Update taglist sample with more functionality

samples/taglist.cpp

@@ -10,20 +10,57 @@
 
 #include <exiv2/exiv2.hpp>
 
-#include <string>
 #include <iostream>
+#include <string>
 
 using namespace Exiv2;
 
 int main(int argc, char* argv[])
-try {
+{
+    try {
         int rc = 0;
 
         switch (argc) {
-    case 2:
-    {
+            case 2: {
                 std::string item(argv[1]);
 
+                if (item == "Groups") {
+                    /*
+                    https://cgit.kde.org/digikam.git/tree/core/libs/dmetadata/metaengine_exif.cpp#n1077
+                           const Exiv2::GroupInfo* gi = Exiv2::ExifTags::groupList();
+
+                           while (gi->tagList_ != 0)
+                           {
+                               // NOTE: See BUG #375809 : MPF tags = exception Exiv2 0.26
+
+                               if (QLatin1String(gi->ifdName_) != QLatin1String("Makernote"))
+                               {
+                                   Exiv2::TagListFct tl     = gi->tagList_;
+                                   const Exiv2::TagInfo* ti = tl();
+
+                                   while (ti->tag_ != 0xFFFF)
+                                   {
+                                       tags << ti;
+                                       ++ti;
+                                   }
+                               }
+
+                               ++gi;
+                           }
+                   */
+                    const GroupInfo* groupList = ExifTags::groupList();
+                    int count = 0;
+                    if (groupList) {
+                        while (groupList->tagList_ && count < 10000) {
+                            count++;
+                            std::cout << groupList->groupName_ << std::endl;
+                            groupList++;
+                        }
+                    }
+                    std::cout << "Groups = " << count << std::endl;
+                    break;
+                }
+
                 if (item == "Exif") {
                     ExifTags::taglist(std::cout);
                     break;
@@ -41,8 +78,7 @@ try {
 
                 try {
                     XmpProperties::printProperties(std::cout, item);
-        }
-        catch(const AnyError&) {
+                } catch (const AnyError&) {
                     rc = 2;
                 }
 
@@ -51,19 +87,49 @@ try {
             case 1:
                 ExifTags::taglist(std::cout);
                 break;
+
+            case 3: {
+                rc = 1;  // assume unhappy ending!
+                std::string item(argv[1]);
+                std::string name(argv[2]);
+
+                if (item == "--group") {
+                    const GroupInfo* groupList = ExifTags::groupList();
+                    if (groupList) {
+                        while (groupList->tagList_) {
+                            int count = 0;
+                            if (name == groupList->groupName_) {
+                                const Exiv2::TagInfo* tagInfo = groupList->tagList_();
+                                while (tagInfo->tag_ != 0xFFFF) {
+                                    std::cout << tagInfo->name_ << std::endl;
+                                    tagInfo++;
+                                    count++;
+                                }
+                                rc = 0;  // result is good
+                                std::cout << "Tags = " << count << std::endl;
+                            }
+                            groupList++;
+                        }
+                    }
+                }
+            } break;
+
             default:
                 rc = 1;
                 break;
         }
+
         if (rc) {
             std::cout << "Usage: " << argv[0]
-                  << " [Exif|Canon|CanonCs|CanonSi|CanonCf|Fujifilm|Minolta|Nikon1|Nikon2|Nikon3|Olympus|Panasonic|Pentax|Sigma|Sony|Iptc"
+                      << " [--group "
+                         "name|Groups|Exif|Canon|CanonCs|CanonSi|CanonCf|Fujifilm|Minolta|Nikon1|Nikon2|Nikon3|Olympus|"
+                         "Panasonic|Pentax|Sigma|Sony|Iptc"
                       << "|dc|xmp|xmpRights|xmpMM|xmpBJ|xmpTPg|xmpDM|pdf|photoshop|crs|tiff|exif|aux|iptc]\n"
                       << "Print Exif tags, MakerNote tags, or Iptc datasets\n";
         }
         return rc;
-}
-catch (AnyError& e) {
+    } catch (AnyError& e) {
         std::cout << "Caught Exiv2 exception '" << e << "'\n";
         return 1;
+    }
 }