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1: /* ViewportLayout.java -- 2: Copyright (C) 2002, 2004 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: package javax.swing; 39: 40: import java.awt.Component; 41: import java.awt.Container; 42: import java.awt.Dimension; 43: import java.awt.LayoutManager; 44: import java.awt.Point; 45: import java.awt.Rectangle; 46: import java.io.Serializable; 47: 48: /** 49: * ViewportLayout 50: * @author Andrew Selkirk 51: * @author Graydon Hoare 52: */ 53: public class ViewportLayout implements LayoutManager, Serializable 54: { 55: private static final long serialVersionUID = -788225906076097229L; 56: 57: public ViewportLayout() 58: { 59: } 60: public void addLayoutComponent(String name, Component c) 61: { 62: } 63: public void removeLayoutComponent(Component c) 64: { 65: } 66: 67: public Dimension preferredLayoutSize(Container parent) 68: { 69: JViewport vp = (JViewport)parent; 70: Component view = vp.getView(); 71: if (view != null) 72: return view.getPreferredSize(); 73: else 74: return new Dimension(); 75: } 76: 77: public Dimension minimumLayoutSize(Container parent) 78: { 79: JViewport vp = (JViewport)parent; 80: Component view = vp.getView(); 81: if (view != null) 82: return view.getMinimumSize(); 83: else 84: return new Dimension(); 85: } 86: 87: /** 88: * Layout the view and viewport to respect the following rules. These are 89: * not precisely the rules described in sun's javadocs, but they are the 90: * rules which sun's swing implementation follows, if you watch its 91: * behavior: 92: * 93: * <ol> 94: * 95: * <li>If the port is larger than the view's minimum size, put the port 96: * at view position <code>(0,0)</code> and make the view's size equal to 97: * the port's.</li> 98: * 99: * <li>If the port is smaller than the view, leave the view at its 100: * minimum size. also, do not move the port, <em>unless</em> the port 101: * extends into space <em>past</em> the edge of the view. If so, move the 102: * port up or to the left, in view space, by the amount of empty space 103: * (keep the lower and right edges lined up)</li> 104: * 105: * </ol> 106: * 107: * @see JViewport#getViewSize 108: * @see JViewport#setViewSize 109: * @see JViewport#getViewPosition 110: * @see JViewport#setViewPosition 111: */ 112: 113: public void layoutContainer(Container parent) 114: { 115: // The way to interpret this function is basically to ignore the names 116: // of methods it calls, and focus on the variable names here. getViewRect 117: // doesn't, for example, return the view; it returns the port bounds in 118: // view space. Likwise setViewPosition doesn't reposition the view; it 119: // positions the port, in view coordinates. 120: 121: JViewport port = (JViewport) parent; 122: Component view = port.getView(); 123: 124: if (view == null) 125: return; 126: 127: // These dimensions and positions are in *view space*. Do not mix 128: // variables in here from port space (eg. parent.getBounds()). This 129: // function should be entirely in view space, because the methods on 130: // the viewport require inputs in view space. 131: 132: Rectangle portBounds = port.getViewRect(); 133: Dimension viewPref = view.getPreferredSize(); 134: Dimension viewMinimum = view.getMinimumSize(); 135: Point portLowerRight = new Point(portBounds.x + portBounds.width, 136: portBounds.y + portBounds.height); 137: 138: // vertical implementation of the above rules 139: if (portBounds.height >= viewMinimum.height) 140: { 141: portBounds.y = 0; 142: viewPref.height = portBounds.height; 143: } 144: else 145: { 146: viewPref.height = viewMinimum.height; 147: int overextension = portLowerRight.y - viewPref.height; 148: if (overextension > 0) 149: portBounds.y -= overextension; 150: } 151: 152: // horizontal implementation of the above rules 153: if (portBounds.width >= viewMinimum.width) 154: { 155: portBounds.x = 0; 156: viewPref.width = portBounds.width; 157: } 158: else 159: { 160: viewPref.width = viewMinimum.width; 161: int overextension = portLowerRight.x - viewPref.width; 162: if (overextension > 0) 163: portBounds.x -= overextension; 164: } 165: 166: port.setViewPosition(portBounds.getLocation()); 167: port.setViewSize(viewPref); 168: } 169: }
GNU Classpath (0.17) |