {
 		final List<?> names = //