1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200
/* * @(#)LayoutStyle.java 1.2 05/11/17 * * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ package javax.swing; import java.awt.Container; import javax.swing.plaf.ComponentUI; import sun.awt.AppContext; /** * <code>LayoutStyle</code> provides information about how to position * components. This class is primarily useful for visual tools and * layout managers. Most developers will not need to use this class. * <p> * You typically don't set or create a * <code>LayoutStyle</code>. Instead use the static method * <code>getInstance</code> to obtain the current instance. * * @version 1.2, 11/17/05 * @since 1.6 */ public abstract class LayoutStyle { /** * Sets the shared instance of <code>LayoutStyle</code>. Specifying * <code>null</code> results in using the <code>LayoutStyle</code> from * the current <code>LookAndFeel</code>. * * @param style the <code>LayoutStyle</code>, or <code>null</code> * @see #getInstance */ public static void setInstance(LayoutStyle style) { synchronized(LayoutStyle.class) { if (style == null) { AppContext.getAppContext().remove(LayoutStyle.class); } else { AppContext.getAppContext().put(LayoutStyle.class, style); } } } /** * Returns the shared instance of <code>LayoutStyle</code>. If an instance * has not been specified in <code>setInstance</code>, this will return * the <code>LayoutStyle</code> from the current <code>LookAndFeel</code>. * * @see LookAndFeel#getLayoutStyle * @return the shared instance of <code>LayoutStyle</code> */ public static LayoutStyle getInstance() { LayoutStyle style; synchronized(LayoutStyle.class) { style = (LayoutStyle)AppContext.getAppContext(). get(LayoutStyle.class); } if (style == null) { return UIManager.getLookAndFeel().getLayoutStyle(); } return style; } /** * <code>ComponentPlacement</code> is an enumeration of the * possible ways two components can be placed relative to each * other. <code>ComponentPlacement</code> is used by the * <code>LayoutStyle</code> method <code>getPreferredGap</code>. Refer to * <code>LayoutStyle</code> for more information. * * @see LayoutStyle#getPreferredGap(JComponent,JComponent, * ComponentPlacement,int,Container) * @since 1.6 */ public enum ComponentPlacement { /** * Enumeration value indicating the two components are * visually related and will be placed in the same parent. * For example, a <code>JLabel</code> providing a label for a * <code>JTextField</code> is typically visually associated * with the <code>JTextField</code>; the constant <code>RELATED</code> * is used for this. */ RELATED, /** * Enumeration value indicating the two components are * visually unrelated and will be placed in the same parent. * For example, groupings of components are usually visually * separated; the constant <code>UNRELATED</code> is used for this. */ UNRELATED, /** * Enumeration value indicating the distance to indent a component * is being requested. For example, often times the children of * a label will be horizontally indented from the label. To determine * the preferred distance for such a gap use the * <code>INDENT</code> type. * <p> * This value is typically only useful with a direction of * <code>EAST</code> or <code>WEST</code>. */ INDENT; } /** * Creates a new <code>LayoutStyle</code>. You generally don't * create a <code>LayoutStyle</code>. Instead use the method * <code>getInstance</code> to obtain the current * <code>LayoutStyle</code>. */ public LayoutStyle() { } /** * Returns the amount of space to use between two components. * The return value indicates the distance to place * <code>component2</code> relative to <code>component1</code>. * For example, the following returns the amount of space to place * between <code>component2</code> and <code>component1</code> * when <code>component2</code> is placed vertically above * <code>component1</code>: * <pre> * int gap = getPreferredGap(component1, component2, * ComponentPlacement.RELATED, * SwingConstants.NORTH, parent); * </pre> * The <code>type</code> parameter indicates the relation between * the two components. If the two components will be contained in * the same parent and are showing similar logically related * items, use <code>RELATED</code>. If the two components will be * contained in the same parent but show logically unrelated items * use <code>UNRELATED</code>. Some look and feels may not * distinguish between the <code>RELATED</code> and * <code>UNRELATED</code> types. * <p> * The return value is not intended to take into account the * current size and position of <code>component2</code> or * <code>component1</code>. The return value may take into * consideration various properties of the components. For * example, the space may vary based on font size, or the preferred * size of the component. * * @param component1 the <code>JComponent</code> * <code>component2</code> is being placed relative to * @param component2 the <code>JComponent</code> being placed * @param position the position <code>component2</code> is being placed * relative to <code>component1</code>; one of * <code>SwingConstants.NORTH</code>, * <code>SwingConstants.SOUTH</code>, * <code>SwingConstants.EAST</code> or * <code>SwingConstants.WEST</code> * @param type how the two components are being placed * @param parent the parent of <code>component2</code>; this may differ * from the actual parent and it may be <code>null</code> * @return the amount of space to place between the two components * @throws NullPointerException if <code>component1</code>, * <code>component2</code> or <code>type</code> is * <code>null</code> * @throws IllegalArgumentException if <code>position</code> is not * one of <code>SwingConstants.NORTH</code>, * <code>SwingConstants.SOUTH</code>, * <code>SwingConstants.EAST</code> or * <code>SwingConstants.WEST</code> * @see LookAndFeel#getLayoutStyle * @since 1.6 */ public abstract int getPreferredGap(JComponent component1, JComponent component2, ComponentPlacement type, int position, Container parent); /** * Returns the amount of space to place between the component and specified * edge of its parent. * * @param component the <code>JComponent</code> being positioned * @param position the position <code>component</code> is being placed * relative to its parent; one of * <code>SwingConstants.NORTH</code>, * <code>SwingConstants.SOUTH</code>, * <code>SwingConstants.EAST</code> or * <code>SwingConstants.WEST</code> * @param parent the parent of <code>component</code>; this may differ * from the actual parent and may be <code>null</code> * @return the amount of space to place between the component and specified * edge * @throws IllegalArgumentException if <code>position</code> is not * one of <code>SwingConstants.NORTH</code>, * <code>SwingConstants.SOUTH</code>, * <code>SwingConstants.EAST</code> or * <code>SwingConstants.WEST</code> */ public abstract int getContainerGap(JComponent component, int position, Container parent); }