first commit

src/main/java/net/vhati/modmanager/ui/TableRowTransferHandler.java

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+package net.vhati.modmanager.ui;
+
+import java.awt.Cursor;
+import java.awt.datatransfer.DataFlavor;
+import java.awt.datatransfer.Transferable;
+import java.awt.dnd.DragSource;
+import javax.swing.JComponent;
+import javax.swing.JTable;
+import javax.swing.TransferHandler;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+
+/**
+ * Allows drag and drop reordering of JTable rows.
+ *
+ * Its TableModel must implement the Reorderable interface.
+ */
+public class TableRowTransferHandler extends TransferHandler {
+
+	private static final Logger log = LogManager.getLogger(TableRowTransferHandler.class);
+
+	private DataFlavor localIntegerFlavor = null;
+
+	private JTable table = null;
+
+
+	public TableRowTransferHandler( JTable table ) {
+		if ( table.getModel() instanceof Reorderable == false ) {
+			throw new IllegalArgumentException( "The tableModel doesn't implement Reorderable." );
+		}
+		this.table = table;
+
+		try {
+			localIntegerFlavor = new DataFlavor( DataFlavor.javaJVMLocalObjectMimeType + ";class=\""+ Integer.class.getName() +"\"" );
+		}
+		catch ( ClassNotFoundException e ) {
+			log.error( e );
+		}
+	}
+
+	@Override
+	protected Transferable createTransferable( JComponent c ) {
+		assert ( c == table );
+		int row = table.getSelectedRow();
+		return new IntegerTransferrable( new Integer(row) );
+	}
+
+	@Override
+	public boolean canImport( TransferHandler.TransferSupport ts ) {
+		boolean b = ( ts.getComponent() == table && ts.isDrop() && ts.isDataFlavorSupported(localIntegerFlavor) );
+		table.setCursor( b ? DragSource.DefaultMoveDrop : DragSource.DefaultMoveNoDrop );
+		return b;
+	}
+
+	@Override
+	public int getSourceActions( JComponent comp ) {
+		return TransferHandler.MOVE;
+	}
+
+	@Override
+	@SuppressWarnings("Unchecked")
+	public boolean importData( TransferHandler.TransferSupport ts ) {
+		if ( !canImport(ts) ) return false;
+
+		JTable target = (JTable)ts.getComponent();
+		JTable.DropLocation dl = (JTable.DropLocation)ts.getDropLocation();
+		int dropRow = dl.getRow();
+		int rowCount = table.getModel().getRowCount();
+		if ( dropRow < 0 || dropRow > rowCount ) dropRow = rowCount;
+
+		target.setCursor( Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR) );
+		try {
+			Integer draggedRow = (Integer)ts.getTransferable().getTransferData(localIntegerFlavor);
+			if ( draggedRow != -1 && draggedRow != dropRow ) {
+				((Reorderable)table.getModel()).reorder( draggedRow, dropRow );
+				if ( dropRow > draggedRow ) dropRow--;
+				target.getSelectionModel().addSelectionInterval( dropRow, dropRow );
+				return true;
+			}
+		} catch (Exception e) {
+			log.error( e );
+		}
+		return false;
+	}
+
+	@Override
+	protected void exportDone( JComponent source, Transferable data, int action ) {
+		if ( action == TransferHandler.MOVE || action == TransferHandler.NONE ) {
+			table.setCursor( Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR) );
+		}
+	}
+
+
+
+	/**
+	 * Drag and drop Integer data, constructed with a raw object
+	 * from a drag source, to be transformed into a flavor
+	 * suitable for the drop target.
+	 */
+	private class IntegerTransferrable implements Transferable{
+		private Integer data;
+
+		public IntegerTransferrable( Integer data ) {
+			this.data = data;
+		}
+
+		@Override
+		public Object getTransferData( DataFlavor flavor ) {
+			if ( flavor.equals( localIntegerFlavor ) ) {
+				return data;
+			}
+			return null;
+		}
+
+		@Override
+		public DataFlavor[] getTransferDataFlavors() {
+			return new DataFlavor[] {localIntegerFlavor};
+		}
+
+		@Override
+		public boolean isDataFlavorSupported( DataFlavor flavor ) {
+			return flavor.equals( localIntegerFlavor );
+		}
+	}
+}