PySide Editable Label

editableLabel.py

#!/usr/bin/env python
from PySide import QtCore, QtGui


class KeyPressHandler(QtCore.QObject):
    """Custom key press handler"""
    escapePressed = QtCore.Signal(bool)
    returnPressed = QtCore.Signal(bool)

    def eventFilter(self, obj, event):
        if event.type() == QtCore.QEvent.KeyPress:
            event_key = event.key()
            if event_key == QtCore.Qt.Key_Escape:
                self.escapePressed.emit(True)
                return True
            if event_key == QtCore.Qt.Key_Return or event_key == QtCore.Qt.Key_Enter:
                self.returnPressed.emit(True)
                return True

        return QtCore.QObject.eventFilter(self, obj, event)


class EditableLabelWidget(QtGui.QWidget):
    """Sample Widget"""
    def __init__(self, parent=None, **kwargs):
        super(EditableLabelWidget, self).__init__(parent)

        # create the editable label
        self.label = EditableLabel(self)
        
        self.mainLayout = QtGui.QHBoxLayout()
        self.mainLayout.addWidget(self.label,)
        self.setLayout(self.mainLayout)

        self.label.setText("click me to edit")
        self.setWindowTitle("Editable Label")

        # connect our custom signal
        self.label.textChanged.connect(self.labelTextChangedAction)

    def labelTextChangedAction(self, text):
        print "# label updated: \"{0}\"".format(text)


class EditableLabel(QtGui.QWidget):
    """Editable label"""
    textChanged = QtCore.Signal(str)
    def __init__(self, parent=None, **kwargs):
        QtGui.QWidget.__init__(self, parent=parent)

        self.is_editable = kwargs.get("editable", True)
        self.keyPressHandler = KeyPressHandler(self)

        self.mainLayout = QtGui.QHBoxLayout(self)
        self.mainLayout.setContentsMargins(0, 0, 0, 0)
        self.mainLayout.setObjectName("mainLayout")
        
        self.label = QtGui.QLabel(self)
        self.label.setObjectName("label")
        self.mainLayout.addWidget(self.label)
        self.lineEdit = QtGui.QLineEdit(self)
        self.lineEdit.setObjectName("lineEdit")
        self.mainLayout.addWidget(self.lineEdit)
        # hide the line edit initially
        self.lineEdit.setHidden(True)

        # setup signals
        self.create_signals()

    def create_signals(self):
        self.lineEdit.installEventFilter(self.keyPressHandler)
        self.label.mousePressEvent = self.labelPressedEvent

        # give the lineEdit both a `returnPressed` and `escapedPressed` action
        self.keyPressHandler.escapePressed.connect(self.escapePressedAction)
        self.keyPressHandler.returnPressed.connect(self.returnPressedAction)

    def text(self):
        """Standard QLabel text getter"""
        return self.label.text()

    def setText(self, text):
        """Standard QLabel text setter"""
        self.label.blockSignals(True)
        self.label.setText(text)
        self.label.blockSignals(False)

    def labelPressedEvent(self, event):
        """Set editable if the left mouse button is clicked"""
        if event.button() == QtCore.Qt.MouseButton.LeftButton:
            self.setLabelEditableAction()

    def setLabelEditableAction(self):
        """Action to make the widget editable"""
        if not self.is_editable:
            return

        self.label.setHidden(True)
        self.label.blockSignals(True)
        self.lineEdit.setHidden(False)
        self.lineEdit.setText(self.label.text())
        self.lineEdit.blockSignals(False)
        self.lineEdit.setFocus(QtCore.Qt.MouseFocusReason)
        self.lineEdit.selectAll()

    def labelUpdatedAction(self):
        """Indicates the widget text has been updated"""
        text_to_update = self.lineEdit.text()

        if text_to_update != self.label.text():
            self.label.setText(text_to_update)
            self.textChanged.emit(text_to_update)

        self.label.setHidden(False)
        self.lineEdit.setHidden(True)
        self.lineEdit.blockSignals(True)
        self.label.blockSignals(False)

    def returnPressedAction(self):
        """Return/enter event handler"""
        self.labelUpdatedAction()

    def escapePressedAction(self):
        """Escape event handler"""
        self.label.setHidden(False)
        self.lineEdit.setHidden(True)
        self.lineEdit.blockSignals(True)
        self.label.blockSignals(False)


if __name__ == '__main__':
    import sys

    app = QtGui.QApplication(sys.argv)
    widget = EditableLabelWidget()
    widget.show()
    widget.move(100, 100)
    widget.resize(300, 45)
    sys.exit(app.exec_())