PyQt4: Unterbinden dass etwas zur QComboBox() hinzugefügt wird

Python und das Qt-Toolkit, erstellen von GUIs mittels des Qt-Designers.
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Sophus
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Beiträge: 1085
Registriert: Freitag 25. April 2014, 12:46
Wohnort: Osnabrück

Samstag 29. Juli 2017, 21:47

Hallo Leute, mir ist etwas Unschönes aufgefallen. Zunächst einmal seht ihr, dass ich mit dem QCompleter() im Zusammenhang mit QComboBox() arbeite, und ich dazu die QComboBox() so eingestellt habe, dass man editieren kann. Tippt man die ersten Buchstaben ein, werden die Treffer in einem PopUp angezeigt. Soweit alles wunderbar. Aber angenommen, ihr tippt einfach wild drauf los, irgendwelche Buchstaben und drückt dann Enter. Das macht ihr mehrmals hintereinander. Und ich klickt dann mit der Maus auf die QComboBox(), dann sieht man, dass die wild eingegebenen Buchstaben ebenfalls in der QComboBox() sind. Wie kann ich das unterbinden? Ich möchte, dass die Benutzer nur mit den Daten aus der Liste arbeiten können, keine neuen Einträge.

Habt ihr eine Idee?

Code: Alles auswählen

# -*- coding: cp1252 -*-
import sys

from PyQt4.QtCore import Qt, QVariant, SIGNAL, QEvent
from PyQt4.QtGui import QApplication, QStandardItemModel, QStandardItem, QTreeView, QComboBox, QDialog, \
                         QVBoxLayout, QPushButton, QAbstractItemView, QCompleter, QSortFilterProxyModel, \
                         QKeyEvent
 
class MyCustomDialog(QDialog):
    def __init__(self, app=None, parent=None):
        QDialog.__init__(self, parent)

        self.app = app

        # Second, we need our QTreeView() and
        # the settings
        self.init_tree_view()
 
        # Create an empty model for the TreeViews' data
        _standard_item_model = QStandardItemModel(0,2)

       # Add some textual items
        self.food_list = [
                    ["0", 'Cookie dough'], 
                    ["1", 'Hummus'], 
                    ["2", 'Spaghetti'], 
                    ["3", 'Dal makhani'],
                    ["6", 'Blolonese'], 
                    ["4", 'Hachfleisch'], 
                    ["3", 'Nudeln'],
                    ["666", 'Flösch'],
                    ["4", 'Chocolate whipped cream'] 
                ]
        # Now its time to populate data
        self.populate(model=_standard_item_model)

        # Apply the model to the list view
        self.set_tree_view_model(_standard_item_model)

        # QComboBox() will be created 
        self.combo_box = QComboBox(self)

        self.init_complete(model=_standard_item_model)

        # layout is a defined QVBoxLayout()
        layout = QVBoxLayout(self)
        layout.addWidget(self.combo_box)
        self.setLayout(layout)

    def init_tree_view(self):
        self.tree_view = QTreeView()
        self.tree_view.setRootIsDecorated(False)
        self.tree_view.setWordWrap(True)

        self.tree_view.setAlternatingRowColors(True)

        self.tree_view.setSelectionMode(QTreeView.ExtendedSelection)
        
        self.tree_view.header().hide()

        self.tree_me = QTreeView()
        self.tree_me.setRootIsDecorated(False)
        self.tree_me.setWordWrap(True)
        self.tree_me.setAlternatingRowColors(True)

        self.tree_me.setSelectionMode(QTreeView.ExtendedSelection)
        
        self.tree_me.header().hide()

    def init_complete(self, model=None):

        # add a completer, which uses the filter model
        # add a filter model to filter matching items
        filterModel = QSortFilterProxyModel(self.combo_box)
        filterModel.setFilterCaseSensitivity(Qt.CaseInsensitive)
        filterModel.setSourceModel(model)
        filterModel.setFilterKeyColumn(0)

        completer = QCompleter(self.combo_box)

