当鼠标悬停在带有 QFileSystemModel 的此 QTreeView 中的项目上时如何打印文件路径

Question

我正在制作一个带有 QFileSystem 模型的自定义 QTreeView，我设置了一个 MouseMoveEvent 来打印悬停项目的路径。

我陷入了困境，并做了各种奇怪的事情来完成这项工作。

这是最新的最小可重现代码：

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import sys

class MainWindow(QWidget):
    def __init__(self):
        QWidget.__init__(self)
        self.resize(500, 300)
        self.layout = QVBoxLayout()
        self.setLayout(self.layout)
        self.myList = CustomTreeWidget()
        self.myList.model.setRootPath("/Volumes/Home/User/Desktop/testsrc")
        self.myList.setObjectName("/Volumes/Home/User/Desktop/testsrc")
        self.layout.addWidget(self.myList)

class CustomTreeWidget(QTreeView):

    def __init__(self):
        super().__init__()
        self.model = QFileSystemModel()
        self.model.setFilter(QDir.NoDotAndDotDot | QDir.Files)
        self.setModel(self.model)
        self.setAlternatingRowColors(True)
        self.setDragDropMode(QAbstractItemView.DragDrop)
        self.setIndentation(0)
        self.setSelectionMode(QAbstractItemView.ExtendedSelection)
        self.setDragEnabled(True)
        self.setAcceptDrops(True)
        self.setContextMenuPolicy(Qt.CustomContextMenu)
        self.setMouseTracking(True)
        self.model.directoryLoaded.connect(self._runwhenloaded)

    def _runwhenloaded(self):
        self.setRootIndex(self.model.index(self.objectName()))
        self.model.setRootPath(self.objectName())

    def mouseMoveEvent(self, event):
        prev = ""
        if self.selectedIndexes():
            prev = self.selectedIndexes()[0]
        x = event.x()
        y = event.y()
        self.setSelection(QRect(x, y, 1, 1), QItemSelectionModel.ClearAndSelect)
        self.setCurrentIndex(self.selectedIndexes()[0])
        print(self.model.filePath(self.currentIndex()))
        if prev:
            self.setCurrentIndex(prev)
        # pos = QCursor.pos()
        # indexat = self.indexAt(pos).row() # why -1?
        # print(indexat) # why -1?
        # print(self.indexAt(pos).row())


if __name__ == "__main__":
    app =  QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

显然这个例子根本不合适，因为它会破坏多个选择并在鼠标移动时滚动到先前选择的项目，并且只是一般的 hack。

我经历了很多次迭代，阅读了所有我能接触到的东西，但我还是想不通。

最接近的答案似乎是，但它是用 C 写的，我看不懂。

所以问题是：当鼠标悬停在这个QTreeView中的一个项目上时，如何打印文件路径？

Answer 1

一个可能的解决方案是创建一个事件过滤器来跟踪悬停事件，并根据该信息发出具有 QModelIndex 的信号：

import sys

from PyQt5.QtCore import (
    pyqtSignal,
    pyqtSlot,
    Qt,
    QDir,
    QEvent,
    QModelIndex,
    QObject,
    QPersistentModelIndex,
    QStandardPaths,
)
from PyQt5.QtWidgets import (
    QAbstractItemView,
    QApplication,
    QFileSystemModel,
    QMainWindow,
    QTreeView,
)
from PyQt5 import sip


class HoverViewHelper(QObject):
    hovered = pyqtSignal(QModelIndex)

    def __init__(self, view):
        super().__init__(view)

        self._current_index = QPersistentModelIndex()
        if not isinstance(view, QAbstractItemView):
            raise TypeError(f"The {view} must be of type QAbstractItemView")
        self._view = view

        self.view.viewport().setAttribute(Qt.WA_Hover)
        self.view.viewport().installEventFilter(self)

    @property
    def view(self):
        return self._view

    def eventFilter(self, obj, event):
        if sip.isdeleted(self.view):
            return True
        if self.view.viewport() is obj:
            if event.type() in (QEvent.HoverMove, QEvent.HoverEnter):
                p = event.pos()
                index = self.view.indexAt(p)
                self._update_index(index)
            elif event.type() == QEvent.HoverLeave:
                if self._current_index.isValid():
                    self._update_index(QModelIndex())
        return super().eventFilter(obj, event)

    def _update_index(self, index):
        pindex = QPersistentModelIndex(index)
        if pindex != self._current_index:
            self._current_index = pindex
            self.hovered.emit(QModelIndex(self._current_index))


class MainWindow(QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.model = QFileSystemModel()
        self.model.setRootPath(QDir.rootPath())

        self.view = QTreeView()
        self.view.setModel(self.model)
        path = QStandardPaths.writableLocation(QStandardPaths.DocumentsLocation)
        self.view.setRootIndex(self.model.index(path))

        self.setCentralWidget(self.view)

        helper = HoverViewHelper(self.view)
        helper.hovered.connect(self.handle_hovered)

    @pyqtSlot(QModelIndex)
    def handle_hovered(self, index):
        if not index.isValid():
            return
        path = self.model.filePath(index)
        print(f"path: {path}")


def main():

    app = QApplication(sys.argv)

    w = MainWindow()
    w.resize(640, 480)
    w.show()

    app.exec_()


if __name__ == "__main__":
    main()

当鼠标悬停在带有 QFileSystemModel 的此 QTreeView 中的项目上时如何打印文件路径

How to print the file path when the mouse hovers over an item in this QTreeView with QFileSystemModel

python

pyqt5

qtreeview