final double border = 5;
final double rowsGap = 5;
final double colsGap = 10;
final double[][] size = {{border, TableLayout.PREFERRED, border}, // Columns
{border, TableLayout.PREFERRED, rowsGap, TableLayout.PREFERRED, rowsGap, TableLayout.PREFERRED, rowsGap, TableLayout.PREFERRED, border}};// Rows
final TableLayout tbl = new TableLayout(size);
_mainPanel = new JPanel(tbl);
_mainPanel.add(getExportDirPanel(), "1, 1, 1, 1");
_mainPanel.add(getFileFormatPanel(), "1, 3, 1, 3");
_mainPanel.add(getBrowserPanel(), "1, 5, 1, 5");