How to highlight QTreeWidgetItem text - qt

Question

When the button is clicked I need the tree-item to turn highlighted (editing mode) (see the image below). Currently I have to double-click the item to set it in to highlighted mode. How to achieve this?
from PyQt4 import QtCore, QtGui
app = QtGui.QApplication([])
class Dialog(QtGui.QDialog):
def __init__(self, parent=None):
super(Dialog, self).__init__(parent)
self.setLayout(QtGui.QVBoxLayout())
tree = QtGui.QTreeWidget()
self.layout().addWidget(tree)
button = QtGui.QPushButton()
button.setText('Add Item')
self.layout().addWidget(button)
button.clicked.connect(self.onClick)
item = QtGui.QTreeWidgetItem()
item.setFlags(item.flags() | QtCore.Qt.ItemIsEditable)
item.setText(0, 'Item number 1')
tree.addTopLevelItem(item)
def onClick(self):
print 'onClick'
dialog=Dialog()
dialog.show()
app.exec_()

Answer 1

from PyQt4 import QtCore, QtGui
app = QtGui.QApplication([])
class ItemDelegate(QtGui.QItemDelegate):
def __init__(self, parent):
QtGui.QItemDelegate.__init__(self, parent)
def createEditor(self, parent, option, index):
if not index: return
line = QtGui.QLineEdit(parent)
line.setText('Please enter the ')
# line.selectAll()
line.setSelection(0, len(line.text()))
line.setFocus()
return line
class Dialog(QtGui.QDialog):
def __init__(self, parent=None):
super(Dialog, self).__init__(parent)
self.setLayout(QtGui.QVBoxLayout())
self.tree = QtGui.QTreeWidget()
self.layout().addWidget(self.tree)
button = QtGui.QPushButton()
button.setText('Add Item')
self.layout().addWidget(button)
button.clicked.connect(self.onClick)
self.tree.setColumnCount(3)
delegate=ItemDelegate(self)
self.tree.setItemDelegate(delegate)
for row in range(5):
rootItem = QtGui.QTreeWidgetItem()
self.tree.addTopLevelItem(rootItem)
for column in range(3):
rootItem.setText(column, 'Root %s row %s'%(row, column))
for child_number in range(2):
childItem = QtGui.QTreeWidgetItem(rootItem)
for col in range(3):
childItem.setText(col, 'Child %s row %s'%(child_number, col))
def onClick(self):
rootItem = QtGui.QTreeWidgetItem()
rootItem.setText(0, 'New Item')
rootItem.setFlags(rootItem.flags() | QtCore.Qt.ItemIsEditable)
self.tree.addTopLevelItem(rootItem)
self.tree.openPersistentEditor(rootItem, 0)
rootItem.setSelected(True)
dialog=Dialog()
dialog.show()
app.exec_()