feat: support load m3u8 playlist

This change is sponsored by @superuser7777

Related: https://github.com/BLumia/pineapple-pictures/issues/153

app/mainwindow.cpp

@@ -175,7 +175,16 @@ MainWindow::~MainWindow()
 void MainWindow::showUrls(const QList<QUrl> &urls)
 {
     if (!urls.isEmpty()) {
-        m_graphicsView->showFileFromPath(urls.first().toLocalFile());
+        const QUrl & firstUrl = urls.first();
+        if (urls.count() == 1) {
+            const QString lowerCaseUrlPath(firstUrl.path().toLower());
+            if (lowerCaseUrlPath.endsWith(".m3u8") || lowerCaseUrlPath.endsWith(".m3u")) {
+                m_pm->loadM3U8Playlist(firstUrl);
+                galleryCurrent(true, true);
+                return;
+            }
+        }
+        m_graphicsView->showFileFromPath(firstUrl.toLocalFile());
         m_pm->loadPlaylist(urls);
     } else {
         m_graphicsView->showText(tr("File url list is empty"));

app/playlistmanager.cpp

@@ -186,6 +186,26 @@ QModelIndex PlaylistManager::loadPlaylist(const QUrl &url)
     return idx;
 }
 
+QModelIndex PlaylistManager::loadM3U8Playlist(const QUrl &url)
+{
+    QFile file(url.toLocalFile());
+    if (file.open(QIODevice::ReadOnly | QIODevice::Text)) {
+        QList<QUrl> urls;
+        while (!file.atEnd()) {
+            QString line = file.readLine();
+            if (line.startsWith('#')) {
+                continue;
+            }
+            QFileInfo fileInfo(file);
+            QUrl item = QUrl::fromUserInput(line, fileInfo.absolutePath());
+            urls.append(item);
+        }
+        return loadPlaylist(urls);
+    } else {
+        return {};
+    }
+}
+
 int PlaylistManager::totalCount() const
 {
     return m_model.rowCount();

app/playlistmanager.h

@@ -61,6 +61,7 @@ public:
     void setPlaylist(const QList<QUrl> & url);
     Q_INVOKABLE QModelIndex loadPlaylist(const QList<QUrl> & urls);
     Q_INVOKABLE QModelIndex loadPlaylist(const QUrl & url);
+    Q_INVOKABLE QModelIndex loadM3U8Playlist(const QUrl & url);
 
     int totalCount() const;
     QModelIndex previousIndex() const;