I would like to perform input validation on a customized QTableWidget that has its setItemDelegate to a subclass of QStyledItemDelegate. The input validation works and my error message pops up correctly, but the focus moves on to the next cell selection (ie: if I pressed TAB it will perform my input validation, print a msg if bad input, and then move the focus to the adjacent cell). I would like the focus to remain on the first cell until the input is correct.
Perhaps if I could edit the TAB traversal so that I manually control the traversal in the table (ie: check if input is valid then traverse with TAB) I could achieve input validation; however, I am unaware of a method to modify the table's (QTableWidget) default TAB traversal (described in the detailed description of the superclass QAbstractItemView).
Below is the relevant code:
class TheEditor(QLineEdit):
# a signal to tell the delegate when we have finished editing
editingFinished = Signal()
def __init__(self, parent=None):
# Initialize the editor object
super(TheEditor, self).__init__(parent)
self.setAutoFillBackground(True)
self.setValidator(QIntValidator(0,999999999, self))
def focusOutEvent(self, event):
# Once focus is lost, tell the delegate we're done editing
self.editingFinished.emit()
class EditDelegate(QStyledItemDelegate):
def __init__(self, parent=None):
super(EditDelegate, self).__init__(parent)
def createEditor(self, parent, option, index):
# Creates and returns the custom editor object we will use to edit the cell
result = index.column()
if result==0:
editor = TheEditor(parent)
editor.editingFinished.connect(self.checkInput)
return editor
else:
return QStyledItemDelegate.createEditor(self, parent, option, index)
def errorMessage(self, error_message):
newQWidget = QWidget()
QtGui.QMessageBox.critical(newQWidget, "Invalid Entry", error_message, QtGui.QMessageBox.Retry)
def checkInput(self):
# ... some code here that does validation
if result == expected: # good input!
self.commitData.emit(editor)
self.closeEditor.emit(editor, QAbstractItemDelegate.EditNextItem)
return True
else: # bad input!
self.errorMessage("Invalid!")
self.closeEditor.emit(editor, QAbstractItemDelegate.NoHint)
return True
Does anyone have any suggestions to achieve input validation? I found a similar question here but I wasn't able to implement it so that it worked.
