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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: { 73: if (view instanceof Scrollable) 74: return ((Scrollable)view).getPreferredScrollableViewportSize(); 75: return view.getPreferredSize(); 76: } 77: else 78: return new Dimension(); 79: } 80: 81: public Dimension minimumLayoutSize(Container parent) 82: { 83: JViewport vp = (JViewport)parent; 84: Component view = vp.getView(); 85: if (view != null) 86: return view.getMinimumSize(); 87: else 88: return new Dimension(); 89: } 90: 91: /** 92: * Layout the view and viewport to respect the following rules. These are 93: * not precisely the rules described in sun's javadocs, but they are the 94: * rules which sun's swing implementation follows, if you watch its 95: * behavior: 96: * 97: * <ol> 98: * 99: * <li>If the port is larger than the view's minimum size, put the port 100: * at view position <code>(0,0)</code> and make the view's size equal to 101: * the port's.</li> 102: * 103: * <li>If the port is smaller than the view, leave the view at its 104: * minimum size. also, do not move the port, <em>unless</em> the port 105: * extends into space <em>past</em> the edge of the view. If so, move the 106: * port up or to the left, in view space, by the amount of empty space 107: * (keep the lower and right edges lined up)</li> 108: * 109: * </ol> 110: * 111: * @see JViewport#getViewSize 112: * @see JViewport#setViewSize 113: * @see JViewport#getViewPosition 114: * @see JViewport#setViewPosition 115: */ 116: 117: public void layoutContainer(Container parent) 118: { 119: // The way to interpret this function is basically to ignore the names 120: // of methods it calls, and focus on the variable names here. getViewRect 121: // doesn't, for example, return the view; it returns the port bounds in 122: // view space. Likwise setViewPosition doesn't reposition the view; it 123: // positions the port, in view coordinates. 124: 125: JViewport port = (JViewport) parent; 126: Component view = port.getView(); 127: 128: if (view == null) 129: return; 130: 131: // These dimensions and positions are in *view space*. Do not mix 132: // variables in here from port space (eg. parent.getBounds()). This 133: // function should be entirely in view space, because the methods on 134: // the viewport require inputs in view space. 135: 136: Rectangle portBounds = port.getViewRect(); 137: Dimension viewPref = view.getPreferredSize(); 138: Dimension viewMinimum = view.getMinimumSize(); 139: Point portLowerRight = new Point(portBounds.x + portBounds.width, 140: portBounds.y + portBounds.height); 141: 142: // vertical implementation of the above rules 143: if (portBounds.height >= viewMinimum.height) 144: { 145: portBounds.y = 0; 146: if ( !(view instanceof Scrollable) || ((Scrollable)view).getScrollableTracksViewportHeight()) 147: viewPref.height = portBounds.height; 148: } 149: else 150: { 151: viewPref.height = viewMinimum.height; 152: int overextension = portLowerRight.y - viewPref.height; 153: if (overextension > 0) 154: portBounds.y -= overextension; 155: } 156: 157: // horizontal implementation of the above rules 158: if (portBounds.width >= viewMinimum.width) 159: { 160: portBounds.x = 0; 161: if ( !(view instanceof Scrollable) || ((Scrollable)view).getScrollableTracksViewportWidth()) 162: viewPref.width = portBounds.width; 163: } 164: else 165: { 166: viewPref.width = viewMinimum.width; 167: int overextension = portLowerRight.x - viewPref.width; 168: if (overextension > 0) 169: portBounds.x -= overextension; 170: } 171: 172: port.setViewPosition(portBounds.getLocation()); 173: port.setViewSize(viewPref); 174: } 175: }
GNU Classpath (0.18) |