我发现@Eric Hulser的回答虽然很好,但当标签放到另一个小部件中时无法正常工作。
我通过将Eric的响应与Qt
Elided Label Example混合在一起来解决这个问题。它应该像普通标签一样运行,但是当文本宽度超过小部件宽度时会水平缩略。它有一个额外的参数用于不同的省略模式。我还为了好玩写了一些测试 :)
如果你想使用PyQt5...
- 将"PySide2"更改为"PyQt5"
- 将"Signal"更改为"pyqtSignal"
享受吧!
省略标签
from PySide2 import QtCore, QtWidgets, QtGui
class ElidingLabel(QtWidgets.QLabel):
"""Label with text elision.
QLabel which will elide text too long to fit the widget. Based on:
https://doc-snapshots.qt.io/qtforpython-5.15/overviews/qtwidgets-widgets-elidedlabel-example.html
Parameters
----------
text : str
Label text.
mode : QtCore.Qt.TextElideMode
Specify where ellipsis should appear when displaying texts that
don’t fit.
Default is QtCore.Qt.ElideMiddle.
Possible modes:
QtCore.Qt.ElideLeft
QtCore.Qt.ElideMiddle
QtCore.Qt.ElideRight
parent : QWidget
Parent widget. Default is None.
f : Qt.WindowFlags()
https://doc-snapshots.qt.io/qtforpython-5.15/PySide2/QtCore/Qt.html#PySide2.QtCore.PySide2.QtCore.Qt.WindowType
"""
elision_changed = QtCore.Signal(bool)
def __init__(self, text='', mode=QtCore.Qt.ElideMiddle, **kwargs):
super().__init__(**kwargs)
self._mode = mode
self.is_elided = False
self.setSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Preferred)
self.setText(text)
def setText(self, text):
self._contents = text
self._elided_line = text
self.update()
def text(self):
return self._contents
def paintEvent(self, event):
super().paintEvent(event)
did_elide = False
painter = QtGui.QPainter(self)
font_metrics = painter.fontMetrics()
text_width = font_metrics.horizontalAdvance(self.text())
text_layout = QtGui.QTextLayout(self._contents, painter.font())
text_layout.beginLayout()
while True:
line = text_layout.createLine()
if not line.isValid():
break
line.setLineWidth(self.width())
if text_width >= self.width():
self._elided_line = font_metrics.elidedText(self._contents, self._mode, self.width())
painter.drawText(QtCore.QPoint(0, font_metrics.ascent()), self._elided_line)
did_elide = line.isValid()
break
else:
line.draw(painter, QtCore.QPoint(0, 0))
text_layout.endLayout()
if did_elide != self.is_elided:
self.is_elided = did_elide
self.elision_changed.emit(did_elide)
if __name__ == '__main__':
app = QtWidgets.QApplication([])
long_text = "this is some long text, wouldn't you say?"
elabel = ElidingLabel(long_text)
elabel.show()
app.exec_()
测试省略标签
import unittest
import unittest.mock
from PySide2 import QtCore, QtWidgets, QtGui, QtTest
import eliding_label
if not QtWidgets.QApplication.instance():
APP = QtWidgets.QApplication([])
class TestElidingLabelArguments(unittest.TestCase):
def test_optional_text_argument(self):
elabel = eliding_label.ElidingLabel()
self.assertEqual(elabel.text(), "")
def test_text_argument_sets_label_text(self):
elabel = eliding_label.ElidingLabel(text="Test text")
self.assertEqual(elabel.text(), "Test text")
def test_optional_elision_mode_argument(self):
elabel = eliding_label.ElidingLabel()
self.assertEqual(elabel._mode, QtCore.Qt.ElideMiddle)
class TestElidingLabel(unittest.TestCase):
def setUp(self):
self.elabel = eliding_label.ElidingLabel()
def test_elabel_is_a_label(self):
self.assertIsInstance(self.elabel, QtWidgets.QLabel)
def test_has_elision_predicate(self):
self.assertEqual(self.elabel.is_elided, False)
def test_elision_predicate_changes_when_text_width_exceeds_widget_width(self):
self.elabel.setFixedWidth(25)
self.assertEqual(self.elabel.width(), 25)
long_text = "This is line is definely longer than 25 pixels."
