JTable and its size

[Mihai Radulescu]

Hi I use a JTable with JScrollPane like this :

JScrollPane scrollPane = new JScrollPane(table);

where the table is my JTable but the resoult is a gigant table.For shrink it (make it smaller) I find two solution:
1.I set a preferred size for the frame and the table goes small
2.I set a prefferd size for the view port with : setPreferredScrollableViewportSize(..

The both solution require "hardcode" and I am not so happy with them.
My question is :
Thare are also other ways to resize the table without "hardcode" ?

[Eric Snell]

Here is a class that will calculate the PreferredScrollableViewportSize (along with some other things). Hope you find it helpful.

 
import javax.swing.JTable;
 
import java.awt.Component;
import java.awt.Dimension;
 
class TableColumnSizer {
   public int getColumnPreferredWidthToFit(final JTable table, final int columnIndex, final boolean includeColumnHeader,
                                           final boolean includeCellEditor) {
      int columnWidth = (includeColumnHeader ? getColumnHeaderPreferredWidth(table, columnIndex) : 0);
      for (int rowIndex = 0; rowIndex < table.getRowCount(); rowIndex++) {
         columnWidth =
         Math.max(getColumnPreferredWidthAtRow(table, rowIndex, columnIndex, includeCellEditor), columnWidth);
      }
      return columnWidth;
   }
 
   private int getColumnHeaderPreferredWidth(final JTable table, final int columnIndex) {
      return table.getTableHeader().getDefaultRenderer().
              getTableCellRendererComponent(table,
                                            table.getModel().getColumnName(columnIndex),
                                            false, false, 0, columnIndex).getPreferredSize().width + 2;
   }
 
   private int getColumnPreferredWidthAtRow(final JTable table, final int rowIndex, final int columnIndex, final boolean includeCellEditor) {
      int width = table.getCellRenderer(rowIndex, columnIndex).
              getTableCellRendererComponent(table,
                                            table.getModel().getValueAt(rowIndex,
                                                                        getModelColumnIndex(table, columnIndex)),
                                            false,
                                            false,
                                            rowIndex,
                                            getModelColumnIndex(table, columnIndex)).getPreferredSize().width + 4;
      if (includeCellEditor && table.isCellEditable(rowIndex, columnIndex)) {
         final Component editor = table.getCellEditor(rowIndex, columnIndex).
                 getTableCellEditorComponent(table,
                                             table.getModel().getValueAt(rowIndex, getModelColumnIndex(table, columnIndex)),
                                             false, rowIndex, getModelColumnIndex(table, columnIndex));
         if (editor != null) {
            width = Math.max(width, editor.getPreferredSize().width);
         }
      }
      return width;
   }
 
   private int getModelColumnIndex(final JTable table, final int columnIndex) {
      return table.getColumnModel().getColumn(columnIndex).getModelIndex();
   }
 
   public Dimension getPreferredScrollableViewportSize(final JTable table, final int visibleRowCount) {
      final Dimension result = new Dimension(0, 0);
      for (int columnIndex = 0, columnCount = getMaxColumnCountForSizingColumns(table);
           columnIndex < columnCount; columnIndex++) {
         result.width +=
         getColumnPreferredWidthToFit(table, columnIndex, true,
                                      table.getRowCount() > 0 ?
                                      table.getModel().isCellEditable(0, columnIndex) : false);
      }
      result.height = visibleRowCount * table.getRowHeight();
      return result;
   }
 
   public void setColumnsWidthToFit(final JTable table, final boolean includeColumnHeader, final boolean includeCellEditor) {
      for (int columnIndex = 0, columnCount = getMaxColumnCountForSizingColumns(table);
           columnIndex < columnCount; columnIndex++) {
         if (preferredWidthIsSettable(table, columnIndex)) {
            setColumnPreferredWidth(table, columnIndex,
                                    getColumnPreferredWidthToFit(table, columnIndex, includeColumnHeader,
                                                                 includeCellEditor));
         }
      }
   }
 
   private int getMaxColumnCountForSizingColumns(final JTable table) {
      return Math.min(table.getColumnModel().getColumnCount(), table.getModel().getColumnCount());
   }
 
   private boolean preferredWidthIsSettable(final JTable table, final int columnIndex) {
      return table.getColumnModel().getColumn(columnIndex).getMaxWidth() != 0;
   }
 
   private void setColumnPreferredWidth(final JTable table, final int column, final int columnWidth) {
      table.getColumnModel().getColumn(column).setPreferredWidth(columnWidth);
   }
}
 
 

[Mihai Radulescu]

Ok it works,Thanks!