wxPython: GetHandle for Mac ?

Mathieu_Malaterre · September 11, 2003, 7:57am

Hi all,

I am not a Mac user, so please bear with me. I would like to know if the method GetHandle works with wxPython.
Otherwise should I add in wxPython/src/helpers.cpp something like:

long wxPyGetWinHandle(wxWindow* win) {
...
#ifdef __WXMAC__
return (long)MAC_WXHWND(win->MacGetRootWindow());
#endif
...
}

Thanks,
mathieu

Robin · September 11, 2003, 6:36pm

Mathieu Malaterre wrote:

Hi all,

I am not a Mac user, so please bear with me. I would like to know if the method GetHandle works with wxPython.

GetHandle in wxMac is still always returning NULL.

Otherwise should I add in wxPython/src/helpers.cpp something like:

long wxPyGetWinHandle(wxWindow* win) {
...
#ifdef __WXMAC__
return (long)MAC_WXHWND(win->MacGetRootWindow());
#endif
...
}

That gets the WindowRef of the toplevel parent of win, which isn't the same thing...

Stefan, is there something equivallent to a window handle that can be used for wxWindow::GetHandle for all types of wxWindows?

···

--
Robin Dunn
Software Craftsman
http://wxPython.org Java give you jitters? Relax with wxPython!

Stefan_Csomor · September 11, 2003, 7:37pm

That gets the WindowRef of the toplevel parent of win, which
isn't the same thing...

Stefan, is there something equivallent to a window handle
that can be used for wxWindow::GetHandle for all types of wxWindows?

Hi

wxWindow has three different counterparts :

- for toplevel windows there is a windowref (MacGetWindowRef)
- for native controls there is a controlhandle (GetMacControl)
- all others have no native counterpart

only once we will move to HIView under 10.2 will we have a native object
(HIObject) of the same superclass for every instance of wxWindow

Best,

Stefan

Robin · September 11, 2003, 7:54pm

Stefan Csomor wrote:

That gets the WindowRef of the toplevel parent of win, which isn't the same thing...

Stefan, is there something equivallent to a window handle that can be used for wxWindow::GetHandle for all types of wxWindows?

Hi

wxWindow has three different counterparts :

- for toplevel windows there is a windowref (MacGetWindowRef)
- for native controls there is a controlhandle (GetMacControl)
- all others have no native counterpart

only once we will move to HIView under 10.2 will we have a native object
(HIObject) of the same superclass for every instance of wxWindow

Ok. Thanks for the info.

···

--
Robin Dunn
Software Craftsman
http://wxPython.org Java give you jitters? Relax with wxPython!

David_Woods4 · September 12, 2003, 5:01pm

Hello all,

I am trying to implement some subtle drag-and-drop behavior, and am stuck on
the issue of providing feedback to the user during the drag about whether
their drop will succeed.

Am I right in thinking that there is no way to look at the contents of a
wxCustomDataObject from within the wxPyDropTarget's OnDragOver method?

See, I'm trying to implement a series of behaviors in my application that
get triggered by dragging wxTreeCtrl nodes around. The various Node Types
can only be dropped on some nodes, not others, in ways that are meaningful,
and I have implemented drag-and-drop feedback in other programming languages
in such a way that my users can see whether the drop will be meaningful
before they let go. (This feedback is pretty important given how my app is
designed.) I've done it by comparing characteristics of the data being
dragged to the characteristics of the potential drop target. However, I
can't seem to access anything about the data being dragged until the drop
has occurred in wxPython.

By way of illustration, I've attached a small app. It shows a tree with
several "Series" nodes and several "Collection" nodes, and at present, I've
got the feedback mechanism working so that only "Collection" nodes will
accept data drops. What I want is to alter the wxPyDropTarget's OnDragOver
method so that "Collections" only receive data picked up from the "Series"
part of the tree and that "Series" can accepts only "Collection" drops.

