vanillaDragAndDropListItems.py

from vanilla import *
from AppKit import NSDragOperationCopy

genericListPboardType = "genericListPboardType"

class DragAndDropListItemsDemo:

    weekdays = {
        'Mon' : [],
        'Tue' : [],
        'Wed' : [],
        'Thu' : [],
        'Fri' : [],
        'Sat' : [],
        'Sun' : [],
    }

    def __init__(self):
        self.w = Window((400, 200), 'drag & drop demo')
        self.w.list1 = List((0, 0, 200, -0),
                list(self.weekdays.keys()),
                allowsMultipleSelection=True,
                selectionCallback=self.list1SelectionCallback,
                selfWindowDropSettings=dict(type=genericListPboardType,
                        allowDropOnRow=True,
                        allowDropBetweenRows=False,
                        operation=NSDragOperationCopy,
                        callback=self.selfDropCallback))
        self.w.list2 = List((200, 0, -0, -0),
                ['banana', 'apple', 'orange', 'melon'],
                dragSettings=dict(type=genericListPboardType,
                        allowDropOnRow=True,
                        allowDropBetweenRows=False,
                        callback=self.dragCallback))
        self.w.open()

    def list1SelectionCallback(self, sender):
        selection = sender.getSelection()
        selectionKeys = [day for i, day in enumerate(sender.get()) if i in selection]
        for k in selectionKeys:
            print(k, self.weekdays[k])

    def dragCallback(self, sender, indexes):
        self.draggedItems = [self.w.list2.get()[i] for i in indexes]

    def selfDropCallback(self, sender, dropInfo):
        isProposal = dropInfo["isProposal"]
        if not isProposal:
            key = self.w.list1.get()[dropInfo['rowIndex']]
            for item in self.draggedItems:
                if item not in self.weekdays[key]:
                    self.weekdays[key] += [item]
        return True

DragAndDropListItemsDemo()