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

[krystosan]

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.




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_())


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

[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

[krystosan]

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


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