My actual application has many more node types and much more complex data
acceptance rules. Any suggestions for how I can extract the dragged data
characteristics would be greatly appreciated.

David Woods, Ph.D.
Wisconsin Center for Education Research
University of Wisconsin, Madison
http://www.transana.org

DragandDrop.pyw (5.72 KB)

Paul_Yeager · September 16, 2003, 7:28pm

David:

I have been struggling with drag and drop myself, so I read your message with interest.

Naturally, I immediately tried to run the demo you attached. It presented a tree display which seemed quite functional, other than that it does not seem to respond to drag attempts at all. It issues "invalid tree item" messages for each attempt.

In what sort of environment are you working? What OS, Python, and wxWindows versions are you using?

Are you interested in dragging items within the tree, or dropping items from other applications, or both?

I do note that in MainWindow.OnBeginDrag(), you are creating and converting some data, but I do not see where you associate that data with a node on the tree. Could this be significant? In a real application, would this not happen before a drag and drop operation commenced?

Best Regards

Paul Yeager
TekTone Sound & Signal Mfg., Inc.

David Woods wrote:

···

Hello all,

I am trying to implement some subtle drag-and-drop behavior, and am stuck on
the issue of providing feedback to the user during the drag about whether
their drop will succeed.

Am I right in thinking that there is no way to look at the contents of a
wxCustomDataObject from within the wxPyDropTarget's OnDragOver method?

See, I'm trying to implement a series of behaviors in my application that
get triggered by dragging wxTreeCtrl nodes around. The various Node Types
can only be dropped on some nodes, not others, in ways that are meaningful,
and I have implemented drag-and-drop feedback in other programming languages
in such a way that my users can see whether the drop will be meaningful
before they let go. (This feedback is pretty important given how my app is
designed.) I've done it by comparing characteristics of the data being
dragged to the characteristics of the potential drop target. However, I
can't seem to access anything about the data being dragged until the drop
has occurred in wxPython.

By way of illustration, I've attached a small app. It shows a tree with
several "Series" nodes and several "Collection" nodes, and at present, I've
got the feedback mechanism working so that only "Collection" nodes will
accept data drops. What I want is to alter the wxPyDropTarget's OnDragOver
method so that "Collections" only receive data picked up from the "Series"
part of the tree and that "Series" can accepts only "Collection" drops.

My actual application has many more node types and much more complex data
acceptance rules. Any suggestions for how I can extract the dragged data
characteristics would be greatly appreciated.

David Woods, Ph.D.
Wisconsin Center for Education Research
University of Wisconsin, Madison
http://www.transana.org

------------------------------------------------------------------------

from wxPython import wx
import cPickle

class MainWindow(wx.wxDialog):
  """ This window displays a variety of GUI Widgets. """
  def __init__(self,parent,id,title):
     wx.wxDialog.__init__(self,parent,-4, title, size = (320,600), style=wx.wxDEFAULT_FRAME_STYLE|wx.wxNO_FULL_REPAINT_ON_RESIZE)
     self.SetBackgroundColour(wx.wxWHITE)

     lay = wx.wxLayoutConstraints()
     lay.top.SameAs(self, wx.wxTop, 10)
     lay.centreX.SameAs(self, wx.wxCentreX)
     lay.height.AsIs()
     lay.width.AsIs()
     self.tree = wx.wxTreeCtrl(self, -1, size=(300, 530), style=wx.wxTR_HAS_BUTTONS)
     self.tree.SetConstraints(lay)
          lay = wx.wxLayoutConstraints()
     lay.top.SameAs(self, wx.wxBottom, -25)
     lay.centreX.SameAs(self, wx.wxCentreX)
     lay.height.AsIs()
     lay.width.AsIs()
     btn = wx.wxButton(self, wx.wxID_OK, "OK")
     btn.SetConstraints(lay)

     self.treeroot = self.tree.AddRoot('Transana Database')

