CODEWITHSUNDEEP
python-3.xdrag-and-dropwxpythonwxformbuilder
user999713
user999713

Reputation: 89

DragNDrop for Python using wxFormBuilder

My existing wxPython app is based on a wxFormBuilder skeleton. It will accept new image files to work with via a file selector dialog. Now, I would like to make drag-n-drop available, but am stuck on how to go about it. After some review of the properties options for the image panel, I see the 'drop_accept_files' option. When I check the box and generate the Python code, I do see new code generated for this

self.m_panelImage = wx.Panel( self.m_splitterMain, wx.ID_ANY, wx.DefaultPosition, wx.DefaultSize, wx.TAB_TRAVERSAL )
self.m_panelImage.DragAcceptFiles( True )  **<<<< new line of added code**

All of this sounds very promising and interesting, but I have not been able to figure out how I would hook up to this facility and use it. Anyone can point me in the right direction or know of a good example to review? TIA

Upvotes: 0

Views: 70

Answers (2)

Mace
Mace

Reputation: 1410

After checking the drag_accept_files property for the panel you need to define the event handler OnDropFiles.

Enable drag_accept_files in Object Properties

======================================

Define an OnDropFiles event

Now you can generate the code with wxFormBuilder.

In the python source for your form you have to program the logic for the defined event handler. In my example on_panel_dnd_drop_files. It just prints the files and directories received.

def on_panel_dnd_drop_files( self, event ):
    for path in event.Files:
        if os.path.isfile(path):
            print(f'dnd file: {path}')
        elif os.path.isdir(path):
            print(f'dnd directory:  {path}')

You can drag and drop files as well as directories as well as a combination. Here is the result of drag and dropping some files and directories from my windows directory:

    dnd file: C:\Windows\bfsvc.exe
    dnd directory:  C:\Windows\WaaS
    dnd directory:  C:\Windows\Web
    dnd directory:  C:\Windows\WinSxS
    dnd file: C:\Windows\ampa.exe
    dnd file: C:\Windows\ATTODiskBenchmark.INI

As you can see in the example event handler, you can use os.path.isfile and os.path.isdir to distinguish between files and directories.

Upvotes: 0

Rolf of Saxony
Rolf of Saxony

Reputation: 22448

As soon as you say wxFormBuilder, my eyes glaze over, as I've always coded directly, so this may or may not be of help.

You need to Bind to an EVT_DROP_EVENT to know that something has been dropped and have set a target to process what got dropped.

Here is an example, sadly no wxFrameBuilder involved:

import wx
import wx.lib.newevent

drop_event, EVT_DROP_EVENT = wx.lib.newevent.NewEvent()

class FileDropTarget(wx.FileDropTarget):
    def __init__(self, obj, multiple_allowed=False):
        wx.FileDropTarget.__init__(self)
        self.obj = obj
        self.multiple_allowed = multiple_allowed

    def OnDropFiles(self, x, y, filenames):
        filename = filenames[0]
        evt = drop_event(data=filename)
        wx.PostEvent(self.obj, evt)
        return True


class MyFrame(wx.Frame):
    def __init__(self, parent, title):
        super(MyFrame, self).__init__(parent, style = wx.DEFAULT_FRAME_STYLE,
                            title=title, size=(500, 500))
        self.panel = wx.Panel(self, size = (-1, -1))
        self.bmp = wx.Bitmap()
        self.bitmap = wx.StaticBitmap(self.panel, -1, self.bmp)

        self.file_drop_target = FileDropTarget(self, multiple_allowed=False)
        self.SetDropTarget(self.file_drop_target)
        self.Bind(EVT_DROP_EVENT, self.OnDropEvent)

    def OnDropEvent(self, event):
        drop_filename = event.data
        self.bitmap.SetBitmap(wx.Bitmap(drop_filename, wx.BITMAP_TYPE_ANY))
        self.Refresh()
        return

if __name__ == "__main__":
    app = wx.App()
    MainFrame = MyFrame(None, title = "Drop Image")
    MainFrame.Show()
    MainFrame.Centre()
    app.MainLoop()

Upvotes: 0

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