[gexiv2] Update gexiv2-dump tool

[Jens Georg <jensgeorg src gnome org>]

commit c777329e8c0197d806c62a697754b567020a85d9
Author: postscript-dev <43813-postscript-dev users noreply gitlab gnome org>
Date:   Thu Feb 18 16:48:51 2021 +0000

    Update gexiv2-dump tool
    
    + Prevent incompatibilities with old version by renaming to gexiv2-tool.
    + Only processes a single image file
    + Add options to print different combinations of tags to screen
    + Add option to output information about a tag (e.g. description, etc)
    + Add option to output Xmp namespace values

 tools/gexiv2-dump.vala |  51 -----------
 tools/gexiv2-tool.vala | 240 +++++++++++++++++++++++++++++++++++++++++++++++++
 tools/meson.build      |   4 +-
 3 files changed, 242 insertions(+), 53 deletions(-)
---
diff --git a/tools/gexiv2-tool.vala b/tools/gexiv2-tool.vala
new file mode 100644
index 0000000..64579d7
--- /dev/null
+++ b/tools/gexiv2-tool.vala
@@ -0,0 +1,240 @@
+/*
+ * gexiv2-tool.vala
+ *
+ * Author(s)
+ *  Jim Nelson <jim yorba org>
+ *
+ * This is free software. See COPYING for details.
+ */
+
+// Global variables used in parsing program paramters
+bool print_exif_tags = false;
+bool print_iptc_tags = false;
+bool print_xmp_tags = false;
+bool print_xmp_ns = false;
+bool print_tag_details = false;
+string print_single_tag;
+
+// Command line optional parameters
+const GLib.OptionEntry[] options = {
+    // [-exif]
+    {"exif", 'e', 0, OptionArg.NONE, ref print_exif_tags, "Print out Exif tags from FILE", null},
+
+    // [-iptc]
+    {"iptc", 'i', 0, OptionArg.NONE, ref print_iptc_tags, "Print out Iptc tags from FILE", null},
+
+    // [-xmp]
+    {"xmp", 'x', 0, OptionArg.NONE, ref print_xmp_tags, "Print out Xmp tags from FILE", null},
+
+    // [-xns]
+    {"xns", 'n', 0, OptionArg.NONE, ref print_xmp_ns, "Print out Xmp namespaces from FILE", null},
+
+    // [-details]
+    {"details", 'd', 0, OptionArg.NONE, ref print_tag_details, "Print additional tag details (interpreted 
value, label, type and description)", null},
+
+    // [-tag TAG]
+    {"tag", 't', 0, OptionArg.STRING, ref print_single_tag, "Only print a specific tag's data from FILE 
(overrides -e, -i and -x)", null},
+
+    // list terminator
+    {null}
+};
+
+/**
+ * main:
+ * @args: Program arguments
+ *
+ * Prints out image metadata from a file.
+ *
+ * The supported image formats can be found at <ulink url="https://www.exiv2.org/manpage.html";></ulink>
+ * and the Exiv2 Tag Reference at <ulink url="https://www.exiv2.org/metadata.html";></ulink>.
+ *
+ * Returns: 0 for success or error code
+ */
+int main(string[] args) {
+
+    var program_name = extract_filename(args[0]);
+    print_single_tag = "";
+
+    // Setup and parse program parameters
+    OptionContext opt_context;
+    try {
+        string summary = "";
+        summary = summary + "Prints out metadata in an image file. If no optional parameters are 
specified,\n";
+        summary = summary + "then the default is print all tags (\"-e -i -x\"). The order of parameters 
is\n";
+        summary = summary + "not respected.\n";
+
+        string desc = "";
+        desc = desc + "Image metadata is stored in 3 types: Exif, Iptc and Xmp and a file may contain\n";
+        desc = desc + "more than one type. Each tag is in the format 'familyName.groupName.tagName',\n";
+        desc = desc + "e.g. 'Exif.Image.DateTime'. Each unique Xmp groupName has a namespace, e.g.\n";
+        desc = desc + "The standard registration for 'dc' is 'http://purl.org/dc/elements/1.1/'\n";
+        desc = desc + " \n";
+        desc = desc + "Supported image formats can be found at https://www.exiv2.org/manpage.html and\n";
+        desc = desc + "Exiv2 metadata tag references at https://www.exiv2.org/metadata.html\n";;
+        desc = desc + " \n";
+        desc = desc + "Examples:\n";
+        desc = desc + "  " + program_name + " FILE                         - Print all the tags in FILE 
(\"-e -i -x\")\n";
+        desc = desc + "  " + program_name + " -d FILE                      - Print all the tag details in 
FILE (\"-d -e -i -x\")\n";
+        desc = desc + "  " + program_name + " -x -n FILE                   - Print the Xmp namespaces and 
Xmp tag values in FILE\n";
+        desc = desc + "  " + program_name + " -d -e -i FILE                - Print the Exif and Iptc tag 
details in FILE\n";
+        desc = desc + "  " + program_name + " -t Xmp.dc.subject -d -e FILE - Print only the 'Xmp.dc.subject' 
tag details in FILE\n";
+
+        opt_context = new OptionContext("FILE");
+        opt_context.set_description(desc);
+        opt_context.set_summary(summary);
+        opt_context.set_help_enabled(true);
+        opt_context.add_main_entries(options, null);
+        opt_context.parse(ref args);
+
+        // Only 1 required parameter allowed
+        if (args.length < 2) {
+            printerr("%s error: no FILE provided\n", program_name);
+            print(opt_context.get_help(true, null));
+            return 1;
+        }
+    
+        if (args.length > 2) {
+            printerr("%s error: Invalid parameters\n", program_name);
+            print(opt_context.get_help(true, null));
+            return 1;
+        }
+
+        // If no user selected tag type options then print them all
+        if (!print_exif_tags && !print_iptc_tags && !print_xmp_tags) {