        # Set the model that the QCompleter uses
        # on model column change, update the model
        # column of the filter and completer as well
        completer.setModel(filterModel)
        completer.setCompletionColumn(0)
        completer.popup().installEventFilter(self)
        completer.popup().selectionModel().selectionChanged.connect(lambda new_index:
                    self.get_id_tree_view(new_index=new_index))

        # always show all (filtered) completions
        completer.setCompletionMode(QCompleter.UnfilteredPopupCompletion)
        
        completer.setPopup( self.tree_me )

        self.tree_me.setColumnHidden(1, True)

        self.combo_box.setEditable(True)
        self.combo_box.setCompleter(completer)

        # on model column change, update the model
        # column of the filter and completer as well        
        self.combo_box.setModel(model)
        self.combo_box.setView(self.tree_view)

        # on model column change, update the model column of
        # the filter and completer as well
        self.combo_box.setModelColumn(0)
        
        self.tree_view.resizeColumnToContents(0)
        
        self.tree_view.setColumnHidden(1, True)

        if self.combo_box.isEditable():
            self.app.connect(self.combo_box.lineEdit(), SIGNAL('textEdited(QString)'), filterModel.setFilterFixedString)

    def set_tree_view_model(self, model):
        
        self.tree_view.setModel(model)
 
    def generator_header_data(self, list_header):
 
        for header_data in list_header:
            yield header_data
           
    def set_header_data(self, list_header_data=None, model=None):
 
        count_column = 0
 
        for header_data in self.generator_header_data(list_header_data):
            model.setHeaderData(count_column, Qt.Horizontal, header_data)
 
            count_column +=1 
 
    def get_id_tree_view(self, new_index=None):
 
        try:
            if not new_index is None:
 
                index = new_index.indexes()[1].data()#.toPyObject()
 
                if isinstance(index, QVariant):
                    print "get_id_tree_view, index", index.toString()
                   
        except IndexError as InErr:
            pass#print "InErr", InErr

    def populate_data_item(self, item_list=None, model=None):
        
        count_items = len(item_list)
 
        if count_items == 2:
 
            item_first, item_second = item_list
 
        two_columns_item = [QStandardItem(item_second), QStandardItem(str(item_first))]
 
        model.appendRow(two_columns_item)
 
    def populate(self, model=None):
        
        for single_list in self.food_list:
            self.populate_data_item(item_list=single_list, model=model)

def main():
    app = QApplication(sys.argv)
    window = MyCustomDialog(app=app)
    window.resize(300, 50)
    window.show()
    try:
        sip.setdestroyonexit(False)
    except:
        # missing in older versions
        pass
    sys.exit(app.exec_())
 
if __name__ == "__main__":
    main()
Benutzeravatar
Sophus
User
Beiträge: 1085
Registriert: Freitag 25. April 2014, 12:46
Wohnort: Osnabrück

Samstag 29. Juli 2017, 22:00

Ok, dass war jetzt ein Schnellschuss, aber es klappt erst einmal. In Zeile 166 habe ich die eventFilter()-Methode re-implementiert, um die Enter-Taste zu ignorieren. In Zeile 105 sieht man, dass ich diesen eventFilter bei der QComboBox() installiert habe. Der Plan scheint erst einmal aufzugehen. Keine weitere, neuen Eintragungen in die QComboBox() mehr, und der Benutzer ist gezwungen, mit den Daten aus der Liste zu arbeiten.

Nur habe ich gehofft und geglaubt, dies wäre auch ohne diesen eventFilter möglich. Vielleicht eine kleine Einstellung bei der QComboBox() selbst, die solche Situation verhindert?

