[gdk-pixbuf/rst-man] Replace DocBook with reStructuredText for man pages

[Emmanuele Bassi <ebassi src gnome org>]

commit 9b3aea45fabc90aaf335eeef8a35579fd8e37a86
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Fri May 13 00:29:25 2022 +0100

    Replace DocBook with reStructuredText for man pages
    
    The dependency on xsltproc and the DocBook style sheets is vaguely
    annoying, and there are better tools these days that do not require
    writing XML.

 docs/gdk-pixbuf-csource.rst       | 101 ++++++++++++++++++++++
 docs/gdk-pixbuf-csource.xml       | 177 --------------------------------------
 docs/gdk-pixbuf-query-loaders.rst |  51 +++++++++++
 docs/gdk-pixbuf-query-loaders.xml |  79 -----------------
 docs/meson.build                  |  52 +++++------
 5 files changed, 179 insertions(+), 281 deletions(-)
---
diff --git a/docs/gdk-pixbuf-csource.rst b/docs/gdk-pixbuf-csource.rst
new file mode 100644
index 000000000..43854bccd
--- /dev/null
+++ b/docs/gdk-pixbuf-csource.rst
@@ -0,0 +1,101 @@
+.. _gdk-pixbuf-csource(1):
+
+==================
+gdk-pixbuf-csource
+==================
+
+----------------------------------------------
+C code generation utility for GdkPixbuf images
+----------------------------------------------
+
+SYNOPSIS
+--------
+|   **gdk-pixbuf-csource** [OPTIONS...] <IMAGE>
+
+DESCRIPTION
+-----------
+
+``gdk-pixbuf-csource`` is a small utility that generates C code containing
+images, useful for compiling images directly into programs.
+
+``gdk-pixbuf-csource`` either takes as input one image file name to generate
+code for, or, using the ``--build-list`` option, a list of (``name``, ``image``)
+pairs to generate code for a list of images into named variables.
+
+This tool is mostly meant to be used for backward compatibility. Newly written
+applications and libraries should use GResource to embed image assets in their
+binary.
+
+OPTIONS
+-------
+
+``--stream``
+
+  Generate pixbuf data stream: a single string containing a serialized
+  ``GdkPixdata`` structure in network byte order.
+
+``--struct``
+
+  Generate ``GdkPixdata`` structure; your code needs the ``GdkPixdata``
+  structure definition from ``gdk-pixdata.h``.
+
+``--macros``
+
+  Generate ``*_ROWSTRIDE``, ``*_WIDTH``, ``*_HEIGHT``, ``*_BYTES_PER_PIXEL``
+  and ``*_RLE_PIXEL_DATA`` or ``*_PIXEL_DATA`` macro definitions for the
+  image.
+
+``--rle``
+
+  Enables run-length encoding for the generated pixel data (default).
+
+``--raw``
+
+  Disables run-length encoding for the generated pixel data.
+
+``--extern``
+
+  Generate extern symbols.
+
+``--static``
+
+  Generate static symbols (default).
+
+``--decoder``
+
+  Provide a ``*_RUN_LENGTH_DECODE(image_buf, rle_data, size, bpp)`` macro
+  definition to decode run-length encoded image data.
+
+``--name=identifier``
+
+  Specifies the identifier name (prefix) for the generated variables or
+  macros (useful only if ``--build-list`` was not specified).
+
+``--build-list``
+
+  Enables (``name``, ``image``) pair parsing mode.
+
+``-h, --help``
+
+  Prints a brief help and exit.
+
+``-v, --version``
+
+  Prints the tool version and exit.
+
+``--g-fatal-warnings``
+
+  Makes warnings fatal, and causes the program to abort.
+
+SEE ALSO
+--------
+
+The ``GdkPixbuf`` documentation, shipped by gdk-pixbuf, and also
+available online on `docs.gtk.org <https://docs.gtk.org/gdk-pixbuf/>`__.
+
+BUGS
+----
+
+The runlength encoder gets out of sync with the pixel boundaries, since
+it includes the rowstride padding in the encoded stream. Furthermore, it
+generates pixbufs with suboptimal rowstride in some cases.
diff --git a/docs/gdk-pixbuf-query-loaders.rst b/docs/gdk-pixbuf-query-loaders.rst
new file mode 100644
index 000000000..8fc9e7eba
--- /dev/null
+++ b/docs/gdk-pixbuf-query-loaders.rst
@@ -0,0 +1,51 @@
+.. _gdk-pixbuf-query-loaders(1):
+
+========================
+gdk-pixbuf-query-loaders
+========================
+
+-------------------------------------
+GdkPixbuf loader registration utility
+-------------------------------------
+
+SYNOPSIS
+--------
+|   **gdk-pixbuf-query-loaders** [OPTIONS...] [MODULES..]
+
+DESCRIPTION
+-----------
+
+``gdk-pixbuf-query-loaders`` collects information about loadable modules for
+``gdk-pixbuf`` and writes it to the default cache file location, or to
+``stdout``.
+
+If called without arguments, it looks for modules in the ``gdk-pixbuf`` loader
+directory.
+
+If called with arguments, it looks for the specified modules. The arguments may
+be absolute or relative paths.
+
+Normally, the output of ``gdk-pixbuf-query-loaders`` is written to
+``$libdir/gdk-pixbuf-2.0/2.10.0/loaders.cache``, where ``gdk-pixbuf`` looks for
+it by default. If it is written to some other location, the environment variable
+``GDK_PIXBUF_MODULE_FILE`` can be set to point ``gdk-pixbuf`` at the file.
+
+OPTIONS
+-------
+
+``--update-cache``
+
+  Writes the output to the default cache location instead of the standard
+  output.
+
+ENVIRONMENT
+-----------
+
+The environment variable ``GDK_PIXBUF_MODULEDIR`` can be used to specify a
+different loader directory.
+
+The default ``gdk-pixbuf`` loader directory is
+``LIBDIR/gdk-pixbuf-2.0/VERSION/loaders``, where:
+
+- ``LIBDIR`` is the libdir used when building ``gdk-pixbuf``
+- ``VERSION`` is the ABI version for ``gdk-pixbuf`` loaders
diff --git a/docs/meson.build b/docs/meson.build
index 9c065f7c4..c4ba5e400 100644
--- a/docs/meson.build
+++ b/docs/meson.build
@@ -65,34 +65,36 @@ if build_docs
   )
 endif
 