+            print_exif_tags = true;
+            print_iptc_tags = true;
+            print_xmp_tags = true;
+        }
+
+        // Try to open the user's file
+        GExiv2.Metadata metadata = new GExiv2.Metadata();
+        var file = File.new_for_commandline_arg(args[1]);
+        metadata.from_stream(file.read());
+
+        // Get tag names from file
+        var exif_tags = metadata.get_exif_tags();
+        var iptc_tags = metadata.get_iptc_tags();
+        var xmp_tags = metadata.get_xmp_tags();
+
+        // Print user selected options
+        if (print_single_tag != "") {
+            if (print_single_tag in exif_tags || print_single_tag in iptc_tags || print_single_tag in 
xmp_tags) {
+                if (print_xmp_ns) {
+                    // Print namespace for the specific tag only
+                    string[] tags = {print_single_tag};
+                    print_all_xmp_namespaces(tags);
+                }
+                print_tag(metadata, print_single_tag, print_tag_details);
+            } else {
+                string error_message = "Tag `" + print_single_tag + "' not found in metadata";
+                throw new GLib.Error(Quark.from_string(program_name), 1, error_message);
+            }
+        } else {
+            if (print_xmp_ns) {
+                print_all_xmp_namespaces(xmp_tags);
+            }
+            if (print_exif_tags) {
+                foreach (var tag in exif_tags) {
+                    print_tag(metadata, tag, print_tag_details);
+                }
+            }
+            if (print_iptc_tags) {
+                foreach (var tag in iptc_tags) {
+                    print_tag(metadata, tag, print_tag_details);
+                }
+            }
+            if (print_xmp_tags) {
+               foreach (var tag in xmp_tags) {
+                    print_tag(metadata, tag, print_tag_details);
+                }
+             }
+        }
+    } catch (OptionError e) {
+        printerr("%s error: %s\n", program_name, e.message);
+        print(opt_context.get_help(true, null));
+        return 1;
+    } catch (Error err) {
+        printerr("%s error: Processing metadata for '%s': %s (%i)\n",
+                 program_name,
+                 args[1],
+                 err.message,
+                 err.code);
+        return 2;
+    }
+
+    return 0;
+}
+
+/**
+ * print_tag:
+ * @metadata: An instance of #GExiv2Metadata
+ * @tag: The tag to print out
+ * @print_details: Whether to print the tag details in addition to the tag value
+ *
+ * Prints out either the tag values or the tag details for the tag
+ *
+ * Returns:
+ */
+void print_tag(GExiv2.Metadata metadata, string tag, bool print_details) throws Error {
+    if (print_details) {
+        print("%-64s%s\n", "Tag", tag);
+        print("%-64s%s\n", "  Value", metadata.try_get_tag_string(tag));
+        print("%-64s%s\n", "  Interpreted value", metadata.get_tag_interpreted_string(tag));
+        print("%-64s%s\n", "  Label", GExiv2.Metadata.get_tag_label(tag));
+        print("%-64s%s\n", "  Type", GExiv2.Metadata.get_tag_type(tag));
+        print("%-64s%s\n", "  Description", GExiv2.Metadata.get_tag_description(tag));
+    } else {
+        print("%-64s%s\n", tag, metadata.get_tag_interpreted_string(tag));
+    }
+}
+
+/**
+ * print_all_xmp_namespaces:
+ * @xmp_tags: A list of Xmp tags
+ *
+ * Prints list of namespaces from Xmp tags with duplicate groupName tags removed.
+ * e.g. "Xmp.dc.subject" has the namespace "http://purl.org/dc/elements/1.1/";
+ *
+ * Returns:
+ */
+void print_all_xmp_namespaces(string[] xmp_tags) throws Error {
+
+    var last_groupName = ""; // Previous iteration's value
+
+    foreach (var tag in xmp_tags) {
+
+        // Extract groupName from tag (format: "familyName.groupName.tagName")
+        var groupName = tag.split(".", 3)[1];
+
+        // Only output one example of a groupName's namespace
+        if (last_groupName != groupName) {
+            print("Xmp ns: %-56s%s\n", groupName, GExiv2.Metadata.get_xmp_namespace_for_tag(groupName));
+            last_groupName = groupName;
+        }
+    }
+}
+
+/**
+ * extract_filename:
+ * @filename_and_path:
+ *
+ * Extract the filename part from the path+filename
+ * e.g. "/usr/home/username/program" would return "program"
+ *      or "C:\temp\program.exe" would return "program.exe"
+ *
+ * Returns: (transfer full) The filename
+ */
+string extract_filename(string filename_and_path) {
+    var pos = 0;
+    for (var i = filename_and_path.length - 1; i >= 0; i--) {
+        if (filename_and_path[i] == '/') {
+            pos = i + 1;
+            break;
+        }
+        if (filename_and_path[i] == '\\') {
+            pos = i + 1;
+            break;
+        }
+    }
+    return filename_and_path.substring(pos, filename_and_path.length - pos);
+}
\ No newline at end of file
diff --git a/tools/meson.build b/tools/meson.build
index 302141d..f6af618 100644
--- a/tools/meson.build
+++ b/tools/meson.build
@@ -1,6 +1,6 @@
 if vapi_available
-  executable('gexiv2-dump',
-             'gexiv2-dump.vala',
+  executable('gexiv2-tool',
+             'gexiv2-tool.vala',
              include_directories : include_directories('..'),
              dependencies : [gobject, vapi, gio],
              vala_args: ['--disable-since-check'],