Adjusts the JTable column width of the row headers table containing the number column. - Java Swing

Java examples for Swing:JTable Column

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Description

Adjusts the JTable column width of the row headers table containing the number column.

Demo Code


import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Point;
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.util.ArrayList;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JViewport;
import javax.swing.UIManager;
import javax.swing.border.Border;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.plaf.UIResource;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.JTableHeader;
import javax.swing.table.TableCellRenderer;

public class Main{
    /**/*from  w  w w.ja  v  a 2 s .  co m*/
     * Adjusts the column width of the row headers table containing the number
     * column. The font metrics are extracted from the label of the row at the
     * bottom of the viewport and used to determing the appropriate width.
     * 
     * The reason why this method is important, is that when the row number increases by an extra digit
     * the column needs to get wider. It also needs to shrink when scrolling to smaller digit numbers.
     * 
     * @param rowHeadersTable - single column table in the row header
     * @param label - label used to get font metrics
     * @param scrollBarValue - int value for determing point of lowest row
     */
    private static void adjustColumnWidth(final JTable rowHeadersTable,
            final JLabel label, int scrollBarValue) {

        label.setFont(rowHeadersTable.getFont());
        label.setOpaque(true);
        label.setHorizontalAlignment(JLabel.CENTER);

        int v = rowHeadersTable.getVisibleRect().height;

        int row = rowHeadersTable.rowAtPoint(new Point(0, v
                + scrollBarValue));

        Integer modelValue = null;
        if (row != -1) {
            modelValue = (Integer) rowHeadersTable.getModel().getValueAt(
                    row, 0);
        } else {
            RowHeadersTableModel tm = (RowHeadersTableModel) rowHeadersTable
                    .getModel();
            modelValue = new Integer(tm.getMaxIntValue());
        }

        label.setText("" + modelValue);
        FontMetrics fontMetrics = label.getFontMetrics(label.getFont());

        int widthFactor = 0;

        if (fontMetrics != null && label.getText() != null) {
            widthFactor = fontMetrics.stringWidth(label.getText());

            rowHeadersTable
                    .setPreferredScrollableViewportSize(new Dimension(
                            widthFactor + 8, 100)); // height
            // is
            // ignored
            rowHeadersTable.repaint();
        }
    }
}

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