1 | /*
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2 | * 10/28/2004
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3 | *
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4 | * DefaultTokenFactory.java - Default token factory.
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5 | *
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6 | * This library is distributed under a modified BSD license. See the included
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7 | * RSyntaxTextArea.License.txt file for details.
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8 | */
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9 | package org.fife.ui.rsyntaxtextarea;
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10 |
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11 | import javax.swing.text.Segment;
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12 |
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13 |
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14 | /**
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15 | * This class generates tokens for a {@link TokenMaker}. This class is here
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16 | * because it reuses tokens when they aren't needed anymore to prevent
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17 | * This class doesn't actually create new tokens every time
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18 | * <code>createToken</code> is called. Instead, it internally keeps a stack of
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19 | * available already-created tokens. When more tokens are needed to properly
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20 | * display a line, more tokens are added to the available stack. This saves
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21 | * from needless repetitive memory allocation. However, it makes it IMPERATIVE
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22 | * that users call <code>resetTokenList</code> when creating a new token list so
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23 | * that the token maker can keep an accurate list of available tokens.<p>
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24 | *
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25 | * NOTE: This class should only be used by {@link TokenMaker}; nobody else
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26 | * needs it!
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27 | *
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28 | * @author Robert Futrell
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29 | * @version 0.1
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30 | */
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31 | class DefaultTokenFactory implements TokenFactory {
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32 |
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33 | private int size;
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34 | private int increment;
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35 | private Token[] tokenList;
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36 | private int currentFreeToken;
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37 |
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38 | protected static final int DEFAULT_START_SIZE = 30;
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39 | protected static final int DEFAULT_INCREMENT = 10;
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40 |
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41 |
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42 | /**
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43 | * Cosnstructor.
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44 | */
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45 | public DefaultTokenFactory() {
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46 | this(DEFAULT_START_SIZE, DEFAULT_INCREMENT);
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47 | }
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48 |
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49 |
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50 | /**
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51 | * Constructor.
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52 | *
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53 | * @param size The initial number of tokens in this factory.
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54 | * @param increment How many tokens to increment by when the stack gets
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55 | * empty.
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56 | */
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57 | public DefaultTokenFactory(int size, int increment) {
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58 |
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59 | this.size = size;
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60 | this.increment = increment;
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61 | this.currentFreeToken = 0;
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62 |
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63 | // Give us some tokens to initially work with.
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64 | tokenList = new Token[size];
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65 | for (int i=0; i<size; i++)
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66 | tokenList[i] = createInternalUseOnlyToken();
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67 |
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68 | }
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69 |
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70 |
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71 | /**
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72 | * Adds tokens to the internal token list. This is called whenever a
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73 | * request is made and no more tokens are available.
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74 | */
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75 | private final void augmentTokenList() {
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76 | Token[] temp = new Token[size + increment];
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77 | System.arraycopy(tokenList,0, temp,0, size);
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78 | size += increment;
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79 | tokenList = temp;
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80 | for (int i=0; i<increment; i++) {
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81 | tokenList[size-i-1] = createInternalUseOnlyToken();
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82 | }
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83 | //System.err.println("... size up to: " + size);
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84 | }
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85 |
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86 |
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87 | /**
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88 | * Creates a token for use internally by this token factory. This method
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89 | * should NOT be called externally; only by this class and possibly
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90 | * subclasses.
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91 | *
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92 | * @return A token to add to this token factory's internal stack. If a
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93 | * subclass wants to produce a stack of a token other than
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94 | * {@link DefaultToken}, then this method can be overridden to
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95 | * return a new instance of the desired token type.
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96 | */
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97 | protected Token createInternalUseOnlyToken() {
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98 | return new DefaultToken();
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99 | }
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100 |
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101 |
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102 | /**
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103 | * Returns a null token.
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104 | *
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105 | * @return A null token.
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106 | */
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107 | public Token createToken() {
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108 | Token token = tokenList[currentFreeToken];
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109 | token.text = null;
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110 | token.type = Token.NULL;
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111 | token.offset = -1;
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112 | token.setNextToken(null);
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113 | currentFreeToken++;
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114 | if (currentFreeToken==size)
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115 | augmentTokenList();
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116 | return token;
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117 | }
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118 |
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119 |
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120 | /**
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121 | * Returns a token.
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122 | *
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123 | * @param line The segment from which to get the token's text.
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124 | * @param beg The starting offset of the token's text in the segment.
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125 | * @param end The ending offset of the token's text in the segment.
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126 | * @param startOffset The offset in the document of the token.
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127 | * @param type The type of token.
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128 | * @return The token.
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129 | */
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130 | public Token createToken(final Segment line, final int beg,
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131 | final int end, final int startOffset, final int type) {
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132 | return createToken(line.array, beg,end, startOffset, type);
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133 | }
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134 |
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135 |
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136 | /**
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137 | * Returns a token.
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138 | *
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139 | * @param line The segment from which to get the token's text.
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140 | * @param beg The starting offset of the token's text in the segment.
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141 | * @param end The ending offset of the token's text in the segment.
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142 | * @param startOffset The offset in the document of the token.
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143 | * @param type The type of token.
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144 | * @return The token.
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145 | */
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146 | public Token createToken(final char[] line, final int beg,
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147 | final int end, final int startOffset, final int type) {
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148 | Token token = tokenList[currentFreeToken];
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149 | token.set(line, beg,end, startOffset, type);
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150 | currentFreeToken++;
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151 | if (currentFreeToken==size)
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152 | augmentTokenList();
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153 | return token;
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154 | }
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155 |
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156 |
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157 | /**
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158 | * Resets the state of this token maker. This method should be called
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159 | * by the <code>TokenMaker</code> every time a token list is generated for
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160 | * a new line so the tokens can be reused.
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161 | */
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162 | public void resetAllTokens() {
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163 | currentFreeToken = 0;
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164 | }
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165 |
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166 |
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167 | } |
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