| /* ViewportLayout.java -- |
| Copyright (C) 2002, 2004, 2006 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath 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 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package javax.swing; |
| |
| import java.awt.Component; |
| import java.awt.Container; |
| import java.awt.Dimension; |
| import java.awt.LayoutManager; |
| import java.awt.Point; |
| import java.awt.Rectangle; |
| import java.io.Serializable; |
| |
| /** |
| * The default layout for {@link JViewport}. The viewport makes its view the |
| * same size as itself, but not smaller than its minimum size. |
| * |
| * If the port extends extends into space <em>past</em> the edge of the view, |
| * this layout manager moves the port up or to the left, in view space, by the |
| * amount of empty space (keep the lower and right edges lined up). |
| * |
| * @author Andrew Selkirk |
| * @author Graydon Hoare |
| * @author Audrius Meskauskas (audriusa@Bioinformatics.org) |
| */ |
| public class ViewportLayout implements LayoutManager, Serializable |
| { |
| private static final long serialVersionUID = -788225906076097229L; |
| |
| public ViewportLayout() |
| { |
| // Nothing to do here. |
| } |
| |
| /** |
| * The method is not used with this manager. |
| */ |
| public void addLayoutComponent(String name, Component c) |
| { |
| // Nothing to do here. |
| } |
| |
| /** |
| * The method is not used with this manager. |
| */ |
| public void removeLayoutComponent(Component c) |
| { |
| // Nothing to do here. |
| } |
| |
| /** |
| * Get the preferred layout size. If the view implements |
| * {@link Scrollable}, this method returns |
| * {@link Scrollable#getPreferredScrollableViewportSize}. |
| * Otherwise, it returns {@link Component#getPreferredSize()}. |
| * |
| * @return the preferred layout size, as described about. |
| */ |
| public Dimension preferredLayoutSize(Container parent) |
| { |
| JViewport vp = (JViewport)parent; |
| Component view = vp.getView(); |
| if (view != null) |
| { |
| if (view instanceof Scrollable) |
| return ((Scrollable)view).getPreferredScrollableViewportSize(); |
| return view.getPreferredSize(); |
| } |
| else |
| return new Dimension(); |
| } |
| |
| /** |
| * Get the minimum layout size. Normally this method returns the value, |
| * returned by the view method {@link Component#getMinimumSize()}. |
| * |
| * If the view is not set, the zero size is returned. |
| * |
| * @param parent the viewport |
| * @return the minimum layout size. |
| */ |
| public Dimension minimumLayoutSize(Container parent) |
| { |
| // These values have been determined by the Mauve test for this method. |
| return new Dimension(4, 4); |
| } |
| |
| /** |
| * Layout the view and viewport to respect the following rules. These are not |
| * precisely the rules described in sun's javadocs, but they are the rules |
| * which sun's swing implementation follows, if you watch its behavior: |
| * <ol> |
| * <li>If the port is smaller than the view, leave the view at its current |
| * size.</li> |
| * <li>If the view is smaller than the port, the view is top aligned.</li> |
| * <li>If the view tracks the port size, the view position is always zero and |
| * the size equal to the viewport size</li> |
| * <li>In {@link JViewport#setViewSize(Dimension)}, the view size is never |
| * set smaller that its minimum size.</li> |
| * </ol> |
| * |
| * @see JViewport#getViewSize |
| * @see JViewport#setViewSize |
| * @see JViewport#getViewPosition |
| * @see JViewport#setViewPosition |
| */ |
| public void layoutContainer(Container parent) |
| { |
| // The way to interpret this function is basically to ignore the names |
| // of methods it calls, and focus on the variable names here. getViewRect |
| // doesn't, for example, return the view; it returns the port bounds in |
| // view space. Likwise setViewPosition doesn't reposition the view; it |
| // positions the port, in view coordinates. |
| |
| JViewport port = (JViewport) parent; |
| Component view = port.getView(); |
| |
| if (view == null) |
| return; |
| |
| // These dimensions and positions are in *view space*. Do not mix |
| // variables in here from port space (eg. parent.getBounds()). This |
| // function should be entirely in view space, because the methods on |
| // the viewport require inputs in view space. |
| |
| Rectangle portBounds = port.getViewRect(); |
| Dimension viewPref = new Dimension(view.getPreferredSize()); |
| |
| Point portLowerRight = new Point(portBounds.x + portBounds.width, |
| portBounds.y + portBounds.height); |
| |
| // vertical implementation of the above rules |
| if (view instanceof Scrollable) |
| { |
| Scrollable sView = (Scrollable) view; |
| |
| // If the view size matches viewport size, the port offset can |
| // only be zero. |
| if (sView.getScrollableTracksViewportWidth()) |
| { |
| viewPref.width = portBounds.width; |
| portBounds.x = 0; |
| } |
| if (sView.getScrollableTracksViewportHeight()) |
| { |
| viewPref.height = portBounds.height; |
| portBounds.y = 0; |
| } |
| } |
| |
| if (viewPref.width < portBounds.width) |
| viewPref.width = portBounds.width; |
| if (viewPref.height < portBounds.height) |
| viewPref.height = portBounds.height; |
| |
| // If the view is larger than the port, the port is top and right |
| // aligned. |
| if (portLowerRight.x > viewPref.width) |
| portBounds.x = 0; |
| |
| if (portLowerRight.y > viewPref.height) |
| portBounds.y = 0; |
| |
| port.setViewSize(viewPref); |
| port.setViewPosition(portBounds.getLocation()); |
| } |
| |
| } |