如何使用QSortFilterProxyModel重新启用QTreeView中的手动列布局

Question

I have a QTreeView which displays data from a SQLite database. The QTreeView has filters and sorting enabled. For filtering I display a QLineEdit into the column header.

Problem: the column layout seems to be fixed by the modifications in order to enable the QLineEdit filtering.

Question: Is there a way to reenable the arrangement of the column layout - via dragging the columns, as it is in the standard QTreeView layout.

I want the user to be able to rearrange his columns the desired way.

Full working code example:

import sys
import re
from PyQt5 import QtWidgets, QtGui, QtCore, QtSql

COUNT_PERS_COLS = 3
col_persID, col_persLAST_NAME, col_persFIRST_NAME = range(COUNT_PERS_COLS)

db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
db.setDatabaseName(':memory:')

modelQuery = QtSql.QSqlQueryModel()
modelTable = QtSql.QSqlRelationalTableModel()

def _human_key(key):
    parts = re.split(r'(\d*\.\d+|\d+)', key)
    return tuple((e.swapcase() if i % 2 == 0 else float(e))
            for i, e in enumerate(parts))

class FilterHeader(QtWidgets.QHeaderView):
    filterActivated = QtCore.pyqtSignal()

    def __init__(self, parent):
        super().__init__(QtCore.Qt.Horizontal, parent)
        self._editors = []
        self._padding = 4
        self.setStretchLastSection(True)        
        self.setSectionResizeMode(QtWidgets.QHeaderView.Stretch)
        self.setDefaultAlignment(QtCore.Qt.AlignLeft | QtCore.Qt.AlignVCenter)
        self.setSortIndicatorShown(False)
        self.sectionResized.connect(self.adjustPositions)
        parent.horizontalScrollBar().valueChanged.connect(self.adjustPositions)

    def setFilterBoxes(self, count):
        while self._editors:
            editor = self._editors.pop()
            editor.deleteLater()
        for index in range(count):
            editor = QtWidgets.QLineEdit(self.parent())            
            editor.setPlaceholderText('Filter')
            editor.setClearButtonEnabled(True)
            editor.returnPressed.connect(self.filterActivated.emit)
            self._editors.append(editor)
        self.adjustPositions()

    def sizeHint(self):
        size = super().sizeHint()
        if self._editors:
            height = self._editors[0].sizeHint().height()
            size.setHeight(size.height() + height + self._padding)
        return size

    def updateGeometries(self):
        if self._editors:
            height = self._editors[0].sizeHint().height()
            self.setViewportMargins(0, 0, 0, height + self._padding)
        else:
            self.setViewportMargins(0, 0, 0, 0)
        super().updateGeometries()
        self.adjustPositions()

    def adjustPositions(self):
        for index, editor in enumerate(self._editors):
            height = editor.sizeHint().height()
            editor.move(
                self.sectionPosition(index) - self.offset() + 2,
                height + (self._padding // 2))
            editor.resize(self.sectionSize(index), height)

    def filterText(self, index):
        if 0 <= index < len(self._editors):
            return self._editors[index].text()
        return ''

    def setFilterText(self, index, text):
        if 0 <= index < len(self._editors):
            self._editors[index].setText(text)

    def clearFilters(self):
        for editor in self._editors:
            editor.clear()        


class HumanProxyModel(QtCore.QSortFilterProxyModel):
    def lessThan(self, source_left, source_right):
        data_left = source_left.data()
        data_right = source_right.data()
        if type(data_left) == type(data_right) == str:
            return _human_key(data_left) < _human_key(data_right)
        return super(HumanProxyModel, self).lessThan(source_left, source_right)

    @property
    def filters(self):
        if not hasattr(self, "_filters"):
            self._filters = []
        return self._filters

    @filters.setter
    def filters(self, filters):
        print(f"filters() called.")        

