| /* |
| * Copyright (c) 1997, 2003, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.swing; |
| |
| import java.awt.LayoutManager; |
| import java.awt.Component; |
| import java.awt.Container; |
| import java.awt.Rectangle; |
| import java.awt.Point; |
| import java.awt.Dimension; |
| import java.awt.Insets; |
| import java.io.Serializable; |
| |
| /** |
| * The default layout manager for <code>JViewport</code>. |
| * <code>ViewportLayout</code> defines |
| * a policy for layout that should be useful for most applications. |
| * The viewport makes its view the same size as the viewport, |
| * however it will not make the view smaller than its minimum size. |
| * As the viewport grows the view is kept bottom justified until |
| * the entire view is visible, subsequently the view is kept top |
| * justified. |
| * <p> |
| * <strong>Warning:</strong> |
| * Serialized objects of this class will not be compatible with |
| * future Swing releases. The current serialization support is |
| * appropriate for short term storage or RMI between applications running |
| * the same version of Swing. As of 1.4, support for long term storage |
| * of all JavaBeans<sup><font size="-2">TM</font></sup> |
| * has been added to the <code>java.beans</code> package. |
| * Please see {@link java.beans.XMLEncoder}. |
| * |
| * @author Hans Muller |
| */ |
| public class ViewportLayout implements LayoutManager, Serializable |
| { |
| // Single instance used by JViewport. |
| static ViewportLayout SHARED_INSTANCE = new ViewportLayout(); |
| |
| /** |
| * Adds the specified component to the layout. Not used by this class. |
| * @param name the name of the component |
| * @param c the the component to be added |
| */ |
| public void addLayoutComponent(String name, Component c) { } |
| |
| /** |
| * Removes the specified component from the layout. Not used by |
| * this class. |
| * @param c the component to remove |
| */ |
| public void removeLayoutComponent(Component c) { } |
| |
| |
| /** |
| * Returns the preferred dimensions for this layout given the components |
| * in the specified target container. |
| * @param parent the component which needs to be laid out |
| * @return a <code>Dimension</code> object containing the |
| * preferred dimensions |
| * @see #minimumLayoutSize |
| */ |
| public Dimension preferredLayoutSize(Container parent) { |
| Component view = ((JViewport)parent).getView(); |
| if (view == null) { |
| return new Dimension(0, 0); |
| } |
| else if (view instanceof Scrollable) { |
| return ((Scrollable)view).getPreferredScrollableViewportSize(); |
| } |
| else { |
| return view.getPreferredSize(); |
| } |
| } |
| |
| |
| /** |
| * Returns the minimum dimensions needed to layout the components |
| * contained in the specified target container. |
| * |
| * @param parent the component which needs to be laid out |
| * @return a <code>Dimension</code> object containing the minimum |
| * dimensions |
| * @see #preferredLayoutSize |
| */ |
| public Dimension minimumLayoutSize(Container parent) { |
| return new Dimension(4, 4); |
| } |
| |
| |
| /** |
| * Called by the AWT when the specified container needs to be laid out. |
| * |
| * @param parent the container to lay out |
| * |
| * @exception AWTError if the target isn't the container specified to the |
| * <code>BoxLayout</code> constructor |
| */ |
| public void layoutContainer(Container parent) |
| { |
| JViewport vp = (JViewport)parent; |
| Component view = vp.getView(); |
| Scrollable scrollableView = null; |
| |
| if (view == null) { |
| return; |
| } |
| else if (view instanceof Scrollable) { |
| scrollableView = (Scrollable) view; |
| } |
| |
| /* All of the dimensions below are in view coordinates, except |
| * vpSize which we're converting. |
| */ |
| |
| Insets insets = vp.getInsets(); |
| Dimension viewPrefSize = view.getPreferredSize(); |
| Dimension vpSize = vp.getSize(); |
| Dimension extentSize = vp.toViewCoordinates(vpSize); |
| Dimension viewSize = new Dimension(viewPrefSize); |
| |
| if (scrollableView != null) { |
| if (scrollableView.getScrollableTracksViewportWidth()) { |
| viewSize.width = vpSize.width; |
| } |
| if (scrollableView.getScrollableTracksViewportHeight()) { |
| viewSize.height = vpSize.height; |
| } |
| } |
| |
| Point viewPosition = vp.getViewPosition(); |
| |
| /* If the new viewport size would leave empty space to the |
| * right of the view, right justify the view or left justify |
| * the view when the width of the view is smaller than the |
| * container. |
| */ |
| if (scrollableView == null || |
| vp.getParent() == null || |
| vp.getParent().getComponentOrientation().isLeftToRight()) { |
| if ((viewPosition.x + extentSize.width) > viewSize.width) { |
| viewPosition.x = Math.max(0, viewSize.width - extentSize.width); |
| } |
| } else { |
| if (extentSize.width > viewSize.width) { |
| viewPosition.x = viewSize.width - extentSize.width; |
| } else { |
| viewPosition.x = Math.max(0, Math.min(viewSize.width - extentSize.width, viewPosition.x)); |
| } |
| } |
| |
| /* If the new viewport size would leave empty space below the |
| * view, bottom justify the view or top justify the view when |
| * the height of the view is smaller than the container. |
| */ |
| if ((viewPosition.y + extentSize.height) > viewSize.height) { |
| viewPosition.y = Math.max(0, viewSize.height - extentSize.height); |
| } |
| |
| /* If we haven't been advised about how the viewports size |
| * should change wrt to the viewport, i.e. if the view isn't |
| * an instance of Scrollable, then adjust the views size as follows. |
| * |
| * If the origin of the view is showing and the viewport is |
| * bigger than the views preferred size, then make the view |
| * the same size as the viewport. |
| */ |
| if (scrollableView == null) { |
| if ((viewPosition.x == 0) && (vpSize.width > viewPrefSize.width)) { |
| viewSize.width = vpSize.width; |
| } |
| if ((viewPosition.y == 0) && (vpSize.height > viewPrefSize.height)) { |
| viewSize.height = vpSize.height; |
| } |
| } |
| vp.setViewPosition(viewPosition); |
| vp.setViewSize(viewSize); |
| } |
| } |
