[gegl] docs: add navigation to operation api source files

[Øyvind "pippin" Kolås <ok src gnome org>]

commit e79f2251ac0e60ca26b3167391d358711b727920
Author: John <jtm home gmail com>
Date:   Mon Feb 15 11:01:52 2021 +0000

    docs: add navigation to operation api source files

 docs/images/GEGL-250.png | Bin 0 -> 14086 bytes
 docs/meson.build         |   1 +
 docs/website/meson.build |   4 ++--
 docs/website/source.adoc |  32 ++++++++++++++++++++++++++++++++
 docs/website/src.adoc    |  11 -----------
 docs/website/src.txt     |   8 --------
 6 files changed, 35 insertions(+), 21 deletions(-)
---
diff --git a/docs/images/GEGL-250.png b/docs/images/GEGL-250.png
new file mode 100644
index 000000000..7f8e6af15
Binary files /dev/null and b/docs/images/GEGL-250.png differ
diff --git a/docs/meson.build b/docs/meson.build
index 95f249406..f8c8b6fd8 100644
--- a/docs/meson.build
+++ b/docs/meson.build
@@ -19,6 +19,7 @@ endif
 # images
 images = files(
   'images' / 'GEGL.png',
+  'images' / 'GEGL-250.png',
   'images' / 'gaussian-blur-graph.png',
 )
 
diff --git a/docs/website/meson.build b/docs/website/meson.build
index 01de760bf..77dc3ae23 100644
--- a/docs/website/meson.build
+++ b/docs/website/meson.build
@@ -72,11 +72,11 @@ source_files = {
     project_source_root / 'operations' / 'common',
 }
 
-# asciidoc source files
+# generate operation api website source files
 foreach _file, _path : source_files
   custom_target(
     '@0@.html'.format(_file).underscorify(),
-    input: 'src.adoc',
+    input: 'source.adoc',
     output: '@0@.html'.format(_file),
     command: [
       asciidoc,
diff --git a/docs/website/source.adoc b/docs/website/source.adoc
new file mode 100644
index 000000000..956ab1efd
--- /dev/null
+++ b/docs/website/source.adoc
@@ -0,0 +1,32 @@
+Operation API
+=============
+
+[[top]]
+image::images/GEGL-250.png[link="index.html"]
+
+
+GEGL Operation API
+------------------
+
+// Use source highlighting if available
+ifeval::["{highlight}" == "true"]
+[source, c]
+.{name}
+-----
+include::{full_path}[]
+-----
+endif::[]
+
+// Otherwise use a literal block
+ifeval::["{highlight}" != "true"]
+.{name}
+.....
+include::{full_path}[]
+.....
+endif::[]
+
+
+
+{empty} +
+xref:top[top]
+[[end]]