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# Copyright (C) 2009 Darryl Wallace, 2009 <wallacdj@gmail.com>
# Copyright (C) 2013 Riverbank Computing Limited.
# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
"""PySide6 port of the itemviews/fetchmore/fetchmore example from Qt v6.x
Navigate to a directory with many entries by doubleclicking and scroll
down the list to see the model being populated on demand.
"""
import sys
from PySide6.QtCore import (QAbstractListModel, QDir, QFileInfo, QLibraryInfo,
QModelIndex, Qt, Signal, Slot)
from PySide6.QtGui import QPalette
from PySide6.QtWidgets import (QApplication, QFileIconProvider, QListView,
QPlainTextEdit, QSizePolicy, QVBoxLayout,
QWidget)
BATCH_SIZE = 100
class FileListModel(QAbstractListModel):
number_populated = Signal(str, int, int, int)
def __init__(self, parent=None):
super().__init__(parent)
self._path = ''
self._file_count = 0
self._file_list = []
self._icon_provider = QFileIconProvider()
def rowCount(self, parent=QModelIndex()):
return self._file_count
def data(self, index, role=Qt.DisplayRole):
if not index.isValid():
return None
row = index.row()
if row >= len(self._file_list) or row < 0:
return None
if role == Qt.DisplayRole:
return self._file_list[row].fileName()
if role == Qt.BackgroundRole:
batch = row // BATCH_SIZE
palette = qApp.palette()
return palette.base() if batch % 2 == 0 else palette.alternateBase()
if role == Qt.DecorationRole:
return self._icon_provider.icon(self._file_list[row])
return None
def canFetchMore(self, index):
return self._file_count < len(self._file_list)
def fetchMore(self, index):
start = self._file_count
total = len(self._file_list)
remainder = total - start
items_to_fetch = min(BATCH_SIZE, remainder)
self.beginInsertRows(QModelIndex(), start, start + items_to_fetch)
self._file_count += items_to_fetch
self.endInsertRows()
self.number_populated.emit(self._path, start, items_to_fetch, total)
@Slot(str)
def set_dir_path(self, path):
self._path = path
directory = QDir(path)
self.beginResetModel()
directory_filter = QDir.AllEntries | QDir.NoDot
self._file_list = directory.entryInfoList(directory_filter, QDir.Name)
self._file_count = 0
self.endResetModel()
def fileinfo_at(self, index):
return self._file_list[index.row()]
class Window(QWidget):
def __init__(self, parent=None):
super().__init__(parent)
self._model = FileListModel(self)
self._model.set_dir_path(QDir.rootPath())
self._view = QListView()
self._view.setModel(self._model)
self._log_viewer = QPlainTextEdit()
self._log_viewer.setSizePolicy(QSizePolicy(QSizePolicy.Preferred,
QSizePolicy.Preferred))
self._model.number_populated.connect(self.update_log)
self._view.activated.connect(self.activated)
layout = QVBoxLayout(self)
layout.addWidget(self._view)
layout.addWidget(self._log_viewer)
self.setWindowTitle("Fetch More Example")
@Slot(str, int, int)
def update_log(self, path, start, number, total):
native_path = QDir.toNativeSeparators(path)
last = start + number - 1
entry = f'{start}..{last}/{total} items from "{native_path}" added.'
self._log_viewer.appendPlainText(entry)
@Slot(QModelIndex)
def activated(self, index):
fileinfo = self._model.fileinfo_at(index)
if fileinfo.isDir():
self._log_viewer.clear()
self._model.set_dir_path(fileinfo.absoluteFilePath())
if __name__ == '__main__':
app = QApplication(sys.argv)
window = Window()
window.resize(400, 500)
window.show()
sys.exit(app.exec())
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