seting QImage size in QTableView column and sluggish resize of window or columnn size

I want to display images of specific thumbnail and column height width to fit accordingly keeping the text i.e. the filename underneath the image.

Code:

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import sys
import os
 
from PyQt4 import QtGui, QtCore
 
class MyListModel(QtCore.QAbstractTableModel): 
	def __init__(self, datain, col ,parent=None, *args): 
		""" datain: a list where each item is a row
		"""
		QtCore.QAbstractListModel.__init__(self, parent, *args) 
		self._listdata = datain
		self._col = col
 
 
	def colData(self, section, orientation, role):
		if role == QtCore.Qt.DisplayRole:
			if orientation == QtCore.Qt.Horizontal:
				return QtCore.QString("Images")
			else:
				return QtCore.QString(os.path.splitext(self._listdata[section])[-1][1:].upper())
 
	def rowCount(self, parent=QtCore.QModelIndex()): 
		return len(self._listdata) 
 
	def columnCount(self, parent):
		return self._col
 
	def data(self, index, role):
 
		if role == QtCore.Qt.EditRole:
			row = index.row()
			column = index.column()
			fileName = os.path.split(self._listdata[row][column])[-1]
			return fileName
 
		if role == QtCore.Qt.ToolTipRole:
			row = index.row()
			column = index.column()
			fileName = os.path.split(self._listdata[row][column])[-1]
			return QtCore.QString(fileName)
 
		if index.isValid() and role == QtCore.Qt.DecorationRole:
			row = index.row()
			column = index.column()
			value = self._listdata[row][column]
			pixmap = QtGui.QPixmap()
			# pixmap.scaled(400,300, QtCore.Qt.KeepAspectRatio)
			pixmap.load(value)
			return QtGui.QImage(pixmap).scaled(120,100)
 
		if index.isValid() and role == QtCore.Qt.DisplayRole:
			row = index.row()
			column = index.column()
			value = self._listdata[row][column]
			fileName = os.path.split(value)[-1]
			return os.path.splitext(fileName)[0]
 
	def flags(self, index):
		return QtCore.Qt.ItemIsEditable | QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable
 
	def setData(self, index, value, role=QtCore.Qt.EditRole):
		if role == QtCore.Qt.EditRole:
			row = index.row()
			column = index.column()
			newName = os.path.join(str(os.path.split(self._listdata[row][column])[0]), str(value.toString()))
			self.__renameFile(self._listdata[row][column], newName)
			self._listdata[row][column] = newName
			self.dataChanged.emit(index, index)
			return True
		return False
 
	def __renameFile(self, fileToRename, newName):
		try:
			os.rename(str(fileToRename), newName)
		except Exception, err:
			print err
 
 
class MyTableView(QtGui.QTableView):
	"""docstring for MyTableView"""
	def __init__(self):
		super(MyTableView, self).__init__()
 
		sw = QtGui.QDesktopWidget().screenGeometry(self).width()
		sh = QtGui.QDesktopWidget().screenGeometry(self).height()
		self.resize(sw, sh)
 
		thumbWidth = 100
		thumbheight = 120
 
		col = sw/thumbWidth
		self.setColumnWidth(thumbWidth, thumbheight)
		crntDir = "/Users/krystosan/Pictures"
		# create table
		list_data = []
		philes = os.listdir(crntDir)
		for phile in philes:
			if phile.endswith(".png") or phile.endswith("jpg"):
				list_data.append(os.path.join(crntDir, phile))
		_twoDLst = convertToTwoDList(list_data, col)
		lm = MyListModel(_twoDLst, col, self)
		self.setModel(lm)
		self.show()
 
def convertToTwoDList(l, n):
	return [l[i:i+n] for i in range(0, len(l), n)]
 
if __name__ == '__main__':
	app = QtGui.QApplication(sys.argv)
	window =  MyTableView()
	window.show()
	window.raise_()
	sys.exit(app.exec_())

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and I don't understand why :mad: resizing the window or changing column height width is happening very slow.

Every time the view asks for the Qt::DecorationRole you load a pixmap from a file, scale it, convert it to a QImage, and return it. None of those operations is cheap, some of them unnecessary. Take a look at QPixmapCache

Quote:

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Originally Posted by ChrisW67

Every time the view asks for the Qt::DecorationRole you load a pixmap from a file, scale it, convert it to a QImage, and return it. None of those operations is cheap, some of them unnecessary. Take a look at QPixmapCache

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I tried this below, but it still seems to slow.

Code:

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def data(self, index, role):
 
		if index.isValid() and role == QtCore.Qt.DecorationRole:
			row = index.row()
			column = index.column()
			value = self._listdata[row][column]
			key = "image:%s"% value
			pixmap = QtGui.QPixmap()
			# pixmap.load(value)
			if not QtGui.QPixmapCache.find(key, pixmap):
				pixmap=self.generatePixmap(value)
				QtGui.QPixmapCache.insert(key, pixmap)
			# pixmap.scaled(400,300, QtCore.Qt.KeepAspectRatio)
			return QtGui.QImage(pixmap)
 
		if index.isValid() and role == QtCore.Qt.DisplayRole:
			row = index.row()
			column = index.column()
			value = self._listdata[row][column]
			fileName = os.path.split(value)[-1]
			return os.path.splitext(fileName)[0]
 
	def generatePixmap(self, value):
		pixmap=QtGui.QPixmap()
		pixmap.load(value)
		pixmap.scaled(100, 120, QtCore.Qt.KeepAspectRatio)
		return pixmap

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