Code: Alles auswählen

# -*- coding: cp1252 -*-
import sys

from PyQt4.QtCore import Qt, QVariant, SIGNAL, QEvent
from PyQt4.QtGui import QApplication, QStandardItemModel, QStandardItem, QTreeView, QComboBox, QDialog, \
                         QVBoxLayout, QPushButton, QAbstractItemView, QCompleter, QSortFilterProxyModel, \
                         QKeyEvent
 
class MyCustomDialog(QDialog):
    def __init__(self, app=None, parent=None):
        QDialog.__init__(self, parent)

        self.app = app

        # Second, we need our QTreeView() and
        # the settings
        self.init_tree_view()
 
        # Create an empty model for the TreeViews' data
        _standard_item_model = QStandardItemModel(0,2)

       # Add some textual items
        self.food_list = [
                    ["0", 'Cookie dough'], 
                    ["1", 'Hummus'], 
                    ["2", 'Spaghetti'], 
                    ["3", 'Dal makhani'],
                    ["6", 'Blolonese'], 
                    ["4", 'Hachfleisch'], 
                    ["3", 'Nudeln'],
                    ["666", 'Flösch'],
                    ["4", 'Chocolate whipped cream'] 
                ]
        # Now its time to populate data
        self.populate(model=_standard_item_model)

        # Apply the model to the list view
        self.set_tree_view_model(_standard_item_model)

        # QComboBox() will be created 
        self.combo_box = QComboBox(self)

        self.init_complete(model=_standard_item_model)

        # layout is a defined QVBoxLayout()
        layout = QVBoxLayout(self)
        layout.addWidget(self.combo_box)
        self.setLayout(layout)

    def init_tree_view(self):
        self.tree_view = QTreeView()
        self.tree_view.setRootIsDecorated(False)
        self.tree_view.setWordWrap(True)

        self.tree_view.setAlternatingRowColors(True)

        self.tree_view.setSelectionMode(QTreeView.ExtendedSelection)
        
        self.tree_view.header().hide()

        self.tree_me = QTreeView()
        self.tree_me.setRootIsDecorated(False)
        self.tree_me.setWordWrap(True)
        self.tree_me.setAlternatingRowColors(True)

        self.tree_me.setSelectionMode(QTreeView.ExtendedSelection)
        
        self.tree_me.header().hide()

    def init_complete(self, model=None):

        # add a completer, which uses the filter model
        # add a filter model to filter matching items
        filterModel = QSortFilterProxyModel(self.combo_box)
        filterModel.setFilterCaseSensitivity(Qt.CaseInsensitive)
        filterModel.setSourceModel(model)
        filterModel.setFilterKeyColumn(0)

        completer = QCompleter(self.combo_box)

        # Set the model that the QCompleter uses
        # on model column change, update the model
        # column of the filter and completer as well
        completer.setModel(filterModel)
        completer.setCompletionColumn(0)
        completer.popup().installEventFilter(self)
        completer.popup().selectionModel().selectionChanged.connect(lambda new_index:
                    self.get_id_tree_view(new_index=new_index))

        # always show all (filtered) completions
        completer.setCompletionMode(QCompleter.UnfilteredPopupCompletion)
        
        completer.setPopup( self.tree_me )

        self.tree_me.setColumnHidden(1, True)

        self.combo_box.setEditable(True)
        self.combo_box.setCompleter(completer)

        # on model column change, update the model
        # column of the filter and completer as well        
        self.combo_box.setModel(model)
        self.combo_box.setView(self.tree_view)

        self.combo_box.installEventFilter(self)

        # on model column change, update the model column of
        # the filter and completer as well
        self.combo_box.setModelColumn(0)
        
        self.tree_view.resizeColumnToContents(0)
        
        self.tree_view.setColumnHidden(1, True)

        if self.combo_box.isEditable():
            self.app.connect(self.combo_box.lineEdit(), SIGNAL('textEdited(QString)'), filterModel.setFilterFixedString)

    def set_tree_view_model(self, model):
        
        self.tree_view.setModel(model)
 
    def generator_header_data(self, list_header):
 
        for header_data in list_header:
            yield header_data
           
    def set_header_data(self, list_header_data=None, model=None):
 
        count_column = 0
 
        for header_data in self.generator_header_data(list_header_data):
            model.setHeaderData(count_column, Qt.Horizontal, header_data)
 
            count_column +=1 
 
    def get_id_tree_view(self, new_index=None):
 
        try:
            if not new_index is None:
 
                index = new_index.indexes()[1].data()#.toPyObject()
 