        self._filters = filters
        self.invalidateFilter()                

    def filterAcceptsRow(self, sourceRow, sourceParent):        
        for i, text in self.filters:
            if 0 <= i < self.columnCount():
                ix = self.sourceModel().index(sourceRow, i, sourceParent)                
                data = ix.data()
                if text not in data:
                    return False            
        return True        

class winMain(QtWidgets.QMainWindow):
    def __init__(self, parent=None):        
        super().__init__(parent)                
        self.setupUi()
        self.setGeometry(300,200,700,500)        

        self.show()        

    def createPersonModel(self,parent):        
        model = QtGui.QStandardItemModel(0, COUNT_PERS_COLS, parent)                
        model.setHorizontalHeaderLabels(['ID', 'Last Name', 'First Name'])

        return model

    def addPerson(self, model, id, last_name, first_name):        
        model.insertRow(0)        
        model.setData(model.index(0, col_persID), id)
        model.setData(model.index(0, col_persLAST_NAME), last_name)
        model.setData(model.index(0, col_persFIRST_NAME), first_name)

    def handleFilterActivated(self):                
        header = self.treeView.header()
        filters = []

        for i in range(header.count()):
            text = header.filterText(i)
            if text:        
                filters.append((i, text))

        proxy = self.treeView.model()
        proxy.filters = filters        

    def setupUi(self):
        self.centralwidget = QtWidgets.QWidget(self)        
        self.horizontalLayout = QtWidgets.QHBoxLayout(self.centralwidget)        

        self.treeView = QtWidgets.QTreeView(self.centralwidget)        

        self.treeView.setSortingEnabled(True)
        self.treeView.setAlternatingRowColors(True)        
        self.treeView.setEditTriggers(QtWidgets.QAbstractItemView.NoEditTriggers)
        self.treeView.setSelectionMode(QtWidgets.QAbstractItemView.ExtendedSelection)
        self.treeView.setAnimated(True)
        self.treeView.setItemsExpandable(True)

        self.horizontalLayout.addWidget(self.treeView)
        self.setCentralWidget(self.centralwidget)

        header = FilterHeader(self.treeView)        
        self.treeView.setHeader(header)        

        self.statusBar = QtWidgets.QStatusBar()
        self.setStatusBar(self.statusBar)        

        modelTable.setTable("person")
        self.treeView.setModel(modelTable)

        proxy = HumanProxyModel(self)
        proxy.setSourceModel(modelTable)
        self.treeView.setModel(proxy)        

        header.setFilterBoxes(modelTable.columnCount())
        header.filterActivated.connect(self.handleFilterActivated)        


def create_sample_data():     
    modelQuery.setQuery("""CREATE TABLE IF NOT EXISTS country (                                    
                                    id   INTEGER PRIMARY KEY UNIQUE NOT NULL,
                                    name TEXT
                                    )""")

    modelQuery.setQuery("""CREATE TABLE IF NOT EXISTS person (
                                   id         INTEGER PRIMARY KEY UNIQUE NOT NULL,
                                   persId     TEXT,
                                   lastName   TEXT,
                                   firstName  TEXT,
                                   country_id INTEGER NOT NULL DEFAULT 3,
              FOREIGN KEY (country_id) REFERENCES country(id)
                                   )""")

    modelQuery.setQuery("INSERT INTO country (id, name) VALUES (0, 'None')")    
    modelQuery.setQuery("INSERT INTO country (id, name) VALUES (1, 'Angola')")    
    modelQuery.setQuery("INSERT INTO country (id, name) VALUES (2, 'Serbia')")
    modelQuery.setQuery("INSERT INTO country (id, name) VALUES (3, 'Georgia')")

    modelQuery.setQuery("INSERT INTO person (id, persId, lastName, firstName, country_id) VALUES (1, '1001', 'Martin', 'Robert', 1)")
    modelQuery.setQuery("INSERT INTO person (id, persId, lastName, firstName, country_id) VALUES (2, '1002', 'Smith', 'Brad', 2)")
    modelQuery.setQuery("INSERT INTO person (id, persId, lastName, firstName, country_id) VALUES (3, '1003', 'Smith', 'Angelina', 3)")

if __name__ == '__main__':                         
    app = QtWidgets.QApplication(sys.argv)         

    create_sample_data()        

    window = winMain()    
    sys.exit(app.exec_())

Answer 1

You have to enable that feature using the setSectionsMovable() method of QHeaderView :

class FilterHeader(QtWidgets.QHeaderView):
    filterActivated = QtCore.pyqtSignal()

    def __init__(self, parent):
        super().__init__(QtCore.Qt.Horizontal, parent)
        self.setSectionsMovable(True) # <---
        # ...