Java tutorial
/* * JCommon : a free general purpose class library for the Java(tm) platform * * * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jcommon/index.html * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This library 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 Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * -------------- * LCBLayout.java * -------------- * (C) Copyright 2000-2005, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * $Id: LCBLayout.java,v 1.5 2005/11/16 15:58:40 taqua Exp $ * * Changes (from 26-Oct-2001) * -------------------------- * 26-Oct-2001 : Changed package to com.jrefinery.layout.* (DG); * 10-Oct-2002 : Fixed errors reported by Checkstyle (DG); */ import java.awt.Component; import java.awt.Container; import java.awt.Dimension; import java.awt.Insets; import java.awt.LayoutManager; import java.io.Serializable; /** * Specialised layout manager for a grid of components. * * @author David Gilbert */ public class LCBLayout implements LayoutManager, Serializable { /** For serialization. */ private static final long serialVersionUID = -2531780832406163833L; /** A constant for the number of columns in the layout. */ private static final int COLUMNS = 3; /** Tracks the column widths. */ private int[] colWidth; /** Tracks the row heights. */ private int[] rowHeight; /** The gap between each label and component. */ private int labelGap; /** The gap between each component and button. */ private int buttonGap; /** The gap between rows. */ private int vGap; /** * Creates a new LCBLayout with the specified maximum number of rows. * * @param maxrows the maximum number of rows. */ public LCBLayout(final int maxrows) { this.labelGap = 10; this.buttonGap = 6; this.vGap = 2; this.colWidth = new int[COLUMNS]; this.rowHeight = new int[maxrows]; } /** * Returns the preferred size using this layout manager. * * @param parent the parent. * * @return the preferred size using this layout manager. */ public Dimension preferredLayoutSize(final Container parent) { synchronized (parent.getTreeLock()) { final Insets insets = parent.getInsets(); final int ncomponents = parent.getComponentCount(); final int nrows = ncomponents / COLUMNS; for (int c = 0; c < COLUMNS; c++) { for (int r = 0; r < nrows; r++) { final Component component = parent.getComponent(r * COLUMNS + c); final Dimension d = component.getPreferredSize(); if (this.colWidth[c] < d.width) { this.colWidth[c] = d.width; } if (this.rowHeight[r] < d.height) { this.rowHeight[r] = d.height; } } } int totalHeight = this.vGap * (nrows - 1); for (int r = 0; r < nrows; r++) { totalHeight = totalHeight + this.rowHeight[r]; } final int totalWidth = this.colWidth[0] + this.labelGap + this.colWidth[1] + this.buttonGap + this.colWidth[2]; return new Dimension(insets.left + insets.right + totalWidth + this.labelGap + this.buttonGap, insets.top + insets.bottom + totalHeight + this.vGap); } } /** * Returns the minimum size using this layout manager. * * @param parent the parent. * * @return the minimum size using this layout manager. */ public Dimension minimumLayoutSize(final Container parent) { synchronized (parent.getTreeLock()) { final Insets insets = parent.getInsets(); final int ncomponents = parent.getComponentCount(); final int nrows = ncomponents / COLUMNS; for (int c = 0; c < COLUMNS; c++) { for (int r = 0; r < nrows; r++) { final Component component = parent.getComponent(r * COLUMNS + c); final Dimension d = component.getMinimumSize(); if (this.colWidth[c] < d.width) { this.colWidth[c] = d.width; } if (this.rowHeight[r] < d.height) { this.rowHeight[r] = d.height; } } } int totalHeight = this.vGap * (nrows - 1); for (int r = 0; r < nrows; r++) { totalHeight = totalHeight + this.rowHeight[r]; } final int totalWidth = this.colWidth[0] + this.labelGap + this.colWidth[1] + this.buttonGap + this.colWidth[2]; return new Dimension(insets.left + insets.right + totalWidth + this.labelGap + this.buttonGap, insets.top + insets.bottom + totalHeight + this.vGap); } } /** * Lays out the components. * * @param parent the parent. */ public void layoutContainer(final Container parent) { synchronized (parent.getTreeLock()) { final Insets insets = parent.getInsets(); final int ncomponents = parent.getComponentCount(); final int nrows = ncomponents / COLUMNS; for (int c = 0; c < COLUMNS; c++) { for (int r = 0; r < nrows; r++) { final Component component = parent.getComponent(r * COLUMNS + c); final Dimension d = component.getPreferredSize(); if (this.colWidth[c] < d.width) { this.colWidth[c] = d.width; } if (this.rowHeight[r] < d.height) { this.rowHeight[r] = d.height; } } } int totalHeight = this.vGap * (nrows - 1); for (int r = 0; r < nrows; r++) { totalHeight = totalHeight + this.rowHeight[r]; } final int totalWidth = this.colWidth[0] + this.colWidth[1] + this.colWidth[2]; // adjust the width of the second column to use up all of parent final int available = parent.getWidth() - insets.left - insets.right - this.labelGap - this.buttonGap; this.colWidth[1] = this.colWidth[1] + (available - totalWidth); // *** DO THE LAYOUT *** int x = insets.left; for (int c = 0; c < COLUMNS; c++) { int y = insets.top; for (int r = 0; r < nrows; r++) { final int i = r * COLUMNS + c; if (i < ncomponents) { final Component component = parent.getComponent(i); final Dimension d = component.getPreferredSize(); final int h = d.height; final int adjust = (this.rowHeight[r] - h) / 2; parent.getComponent(i).setBounds(x, y + adjust, this.colWidth[c], h); } y = y + this.rowHeight[r] + this.vGap; } x = x + this.colWidth[c]; if (c == 0) { x = x + this.labelGap; } if (c == 1) { x = x + this.buttonGap; } } } } /** * Not used. * * @param comp the component. */ public void addLayoutComponent(final Component comp) { // not used } /** * Not used. * * @param comp the component. */ public void removeLayoutComponent(final Component comp) { // not used } /** * Not used. * * @param name the component name. * @param comp the component. */ public void addLayoutComponent(final String name, final Component comp) { // not used } /** * Not used. * * @param name the component name. * @param comp the component. */ public void removeLayoutComponent(final String name, final Component comp) { // not used } }