使用QToolBar和QListView导航面包屑 [英] Breadcrumbs navigation using QToolBar and QListView

问题描述

我有类似这样的JSON数据

I have JSON data something like this

{"books":{
    "web":{
      "front-end":{
        "html":["the missing manual", "core html5 canvas"],
        "css":["css pocket reference", "css in depth"],
        "js":["you don't know js", "eloquent javascript"]
      },
      "back-end":{
        "php":["modern php", "php web services"],
        "python":["dive into python", "python for everybody", 
        "Think Python", "Effective Python", "Fluent Python"]
      }
    },
    "database":{
      "sql":{
        "mysql":["mysql in a nutshell", "mysql cookbook"],
        "postgresql":["postgresql up and running", "practical postgresql"]
      },
      "nosql":{
        "mongodb":["mongodb in action", "scaling mongodb"],
        "cassandra":["practical cassandra", "mastering cassandra"]
}}}}

现在，我想使用QAbstractListModel和QToolBar作为面包屑导航(QAction)在QListView中填充此数据. QListView将以用户身份更新 触发键.那么我该如何实现呢?

Now I want to populate this data in QListView using QAbstractListModel with the QToolBar as breadcrumb navigation (QAction). QListView will update as user triggers key. So how can I implement this?

推荐答案

第一件事是将json转换为模型，在这种情况下使用QStandardItemModel.然后，我们在QListView中使用该模型，并使用setRootIndex()指示将要显示的项目，另一方面，使用父树将QActions添加到QToolBar中.

The first thing is to convert the json into a model, in this case QStandardItemModel is used. Then we use that model in the QListView using setRootIndex() to indicate the items that will be displayed, on the other hand QActions are added to the QToolBar using the parent tree.

from PyQt5 import QtCore, QtGui, QtWidgets

data = {"books":{
    "web":{
      "front-end":{
        "html":["the missing manual", "core html5 canvas"],
        "css":["css pocket reference", "css in depth"],
        "js":["you don't know js", "eloquent javascript"]
      },
      "back-end":{
        "php":["modern php", "php web services"],
        "python":["dive into python", "python for everybody", 
        "Think Python", "Effective Python", "Fluent Python"]
      }
    },
    "database":{
      "sql":{
        "mysql":["mysql in a nutshell", "mysql cookbook"],
        "postgresql":["postgresql up and running", "practical postgresql"]
      },
      "nosql":{
        "mongodb":["mongodb in action", "scaling mongodb"],
        "cassandra":["practical cassandra", "mastering cassandra"]
}}}}

def dict_to_model(item, d):
    if isinstance(d, dict):
        for k, v in d.items():
            it = QtGui.QStandardItem(k)
            item.appendRow(it)
            dict_to_model(it, v)
    elif isinstance(d, list):
        for v in d:
            dict_to_model(item, v)
    else:
        item.appendRow(QtGui.QStandardItem(str(d)))

class Navigation(QtCore.QObject):
    clicked = QtCore.pyqtSignal(QtCore.QModelIndex)
    def __init__(self, json_data, parent=None):
        super(Navigation, self).__init__(parent)
        self.toolbar = QtWidgets.QToolBar()
        self.toolbar.actionTriggered.connect(self.on_actionTriggered)
        self.model =  QtGui.QStandardItemModel(self)
        dict_to_model(self.model.invisibleRootItem(), json_data)
        it = self.model.item(0, 0)
        ix = self.model.indexFromItem(it)
        root_action = self.toolbar.addAction(it.text())
        root_action.setData(QtCore.QPersistentModelIndex(ix))
        self.listview = QtWidgets.QListView()
        self.listview.setEditTriggers(QtWidgets.QAbstractItemView.NoEditTriggers)
        self.listview.clicked.connect(self.on_clicked)
        self.listview.setModel(self.model)
        self.listview.setRootIndex(ix)

    @QtCore.pyqtSlot(QtCore.QModelIndex)
    def on_clicked(self, index):
        if not self.model.hasChildren(index):
            self.clicked.emit(index)
            return
        action = self.toolbar.addAction(index.data())
        action.setData(QtCore.QPersistentModelIndex(index))
        self.listview.setRootIndex(index)

    @QtCore.pyqtSlot(QtWidgets.QAction)
    def on_actionTriggered(self, action):
        ix = action.data()
        model = ix.model()
        self.listview.setRootIndex(QtCore.QModelIndex(ix))
        self.toolbar.clear()
        ixs = []
        while  ix.isValid():
            ixs.append(ix)
            ix = ix.parent()
        for ix in reversed(ixs):
            action = self.toolbar.addAction(ix.data())
            action.setData(ix)

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

        navigation = Navigation(data, self)
        navigation.clicked.connect(self.on_clicked)

        tree_view = QtWidgets.QTreeView()
        tree_view.setModel(navigation.model)
        navigation.model.setHorizontalHeaderLabels(["Tree Example"])
        tree_view.expandAll()

        self.addToolBar(navigation.toolbar)

        widget = QtWidgets.QWidget()
        self.setCentralWidget(widget)
        lay = QtWidgets.QHBoxLayout(widget)
        lay.addWidget(navigation.listview)
        lay.addWidget(tree_view)

    @QtCore.pyqtSlot(QtCore.QModelIndex)
    def on_clicked(self, index):
        print(index.data())

if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())

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