def _init_images(self):
A, = 'A'.encode('ascii')
gs = Qt.QGraphicsScene()
sti = Qt.QGraphicsSimpleTextItem()
sti.setFont(Qt.QFont('Courier', pointSize=24, weight=Qt.QFont.Bold))
gs.addItem(sti)
self.images = []
for char in range(A, A + 26):
for i in range(0, 10):
text = bytes([char]).decode('ascii') + str(i)
sti.setText(text)
scene_rect_f = gs.itemsBoundingRect()
scene_rect = Qt.QRect(
0,
0,
math.ceil(scene_rect_f.width()),
math.ceil(scene_rect_f.height()))
gs.setSceneRect(scene_rect_f)
buffer = numpy.empty((scene_rect.height(), scene_rect.width(), 4), dtype=numpy.uint8)
buffer[:] = 255
qimage = Qt.QImage(sip.voidptr(buffer.ctypes.data), scene_rect.size().width(), scene_rect.size().height(), Qt.QImage.Format_RGBA8888)
qpainter = Qt.QPainter()
qpainter.begin(qimage)
qpainter.setRenderHint(Qt.QPainter.Antialiasing)
qpainter.setRenderHint(Qt.QPainter.HighQualityAntialiasing)
gs.render(qpainter)
qpainter.end()
self.images.append(Image(buffer.copy(), shape_is_width_height=False, name=text))
def _update_picture(self):
if self._picture is None:
self._picture = Qt.QPicture()
ppainter = Qt.QPainter()
with ExitStack() as stack:
ppainter.begin(self._picture)
stack.callback(ppainter.end)
# The Qt API calls required for formatting multiline text such that it can be rendered to
# a path are private, as can be seen in the implementation of
# QGraphicsSimpleTextItem::paint, pasted below. (Specifically, QStackTextEngine is a private
# component and thus not available through PyQt).
#
# void QGraphicsSimpleTextItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
# {
# Q_UNUSED(widget);
# Q_D(QGraphicsSimpleTextItem);
#
# painter->setFont(d->font);
#
# QString tmp = d->text;
# tmp.replace(QLatin1Char('\n'), QChar::LineSeparator);
# QStackTextEngine engine(tmp, d->font);
# QTextLayout layout(&engine);
#
# QPen p;
# p.setBrush(d->brush);
# painter->setPen(p);
# if (d->pen.style() == Qt::NoPen && d->brush.style() == Qt::SolidPattern) {
# painter->setBrush(Qt::NoBrush);
# } else {
# QTextLayout::FormatRange range;
# range.start = 0;
# range.length = layout.text().length();
# range.format.setTextOutline(d->pen);
# QList<QTextLayout::FormatRange> formats;
# formats.append(range);
# layout.setAdditionalFormats(formats);
# }
#
# setupTextLayout(&layout);
# layout.draw(painter, QPointF(0, 0));
#
# if (option->state & (QStyle::State_Selected | QStyle::State_HasFocus))
# qt_graphicsItem_highlightSelected(this, painter, option);
# }
#
# We would just use QGraphicsSimpleTextItem directly, but it is not derived from QGraphicsObject, so
# it lacks the QObject base class required for emitting signals. It is not possible to add a QObject
# base to a QGraphicsItem derivative in Python (it can be done in C++ - this is how QGraphicsObject
# is implemented).
#
# Total lack of signal support is not acceptable; it would greatly complicate the task of
# positioning a non-child item relative to a ContextualInfoItem.
#
# However, it's pretty easy to use that very paint function to generate paint commands that
# we cache in self._picture, so we do that. For strings large enough that the relayout
# performed on each refresh by QGraphicsSimpleTextItem exceeds the CPython interpreter overhead
# for initiating the QPicture replay, our paint function is faster.
#
# Additionally, QGraphicsTextItem is very featureful, has a QObject base, and would be the first
# choice, but the one thing it can not do is outline text, so it's out.
i = Qt.QGraphicsSimpleTextItem(self.contextual_info.value)
i.setFont(self._font)
# Disabling brush/pen via setBrush/Pen(Qt.QBrush/Pen(Qt.Qt.NoBrush/Pen)) ought to be more intelligent
# than disablind via setting to transparent color. However, using NoBrush or NoPen here seems to
# cause extreme painting slowdowns on OS X.
transparent_color = Qt.QColor(Qt.Qt.transparent)
if self._pen is None or self._brush is None:
i.setPen(Qt.QPen(transparent_color) if self._pen is None else self._pen)
i.setBrush(Qt.QBrush(transparent_color) if self._brush is None else self._brush)
i.paint(ppainter, Qt.QStyleOptionGraphicsItem(), None)
else:
# To ensure that character outlines never obscure the entirety of character interior, outline
# is drawn first and interior second. If both brush and pen are nonempty, Qt draws interior first
# and outline second.
i.setBrush(Qt.QBrush(transparent_color))
i.setPen(self._pen)
i.paint(ppainter, Qt.QStyleOptionGraphicsItem(), None)
i.setBrush(self._brush)
i.setPen(Qt.QPen(transparent_color))
i.paint(ppainter, Qt.QStyleOptionGraphicsItem(), None)
self._bounding_rect = i.boundingRect()
