1 files changed, 79 insertions, 0 deletions
diff --git a/nephilim/metadata_fetcher.py b/nephilim/metadata_fetcher.py
new file mode 100644
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+++ b/nephilim/metadata_fetcher.py
@@ -0,0 +1,79 @@
+#
+#    Copyright (C) 2010 Anton Khirnov <anton@khirnov.net>
+#
+#    Nephilim is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation, either version 3 of the License, or
+#    (at your option) any later version.
+#
+#    Nephilim is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with Nephilim.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+from PyQt4 import QtCore, QtNetwork
+from PyQt4.QtCore import pyqtSignal as Signal
+
+from song import Song
+
+class MetadataFetcher(QtCore.QObject):
+    """A basic class for metadata fetchers. Provides a fetch(song) function,
+       emits a finished(song, metadata) signal when done; lyrics is either a Python
+       unicode string or None if not found."""
+    #public, read-only
+    logger = None
+    name   = ''
+
+    #private
+    nam  = None  # NetworkAccessManager
+    rep = None   # current NetworkReply.
+    song = None  # current song
+
+    # SIGNALS
+    finished = Signal([Song, object])
+
+    #### private ####
+    def __init__(self, plugin):
+        QtCore.QObject.__init__(self, plugin)
+
+        self.nam = QtNetwork.QNetworkAccessManager()
+        self.logger = plugin.logger
+
+    def fetch2(self, song, url):
+        """A private convenience function to initiate fetch process."""
+        # abort any existing connections
+        self.abort()
+        self.song = song
+
+        self.logger.info('Searching %s: %s.'%(self. name, url.toString()))
+        self.rep = self.nam.get(QtNetwork.QNetworkRequest(url))
+        self.rep.error.connect(self.handle_error)
+
+    def finish(self, metadata = None):
+        """A private convenience function to clean up and emit finished().
+           Feel free to reimplement/not use it."""
+        self.rep = None
+        self.finished.emit(self.song, metadata)
+        self.song = None
+
+    def handle_error(self):
+        """Print the error and abort."""
+        self.logger.error(self.rep.errorString())
+        self.abort()
+        self.finish()
+
+    #### public ####
+    def fetch(self, song):
+        """Reimplement this in subclasses."""
+        pass
+
+    def abort(self):
+        """Abort all downloads currently in progress."""
+        if self.rep:
+            self.rep.blockSignals(True)
+            self.rep.abort()
+            self.rep = None