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

Question

我有QListView和QFileSystemModel。根据QTreeView中的选择，QListView显示该文件夹的内容。
现在我需要根据某些条件更改文件名的颜色。
最初的想法是遍历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QFileSystemModel的setData()方法只接受更改EditRole，忽略像[见this]

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

这也被指出here ，并在后者的建议是，子类QItemDelegate，用于对QListView中的项目进行着色。

因此，我将子类别QStyledItemDelegate并重新实​​现了它的paint()方法，以绿色显示文件名，如果条件满足 - 哪些工作正常。然而它现在看起来很丑陋：文件图标丢失，“mouse_over”效果不再有效。

虽然这个子类反正是一个混乱的变通办法，我顶层的问题是

• 有没有办法上色根据条件在连接到一个QFileSystemModel项目QListView？

现在提供的，这可能并非如此，坚持QItemDelegate的子类，

• 有没有办法让漂亮的选择和图标回到原来的行为？
• 有谁知道哪个ItemDelegate最初用于QListView中的QFileSystemModel以及如何使用它？
• 是否有可能获得它的源代码并从那里复制绘画方法？

这是一个最小的代码，它使用了子类并显示了descibed行为。它使用一个可以输入字符串的QLineEdit，这样所有包含该字符串的文件都会以绿色突出显示。

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_()) 

这是它的外观与不继承QItemDelegate比较：

只提，这个代码是，一旦条件发生变化，需要另一个问题将鼠标移动到QFileView中以启动重新绘制。我想知道我可以使用哪个插槽连接信号来直接完成此操作。

Answer 1

不需要物品代理。它可以更简单地通过重新实现QFileSystemModel的data方法来实现：

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)