= 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 [[PyQt/Animated items using delegates and movies|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.

{{{
#!python
import sys
from PyQt4.QtCore import pyqtSignal, Qt, QVariant
from PyQt4.QtGui import *

# Icons used for animation:
_icon0_xpm = [
    "16 16 4 1",
    ".	c None",
    "s	c #cccc00",
    "x	c #ffffff",
    " 	c #000000",
    "................",
    ".              .",
    ". xxxxxxxxxxxx .",
    ". x          x .",
    ".. x ssssss x ..",
    "... x ssss x ...",
    ".... x ss x ....",
    "..... x  x .....",
    "..... x  x .....",
    ".... x    x ....",
    "... x      x ...",
    ".. x        x ..",
    ". x          x .",
    ". xxxxxxxxxxxx .",
    ".              .",
    "................"]

_icon1_xpm = [
    "16 16 4 1",
    ".	c None",
    "s	c #cccc00",
    "x	c #ffffff",
    " 	c #000000",
    "................",
    ".              .",
    ". xxxxxxxxxxxx .",
    ". x          x .",
    ".. x s    s x ..",
    "... x ssss x ...",
    ".... x ss x ....",
    "..... x  x .....",
    "..... x  x .....",
    ".... x ss x ....",
    "... x  ss  x ...",
    ".. x        x ..",
    ". x          x .",
    ". xxxxxxxxxxxx .",
    ".              .",
    "................"]

_icon2_xpm = [
    "16 16 4 1",
    ".	c None",
    "s	c #cccc00",
    "x	c #ffffff",
    " 	c #000000",
    "................",
    ".              .",
    ". xxxxxxxxxxxx .",
    ". x          x .",
    ".. x        x ..",
    "... x ssss x ...",
    ".... x ss x ....",
    "..... x  x .....",
    "..... x  x .....",
    ".... x ss x ....",
    "... x  ss  x ...",
    ".. x   ss   x ..",
    ". x          x .",
    ". xxxxxxxxxxxx .",
    ".              .",
    "................"]

_icon3_xpm = [
    "16 16 4 1",
    ".	c None",
    "s	c #cccc00",
    "x	c #ffffff",
    " 	c #000000",
    "................",
    ".              .",
    ". xxxxxxxxxxxx .",
    ". x          x .",
    ".. x        x ..",
    "... x      x ...",
    ".... x    x ....",
    "..... x  x .....",
    "..... x  x .....",
    ".... x ss x ....",
    "... x ssss x ...",
    ".. x ssssss x ..",
    ". x          x .",
    ". xxxxxxxxxxxx .",
    ".              .",
    "................"]


class Delegate(QItemDelegate):

    needsRedraw = pyqtSignal()
    
    def __init__(self, parent = None):
    
        QItemDelegate.__init__(self, parent)
        self.current = 0
        self.timerId = self.startTimer(250)
        self.model = QStandardItemModel()
        self.pixmaps = (QPixmap(_icon0_xpm),
                        QPixmap(_icon1_xpm),
                        QPixmap(_icon2_xpm),
                        QPixmap(_icon3_xpm))
    
    def timerEvent(self, event):
    
        if event.timerId() == self.timerId:
            self.current = (self.current + 1) % 4
            self.needsRedraw.emit()
    
    def paint(self, painter, option, index):
    
        waiting = index.data(Qt.UserRole).toBool()
        if waiting:
            option = option.__class__(option)
            painter.drawPixmap(option.rect.topLeft(), self.pixmaps[self.current])
            option.rect = option.rect.translated(20, 0)
        
        QItemDelegate.paint(self, painter, option, index)


app = QApplication(sys.argv)
view = QListView()
model = QStandardItemModel()
waiting = True

for i in range(5):

    item = QStandardItem("Test %i" % i)
    item.setData(QVariant(waiting), Qt.UserRole)
    waiting = not waiting
    model.appendRow(item)

view.setModel(model)

delegate = Delegate()
view.setItemDelegate(delegate)
delegate.needsRedraw.connect(view.viewport().update)

view.show()
sys.exit(app.exec_())
}}}