     self.seriesroot = self.tree.AppendItem(self.treeroot, 'Series')
          item = self.tree.AppendItem(self.seriesroot, 'Series 1')

     item = self.tree.AppendItem(self.seriesroot, 'Series 2')

     item = self.tree.AppendItem(self.seriesroot, 'Series 3')

     self.collectionsroot = self.tree.AppendItem(self.treeroot, 'Collections')

     item = self.tree.AppendItem(self.collectionsroot, 'Collection 1')

     item = self.tree.AppendItem(self.collectionsroot, 'Collection 2')

     item = self.tree.AppendItem(self.collectionsroot, 'Collection 3')

     self.tree.Expand(self.treeroot)
     self.tree.Expand(self.seriesroot)
     self.tree.Expand(self.collectionsroot)

     # Define the Begin Drag Event
     wx.EVT_TREE_BEGIN_DRAG(self.tree, self.tree.GetId(), self.OnBeginDrag)

     # Define the Drop Target
     dt = TestDropTarget(self.tree)
     self.tree.SetDropTarget(dt)

     self.Layout()
     self.SetAutoLayout(wx.true)
          self.ShowModal()
     self.Destroy()

  def OnBeginDrag(self, event):
     """ Left Mouse Button initiates "Drag" for Clips (Sort Order, Copy, Move) and Keywords (Assign) """
     # Items in the tree are not automatically selected with a left click.
     # We must select the item that is initially clicked manually!!
     # We do this by looking at the screen point clicked and applying the tree's HitTest method
     sel_item, flags = self.tree.HitTest(event.GetPoint())
     self.tree.SelectItem(sel_item)
            tempStr = "%s" % (self.tree.GetItemText(sel_item))

     # Determine what Item is being "dragged", and grab it's data
     print "A node called %s is being dragged" % (tempStr)

     # Create a custom Data Type for Drag and Drop
     ddd = TestDragDropData()
     ddd.SetSource(tempStr)

     pddd = cPickle.dumps(ddd, 1)

     # Now convert it to a wxCustomDataObject for dragging and dropping
     cdo = wx.wxCustomDataObject(wx.wxCustomDataFormat('TransanaData'))
     cdo.SetData(pddd)

     # Now put the CustomDataObject into a DataObjectComposite
     tdo = wx.wxDataObjectComposite()
     tdo.Add(cdo)
          # Create a DropSource Object
     tds = wx.wxDropSource(self)
     # Associate the Data with the Drop Source Object
     tds.SetData(tdo)
     # Initiate the Drag Operation
     dragResult = tds.DoDragDrop(wx.true)

     if dragResult == wx.wxDragCopy:
         print "Result indicated successful copy"
     elif dragResult == wx.wxDragMove:
         print "Result indicated successful move"
     else:
         print "Result indicated failed drop"

class TestDragDropData(object):
  def __init__(self):
     self.SourceText = ''
     self.DestText = ''

  def __repr__(self):
     return "SourceText = '%s', DestText = '%s'" % (self.SourceText, self.DestText)

  def SetSource(self, txt):
     self.SourceText = txt

  def SetDest(self, txt):
     self.DestText = txt

class TestDropTarget(wx.wxPyDropTarget):
  def __init__(self, tree):
     wx.wxPyDropTarget.__init__(self)
     self.tree = tree

     # specify the data to accept
     self.df = wx.wxCustomDataFormat('TransanaData')
     self.cdo = wx.wxCustomDataObject(self.df)
     self.SetDataObject(self.cdo)

  def OnEnter(self, x, y, d):
     print "OnEnter %s, %s, %s" % (x, y, d)
     return d

  def OnLeave(self):
     print "OnLeave"
     pass

  def OnDrop(self, x, y):
       print "Drop: x=%s, y=%s" % (x, y)
       (id, flag) = self.tree.HitTest((x, y))
       tempStr = self.tree.GetItemText(id)
       print "Dropped on %s." % tempStr
       return(wx.true)

