SourcePositions.java revision 2571:10fc81ac75b4 
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14 * version 2 for more details (a copy is included in the LICENSE file that
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25
26package com.sun.source.util;
27
28import com.sun.source.tree.*;
29
30/**
31 * Provides methods to obtain the position of a Tree within a CompilationUnit.
32 * A position is defined as a simple character offset from the start of a
33 * CompilationUnit where the first character is at offset 0.
34 *
35 * @author Peter von der Ahé
36 * @since 1.6
37 */
38@jdk.Exported
39public interface SourcePositions {
40
41    /**
42     * Returns the starting position of tree within file.  If tree is not found within
43     * file, or if the starting position is not available,
44     * return {@link javax.tools.Diagnostic#NOPOS}.
45     * The returned position must be at the start of the yield of this tree, that
46     * is for any sub-tree of this tree, the following must hold:
47     *
48     * <p>
49     * {@code tree.getStartPosition() <= subtree.getStartPosition()} or <br>
50     * {@code tree.getStartPosition() == NOPOS} or <br>
51     * {@code subtree.getStartPosition() == NOPOS}
52     * </p>
53     *
54     * @param file CompilationUnit in which to find tree.
55     * @param tree tree for which a position is sought.
56     * @return the start position of tree.
57     */
58     long getStartPosition(CompilationUnitTree file, Tree tree);
59
60    /**
61     * Returns the ending position of tree within file.  If tree is not found within
62     * file, or if the ending position is not available,
63     * return {@link javax.tools.Diagnostic#NOPOS}.
64     * The returned position must be at the end of the yield of this tree,
65     * that is for any sub-tree of this tree, the following must hold:
66     *
67     * <p>
68     * {@code tree.getEndPosition() >= subtree.getEndPosition()} or <br>
69     * {@code tree.getEndPosition() == NOPOS} or <br>
70     * {@code subtree.getEndPosition() == NOPOS}
71     * </p>
72     *
73     * In addition, the following must hold:
74     *
75     * <p>
76     * {@code tree.getStartPosition() <= tree.getEndPosition()}  or <br>
77     * {@code tree.getStartPosition() == NOPOS} or <br>
78     * {@code tree.getEndPosition() == NOPOS}
79     * </p>
80     *
81     * @param file CompilationUnit in which to find tree.
82     * @param tree tree for which a position is sought.
83     * @return the end position of tree.
84     */
85     long getEndPosition(CompilationUnitTree file, Tree tree);
86
87}
88