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1   package nom.tam.fits.header.hierarch;
2   
3   /*
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33  
34  import nom.tam.fits.utilities.FitsLineAppender;
35  
36  /**
37   * Interface for formatting HIERARCH-style header keywords. Our own standard is to define such keywords internally as
38   * starting with the string <code>HIERARCH.</code> followed by a dot-separated hierarchy, or just an unusually long FITS
39   * keywords that cannot be represented by a standard 8-byte keyword. The HIERARCH formatted will take such string
40   * keywords and will format them according to its rules when writing them to FITS headers.
41   * 
42   * @see nom.tam.fits.FitsFactory#setHierarchFormater(IHierarchKeyFormatter)
43   * @see Hierarch
44   */
45  @SuppressWarnings("deprecation")
46  public interface IHierarchKeyFormatter {
47  
48      /**
49       * Returns the string reppresentation of the specified HIERARCH keyword in the FITS header
50       *
51       * @param  key the HIERARCH keyword, in the dot separated convention of this library
52       *
53       * @return     how this key looks in the FITS header with this formatting convention.
54       *
55       * @since      1.16
56       */
57      String toHeaderString(String key);
58  
59      /**
60       * Appends the formatted HIERARCH keyword to the Fits line buffer. For example as a step towards builing up the
61       * header card for this keyword.
62       * 
63       * @param key    The HIERARCH keyword in out own internal representation (<code>HIERARCH.</code> followed by the
64       *                   dot-sepatated hierarchical components).
65       * @param buffer The FITS line buffer to which we want the formatted HIERARCH-style keyword to be appended.
66       */
67      void append(String key, FitsLineAppender buffer);
68  
69      /**
70       * Returns the extra spaces required when printing the key, relative to a space separated components following
71       * "HIERARCH " and the "= " prior to the value.
72       *
73       * @param  key the HIERARCH-style header key.
74       *
75       * @return     the number of extra spaces relative to the most compact notation for the components.
76       *
77       * @since      1.16
78       */
79      int getExtraSpaceRequired(String key);
80  
81      /**
82       * Sets whether case-sensitive (mixed-case) HIERARCH keywords are supported.
83       *
84       * @param value If <code>false</code> (default), then all HIERARCH keywords will be converted to upper-case.
85       *                  Otherwise, case will be preserved.
86       *
87       * @see         #isCaseSensitive()
88       *
89       * @since       1.16
90       */
91      void setCaseSensitive(boolean value);
92  
93      /**
94       * Checks if this formatter allows support for case-sensitive (mixed-case) hierarchical keywords.
95       *
96       * @return If <code>false</code> (default), then all HIERARCH keywords will be converted to upper-case. Otherwise,
97       *             case will be preserved.
98       *
99       * @since  1.16
100      */
101     boolean isCaseSensitive();
102 
103     /**
104      * Returns the assignment string that separates the hierarchical key and value components, for the given amount of
105      * space available. For example, the ESO HIERARCH convention just requires an '=' character (1 byte), but it is
106      * common to surround it with spaces before and after (3 bytes). As the spaces before an after are optional, the
107      * assignment can occupy anywhere between 1 to 3 bytes in the header card. So we can use the 3-byte version if there
108      * is room, or squeeze it down as needed.
109      * 
110      * @param  space (bytes) Number of characters available for the assignment marker to separate the keyword from the
111      *                   value part.
112      * 
113      * @return       The string to use for the assignment marker. If the space is smaller than the minimum assignment
114      *                   string length, then it returns the minimal assignment string.
115      * 
116      * @since        1.20.2
117      * 
118      * @see          #getMinAssignLength()
119      */
120     default String getAssignStringForSpace(int space) {
121         switch (space) {
122         case 1:
123             return "="; // minimal '='
124         case 2:
125             return "= "; // standard FITS style assigmnment marker
126         default:
127             return " = "; // easy to read commonly used marker
128         }
129     }
130 
131     /**
132      * Returns the minimum length of the sequence that separates keywords from values.
133      * 
134      * @return the length of the minimal key/value separator string.
135      * 
136      * @since  1.20.2
137      * 
138      * @see    #getAssignStringForSpace(int)
139      */
140     default int getMinAssignLength() {
141         return 1;
142     }
143 }