AVFoundation: fix metadata control

Correctly emit metaDataAvailableChanged and metaDataChanged signals.

Task-number: QTBUG-46368
Change-Id: Ic79acd519b47f4d864fa335c8f75758fe9185c39
Reviewed-by: Christian Stromme <christian.stromme@qt.io>

src/plugins/avfoundation/mediaplayer/avfmediaplayermetadatacontrol.h

@@ -58,7 +58,7 @@ private Q_SLOTS:
 
 private:
     AVFMediaPlayerSession *m_session;
-    QMap<QString, QVariant> m_tags;
+    QVariantMap m_tags;
     void *m_asset;
 
 };

src/plugins/avfoundation/mediaplayer/avfmediaplayermetadatacontrol.mm

@@ -75,6 +75,41 @@ QStringList AVFMediaPlayerMetaDataControl::availableMetaData() const
     return m_tags.keys();
 }
 
+static QString itemKey(AVMetadataItem *item)
+{
+    NSString *keyString = [item commonKey];
+
+    if (keyString.length != 0) {
+        if ([keyString isEqualToString:AVMetadataCommonKeyTitle]) {
+            return QMediaMetaData::Title;
+        } else if ([keyString isEqualToString: AVMetadataCommonKeySubject]) {
+            return QMediaMetaData::SubTitle;
+        } else if ([keyString isEqualToString: AVMetadataCommonKeyDescription]) {
+            return QMediaMetaData::Description;
+        } else if ([keyString isEqualToString: AVMetadataCommonKeyPublisher]) {
+            return QMediaMetaData::Publisher;
+        } else if ([keyString isEqualToString: AVMetadataCommonKeyCreationDate]) {
+            return QMediaMetaData::Date;
+        } else if ([keyString isEqualToString: AVMetadataCommonKeyType]) {
+            return QMediaMetaData::MediaType;
+        } else if ([keyString isEqualToString: AVMetadataCommonKeyLanguage]) {
+            return QMediaMetaData::Language;
+        } else if ([keyString isEqualToString: AVMetadataCommonKeyCopyrights]) {
+            return QMediaMetaData::Copyright;
+        } else if ([keyString isEqualToString: AVMetadataCommonKeyAlbumName]) {
+            return QMediaMetaData::AlbumTitle;
+        } else if ([keyString isEqualToString: AVMetadataCommonKeyAuthor]) {
+            return QMediaMetaData::Author;
+        } else if ([keyString isEqualToString: AVMetadataCommonKeyArtist]) {
+            return QMediaMetaData::ContributingArtist;
+        } else if ([keyString isEqualToString: AVMetadataCommonKeyArtwork]) {
+            return QMediaMetaData::PosterUrl;
+        }
+    }
+
+    return QString();
+}
+
 void AVFMediaPlayerMetaDataControl::updateTags()
 {
 #ifdef QT_DEBUG_AVF
@@ -83,67 +118,38 @@ void AVFMediaPlayerMetaDataControl::updateTags()
     AVAsset *currentAsset = (AVAsset*)m_session->currentAssetHandle();
 
     //Don't read the tags from the same asset more than once
-    if (currentAsset == m_asset) {
+    if (currentAsset == m_asset)
         return;
-    }
 
     m_asset = currentAsset;
 
+    QVariantMap oldTags = m_tags;
     //Since we've changed assets, clear old tags
     m_tags.clear();
+    bool changed = false;
 
-    NSArray *metadataFormats = [currentAsset availableMetadataFormats];
+    // TODO: also process ID3, iTunes and QuickTime metadata
-    for ( NSString *format in metadataFormats) {
-#ifdef QT_DEBUG_AVF
-        qDebug() << "format: " << [format UTF8String];
-#endif
-        NSArray *metadataItems = [currentAsset metadataForFormat:format];
-        for (AVMetadataItem* item in metadataItems) {
-            NSString *keyString = [item commonKey];
-            NSString *value = [item stringValue];
 
-            if (keyString.length != 0) {
+    NSArray *metadataItems = [currentAsset commonMetadata];
-                //Process "commonMetadata" tags here:
+    for (AVMetadataItem* item in metadataItems) {
-                if ([keyString isEqualToString:AVMetadataCommonKeyTitle]) {
+        const QString key = itemKey(item);
-                    m_tags.insert(QMediaMetaData::Title, QString([value UTF8String]));
+        if (!key.isEmpty()) {
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyCreator]) {
+            const QString value = QString::fromNSString([item stringValue]);
-                    m_tags.insert(QMediaMetaData::Author, QString([value UTF8String]));
+            if (!value.isNull()) {
-                } else if ([keyString isEqualToString: AVMetadataCommonKeySubject]) {
+                m_tags.insert(key, value);
-                    m_tags.insert(QMediaMetaData::SubTitle, QString([value UTF8String]));
+                if (value != oldTags.value(key)) {
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyDescription]) {
+                    changed = true;
-                    m_tags.insert(QMediaMetaData::Description, QString([value UTF8String]));
+                    Q_EMIT metaDataChanged(key, value);
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyPublisher]) {
-                    m_tags.insert(QMediaMetaData::Publisher, QString([value UTF8String]));
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyContributor]) {
-                    m_tags.insert(QMediaMetaData::ContributingArtist, QString([value UTF8String]));
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyCreationDate]) {
-                    m_tags.insert(QMediaMetaData::Date, QString([value UTF8String]));
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyType]) {
-                    m_tags.insert(QMediaMetaData::MediaType, QString([value UTF8String]));
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyLanguage]) {
-                    m_tags.insert(QMediaMetaData::Language, QString([value UTF8String]));
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyCopyrights]) {
-                    m_tags.insert(QMediaMetaData::Copyright, QString([value UTF8String]));
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyAlbumName]) {
-                    m_tags.insert(QMediaMetaData::AlbumTitle, QString([value UTF8String]));
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyAuthor]) {
-                    m_tags.insert(QMediaMetaData::Author, QString([value UTF8String]));
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyArtist]) {
-                    m_tags.insert(QMediaMetaData::AlbumArtist, QString([value UTF8String]));
-                } else if ([keyString isEqualToString: AVMetadataCommonKeyArtwork]) {
-                    m_tags.insert(QMediaMetaData::PosterUrl, QString([value UTF8String]));
                 }
             }
-
-            if ([format isEqualToString:AVMetadataFormatID3Metadata]) {
-                //TODO: Process ID3 metadata
-            } else if ([format isEqualToString:AVMetadataFormatiTunesMetadata]) {
-                //TODO: Process iTunes metadata
-            } else if ([format isEqualToString:AVMetadataFormatQuickTimeUserData]) {
-                //TODO: Process QuickTime metadata
-            }
         }
     }
 
-    Q_EMIT metaDataChanged();
+    if (oldTags.isEmpty() != m_tags.isEmpty()) {
+        Q_EMIT metaDataAvailableChanged(!m_tags.isEmpty());
+        changed = true;
+    }
+
+    if (changed)
+        Q_EMIT metaDataChanged();
 }