-xsltproc = find_program('xsltproc', required: false)
-if get_option('man') and xsltproc.found()
-  xlstproc_flags = [
-    '--nonet',
-    '--stringparam', 'man.output.quietly', '1',
-    '--stringparam', 'funcsynopsis.style', 'ansi',
-    '--stringparam', 'man.th.extra1.suppress', '1',
-    '--stringparam', 'man.authors.section.enabled', '0',
-    '--stringparam', 'man.copyright.section.enabled', '0',
+rst2man = find_program('rst2man', required: false)
+if get_option('man') and not rst2man.found()
+  error('No rst2man found, but man pages were explicitly enabled')
+endif
+
+if get_option('man') and rst2man.found()
+  rst_files = [
+    [ 'gdk-pixbuf-csource', ],
+    [ 'gdk-pixbuf-query-loaders', ],
   ]
 
-  man_files = [
-    'gdk-pixbuf-csource',
-    'gdk-pixbuf-query-loaders',
+  rst2man_flags = [
+    '--syntax-highlight=none',
   ]
 
-  foreach m: man_files
-    custom_target(m + '-man',
-                  input: '@0@.xml'.format(m),
-                  output: '@0@.1'.format(m),
-                  command: [
-                    xsltproc,
-                    xlstproc_flags,
-                    '-o', '@OUTPUT@',
-                    'http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl',
-                    '@INPUT@',
-                  ],
-                  install: true,
-                  install_dir: join_paths(gdk_pixbuf_mandir, 'man1'))
+  foreach rst: rst_files
+    man_name = rst[0]
+    man_section = rst.get(1, '1')
+
+    custom_target('man-@0@'.format(man_name),
+      input: '@0@.rst'.format(man_name),
+      output: '@0@.@1@'.format(man_name, man_section),
+      command: [
+        rst2man,
+        rst2man_flags,
+        '@INPUT@',
+      ],
+      capture: true,
+      install: true,
+      install_dir: get_option('mandir') / 'man@0@'.format(man_section),
+    )
   endforeach
 endif