                if isinstance(index, QVariant):
                    print "get_id_tree_view, index", index.toString()
                   
        except IndexError as InErr:
            pass#print "InErr", InErr

    def populate_data_item(self, item_list=None, model=None):
        
        count_items = len(item_list)
 
        if count_items == 2:
 
            item_first, item_second = item_list
 
        two_columns_item = [QStandardItem(item_second), QStandardItem(str(item_first))]
 
        model.appendRow(two_columns_item)
 
    def populate(self, model=None):
        
        for single_list in self.food_list:
            self.populate_data_item(item_list=single_list, model=model)

    def eventFilter(self, widget, event):
        """Reimplemented to handle key press events"""
        
        if (event.type() == QEvent.KeyPress):
            # use the in operator to test if the key is in a list or tuple
            if event.key() in (Qt.Key_Enter, Qt.Key_Return):
                return True
            
        return QDialog.eventFilter(self, widget, event)

def main():
    app = QApplication(sys.argv)
    window = MyCustomDialog(app=app)
    window.resize(300, 50)
    window.show()
    try:
        sip.setdestroyonexit(False)
    except:
        # missing in older versions
        pass
    sys.exit(app.exec_())
 
if __name__ == "__main__":
    main()
Benutzeravatar
Sophus
User
Beiträge: 1085
Registriert: Freitag 25. April 2014, 12:46
Wohnort: Osnabrück

Mittwoch 2. August 2017, 22:46

Ich glaube, ich kann jetzt auf die re-implementierte evenFilter()-Methode verzichten. Nach langem Suchen fand ich einen Hinweis.

Allgemeines Verhalten der QComboBox(), welche man editieren kann:
When the user enters a new string in an editable combobox, the widget may or may not insert it, and it can insert it in several locations. The default policy is is AtBottom but you can change this using setInsertPolicy().
(Quelle: Qt-Dokumentation - Detailed Description).

Und genau das wollte ich ja unterbinden, dass keine neuen Daten in die QComboBox() hinzugefügt werden, sobald der Benutzer die Enter-Taste betätigt. Also fand ich das hier:
void setInsertPolicy(InsertPolicy policy)

QComboBox::NoInsert - The string will not be inserted into the combobox.
(Quelle: Qt-Dokumentation - enum QComboBox::InsertPolicy)

Also sieht mein Quelltext wie folgt aus: In Zeile 42 habe ich die QComboBox() so eingestellt, dass keine weiteren Strings hinzugefügt werden soll.

Code: Alles auswählen

# -*- coding: cp1252 -*-
import sys
 
from PyQt4.QtCore import Qt, QVariant, SIGNAL, QEvent
from PyQt4.QtGui import QApplication, QStandardItemModel, QStandardItem, QTreeView, QComboBox, QDialog, \
                         QVBoxLayout, QPushButton, QAbstractItemView, QCompleter, QSortFilterProxyModel, \
                         QKeyEvent
 
class MyCustomDialog(QDialog):
    def __init__(self, app=None, parent=None):
        QDialog.__init__(self, parent)
 
        self.app = app
 
        # Second, we need our QTreeView() and
        # the settings
        self.init_tree_view()
 
        # Create an empty model for the TreeViews' data
        _standard_item_model = QStandardItemModel(0,2)
 
       # Add some textual items
        self.food_list = [
                    ["0", 'Cookie dough'],
                    ["1", 'Hummus'],
                    ["2", 'Spaghetti'],
                    ["3", 'Dal makhani'],
                    ["6", 'Blolonese'],
                    ["4", 'Hachfleisch'],
                    ["3", 'Nudeln'],
                    ["666", 'Flösch'],
                    ["4", 'Chocolate whipped cream']
                ]
        # Now its time to populate data
        self.populate(model=_standard_item_model)
 
        # Apply the model to the list view
        self.set_tree_view_model(_standard_item_model)
 
        # QComboBox() will be created
        self.combo_box = QComboBox(self)
        self.combo_box.setInsertPolicy(QComboBox.NoInsert) #The string will not be inserted into the combobox.
 
