PySide: Drag and drop files into QListWidget

Question

This is my first entry here so apologies for any newbie mistakes. I've searched both here and Google with no luck before posting.

I want to be able to add images to a QListWidget, using drag and drop from a file browser. Dropping a valid file on the list widget also needs to trigger a function in the main class of my app, and pass it the image path.

I found this code that does exactly that, but for PyQt4. Importing QtCore and QtGui from PySide instead of PyQt4 produces a segmentation fault when triggering a drag and drop event. There are no error messages.

I think I've traced this to an old way of handling signals and have tried using the new, more pythonic way described here. I can't seem to get it working, while still passing a list of URLs between classes however.

Any help would be greatly appreciated!

import sys
import os
from PyQt4 import QtGui, QtCore

class TestListView(QtGui.QListWidget):
    def __init__(self, type, parent=None):
        super(TestListView, self).__init__(parent)
        self.setAcceptDrops(True)
        self.setIconSize(QtCore.QSize(72, 72))

    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 MainForm(QtGui.QMainWindow):
    def __init__(self, parent=None):
        super(MainForm, self).__init__(parent)

        self.view = TestListView(self)
        self.connect(self.view, QtCore.SIGNAL("dropped"), self.pictureDropped)
        self.setCentralWidget(self.view)

    def pictureDropped(self, l):
        for url in l:
            if os.path.exists(url):
                print(url)                
                icon = QtGui.QIcon(url)
                pixmap = icon.pixmap(72, 72)                
                icon = QtGui.QIcon(pixmap)
                item = QtGui.QListWidgetItem(url, self.view)
                item.setIcon(icon)        
                item.setStatusTip(url)        

def main():
    app = QtGui.QApplication(sys.argv)
    form = MainForm()
    form.show()
    app.exec_()

if __name__ == '__main__':
    main()

Answer 1

Found out how PySide signals work in the end. Here's the PyQt4 code above, ported to PySide. I'd love to hear if there are better solutions out there.

import sys
import os
from PySide import QtGui, QtCore

class TestListView(QtGui.QListWidget):

    fileDropped = QtCore.Signal(list)

    def __init__(self, type, parent=None):
        super(TestListView, self).__init__(parent)
        self.setAcceptDrops(True)
        self.setIconSize(QtCore.QSize(72, 72))

    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.fileDropped.emit(links)
        else:
            event.ignore()

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

        self.view = TestListView(self)
        self.view.fileDropped.connect(self.pictureDropped)
        self.setCentralWidget(self.view)

    def pictureDropped(self, l):
        for url in l:
            if os.path.exists(url):
                print(url)                
                icon = QtGui.QIcon(url)
                pixmap = icon.pixmap(72, 72)                
                icon = QtGui.QIcon(pixmap)
                item = QtGui.QListWidgetItem(url, self.view)
                item.setIcon(icon)        
                item.setStatusTip(url)        

def main():
    app = QtGui.QApplication(sys.argv)
    form = MainForm()
    form.show()
    app.exec_()

if __name__ == '__main__':
    main()

Answer 2

For me this worked fine (tested on PySide2 & PyQt5). This is not a drop signal, but a signal when the rows of a QListWidget have been moved. In my case this is always happening after dropping.

self.window.my_list_widget.model().rowsMoved.connect(self.my_method)

Answer 3

I made some changes of @thimic 's code, so that it can run in my computer:

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

class TestListView(QListWidget):


    def __init__(self, type, parent=None):
        super(TestListView, self).__init__(parent)
        self.setAcceptDrops(True)
        self.setIconSize(QtCore.QSize(72, 72))

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

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

    def dropEvent(self, event):
        if event.mimeData().hasUrls:
            event.setDropAction(Qt.CopyAction)
            event.accept()
            links = []
            for url in event.mimeData().urls():
                links.append(str(url.toLocalFile()))
            print('Has drop Event! ')
        else:
            event.ignore()

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

        self.view = TestListView(self)
        self.view.fileDropped.connect(self.pictureDropped)
        self.setCentralWidget(self.view)

    def pictureDropped(self, l):
        for url in l:
            if os.path.exists(url):
                print(url)
                icon = QtGui.QIcon(url)
                pixmap = icon.pixmap(72, 72)
                icon = QtGui.QIcon(pixmap)
                item = QtGui.QListWidgetItem(url, self.view)
                item.setIcon(icon)
                item.setStatusTip(url)

def main():
    app = QApplication(sys.argv)
    form = MainForm()
    form.show()
    app.exec_()

if __name__ == '__main__':
    main()