Java tutorial
/* * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ /* * JTableHelper.java * Copyright (C) 2005-2012 University of Waikato, Hamilton, New Zealand * */ package weka.gui; import java.awt.Component; import java.awt.Point; import java.awt.Rectangle; import javax.swing.JTable; import javax.swing.JViewport; import javax.swing.table.JTableHeader; import javax.swing.table.TableCellRenderer; import javax.swing.table.TableColumn; import javax.swing.table.TableColumnModel; import javax.swing.table.TableModel; /** * A helper class for JTable, e.g. calculating the optimal colwidth. * * * @author FracPete (fracpete at waikato dot ac dot nz) * @version $Revision$ */ public class JTableHelper { // the table to work with private final JTable jtable; /** * initializes the object */ public JTableHelper(JTable jtable) { this.jtable = jtable; } /** * returns the JTable */ public JTable getJTable() { return jtable; } /** * calcs the optimal column width of the given column */ public int calcColumnWidth(int col) { return calcColumnWidth(getJTable(), col); } /** * Calculates the optimal width for the column of the given table. The * calculation is based on the preferred width of the header and cell * renderer. <br> * Taken from the newsgoup de.comp.lang.java with some modifications.<br> * Taken from FOPPS/EnhancedTable - http://fopps.sourceforge.net/<br> * * @param table the table to calculate the column width * @param col the column to calculate the widths * @return the width, -1 if error */ public static int calcColumnWidth(JTable table, int col) { int width = calcHeaderWidth(table, col); if (width == -1) { return width; } TableColumnModel columns = table.getColumnModel(); TableModel data = table.getModel(); int rowCount = data.getRowCount(); columns.getColumn(col); try { for (int row = rowCount - 1; row >= 0; --row) { Component c = table.prepareRenderer(table.getCellRenderer(row, col), row, col); width = Math.max(width, c.getPreferredSize().width + 10); } } catch (Exception e) { e.printStackTrace(); } return width; } /** * calcs the optimal header width of the given column */ public int calcHeaderWidth(int col) { return calcHeaderWidth(getJTable(), col); } /** * Calculates the optimal width for the header of the given table. The * calculation is based on the preferred width of the header renderer. * * @param table the table to calculate the column width * @param col the column to calculate the widths * @return the width, -1 if error */ public static int calcHeaderWidth(JTable table, int col) { if (table == null) { return -1; } if (col < 0 || col > table.getColumnCount()) { System.out.println("invalid col " + col); return -1; } JTableHeader header = table.getTableHeader(); TableCellRenderer defaultHeaderRenderer = null; if (header != null) { defaultHeaderRenderer = header.getDefaultRenderer(); } TableColumnModel columns = table.getColumnModel(); table.getModel(); TableColumn column = columns.getColumn(col); int width = -1; TableCellRenderer h = column.getHeaderRenderer(); if (h == null) { h = defaultHeaderRenderer; } if (h != null) { // Not explicitly impossible Component c = h.getTableCellRendererComponent(table, column.getHeaderValue(), false, false, -1, col); width = c.getPreferredSize().width + 5; } return width; } /** * sets the optimal column width for the given column */ public void setOptimalColumnWidth(int col) { setOptimalColumnWidth(getJTable(), col); } /** * sets the optimal column width for the given column */ public static void setOptimalColumnWidth(JTable jtable, int col) { int width; TableColumn column; JTableHeader header; if ((col >= 0) && (col < jtable.getColumnModel().getColumnCount())) { width = calcColumnWidth(jtable, col); if (width >= 0) { header = jtable.getTableHeader(); column = jtable.getColumnModel().getColumn(col); column.setPreferredWidth(width); jtable.sizeColumnsToFit(-1); header.repaint(); } } } /** * sets the optimal column width for all columns */ public void setOptimalColumnWidth() { setOptimalColumnWidth(getJTable()); } /** * sets the optimal column width for alls column if the given table */ public static void setOptimalColumnWidth(JTable jtable) { int i; for (i = 0; i < jtable.getColumnModel().getColumnCount(); i++) { setOptimalColumnWidth(jtable, i); } } /** * sets the optimal header width for the given column */ public void setOptimalHeaderWidth(int col) { setOptimalHeaderWidth(getJTable(), col); } /** * sets the optimal header width for the given column */ public static void setOptimalHeaderWidth(JTable jtable, int col) { int width; TableColumn column; JTableHeader header; if ((col >= 0) && (col < jtable.getColumnModel().getColumnCount())) { width = calcHeaderWidth(jtable, col); if (width >= 0) { header = jtable.getTableHeader(); column = jtable.getColumnModel().getColumn(col); column.setPreferredWidth(width); jtable.sizeColumnsToFit(-1); header.repaint(); } } } /** * sets the optimal header width for all columns */ public void setOptimalHeaderWidth() { setOptimalHeaderWidth(getJTable()); } /** * sets the optimal header width for alls column if the given table */ public static void setOptimalHeaderWidth(JTable jtable) { int i; for (i = 0; i < jtable.getColumnModel().getColumnCount(); i++) { setOptimalHeaderWidth(jtable, i); } } /** * Assumes table is contained in a JScrollPane. Scrolls the cell (rowIndex, * vColIndex) so that it is visible within the viewport. */ public void scrollToVisible(int row, int col) { scrollToVisible(getJTable(), row, col); } /** * Assumes table is contained in a JScrollPane. Scrolls the cell (rowIndex, * vColIndex) so that it is visible within the viewport. */ public static void scrollToVisible(JTable table, int row, int col) { if (!(table.getParent() instanceof JViewport)) { return; } JViewport viewport = (JViewport) table.getParent(); // This rectangle is relative to the table where the // northwest corner of cell (0,0) is always (0,0). Rectangle rect = table.getCellRect(row, col, true); // The location of the viewport relative to the table Point pt = viewport.getViewPosition(); // Translate the cell location so that it is relative // to the view, assuming the northwest corner of the // view is (0,0) rect.setLocation(rect.x - pt.x, rect.y - pt.y); // Scroll the area into view viewport.scrollRectToVisible(rect); } }