这是一个非常有趣的话题,因为 Qt 没有提供这样的功能,但它可以实现。
以下示例远非完美,我将列出其主要优点/缺点。
优点
- 有效 ;-)
- 更改水平标题标签会自动更新标题高度
- 支持水平滚动“超过”最后一项位置(如果表格视图小于其内容,水平滚动条允许查看完整的标题文本)
- 有效:-D
缺点
- 部分是固定的
- 部分不可移动
- QAbstractItemView.ScrollPerPixel 对于此实现中的水平滚动模式是必需的。 Qt 的 ScrollPerItem 模式有点复杂,如果没有用 huge care 覆盖它会出现一些问题。这并不意味着不能使用该模式,而是需要付出很多努力,可能需要仔细阅读和理解 QTableView 和 QAbstractItemView 的源代码。长话短说: ScrollPerItem 一直有效,直到达到水平滚动条的最大值;此时,视图将尝试调整其视口和滚动条值/范围并调整其大小,并且最后的标题标签将被“切掉”。
- 如果所有水平列都可见(意味着项目不需要水平滚动),最后的水平标题不会完全显示,因为不需要水平滚动条。
我认为它应该可以支持所有标题功能(自定义/可拉伸部分大小、可移动部分、项目滚动等),但这需要对两者进行非常深入的重新实现过程QTableView 和 QHeaderView 方法。
无论如何,这就是我目前得到的结果,它支持滚动、绘画和基本的鼠标交互(点击时突出显示部分)。
示例截图:
滚动(靠近右边缘)屏幕截图:
表格的大小在最后一个水平列的右边缘之后稍稍调整:
示例代码
import sys
from math import sqrt, sin, acos, hypot, degrees, radians
from PyQt5 import QtCore, QtGui, QtWidgets
class AngledHeader(QtWidgets.QHeaderView):
borderPen = QtGui.QColor(0, 190, 255)
labelBrush = QtGui.QColor(255, 212, 0)
def __init__(self, parent=None):
QtWidgets.QHeaderView.__init__(self, QtCore.Qt.Horizontal, parent)
self.setSectionResizeMode(self.Fixed)
self.setDefaultSectionSize(sqrt((self.fontMetrics().height() + 4)** 2 *2))
self.setSectionsClickable(True)
self.setDefaultSectionSize(int(sqrt((self.fontMetrics().height() + 4)** 2 *2)))
self.setMaximumHeight(100)
# compute the ellipsis size according to the angle; remember that:
# 1. if the angle is not 45 degrees, you'll need to compute this value
# using trigonometric functions according to the angle;
# 2. we assume ellipsis is done with three period characters, so we can
# "half" its size as (usually) they're painted on the bottom line and
# they are large enough, allowing us to show as much as text is possible
self.fontEllipsisSize = int(hypot(*[self.fontMetrics().height()] * 2) * .5)
self.setSectionsClickable(True)
def sizeHint(self):
# compute the minimum height using the maximum header label "hypotenuse"'s
hint = QtWidgets.QHeaderView.sizeHint(self)
count = self.count()
if not count:
return hint
fm = self.fontMetrics()
width = minSize = self.defaultSectionSize()
# set the minimum width to ("hypotenuse" * sectionCount) + minimumHeight
# at least, ensuring minimal horizontal scroll bar interaction
hint.setWidth(width * count + self.minimumHeight())
maxDiag = maxWidth = maxHeight = 1
for s in range(count):
if self.isSectionHidden(s):
continue
# compute the diagonal of the text's bounding rect,
# shift its angle by 45° to get the minimum required
# height
rect = fm.boundingRect(
str(self.model().headerData(s, QtCore.Qt.Horizontal)) + ' ')
# avoid math domain errors for empty header labels
diag = max(1, hypot(rect.width(), rect.height()))
if diag > maxDiag:
maxDiag = diag
maxWidth = max(1, rect.width())
maxHeight = max(1, rect.height())
# get the angle of the largest boundingRect using the "Law of cosines":
# https://en.wikipedia.org/wiki/Law_of_cosines
angle = degrees(acos(
(maxDiag ** 2 + maxWidth ** 2 - maxHeight ** 2) /
(2. * maxDiag * maxWidth)
))
# compute the minimum required height using the angle found above
minSize = max(minSize, sin(radians(angle + 45)) * maxDiag)
hint.setHeight(min(self.maximumHeight(), minSize))
return hint
def mousePressEvent(self, event):
width = self.defaultSectionSize()
start = self.sectionViewportPosition(0)
rect = QtCore.QRect(0, 0, width, -self.height())
transform = QtGui.QTransform().translate(0, self.height()).shear(-1, 0)
for s in range(self.count()):
if self.isSectionHidden(s):
continue
if transform.mapToPolygon(
rect.translated(s * width + start, 0)).containsPoint(
event.pos(), QtCore.Qt.WindingFill):
self.sectionPressed.emit(s)
