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comparison dwtx/jface/text/CopyOnWriteTextStore.d @ 129:eb30df5ca28b

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Added JFace Text sources
author Frank Benoit <benoit@tionex.de>
date Sat, 23 Aug 2008 19:10:48 +0200
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children c4fb132a086c
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128:8df1d4193877 129:eb30df5ca28b
1 /*******************************************************************************
2 * Copyright (c) 2005, 2008 IBM Corporation and others.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Eclipse Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html
7 *
8 * Contributors:
9 * Anton Leherbauer (anton.leherbauer@windriver.com) - initial API and implementation
10 * Port to the D programming language:
11 * Frank Benoit <benoit@tionex.de>
12 *******************************************************************************/
13 module dwtx.jface.text.CopyOnWriteTextStore;
14
15 import dwt.dwthelper.utils;
16
17 import dwtx.core.runtime.Assert;
18
19
20 /**
21 * Copy-on-write <code>ITextStore</code> wrapper.
22 * <p>
23 * This implementation uses an unmodifiable text store for the initial content.
24 * Upon first modification attempt, the unmodifiable store is replaced with
25 * a modifiable instance which must be supplied in the constructor.</p>
26 * <p>
27 * This class is not intended to be subclassed.
28 * </p>
29 *
30 * @since 3.2
31 * @noextend This class is not intended to be subclassed by clients.
32 */
33 public class CopyOnWriteTextStore : ITextStore {
34
35 /**
36 * An unmodifiable String based text store. It is not possible to modify the content
37 * other than using {@link #set}. Trying to {@link #replace} a text range will
38 * throw an <code>UnsupportedOperationException</code>.
39 */
40 private static class StringTextStore : ITextStore {
41
42 /** Represents the content of this text store. */
43 private String fText= ""; //$NON-NLS-1$
44
45 /**
46 * Create an empty text store.
47 */
48 private StringTextStore() {
49 super();
50 }
51
52 /**
53 * Create a text store with initial content.
54 * @param text the initial content
55 */
56 private StringTextStore(String text) {
57 super();
58 set(text);
59 }
60
61 /*
62 * @see dwtx.jface.text.ITextStore#get(int)
63 */
64 public char get(int offset) {
65 return fText.charAt(offset);
66 }
67
68 /*
69 * @see dwtx.jface.text.ITextStore#get(int, int)
70 */
71 public String get(int offset, int length) {
72 return fText.substring(offset, offset + length);
73 }
74
75 /*
76 * @see dwtx.jface.text.ITextStore#getLength()
77 */
78 public int getLength() {
79 return fText.length();
80 }
81
82 /*
83 * @see dwtx.jface.text.ITextStore#replace(int, int, java.lang.String)
84 */
85 public void replace(int offset, int length, String text) {
86 // modification not supported
87 throw new UnsupportedOperationException();
88 }
89
90 /*
91 * @see dwtx.jface.text.ITextStore#set(java.lang.String)
92 */
93 public void set(String text) {
94 fText= text !is null ? text : ""; //$NON-NLS-1$
95 }
96
97 }
98
99 /** The underlying "real" text store */
100 protected ITextStore fTextStore= new StringTextStore();
101
102 /** A modifiable <code>ITextStore</code> instance */
103 private final ITextStore fModifiableTextStore;
104
105 /**
106 * Creates an empty text store. The given text store will be used upon first
107 * modification attempt.
108 *
109 * @param modifiableTextStore
110 * a modifiable <code>ITextStore</code> instance, may not be
111 * <code>null</code>
112 */
113 public CopyOnWriteTextStore(ITextStore modifiableTextStore) {
114 Assert.isNotNull(modifiableTextStore);
115 fTextStore= new StringTextStore();
116 fModifiableTextStore= modifiableTextStore;
117 }
118
119 /*
120 * @see dwtx.jface.text.ITextStore#get(int)
121 */
122 public char get(int offset) {
123 return fTextStore.get(offset);
124 }
125
126 /*
127 * @see dwtx.jface.text.ITextStore#get(int, int)
128 */
129 public String get(int offset, int length) {
130 return fTextStore.get(offset, length);
131 }
132
133 /*
134 * @see dwtx.jface.text.ITextStore#getLength()
135 */
136 public int getLength() {
137 return fTextStore.getLength();
138 }
139
140 /*
141 * @see dwtx.jface.text.ITextStore#replace(int, int, java.lang.String)
142 */
143 public void replace(int offset, int length, String text) {
144 if (fTextStore !is fModifiableTextStore) {
145 String content= fTextStore.get(0, fTextStore.getLength());
146 fTextStore= fModifiableTextStore;
147 fTextStore.set(content);
148 }
149 fTextStore.replace(offset, length, text);
150 }
151
152 /*
153 * @see dwtx.jface.text.ITextStore#set(java.lang.String)
154 */
155 public void set(String text) {
156 fTextStore= new StringTextStore(text);
157 fModifiableTextStore.set(""); //$NON-NLS-1$
158 }
159
160 }