76 lines
2.1 KiB
Python
76 lines
2.1 KiB
Python
"""
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A PyQT4 class to load a page image from a ComicArchive in a background thread
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"""
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"""
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Copyright 2012-2014 Anthony Beville
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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"""
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from PyQt4 import QtCore, QtGui, uic
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from PyQt4.QtCore import pyqtSignal
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from comicarchive import ComicArchive
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import utils
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"""
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This class holds onto a reference of each instance in a list
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since problems occur if the ref count goes to zero and the GC
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tries to reap the object while the thread is going.
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If the client class wants to stop the thread, they should mark
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it as "abandoned", and no signals will be issued
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"""
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class PageLoader( QtCore.QThread ):
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loadComplete = pyqtSignal( QtGui.QImage )
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instanceList = []
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mutex = QtCore.QMutex()
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"""
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Remove all finished threads from the list
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"""
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@staticmethod
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def reapInstances():
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for obj in reversed(PageLoader.instanceList ):
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if obj.isFinished():
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PageLoader.instanceList.remove(obj)
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def __init__(self, ca, page_num ):
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QtCore.QThread.__init__(self)
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self.ca = ca
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self.page_num = page_num
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self.abandoned = False
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# remove any old instances, and then add ourself
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PageLoader.mutex.lock()
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PageLoader.reapInstances()
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PageLoader.instanceList.append( self )
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PageLoader.mutex.unlock()
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def run(self):
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image_data = self.ca.getPage( self.page_num )
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if self.abandoned:
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return
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if image_data is not None:
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img = utils.getQImageFromData( image_data)
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if self.abandoned:
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return
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self.loadComplete.emit( img )
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