1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package javax.swing.text;
26
27 import java.io.Serializable;
28
29 /**
30 * This class encapsulates a single tab stop (basically as tab stops
31 * are thought of by RTF). A tab stop is at a specified distance from the
32 * left margin, aligns text in a specified way, and has a specified leader.
33 * TabStops are immutable, and usually contained in TabSets.
34 * <p>
35 * <strong>Warning:</strong>
36 * Serialized objects of this class will not be compatible with
37 * future Swing releases. The current serialization support is
38 * appropriate for short term storage or RMI between applications running
39 * the same version of Swing. As of 1.4, support for long term storage
40 * of all JavaBeans™
41 * has been added to the <code>java.beans</code> package.
42 * Please see {@link java.beans.XMLEncoder}.
43 *
44 */
45 @SuppressWarnings("serial") // Same-version serialization only
46 public class TabStop implements Serializable {
47
48 /** Character following tab is positioned at location. */
49 public static final int ALIGN_LEFT = 0;
50 /** Characters following tab are positioned such that all following
51 * characters up to next tab/newline end at location. */
52 public static final int ALIGN_RIGHT = 1;
53 /** Characters following tab are positioned such that all following
54 * characters up to next tab/newline are centered around the tabs
55 * location. */
56 public static final int ALIGN_CENTER = 2;
57 /** Characters following tab are aligned such that next
58 * decimal/tab/newline is at the tab location, very similar to
59 * RIGHT_TAB, just includes decimal as additional character to look for.
60 */
61 public static final int ALIGN_DECIMAL = 4;
62 public static final int ALIGN_BAR = 5;
63
64 /* Bar tabs (whatever they are) are actually a separate kind of tab
65 in the RTF spec. However, being a bar tab and having alignment
66 properties are mutually exclusive, so the reader treats barness
67 as being a kind of alignment. */
68
69 public static final int LEAD_NONE = 0;
70 public static final int LEAD_DOTS = 1;
71 public static final int LEAD_HYPHENS = 2;
72 public static final int LEAD_UNDERLINE = 3;
73 public static final int LEAD_THICKLINE = 4;
74 public static final int LEAD_EQUALS = 5;
75
76 /** Tab type. */
77 private int alignment;
78 /** Location, from the left margin, that tab is at. */
79 private float position;
80 private int leader;
81
82 /**
83 * Creates a tab at position <code>pos</code> with a default alignment
84 * and default leader.
85 */
86 public TabStop(float pos) {
87 this(pos, ALIGN_LEFT, LEAD_NONE);
88 }
89
90 /**
91 * Creates a tab with the specified position <code>pos</code>,
92 * alignment <code>align</code> and leader <code>leader</code>.
93 */
94 public TabStop(float pos, int align, int leader) {
95 alignment = align;
96 this.leader = leader;
97 position = pos;
98 }
99
100 /**
101 * Returns the position, as a float, of the tab.
102 * @return the position of the tab
103 */
104 public float getPosition() {
105 return position;
106 }
107
108 /**
109 * Returns the alignment, as an integer, of the tab.
110 * @return the alignment of the tab
111 */
112 public int getAlignment() {
113 return alignment;
114 }
115
116 /**
117 * Returns the leader of the tab.
118 * @return the leader of the tab
119 */
120 public int getLeader() {
121 return leader;
122 }
123
124 /**
125 * Returns true if the tabs are equal.
126 * @return true if the tabs are equal, otherwise false
127 */
128 public boolean equals(Object other)
129 {
130 if (other == this) {
131 return true;
132 }
133 if (other instanceof TabStop) {
134 TabStop o = (TabStop)other;
135 return ( (alignment == o.alignment) &&
136 (leader == o.leader) &&
137 (position == o.position) ); /* TODO: epsilon */
138 }
139 return false;
140 }
141
142 /**
143 * Returns the hashCode for the object. This must be defined
144 * here to ensure 100% pure.
145 *
146 * @return the hashCode for the object
147 */
148 public int hashCode() {
149 return alignment ^ leader ^ Math.round(position);
150 }
151
152 /* This is for debugging; perhaps it should be removed before release */
153 public String toString() {
154 String buf;
155 switch(alignment) {
156 default:
157 case ALIGN_LEFT:
158 buf = "";
159 break;
160 case ALIGN_RIGHT:
161 buf = "right ";
162 break;
163 case ALIGN_CENTER:
164 buf = "center ";
165 break;
166 case ALIGN_DECIMAL:
167 buf = "decimal ";
168 break;
169 case ALIGN_BAR:
170 buf = "bar ";
171 break;
172 }
173 buf = buf + "tab @" + String.valueOf(position);
174 if (leader != LEAD_NONE)
175 buf = buf + " (w/leaders)";
176 return buf;
177 }
178 }