Question

I’d like to make a simple GUI that offers buttons which I can drag and drop into other Windows applications such that this other applications receives a certain string depending on the button chosen.

What would be the easiest GUI framework for Python that allows this drag and drop?

Answer 1

Any of the UI Libraries are likely to have support for this in some fashion. In wxPython we allow List Items to be moved between various lists. Things might look like this:

class JobList(VirtualList):
  def __init__(self, parent, colref = 'job_columns'):
    VirtualList.__init__(self, parent, colref)

  def _bind(self):
    VirtualList._bind(self)
    self.Bind(wx.EVT_LIST_BEGIN_DRAG, self._startDrag)

  def _startDrag(self, evt):
    # Create a data object to pass around.
    data = wx.CustomDataObject('JobIdList')
    data.SetData(str([self.data[idx]['Id'] for idx in self.selected]))

    # Create the dropSource and begin the drag-and-drop.
    dropSource = wx.DropSource(self)
    dropSource.SetData(data)
    dropSource.DoDragDrop(flags = wx.Drag_DefaultMove)

Then, there’s a ListDrop class that facilitates the dropping of things onto the lists:

class ListDrop(wx.PyDropTarget):
  """
    Utility class - Required to support List Drag & Drop.
    Using example code from http://wiki.wxpython.org/ListControls.
  """
  def __init__(self, setFn, dataType, acceptFiles = False):
    wx.PyDropTarget.__init__(self)

    self.setFn = setFn

    # Data type to accept.
    self.data = wx.CustomDataObject(dataType)

    self.comp = wx.DataObjectComposite()
    self.comp.Add(self.data)

    if acceptFiles:
      self.data2 = wx.FileDataObject()
      self.comp.Add(self.data2)

    self.SetDataObject(self.comp)

  def OnData(self, x, y, d):
    if self.GetData():
      if self.comp.GetReceivedFormat().GetType() == wx.DF_FILENAME:
        self.setFn(x, y, self.data2.GetFilenames())
      else:
        self.setFn(x, y, self.data.GetData())

    return d

And finally, a List where things can be dropped:

class QueueList(VirtualList):
  def __init__(self, parent, colref = 'queue_columns'):
    VirtualList.__init__(self, parent, colref)

    self.SetDropTarget(ListDrop(self.onJobDrop, 'JobIdList', True))

  def onJobDrop(self, x, y, data):
    idx, flags = self.HitTest((x, y)) #@UnusedVariable

    if idx == -1: # Not dropped on a list item in the target list.
      return 

    # Code here to handle incoming data.