有条件地更改连接到QFileSystemModel的QListView中的文件颜色

Question

我QListView有一个QFileSystemModel.根据a中的选择QTreeView,QListView显示文件夹的内容.
现在我需要根据某些条件更改文件名的颜色.
最初的想法是迭代QListView中的项目,并根据条件是否满足来设置每个项目的颜色.然而这似乎是不可能的,因为只接受改变的setData()方法,忽略像[见这个 ]的 东西QFileSystemModelEditRole

self.FileModel.setData(index, QtGui.QBrush(QtCore.Qt.red), role=QtCore.Qt.ForegroundRole)

这也被指出了这里 ,并在后者的建议是,子类QItemDelegate用于着色的而QListView项目的目的.

因此,如果满足条件,我将子类化QStyledItemDelegate并重新实现其paint()方法以绿色显示文件名 - 这很好.然而它现在看起来有点丑陋:文件图标丢失,"mouse_over"效果不再起作用.

虽然这个子类化无论如何都是一个混乱的解决方法,但我的顶级问题是

• 有没有办法根据条件为QListView连接的项目着色QFileSystemModel？

现在规定可能不是这种情况并且坚持QItemDelegate的子类化,

• 有没有办法通过漂亮的选择和图标来恢复原始行为？
• 有谁知道哪个ItemDelegate最初用于QListView中的QFileSystemModel以及如何使用它？
• 是否可以获取其源代码并从那里复制paint方法？

这是一个使用子类的最小代码,并显示了descibed行为.它使用QLineEdit可以键入字符串的位置,以便包含该字符串的所有文件都以绿色突出显示.

import sys
from PyQt4 import QtGui, QtCore


class MyFileViewDelegate(QtGui.QStyledItemDelegate ):
    def __init__(self, parent=None, *args, **kwargs):
        QtGui.QItemDelegate.__init__(self, parent, *args)

        self.condition = None
        self.isMatch = False

        self.brush_active =         QtGui.QBrush(QtGui.QColor("#79b9ed"))
        self.brush_active_matched = QtGui.QBrush(QtGui.QColor("#58cd1c"))
        self.pen =                  QtGui.QPen(QtGui.QColor("#414141") )
        self.pen_matched =          QtGui.QPen(QtGui.QColor("#39c819") )
        self.pen_active =           QtGui.QPen(QtGui.QColor("#eef2fd") )
        self.pen_active_matched =   QtGui.QPen(QtGui.QColor("#e7fade") )


    def paint(self, painter, option, index):
        text = index.data(QtCore.Qt.DisplayRole)
        self.matchText(text)

        painter.save()
        ######## set background 
        painter.setPen(QtGui.QPen(QtCore.Qt.NoPen))
        if option.state & QtGui.QStyle.State_Selected:
            if self.isMatch:
                painter.setBrush(self.brush_active_matched)
            else:
                painter.setBrush(self.brush_active)

        painter.drawRect(option.rect)
        ######## set font color
        if option.state & QtGui.QStyle.State_Selected:
            if self.isMatch:
                painter.setPen(self.pen_active_matched)
            else:
                painter.setPen(self.pen_active)
        else:
            if self.isMatch:
                painter.setPen(self.pen_matched) 
            else:
                painter.setPen(self.pen) 

        painter.drawText(option.rect, QtCore.Qt.AlignLeft, text)

        painter.restore()

    def matchText(self, filename):
        # testing condition. In the real case this is much more complicated
        if (self.condition != None) and (self.condition != "") and (self.condition in filename):
            self.isMatch = True
        else:
            self.isMatch = False

    def setCondition(self, condition):
        self.condition = condition


class MainWidget(QtGui.QWidget):
    def __init__(self, parent=None, useDelegate = False):
        super(MainWidget, self).__init__(parent)
        self.setLayout(QtGui.QVBoxLayout())

        self.FolderModel = QtGui.QFileSystemModel()
        self.FolderModel.setFilter(QtCore.QDir.NoDotAndDotDot | QtCore.QDir.AllDirs)
        self.FolderModel.setRootPath("")

        self.FolderView = QtGui.QTreeView(parent=self)
        self.FolderView.setModel(self.FolderModel)

        self.FolderView.setHeaderHidden(True)
        self.FolderView.hideColumn(1)
        self.FolderView.hideColumn(2)
        self.FolderView.hideColumn(3)
        self.FolderView.expanded.connect(self.FolderView.scrollTo)
        self.FolderView.clicked[QtCore.QModelIndex].connect(self.browserClicked)

        self.FileModel = QtGui.QFileSystemModel()
        self.FileModel.setFilter(QtCore.QDir.NoDotAndDotDot | QtCore.QDir.Files)

        self.FileView = QtGui.QListView(parent=self)
        self.FileView.setModel(self.FileModel)

        self.FileViewDelegate = None
        if useDelegate:
            self.FileViewDelegate = MyFileViewDelegate()
            self.FileView.setItemDelegate(self.FileViewDelegate)

        self.FileView.setSelectionMode(  QtGui.QAbstractItemView.ExtendedSelection  ) 

        self.LineEdit = QtGui.QLineEdit()
        self.LineEdit.textChanged.connect(self.changeCondition)

        # Add Widgets to layout
        self.layout().addWidget(self.FolderView)
        self.layout().addWidget(self.FileView)
        self.layout().addWidget(self.LineEdit)

    def changeCondition(self, text):
        if self.FileViewDelegate:
            self.FileViewDelegate.setCondition(text)

    def browserClicked(self, index):
        # the signal passes the index of the clicked item
        # set the FileView's root_index to the clicked index
        dir_path =  self.FileModel.filePath(index) 
        root_index = self.FileModel.setRootPath(dir_path)
        self.FileView.setRootIndex(root_index)


class App(QtGui.QMainWindow):
    def __init__(self, parent=None, useDelegate=False):
        super(App, self).__init__(parent)
        self.central = MainWidget(parent =self, useDelegate=useDelegate)
        self.setCentralWidget(self.central)

if __name__=='__main__':
    app = QtGui.QApplication(sys.argv)
    thisapp = App(None, True) # set False to view App without custom FileViewDelegate
    thisapp.show()
    sys.exit(app.exec_())

这是它与QItemDelegate子类化的外观比较:

只是要提一下,这段代码的另一个问题是,一旦条件发生变化,就需要将鼠标移动到QFileView中以启动重新绘制.我想知道哪个插槽可以用来连接LineEdit.textChange信号直接做到这一点.

Answer 1

不需要项目委托。data通过重新实现的方法可以更简单地实现QFileSystemModel：

class FileSystemModel(QtGui.QFileSystemModel):
    def __init__(self, *args, **kwargs):
        super(FileSystemModel, self).__init__(*args, **kwargs)
        self.condition = None

    def setCondition(self, condition):
        self.condition = condition
        self.dataChanged.emit(QtCore.QModelIndex(), QtCore.QModelIndex())

    def data(self, index, role=QtCore.Qt.DisplayRole):
        if self.condition and role == QtCore.Qt.TextColorRole:
            text = index.data(QtCore.Qt.DisplayRole)
            if self.condition in text:
                return QtGui.QColor("#58cd1c")
        return super(FileSystemModel, self).data(index, role)

class MainWidget(QtGui.QWidget):
    def __init__(self, parent=None, useDelegate = False):
        super(MainWidget, self).__init__(parent)
        ...
        self.FileModel = FileSystemModel(self)
        ...

    def changeCondition(self, text):
        self.FileModel.setCondition(text)