return
def paintEvent(self, event):
qp = QtGui.QPainter(self.viewport())
qp.setRenderHints(qp.Antialiasing)
width = self.defaultSectionSize()
delta = self.height()
# add offset if the view is horizontally scrolled
qp.translate(self.sectionViewportPosition(0) - .5, -.5)
fmDelta = (self.fontMetrics().height() - self.fontMetrics().descent()) * .5
# create a reference rectangle (note that the negative height)
rect = QtCore.QRectF(0, 0, width, -delta)
diagonal = hypot(delta, delta)
for s in range(self.count()):
if self.isSectionHidden(s):
continue
qp.save()
qp.save()
qp.setPen(self.borderPen)
# apply a "shear" transform making the rectangle a parallelogram;
# since the transformation is applied top to bottom
# we translate vertically to the bottom of the view
# and draw the "negative height" rectangle
qp.setTransform(qp.transform().translate(s * width, delta).shear(-1, 0))
qp.drawRect(rect)
qp.setPen(QtCore.Qt.NoPen)
qp.setBrush(self.labelBrush)
qp.drawRect(rect.adjusted(2, -2, -2, 2))
qp.restore()
qp.translate(s * width + width, delta)
qp.rotate(-45)
label = str(self.model().headerData(s, QtCore.Qt.Horizontal))
elidedLabel = self.fontMetrics().elidedText(
label, QtCore.Qt.ElideRight, diagonal - self.fontEllipsisSize)
qp.drawText(0, -fmDelta, elidedLabel)
qp.restore()
class AngledTable(QtWidgets.QTableView):
def __init__(self, *args, **kwargs):
QtWidgets.QTableView.__init__(self, *args, **kwargs)
self.setHorizontalHeader(AngledHeader(self))
self.verticalScrollBarSpacer = QtWidgets.QWidget()
self.addScrollBarWidget(self.verticalScrollBarSpacer, QtCore.Qt.AlignTop)
self.fixLock = False
def setModel(self, model):
if self.model():
self.model().headerDataChanged.disconnect(self.fixViewport)
QtWidgets.QTableView.setModel(self, model)
model.headerDataChanged.connect(self.fixViewport)
def fixViewport(self):
if self.fixLock:
return
self.fixLock = True
# delay the viewport/scrollbar states since the view has to process its
# new header data first
QtCore.QTimer.singleShot(0, self.delayedFixViewport)
def delayedFixViewport(self):
# add a right margin through the horizontal scrollbar range
QtWidgets.QApplication.processEvents()
header = self.horizontalHeader()
if not header.isVisible():
self.verticalScrollBarSpacer.setFixedHeight(0)
self.updateGeometries()
return
self.verticalScrollBarSpacer.setFixedHeight(header.sizeHint().height())
bar = self.horizontalScrollBar()
bar.blockSignals(True)
step = bar.singleStep() * (header.height() / header.defaultSectionSize())
bar.setMaximum(bar.maximum() + step)
bar.blockSignals(False)
self.fixLock = False
def resizeEvent(self, event):
# ensure that the viewport and scrollbars are updated whenever
# the table size change
QtWidgets.QTableView.resizeEvent(self, event)
self.fixViewport()
class TestWidget(QtWidgets.QWidget):
def __init__(self):
QtWidgets.QWidget.__init__(self)
l = QtWidgets.QGridLayout()
self.setLayout(l)
self.table = AngledTable()
l.addWidget(self.table)
model = QtGui.QStandardItemModel(4, 5)
self.table.setModel(model)
self.table.setHorizontalScrollMode(self.table.ScrollPerPixel)
model.setVerticalHeaderLabels(['Location {}'.format(l + 1) for l in range(8)])
columns = ['Column {}'.format(c + 1) for c in range(8)]
columns[3] += ' very, very, very, very, very, very, long'
model.setHorizontalHeaderLabels(columns)
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
w = TestWidget()
w.show()
sys.exit(app.exec_())
请注意,我使用 QTransforms 而不是 QPolygons 编辑了绘画和点击检测代码:虽然理解其机制有点复杂,但它比每次必须绘制列标题时创建多边形并计算其点要快。
此外,我还添加了对最大标题高度的支持(以防任何标题标签变得太长),以及将垂直滚动条移动到表格内容的实际“开始”的“间隔”小部件。