From 99a30398f7184ccbd313f5d589285f343d9eb658 Mon Sep 17 00:00:00 2001
From: Colin Clark <colin.clark@cclark.uk>
Date: Sun, 30 Jun 2019 12:22:19 +0100
Subject: [PATCH] Enable lua scripts to be called from Info sidebar

A lua script can be called from any of the List Panes in the Info
sidebar.

Add a new entry and in the Key field use:
lua.<lua script name>

The output of the script should of course be text.
---
 doc/docbook/GuideReferenceLua.xml |  4 +++-
 doc/docbook/GuideSidebarsInfo.xml |  9 ++++++++-
 src/exif-common.c                 | 24 ++++++++++++++++++++++++
 src/exif.h                        |  1 +
 src/metadata.c                    |  6 ++++++
 5 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/doc/docbook/GuideReferenceLua.xml b/doc/docbook/GuideReferenceLua.xml
index cb6542dc..4a2e8872 100644
--- a/doc/docbook/GuideReferenceLua.xml
+++ b/doc/docbook/GuideReferenceLua.xml
@@ -4,7 +4,9 @@
   <para>
     Lua scripts allow the functionality of Geeqie to be extended. Lua scripts may only be used in conjunction with the
     <link linkend="OverlayScreenDisplay">Overlay Screen Display</link>
-    and the
+    ,
+    <link linkend="GuideSidebarsInfo" endterm="Listpanes-ExifFileinfoCopyrightLocationandGPS">List panes</link>
+    on the Info Sidebar, and the
     <programlisting xml:space="preserve">geeqie --remote --lua:</programlisting>
     command line option.
   </para>
diff --git a/doc/docbook/GuideSidebarsInfo.xml b/doc/docbook/GuideSidebarsInfo.xml
index 498d1550..6e110fd0 100644
--- a/doc/docbook/GuideSidebarsInfo.xml
+++ b/doc/docbook/GuideSidebarsInfo.xml
@@ -206,7 +206,7 @@
       <link linkend="GuideOtherWindowsExif" endterm="titleGuideOtherWindowsExif" />
       onto any pane.
     </para>
-    <para>As an aide, in addition to standard metadata tags, Geeqie provides certain pre-formatted tags. These are:</para>
+    <para>As an aide, in addition to standard metadata tags, Geeqie can call lua scripts and also provides certain pre-formatted tags. These tags are:</para>
     <table id="formatted_exif">
       <tgroup cols="2" rowsep="1" colsep="1">
         <tbody>
@@ -340,6 +340,13 @@
             <entry>file.link</entry>
             <entry>if the file is a symbolic link, shows the path of the source file</entry>
           </row>
+          <row>
+            <entry>lua.&lt;lua script&gt;</entry>
+            <entry>
+              Call a lua script
+              <footnote id='lua_ref1'>The output is expected to be text.</footnote>
+            </entry>
+          </row>
         </tbody>
       </tgroup>
     </table>
diff --git a/src/exif-common.c b/src/exif-common.c
index 9463a5b4..fd2c6a3a 100644
--- a/src/exif-common.c
+++ b/src/exif-common.c
@@ -53,6 +53,7 @@
 #include "filefilter.h"
 #include "filecache.h"
 #include "format_raw.h"
+#include "glua.h"
 #include "ui_fileops.h"
 #include "cache.h"
 #include "jpeg_parser.h"
@@ -1218,5 +1219,28 @@ gchar *metadata_file_info(FileData *fd, const gchar *key, MetadataFormat format)
 	return g_strdup("");
 }
 
+#ifdef HAVE_LUA
+gchar *metadata_lua_info(FileData *fd, const gchar *key, MetadataFormat format)
+{
+	gchar *script_name;
+	gchar *script_name_utf8;
+	gchar *data;
+	gchar *raw_data;
+	gchar *valid_data;
+
+	script_name_utf8 = g_strdup(key + 4);
+	script_name = path_from_utf8(script_name_utf8);
+
+	raw_data = lua_callvalue(fd, script_name, NULL);
+	valid_data = g_utf8_make_valid(raw_data, -1);
+	data = g_utf8_substring(valid_data, 0, 150);
 
+	g_free(script_name);
+	g_free(script_name_utf8);
+	g_free(raw_data);
+	g_free(valid_data);
+
+	return data;
+}
+#endif
 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */
diff --git a/src/exif.h b/src/exif.h
index 06dec25a..6e2ca064 100644
--- a/src/exif.h
+++ b/src/exif.h
@@ -167,6 +167,7 @@ guchar *exif_get_preview(ExifData *exif, guint *data_len, gint requested_width,
 void exif_free_preview(guchar *buf);
 
 gchar *metadata_file_info(FileData *fd, const gchar *key, MetadataFormat format);
+gchar *metadata_lua_info(FileData *fd, const gchar *key, MetadataFormat format);
 
 #endif
 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */
diff --git a/src/metadata.c b/src/metadata.c
index c3ffdbc1..e2e36113 100644
--- a/src/metadata.c
+++ b/src/metadata.c
@@ -709,6 +709,12 @@ GList *metadata_read_list(FileData *fd, const gchar *key, MetadataFormat format)
 		{
 	        return g_list_append(NULL, metadata_file_info(fd, key, format));
 		}
+#ifdef HAVE_LUA
+	else if (strncmp(key, "lua.", 4) == 0)
+		{
+		return g_list_append(NULL, metadata_lua_info(fd, key, format));
+		}
+#endif
 
 	exif = exif_read_fd(fd); /* this is cached, thus inexpensive */
 	if (!exif) return NULL;
-- 
2.20.1