我有一个QTableWidget,其中包含需要大量水平空间的浮点数或复杂条目。通过字符串格式化显示减少位数的值工作正常,但显然我在表中编辑和存储条目时会失去精度。
我通过使用eventFilter找到了QLineEdit小部件的解决方案:FocusIn
事件将存储的值以完全精度复制到QLineEdit文本字段,FocusOut
个事件或Return_Key
个商店更改的值并用减少的位数覆盖文本字段。
使用与QTableWidgets相同的方法会给出以下(可能相关)问题:
我已经尝试过评估QTableWidgetItem事件,但我没有收到任何事件 - 我是否需要在每个QTableWidgetItem上设置事件过滤器?如果是这样,每次调整表格大小时(我的应用程序中经常这样做),是否需要断开QTableWidgetItem eventFilters?用QLineEdit小部件填充我的表是否有意义?
附加的MWE并不是很小,但我可以进一步缩小它。
# -*- coding: utf-8 -*-
#from PyQt5.QWidgets import ( ...)
from PyQt4.QtGui import (QApplication, QWidget, QTableWidget, QTableWidgetItem,
QLabel, QVBoxLayout)
import PyQt4.QtCore as QtCore
from PyQt4.QtCore import QEvent
from numpy.random import randn
class EventTable (QWidget):
def __init__(self, parent = None):
super(EventTable, self).__init__(parent)
self.myTable = QTableWidget(self)
self.myTable.installEventFilter(self) # route all events to self.eventFilter()
myQVBoxLayout = QVBoxLayout()
myQVBoxLayout.addWidget(self.myTable)
self.setLayout(myQVBoxLayout)
self.rows = 3; self.columns = 4 # table + data dimensions
self.data = randn(self.rows, self.columns) # initial data
self._update_table() # create table
def eventFilter(self, source, event):
if isinstance(source, (QTableWidget, QTableWidgetItem)):
# print(type(source).__name__, event.type()) #too much noise
if event.type() == QEvent.FocusIn: # 8: enter widget
print(type(source).__name__, "focus in")
self.item_edited = False
self._update_table_item() # focus: display data with full precision
return True # event processing stops here
elif event.type() == QEvent.KeyPress:
print(type(source).__name__, "key pressed")
self.item_edited = True # table item has been changed
key = event.key() # key press: 6, key release: 7
if key in {QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter}: # store entry
self._store_item() # store edited data in self.data
return True
elif key == QtCore.Qt.Key_Escape: # revert changes
self.item_edited = False
self._update_table() # update table from self.data
return True
elif event.type() == QEvent.FocusOut: # 9: leave widget
print(type(source).__name__, "focus out")
self._store_item()
self._update_table_item() # no focus: use reduced precision
return True
return super(EventTable, self).eventFilter(source, event)
def _update_table(self):
"""(Re-)Create the table with rounded data from self.data """
self.myTable.setRowCount(self.rows)
self.myTable.setColumnCount(self.columns)
for col in range(self.columns):
for row in range(self.rows):
self.myTable.setItem(row,col,
QTableWidgetItem(str("{:.3g}".format(self.data[row][col]))))
self.myTable.resizeColumnsToContents()
self.myTable.resizeRowsToContents()
def _update_table_item(self, source = None):
""" Re-)Create the current table item with full or reduced precision. """
row = self.myTable.currentRow()
col = self.myTable.currentColumn()
item = self.myTable.item(row, col)
if item: # is something selected?
if not item.isSelected(): # no focus, show self.data[row][col] with red. precision
print("\n_update_item (not selected):", row, col)
item.setText(str("{:.3g}".format(self.data[row][col])))
else: # in focus, show self.data[row][col] with full precision
item.setText(str(self.data[row][col]))
print("\n_update_item (selected):", row, col)
def _store_item(self):
""" Store the content of item in self.data """
if self.item_edited:
row = self.myTable.currentRow()
col = self.myTable.currentColumn()
item_txt = self.myTable.item(row, col).text()
self.data[row][col] = float(str(item_txt))
print("\n_store_entry - current item/data:", item_txt, self.data[row][col])
if __name__ == "__main__":
import sys
app = QApplication(sys.argv)
mainw = EventTable()
app.setActiveWindow(mainw)
mainw.show()
sys.exit(app.exec_())
答案 0 :(得分:1)
你以完全错误的方式解决这个问题。现有的API已经满足了这些用例的需求,因此有几种解决方案比您现有的解决方案简单得多。
最简单的可能是使用QStyledItemDelegate并重新实现其dispalyText方法。这将允许您将完整值存储在表中,但以不同方式对其进行格式化以便显示。编辑时,将始终显示完整值(作为字符串):
from PyQt4.QtGui import (QApplication, QWidget, QTableWidget, QTableWidgetItem,
QLabel, QVBoxLayout,QStyledItemDelegate)
import PyQt4.QtCore as QtCore
from PyQt4.QtCore import QEvent
from numpy.random import randn
class ItemDelegate(QStyledItemDelegate):
def displayText(self, text, locale):
return "{:.3g}".format(float(text))
class EventTable (QWidget):
def __init__(self, parent = None):
super(EventTable, self).__init__(parent)
self.myTable = QTableWidget(self)
self.myTable.setItemDelegate(ItemDelegate(self))
myQVBoxLayout = QVBoxLayout()
myQVBoxLayout.addWidget(self.myTable)
self.setLayout(myQVBoxLayout)
self.rows = 3; self.columns = 4 # table + data dimensions
self.data = randn(self.rows, self.columns) # initial data
self._update_table() # create table
def _update_table(self):
self.myTable.setRowCount(self.rows)
self.myTable.setColumnCount(self.columns)
for col in range(self.columns):
for row in range(self.rows):
item = QTableWidgetItem(str(self.data[row][col]))
self.myTable.setItem(row, col, item)
self.myTable.resizeColumnsToContents()
self.myTable.resizeRowsToContents()
if __name__ == "__main__":
import sys
app = QApplication(sys.argv)
mainw = EventTable()
app.setActiveWindow(mainw)
mainw.show()
sys.exit(app.exec_())
注意:使用item roles来解决此问题很诱人。但是,QTableWidgetItem
和QStandardItem
都将DisplayRole
和EditRole
视为一个角色,这意味着有必要重新实现其data
和{{1}获取所需功能的方法。