PyQt:如何获得大部分 QListWidget

2022-01-11 00:00:00 python pyqt pyqt4 drag-and-drop qlistwidget

问题描述

代码构建了一个带有单个 QListWidget 和单个 QPushButton 的对话框.

The code builds a dialog box with a single QListWidget and a single QPushButton.

单击该按钮会添加一个列表项.

Clicking the button adds a single List Item.

右键单击列表项会弹出一个右键菜单，其中包含删除项"命令.

Right-click on a List Item brings up a right-click menu with "Remove Item" command available.

选择移除项目"命令会从列表小部件中移除一个列表项目.

Choosing "Remove Item" command removes a List Item from List Widget.

看看如何实现以下 ListWidgets 操作会很有趣:

Would be interesting to see how the following ListWidgets ops could be implemented:

  1. 能够上下移动列表项(重新排列).
  2. 能够多选和多删除列表项.
  3. 更好更健壮的列表项排序.

示例:

import sys, os
from PyQt4 import QtCore, QtGui    

class ThumbListWidget(QtGui.QListWidget):
    def __init__(self, type, parent=None):
        super(ThumbListWidget, self).__init__(parent)
        self.setAcceptDrops(True)
        self.setIconSize(QtCore.QSize(124, 124))

    def dragEnterEvent(self, event):
        if event.mimeData().hasUrls:
            event.accept()
        else:
            event.ignore()

    def dragMoveEvent(self, event):
        if event.mimeData().hasUrls:
            event.setDropAction(QtCore.Qt.CopyAction)
            event.accept()
        else:
            event.ignore()

    def dropEvent(self, event):
        if event.mimeData().hasUrls:
            event.setDropAction(QtCore.Qt.CopyAction)
            event.accept()
            links = []
            for url in event.mimeData().urls():
                links.append(str(url.toLocalFile()))
            self.emit(QtCore.SIGNAL("dropped"), links)
        else:
            event.ignore()

class Dialog_01(QtGui.QMainWindow):
    def __init__(self):
        super(QtGui.QMainWindow,self).__init__()
        self.listItems={}

        myQWidget = QtGui.QWidget()
        myBoxLayout = QtGui.QVBoxLayout()
        myQWidget.setLayout(myBoxLayout)
        self.setCentralWidget(myQWidget)

        self.myListWidget = ThumbListWidget(self)  
        self.myListWidget.setContextMenuPolicy(QtCore.Qt.CustomContextMenu)
        self.myListWidget.connect(self.myListWidget, QtCore.SIGNAL("customContextMenuRequested(QPoint)" ), self.listItemRightClicked)

        myButton = QtGui.QPushButton("Add List Item")

        myBoxLayout.addWidget(self.myListWidget)
        myBoxLayout.addWidget(myButton)
        myButton.clicked.connect(self.addListWidgetItem)                

    def addListWidgetItem(self):
        listItemName='Item '+str(len(self.listItems.keys()))        
        self.listItems[listItemName]=None
        self.rebuildListWidget() 

    def listItemRightClicked(self, QPos): 
        self.listMenu= QtGui.QMenu()
        menu_item = self.listMenu.addAction("Remove Item")
        if len(self.listItems.keys())==0: menu_item.setDisabled(True)
        self.connect(menu_item, QtCore.SIGNAL("triggered()"), self.menuItemClicked) 

        parentPosition = self.myListWidget.mapToGlobal(QtCore.QPoint(0, 0))        
        self.listMenu.move(parentPosition + QPos)

        self.listMenu.show() 

    def menuItemClicked(self):
        if len(self.listItems.keys())==0: print 'return from menuItemClicked'; return
        currentItemName=str(self.myListWidget.currentItem().text() )
        self.listItems.pop(currentItemName, None)
        self.rebuildListWidget()

    def rebuildListWidget(self):
        self.myListWidget.clear()
        items=self.listItems.keys()
        if len(items)>1: items.sort()
        for listItemName in items:
            listItem = QtGui.QListWidgetItem( listItemName, self.myListWidget )
            self.listItems[listItemName]=listItem


if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    dialog_1 = Dialog_01()
    dialog_1.show()
    dialog_1.resize(480,320)
    sys.exit(app.exec_())

解决方案

List-widget项目可以通过拖放上下移动，但默认不启用.要打开它，请执行以下操作:

List-widget items can be moved up and down via drag and drop, but it is not enabled by default. To switch it on, do this:

    self.listWidget.setDragDropMode(QtGui.QAbstractItemView.InternalMove)

多重选择是几个可用的选择模式之一.要打开它，请执行以下操作:

Multiple-selection is one of several selection-modes available. To switch it on, do this:

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

默认情况下禁用排序.要打开它，请执行以下操作:

Sorting is disabled by default. To switch it on, do this:

    self.listWidget.setSortingEnabled(True)

要重新排序列表，请执行以下操作之一:

To re-sort the list, do one of these:

    self.listWidget.sortItems() # ascending by default
    self.listWidget.sortItems(QtCore.Qt.DescendingOrder)

默认情况下，排序是按字母顺序和不区分大小写的.如果您想要自定义排序顺序，请继承 QListWidgetItem 并重新实现其小于运算符:

Sorting is alphabetical and case-insensitive by default. If you want a custom sort-order, subclass QListWidgetItem and re-implement its less-than operator:

class ListWidgetItem(QtGui.QListWidgetItem):
    def __lt__(self, other):
        return self.text() < other.text() # or whatever

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