我想在表格标签中添加数学表达式(例如: 2^3 应该被正确格式化)
这里是一个简单的表格示例: http://thomas-cokelaer.info/blog/2012/10/pyqt4-example-of-tablewidget-usage/
setHorizontalHeaderLabels只接受字符串。 我想知道是否可能以某种方式实现此 matplotlib 方法: matplotlib - write TeX on Qt form
还有其他选项吗?
我想在表格标签中添加数学表达式(例如: 2^3 应该被正确格式化)
这里是一个简单的表格示例: http://thomas-cokelaer.info/blog/2012/10/pyqt4-example-of-tablewidget-usage/
setHorizontalHeaderLabels只接受字符串。 我想知道是否可能以某种方式实现此 matplotlib 方法: matplotlib - write TeX on Qt form
还有其他选项吗?
我一直在尝试在QTableWidget的表头中显示复杂标签。我通过重新实现QHeaderView的paintSection方法,并使用QTextDocument手动绘制标签,如Qt Centre上的一个帖子所述。
然而,与LaTex相比,这种解决方案有些局限性。我觉得你在你的OP中提出的方法可能是个好主意,即使用matplotlib在PySide中渲染LaTex。
在这种方法中需要的第一件事情是能够将matplotlib图形转换为可以轻松绘制在任何QWidget上的格式。下面是一个函数,它以mathTex表达式作为输入,并通过matplotlib将其转换为一个QPixmap。
import sys
import matplotlib as mpl
from matplotlib.backends.backend_agg import FigureCanvasAgg
from PySide import QtGui, QtCore
def mathTex_to_QPixmap(mathTex, fs):
#---- set up a mpl figure instance ----
fig = mpl.figure.Figure()
fig.patch.set_facecolor('none')
fig.set_canvas(FigureCanvasAgg(fig))
renderer = fig.canvas.get_renderer()
#---- plot the mathTex expression ----
ax = fig.add_axes([0, 0, 1, 1])
ax.axis('off')
ax.patch.set_facecolor('none')
t = ax.text(0, 0, mathTex, ha='left', va='bottom', fontsize=fs)
#---- fit figure size to text artist ----
fwidth, fheight = fig.get_size_inches()
fig_bbox = fig.get_window_extent(renderer)
text_bbox = t.get_window_extent(renderer)
tight_fwidth = text_bbox.width * fwidth / fig_bbox.width
tight_fheight = text_bbox.height * fheight / fig_bbox.height
fig.set_size_inches(tight_fwidth, tight_fheight)
#---- convert mpl figure to QPixmap ----
buf, size = fig.canvas.print_to_buffer()
qimage = QtGui.QImage.rgbSwapped(QtGui.QImage(buf, size[0], size[1],
QtGui.QImage.Format_ARGB32))
qpixmap = QtGui.QPixmap(qimage)
return qpixmap
下一步是在 QTableWidget 的标题中绘制 QPixmap。如下所示,我通过子类化 QTableWidget 并重新实现 setHorizontalHeaderLabels 方法来完成,该方法用于将标签的 mathTex 表达式转换为 QPixmap,并将其作为列表传递给 QHeaderView 的子类。然后,在 QHeaderView 的 paintSection 方法的重新实现中绘制 QPixmap,并在 sizeHint 方法的重新实现中设置标题的高度以适应 mathTex 表达式的高度。
class MyQTableWidget(QtGui.QTableWidget):
def __init__(self, parent=None):
super(MyQTableWidget, self).__init__(parent)
self.setHorizontalHeader(MyHorizHeader(self))
def setHorizontalHeaderLabels(self, headerLabels, fontsize):
qpixmaps = []
indx = 0
for labels in headerLabels:
qpixmaps.append(mathTex_to_QPixmap(labels, fontsize))
self.setColumnWidth(indx, qpixmaps[indx].size().width() + 16)
indx += 1
self.horizontalHeader().qpixmaps = qpixmaps
super(MyQTableWidget, self).setHorizontalHeaderLabels(headerLabels)
class MyHorizHeader(QtGui.QHeaderView):
def __init__(self, parent):
super(MyHorizHeader, self).__init__(QtCore.Qt.Horizontal, parent)
self.setClickable(True)
self.setStretchLastSection(True)
self.qpixmaps = []
def paintSection(self, painter, rect, logicalIndex):
if not rect.isValid():
return
#------------------------------ paint section (without the label) ----
opt = QtGui.QStyleOptionHeader()
self.initStyleOption(opt)
opt.rect = rect
opt.section = logicalIndex
opt.text = ""
#---- mouse over highlight ----
mouse_pos = self.mapFromGlobal(QtGui.QCursor.pos())
if rect.contains(mouse_pos):
opt.state |= QtGui.QStyle.State_MouseOver
#---- paint ----
painter.save()
self.style().drawControl(QtGui.QStyle.CE_Header, opt, painter, self)
painter.restore()
#------------------------------------------- paint mathText label ----
qpixmap = self.qpixmaps[logicalIndex]
#---- centering ----
xpix = (rect.width() - qpixmap.size().width()) / 2. + rect.x()
ypix = (rect.height() - qpixmap.size().height()) / 2.
#---- paint ----
rect = QtCore.QRect(xpix, ypix, qpixmap.size().width(),
qpixmap.size().height())
painter.drawPixmap(rect, qpixmap)
def sizeHint(self):
baseSize = QtGui.QHeaderView.sizeHint(self)
baseHeight = baseSize.height()
if len(self.qpixmaps):
for pixmap in self.qpixmaps:
baseHeight = max(pixmap.height() + 8, baseHeight)
baseSize.setHeight(baseHeight)
self.parentWidget().repaint()
return baseSize
以下是上述内容的一个简单应用示例。
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
w = MyQTableWidget()
w.verticalHeader().hide()
headerLabels = [
'$C_{soil}=(1 - n) C_m + \\theta_w C_w$',
'$k_{soil}=\\frac{\\sum f_j k_j \\theta_j}{\\sum f_j \\theta_j}$',
'$\\lambda_{soil}=k_{soil} / C_{soil}$']
w.setColumnCount(len(headerLabels))
w.setHorizontalHeaderLabels(headerLabels, 25)
w.setRowCount(3)
w.setAlternatingRowColors(True)
k = 1
for j in range(3):
for i in range(3):
w.setItem(i, j, QtGui.QTableWidgetItem('Value %i' % (k)))
k += 1
w.show()
w.resize(700, 200)
sys.exit(app.exec_())