fix(glossary): handle save errors and improve playlist controls

src/translate/translationservice.cpp

@@ -139,25 +139,51 @@ QString TranslationService::glossaryDirectory() const
     return m_glossary.directory;
 }
 
+QString TranslationService::glossaryError() const
+{
+    return m_glossaryError;
+}
+
 void TranslationService::loadGlossary(const QUrl &videoUrl)
 {
     const QString directory = videoUrl.isLocalFile() ? QFileInfo(videoUrl.toLocalFile()).absolutePath() : QString();
     m_glossary = directory.isEmpty() ? GlossaryStore::Glossary{} : GlossaryStore::load(directory);
+    if (!m_glossaryError.isEmpty()) {
+        m_glossaryError.clear();
+        Q_EMIT glossaryErrorChanged();
+    }
     Q_EMIT glossaryChanged();
 }
 
-void TranslationService::saveGlossary(const QVariantList &entries)
+bool TranslationService::saveGlossary(const QVariantList &entries)
 {
     QList<GlossaryStore::Entry> result;
     for (const QVariant &value : entries) {
         const QVariantMap map = value.toMap();
         result.append({map.value(u"source"_s).toString().trimmed(), map.value(u"target"_s).toString().trimmed()});
     }
-    m_glossary.entries = result;
-    if (!m_glossary.directory.isEmpty()) {
-        GlossaryStore::save(m_glossary);
+
+    GlossaryStore::Glossary candidate = m_glossary;
+    candidate.entries = result;
+    if (!candidate.directory.isEmpty()) {
+        QString error;
+        if (!GlossaryStore::save(candidate, &error)) {
+            const QString message = error.isEmpty() ? i18n("Could not save the translation glossary.")
+                                                     : i18n("Could not save the translation glossary: %1", error);
+            if (m_glossaryError != message) {
+                m_glossaryError = message;
+                Q_EMIT glossaryErrorChanged();
+            }
+            return false;
+        }
+    }
+    m_glossary = candidate;
+    if (!m_glossaryError.isEmpty()) {
+        m_glossaryError.clear();
+        Q_EMIT glossaryErrorChanged();
     }
     Q_EMIT glossaryChanged();
+    return true;
 }
 
 void TranslationService::clearGlossary()