Animated items using delegates

A nasty hack involving a custom delegate, timer events and a signal to inform a view that it needs to repaint itself. It is just a proof of concept.

Perhaps a better example might be Animated items using delegates and movies.

Things that are wrong with this code:

It starts a timer and never stops it.
The signal in the delegate is connected to the viewport of the view instead of the view itself (it doesn't work otherwise).
The delegate simply shifts the normal content of the waiting items and paints a pixmap - it doesn't try to replace or add an icon to existing items.

 1 import sys
 2 from PyQt4.QtCore import pyqtSignal, Qt, QVariant
 3 from PyQt4.QtGui import *
 4 
 5 # Icons used for animation:
 6 _icon0_xpm = [
 7  "16 16 4 1",
 8  ". c None",
 9  "s c #cccc00",
 10  "x c #ffffff",
 11  " c #000000",
 12  "................",
 13  ". .",
 14  ". xxxxxxxxxxxx .",
 15  ". x x .",
 16  ".. x ssssss x ..",
 17  "... x ssss x ...",
 18  ".... x ss x ....",
 19  "..... x x .....",
 20  "..... x x .....",
 21  ".... x x ....",
 22  "... x x ...",
 23  ".. x x ..",
 24  ". x x .",
 25  ". xxxxxxxxxxxx .",
 26  ". .",
 27  "................"]
 28 
 29 _icon1_xpm = [
 30  "16 16 4 1",
 31  ". c None",
 32  "s c #cccc00",
 33  "x c #ffffff",
 34  " c #000000",
 35  "................",
 36  ". .",
 37  ". xxxxxxxxxxxx .",
 38  ". x x .",
 39  ".. x s s x ..",
 40  "... x ssss x ...",
 41  ".... x ss x ....",
 42  "..... x x .....",
 43  "..... x x .....",
 44  ".... x ss x ....",
 45  "... x ss x ...",
 46  ".. x x ..",
 47  ". x x .",
 48  ". xxxxxxxxxxxx .",
 49  ". .",
 50  "................"]
 51 
 52 _icon2_xpm = [
 53  "16 16 4 1",
 54  ". c None",
 55  "s c #cccc00",
 56  "x c #ffffff",
 57  " c #000000",
 58  "................",
 59  ". .",
 60  ". xxxxxxxxxxxx .",
 61  ". x x .",
 62  ".. x x ..",
 63  "... x ssss x ...",
 64  ".... x ss x ....",
 65  "..... x x .....",
 66  "..... x x .....",
 67  ".... x ss x ....",
 68  "... x ss x ...",
 69  ".. x ss x ..",
 70  ". x x .",
 71  ". xxxxxxxxxxxx .",
 72  ". .",
 73  "................"]
 74 
 75 _icon3_xpm = [
 76  "16 16 4 1",
 77  ". c None",
 78  "s c #cccc00",
 79  "x c #ffffff",
 80  " c #000000",
 81  "................",
 82  ". .",
 83  ". xxxxxxxxxxxx .",
 84  ". x x .",
 85  ".. x x ..",
 86  "... x x ...",
 87  ".... x x ....",
 88  "..... x x .....",
 89  "..... x x .....",
 90  ".... x ss x ....",
 91  "... x ssss x ...",
 92  ".. x ssssss x ..",
 93  ". x x .",
 94  ". xxxxxxxxxxxx .",
 95  ". .",
 96  "................"]
 97 
 98 
 99 class Delegate(QItemDelegate):
 100 
 101  needsRedraw = pyqtSignal()
 102  
 103  def __init__(self, parent = None):
 104  
 105  QItemDelegate.__init__(self, parent)
 106  self.current = 0
 107  self.timerId = self.startTimer(250)
 108  self.model = QStandardItemModel()
 109  self.pixmaps = (QPixmap(_icon0_xpm),
 110  QPixmap(_icon1_xpm),
 111  QPixmap(_icon2_xpm),
 112  QPixmap(_icon3_xpm))
 113  
 114  def timerEvent(self, event):
 115  
 116  if event.timerId() == self.timerId:
 117  self.current = (self.current + 1) % 4
 118  self.needsRedraw.emit()
 119  
 120  def paint(self, painter, option, index):
 121  
 122  waiting = index.data(Qt.UserRole).toBool()
 123  if waiting:
 124  option = option.__class__(option)
 125  painter.drawPixmap(option.rect.topLeft(), self.pixmaps[self.current])
 126  option.rect = option.rect.translated(20, 0)
 127  
 128  QItemDelegate.paint(self, painter, option, index)
 129 
 130 
 131 app = QApplication(sys.argv)
 132 view = QListView()
 133 model = QStandardItemModel()
 134 waiting = True
 135 
 136 for i in range(5):
 137 
 138  item = QStandardItem("Test %i" % i)
 139  item.setData(QVariant(waiting), Qt.UserRole)
 140  waiting = not waiting
 141  model.appendRow(item)
 142 
 143 view.setModel(model)
 144 
 145 delegate = Delegate()
 146 view.setItemDelegate(delegate)
 147 delegate.needsRedraw.connect(view.viewport().update)
 148 
 149 view.show()
 150 sys.exit(app.exec_())