1 files changed, 99 insertions, 0 deletions
diff --git a/Documentation/sphinx/translations.py b/Documentation/sphinx/translations.py
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+++ b/Documentation/sphinx/translations.py
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+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright © 2023, Oracle and/or its affiliates.
+# Author: Vegard Nossum <vegard.nossum@oracle.com>
+#
+# Add translation links to the top of the document.
+#
+
+import os
+
+from docutils import nodes
+from docutils.transforms import Transform
+
+import sphinx
+from sphinx import addnodes
+from sphinx.errors import NoUri
+
+all_languages = {
+    # English is always first
+    None: 'English',
+
+    # Keep the rest sorted alphabetically
+    'zh_CN': 'Chinese (Simplified)',
+    'zh_TW': 'Chinese (Traditional)',
+    'it_IT': 'Italian',
+    'ja_JP': 'Japanese',
+    'ko_KR': 'Korean',
+    'sp_SP': 'Spanish',
+}
+
+class LanguagesNode(nodes.Element):
+    pass
+
+class TranslationsTransform(Transform):
+    default_priority = 900
+
+    def apply(self):
+        app = self.document.settings.env.app
+        docname = self.document.settings.env.docname
+
+        this_lang_code = None
+        components = docname.split(os.sep)
+        if components[0] == 'translations' and len(components) > 2:
+            this_lang_code = components[1]
+
+            # normalize docname to be the untranslated one
+            docname = os.path.join(*components[2:])
+
+        new_nodes = LanguagesNode()
+        new_nodes['current_language'] = all_languages[this_lang_code]
+
+        for lang_code, lang_name in all_languages.items():
+            if lang_code == this_lang_code:
+                continue
+
+            if lang_code is None:
+                target_name = docname
+            else:
+                target_name = os.path.join('translations', lang_code, docname)
+
+            pxref = addnodes.pending_xref('', refdomain='std',
+                reftype='doc', reftarget='/' + target_name, modname=None,
+                classname=None, refexplicit=True)
+            pxref += nodes.Text(lang_name)
+            new_nodes += pxref
+
+        self.document.insert(0, new_nodes)
+
+def process_languages(app, doctree, docname):
+    for node in doctree.traverse(LanguagesNode):
+        if app.builder.format not in ['html']:
+            node.parent.remove(node)
+            continue
+
+        languages = []
+
+        # Iterate over the child nodes; any resolved links will have
+        # the type 'nodes.reference', while unresolved links will be
+        # type 'nodes.Text'.
+        languages = list(filter(lambda xref:
+            isinstance(xref, nodes.reference), node.children))
+
+        html_content = app.builder.templates.render('translations.html',
+            context={
+                'current_language': node['current_language'],
+                'languages': languages,
+            })
+
+        node.replace_self(nodes.raw('', html_content, format='html'))
+
+def setup(app):
+    app.add_node(LanguagesNode)
+    app.add_transform(TranslationsTransform)
+    app.connect('doctree-resolved', process_languages)
+
+    return {
+        'parallel_read_safe': True,
+        'parallel_write_safe': True,
+    }