        self.init_complete(model=_standard_item_model)
 
        # layout is a defined QVBoxLayout()
        layout = QVBoxLayout(self)
        layout.addWidget(self.combo_box)
        self.setLayout(layout)
 
    def init_tree_view(self):
        self.tree_view = QTreeView()
        self.tree_view.setRootIsDecorated(False)
        self.tree_view.setWordWrap(True)
 
        self.tree_view.setAlternatingRowColors(True)
 
        self.tree_view.setSelectionMode(QTreeView.ExtendedSelection)
       
        self.tree_view.header().hide()
 
        self.tree_me = QTreeView()
        self.tree_me.setRootIsDecorated(False)
        self.tree_me.setWordWrap(True)
        self.tree_me.setAlternatingRowColors(True)
 
        self.tree_me.setSelectionMode(QTreeView.ExtendedSelection)
       
        self.tree_me.header().hide()
 
    def init_complete(self, model=None):
 
        # add a completer, which uses the filter model
        # add a filter model to filter matching items
        filterModel = QSortFilterProxyModel(self.combo_box)
        filterModel.setFilterCaseSensitivity(Qt.CaseInsensitive)
        filterModel.setSourceModel(model)
        filterModel.setFilterKeyColumn(0)
 
        completer = QCompleter(self.combo_box)
 
        # Set the model that the QCompleter uses
        # on model column change, update the model
        # column of the filter and completer as well
        completer.setModel(filterModel)
        completer.setCompletionColumn(0)
        completer.popup().selectionModel().selectionChanged.connect(lambda new_index:
                    self.get_id_tree_view(new_index=new_index))
 
        # always show all (filtered) completions
        completer.setCompletionMode(QCompleter.UnfilteredPopupCompletion)
       
        completer.setPopup( self.tree_me )
 
        self.tree_me.setColumnHidden(1, True)
 
        self.combo_box.setEditable(True)
        self.combo_box.setCompleter(completer)
 
        # on model column change, update the model
        # column of the filter and completer as well        
        self.combo_box.setModel(model)
        self.combo_box.setView(self.tree_view)

        # on model column change, update the model column of
        # the filter and completer as well
        self.combo_box.setModelColumn(0)
       
        self.tree_view.resizeColumnToContents(0)
       
        self.tree_view.setColumnHidden(1, True)
 
        if self.combo_box.isEditable():
            self.app.connect(self.combo_box.lineEdit(), SIGNAL('textEdited(QString)'), filterModel.setFilterFixedString)
 
    def set_tree_view_model(self, model):
       
        self.tree_view.setModel(model)
 
    def generator_header_data(self, list_header):
 
        for header_data in list_header:
            yield header_data
           
    def set_header_data(self, list_header_data=None, model=None):
 
        count_column = 0
 
        for header_data in self.generator_header_data(list_header_data):
            model.setHeaderData(count_column, Qt.Horizontal, header_data)
 
            count_column +=1
 
    def get_id_tree_view(self, new_index=None):
 
        try:
            if not new_index is None:
 
                index = new_index.indexes()[1].data()#.toPyObject()
 
                if isinstance(index, QVariant):
                    print "get_id_tree_view, index", index.toString()
                   
        except IndexError as InErr:
            pass#print "InErr", InErr
 
    def populate_data_item(self, item_list=None, model=None):
       
        count_items = len(item_list)
 
        if count_items == 2:
 
            item_first, item_second = item_list
 
        two_columns_item = [QStandardItem(item_second), QStandardItem(str(item_first))]
 
        model.appendRow(two_columns_item)
 
    def populate(self, model=None):
       
        for single_list in self.food_list:
            self.populate_data_item(item_list=single_list, model=model)
 
def main():
    app = QApplication(sys.argv)
    window = MyCustomDialog(app=app)
    window.resize(300, 50)
    window.show()
    try:
        sip.setdestroyonexit(False)
    except:
        # missing in older versions
        pass
    sys.exit(app.exec_())
 
if __name__ == "__main__":
    main()
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