def paint(self, painter, option, index):
""" Paint the items in the table.
If the item referred to by <index> is a StarRating, we handle the
painting ourselves. For the other items, we let the base class
handle the painting as usual.
In a polished application, we'd use a better check than the
column number to find out if we needed to paint the stars, but
it works for the purposes of this example.
"""
if index.column() == 3:
starRating = StarRating(index.data())
# If the row is currently selected, we need to make sure we
# paint the background accordingly.
if option.state & QStyle.State_Selected:
# The original C++ example used option.palette.foreground() to
# get the brush for painting, but there are a couple of
# problems with that:
# - foreground() is obsolete now, use windowText() instead
# - more importantly, windowText() just returns a brush
# containing a flat color, where sometimes the style
# would have a nice subtle gradient or something.
# Here we just use the brush of the painter object that's
# passed in to us, which keeps the row highlighting nice
# and consistent.
painter.fillRect(option.rect, painter.brush())
# Now that we've painted the background, call starRating.paint()
# to paint the stars.
starRating.paint(painter, option.rect, option.palette)
else:
QStyledItemDelegate.paint(self, painter, option, index)
def paint(self, painter, option, index):
""" Paint the items in the table.
If the item referred to by <index> is a StarRating, we handle the
painting ourselves. For the other items, we let the base class
handle the painting as usual.
In a polished application, we'd use a better check than the
column number to find out if we needed to paint the stars, but
it works for the purposes of this example.
"""
if index.column() == 3:
starRating = StarRating(index.data())
# If the row is currently selected, we need to make sure we
# paint the background accordingly.
if option.state & QStyle.State_Selected:
# The original C++ example used option.palette.foreground() to
# get the brush for painting, but there are a couple of
# problems with that:
# - foreground() is obsolete now, use windowText() instead
# - more importantly, windowText() just returns a brush
# containing a flat color, where sometimes the style
# would have a nice subtle gradient or something.
# Here we just use the brush of the painter object that's
# passed in to us, which keeps the row highlighting nice
# and consistent.
painter.fillRect(option.rect, painter.brush())
# Now that we've painted the background, call starRating.paint()
# to paint the stars.
starRating.paint(painter, option.rect, option.palette)
else:
QStyledItemDelegate.paint(self, painter, option, index)
class StarEditor(QWidget):
""" The custom editor for editing StarRatings. """
# A signal to tell the delegate when we've finished editing.
editingFinished = Signal()
def __init__(self, parent=None):
""" Initialize the editor object, making sure we can watch mouse
events.
"""
super(StarEditor, self).__init__(parent)
self.setMouseTracking(True)
self.setAutoFillBackground(True)
self.starRating = StarRating()
def sizeHint(self):
""" Tell the caller how big we are. """
return self.starRating.sizeHint()
def paintEvent(self, event):
""" Paint the editor, offloading the work to the StarRating class. """
painter = QPainter(self)
self.starRating.paint(painter,
self.rect(),
self.palette(),
isEditable=True)
def mouseMoveEvent(self, event):
""" As the mouse moves inside the editor, track the position and
update the editor to display as many stars as necessary.
"""
star = self.starAtPosition(event.x())
if (star != self.starRating.starCount) and (star != -1):
self.starRating.starCount = star
self.update()
def mouseReleaseEvent(self, event):
""" Once the user has clicked his/her chosen star rating, tell the
delegate we're done editing.
"""
self.editingFinished.emit()
def starAtPosition(self, x):
""" Calculate which star the user's mouse cursor is currently
hovering over.
"""
star = (x / (self.starRating.sizeHint().width() /
self.starRating.maxStarCount)) + 1
if (star <= 0) or (star > self.starRating.maxStarCount):
return -1
return star
