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Diffstat (limited to 'libjava/classpath/javax/swing/ViewportLayout.java')
| -rw-r--r-- | libjava/classpath/javax/swing/ViewportLayout.java | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/libjava/classpath/javax/swing/ViewportLayout.java b/libjava/classpath/javax/swing/ViewportLayout.java new file mode 100644 index 0000000..18b4912 --- /dev/null +++ b/libjava/classpath/javax/swing/ViewportLayout.java @@ -0,0 +1,169 @@ +/* ViewportLayout.java -- + Copyright (C) 2002, 2004 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; + +/** + * ViewportLayout + * @author Andrew Selkirk + * @author Graydon Hoare + */ +public class ViewportLayout implements LayoutManager, Serializable +{ + private static final long serialVersionUID = -788225906076097229L; + + public ViewportLayout() + { + } + public void addLayoutComponent(String name, Component c) + { + } + public void removeLayoutComponent(Component c) + { + } + + public Dimension preferredLayoutSize(Container parent) + { + JViewport vp = (JViewport)parent; + Component view = vp.getView(); + if (view != null) + return view.getPreferredSize(); + else + return new Dimension(); + } + + public Dimension minimumLayoutSize(Container parent) + { + JViewport vp = (JViewport)parent; + Component view = vp.getView(); + if (view != null) + return view.getMinimumSize(); + else + return new Dimension(); + } + + /** + * 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 larger than the view's minimum size, put the port + * at view position <code>(0,0)</code> and make the view's size equal to + * the port's.</li> + * + * <li>If the port is smaller than the view, leave the view at its + * minimum size. also, do not move the port, <em>unless</em> the port + * extends into space <em>past</em> the edge of the view. If so, move the + * port up or to the left, in view space, by the amount of empty space + * (keep the lower and right edges lined up)</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 = view.getPreferredSize(); + Dimension viewMinimum = view.getMinimumSize(); + Point portLowerRight = new Point(portBounds.x + portBounds.width, + portBounds.y + portBounds.height); + + // vertical implementation of the above rules + if (portBounds.height >= viewMinimum.height) + { + portBounds.y = 0; + viewPref.height = portBounds.height; + } + else + { + viewPref.height = viewMinimum.height; + int overextension = portLowerRight.y - viewPref.height; + if (overextension > 0) + portBounds.y -= overextension; + } + + // horizontal implementation of the above rules + if (portBounds.width >= viewMinimum.width) + { + portBounds.x = 0; + viewPref.width = portBounds.width; + } + else + { + viewPref.width = viewMinimum.width; + int overextension = portLowerRight.x - viewPref.width; + if (overextension > 0) + portBounds.x -= overextension; + } + + port.setViewPosition(portBounds.getLocation()); + port.setViewSize(viewPref); + } +} |