1 package nom.tam.util;
2
3 /*-
4 * #%L
5 * nom.tam FITS library
6 * %%
7 * Copyright (C) 1996 - 2024 nom-tam-fits
8 * %%
9 * This is free and unencumbered software released into the public domain.
10 *
11 * Anyone is free to copy, modify, publish, use, compile, sell, or
12 * distribute this software, either in source code form or as a compiled
13 * binary, for any purpose, commercial or non-commercial, and by any
14 * means.
15 *
16 * In jurisdictions that recognize copyright laws, the author or authors
17 * of this software dedicate any and all copyright interest in the
18 * software to the public domain. We make this dedication for the benefit
19 * of the public at large and to the detriment of our heirs and
20 * successors. We intend this dedication to be an overt act of
21 * relinquishment in perpetuity of all present and future rights to this
22 * software under copyright law.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
27 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
28 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
29 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
30 * OTHER DEALINGS IN THE SOFTWARE.
31 * #L%
32 */
33
34 /**
35 * Interface for FITS-specific output. It mainly just provides an #isAtStart()
36 * method that can be used to determine whether or not we are at the head of the
37 * file or stream, in order to decide if an HDU here should be written as
38 * primary or as a FITS extension. The decision is made by
39 * {@link nom.tam.fits.BasicHDU#write(ArrayDataOutput)} and there is no need for
40 * any user interaction beyond it.
41 *
42 * @author Attila Kovacs
43 * @since 1.17
44 */
45 public interface FitsOutput extends ArrayDataOutput {
46
47 /**
48 * Checks whether we are currently at the start of this output file or
49 * stream.
50 *
51 * @return <code>true</code> if we are currently at the start of stream
52 * (where a primary HDU is to be written), or <code>false</code> if
53 * we are further along, where HDUs should be written as extensions.
54 * @see RandomAccess#position()
55 * @see FitsEncoder#getCount()
56 */
57 boolean isAtStart();
58 }