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//! [0]
class AppendText(QUndoCommand):
self.m_document = ''
self.m_text = ''
def AppendText(self, doc, text):
self.m_document = doc
self.m_text = text
self.setText("append text")
def undo(self):
self.m_document.chop(self.m_text.length())
def redo(self):
self.m_document->append(self.m_text)
//! [0]
//! [1]
command1 = MyCommand()
stack.push(command1)
command2 = MyCommand()
stack.push(command2)
stack.undo()
command3 = MyCommand()
stack.push(command3) # command2 gets deleted
//! [1]
//! [2]
insertRed = QUndoCommand() # an empty command
insertRed.setText("insert red text")
InsertText(document, idx, text, insertRed) # becomes child of insertRed
SetColor(document, idx, text.length(), Qt.red, insertRed)
stack.push(insertRed)
//! [2]
//! [3]
class AppendText(QUndoCommand):
...
def mergeWith(self, other):
if other.id() != self.id(): # make sure other is also an AppendText command
return False
m_text += other.m_text
return True
//! [3]
//! [4]
stack.beginMacro("insert red text")
stack.push(InsertText(document, idx, text))
stack.push(SetColor(document, idx, text.length(), Qt.red))
stack.endMacro() # indexChanged() is emitted
//! [4]
//! [5]
insertRed = QUndoCommand() # an empty command
insertRed.setText("insert red text")
InsertText(document, idx, text, insertRed) # becomes child of insertRed
SetColor(document, idx, text.length(), Qt.red, insertRed)
stack.push(insertRed)
//! [5]
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