painter = QtGui.QPainter()
font_metrics = painter.fontMetrics()
long_text_width = font_metrics.horizontalAdvance(long_text)
self.assertGreater(long_text_width, 25)
self.elabel.setText(long_text)
x = self.elabel.x()
y = self.elabel.y()
w = self.elabel.width()
h = self.elabel.height()
paint_event = QtGui.QPaintEvent(QtGui.QRegion(x, y, w, h))
self.elabel.paintEvent(paint_event)
self.assertEqual(self.elabel.is_elided, True)
def test_text_is_elided_when_text_width_exceeds_widget_width(self):
self.elabel.setFixedWidth(25)
self.assertEqual(self.elabel.width(), 25)
long_text = "This is line is definely longer than 25 pixels."
painter = QtGui.QPainter()
font_metrics = painter.fontMetrics()
long_text_width = font_metrics.horizontalAdvance(long_text)
self.assertGreater(long_text_width, 25)
self.elabel.setText(long_text)
x = self.elabel.x()
y = self.elabel.y()
w = self.elabel.width()
h = self.elabel.height()
paint_event = QtGui.QPaintEvent(QtGui.QRegion(x, y, w, h))
self.elabel.paintEvent(paint_event)
self.assertEqual(self.elabel._elided_line, '…')
def test_text_is_not_elided_when_text_width_is_less_than_widget_width(self):
self.elabel.setFixedWidth(500)
self.assertEqual(self.elabel.width(), 500)
short_text = "Less than 500"
painter = QtGui.QPainter()
font_metrics = painter.fontMetrics()
short_text_width = font_metrics.horizontalAdvance(short_text)
self.assertLess(short_text_width, 500)
self.elabel.setText(short_text)
x = self.elabel.x()
y = self.elabel.y()
w = self.elabel.width()
h = self.elabel.height()
paint_event = QtGui.QPaintEvent(QtGui.QRegion(x, y, w, h))
self.elabel.paintEvent(paint_event)
self.assertEqual(self.elabel._elided_line, short_text)
def test_stores_full_text_even_when_elided(self):
self.elabel.setFixedWidth(25)
self.assertEqual(self.elabel.width(), 25)
long_text = "This is line is definely longer than 25 pixels."
painter = QtGui.QPainter()
font_metrics = painter.fontMetrics()
long_text_width = font_metrics.horizontalAdvance(long_text)
self.assertGreater(long_text_width, 25)
self.elabel.setText(long_text)
x = self.elabel.x()
y = self.elabel.y()
w = self.elabel.width()
h = self.elabel.height()
paint_event = QtGui.QPaintEvent(QtGui.QRegion(x, y, w, h))
self.elabel.paintEvent(paint_event)
self.assertEqual(self.elabel._elided_line, '…')
self.assertEqual(self.elabel.text(), long_text)
def test_has_elision_changed_signal(self):
self.assertIsInstance(self.elabel.elision_changed, QtCore.Signal)
def test_elision_changed_signal_emits_on_change_to_is_elided_predicate(self):
mock = unittest.mock.Mock()
self.elabel.elision_changed.connect(mock.method)
self.elabel.setFixedWidth(150)
self.assertEqual(self.elabel.width(), 150)
long_text = "This line is definitely going to be more than 150 pixels"
painter = QtGui.QPainter()
font_metrics = painter.fontMetrics()
long_text_width = font_metrics.horizontalAdvance(long_text)
self.assertGreater(long_text_width, 150)
self.elabel.setText(long_text)
self.assertEqual(self.elabel.is_elided, False)
x = self.elabel.x()
y = self.elabel.y()
w = self.elabel.width()
h = self.elabel.height()
paint_event = QtGui.QPaintEvent(QtGui.QRegion(x, y, w, h))
self.elabel.paintEvent(paint_event)
self.assertEqual(self.elabel.is_elided, True)
mock.method.assert_called_once()
short_text = "Less than 150"
painter = QtGui.QPainter()
font_metrics = painter.fontMetrics()
short_text_width = font_metrics.horizontalAdvance(short_text)
self.assertLess(short_text_width, 150)
self.elabel.setText(short_text)
self.assertEqual(self.elabel.is_elided, True)
x = self.elabel.x()
y = self.elabel.y()
w = self.elabel.width()
h = self.elabel.height()
paint_event = QtGui.QPaintEvent(QtGui.QRegion(x, y, w, h))
self.elabel.paintEvent(paint_event)
self.assertEqual(self.elabel.is_elided, False)
self.assertEqual(mock.method.call_count, 2)