  def OnDragOver(self, x, y, d):
# print "OnDragOver %s, %s, %s" % (x, y, d)
     # Determine Source Characteristics
# if self.GetData():
# data = cPickle.loads(self.cdo.GetData())
# print data
             # Determine Destination Characteristics
     (id, flag) = self.tree.HitTest((x, y))
     tempStr = self.tree.GetItemText(id)
          if (tempStr[0:10] == 'Collection'): # and (data.SourceText[0:7] == 'Series'):
        return d
     else:
        return wx.wxDragNone

  def OnData(self, x, y, d):
     print "OnData %s, %s, %s" % (x, y, d)
     if self.GetData():
        data = cPickle.loads(self.cdo.GetData())
        print "Drop Data = '%s'" % (data)
        data.SetDest('Set in Destination') # data is a COPY of the data, not the original, so this has no effect
             if d == wx.wxDragCopy:
         print "OnData Result indicated successful copy"
     elif d == wx.wxDragMove:
         print "OnData Result indicated successful move"
     else:
         print "OnData Result indicated failed drop"
     return d

class MyApp(wx.wxApp):
  def OnInit(self):
     frame = MainWindow(None, -1, "Drag and Drop Test")
     self.SetTopWindow(frame)
     return wx.true

app = MyApp(0)
app.MainLoop()

------------------------------------------------------------------------

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-users-unsubscribe@lists.wxwindows.org
For additional commands, e-mail: wxPython-users-help@lists.wxwindows.org

David_Woods4 · September 16, 2003, 8:05pm

I'll try to take your questions in order:

Naturally, I immediately tried to run the demo you attached. It
presented a tree display which seemed quite functional, other than that
it does not seem to respond to drag attempts at all. It issues "invalid
tree item" messages for each attempt.

The sample I attached does not accept outside data. Since I am trying to
figure out selective dragging between tree nodes of different types, that
example allows you to drag any tree node and drop it only on the
"Collection" nodes. It doesn't accept any other kind of data. I can't seem
to get the "invalid tree item" message you mention, so am not sure what you
are referring to there. Could that be platform-related?

In what sort of environment are you working? What OS, Python, and
wxWindows versions are you using?

OS is Windows 2000. Python is version 2.2. wxPython version is 2.4.1.2.

Are you interested in dragging items within the tree, or dropping items
from other applications, or both?

My particular interest is dragging within the tree only, at least until I
get it figured out. In my application, I use the tree control to represent
a hierarchical data structure, and use drag-and-drop within the tree to
implement a variety of different data manipulations. For example, you can
copy data between parallel nodes, which will trigger the copying of records
in the database and the corresponding addition of nodes in the tree. You
can also drag one type of node onto another as a way of signalling that the
one should be "applied to" the other, which would trigger a new record in
the database that would not be reflected in the tree because it's not a
relationship that is represented visually. So I need to know what kind of
node is being dragged and what kind of node is receiving the drop, and I
need to provide feedback to the user about when drops are legal and when
they aren't. So what I'm working on as a simplified example, which you see
the first iteration of, is something with "series" nodes and "collection"
nodes, and I am trying to enable the dragging of series nodes only onto
collection nodes and the dragging of collection nodes only onto series
nodes. I figure once I've got that figured out, I can develop everything I
need to to write that part of my application. I've got an example finished
that implements the drag-drop behavior and user feedback I want, which I
will post to the wxPython wiki (under wxTreeCtrl) within the next few hours.

I do note that in MainWindow.OnBeginDrag(), you are creating and
converting some data, but I do not see where you associate that data
with a node on the tree. Could this be significant? In a real
application, would this not happen before a drag and drop operation
commenced?

In this simplified example, the only data I'm interested in dragging is the
node's name, which is what gets sent (as tempStr) to SetData() in the
OnBeginDrag() method. When I implement this for real, I have a data
structure attached to each tree node that identifies the proper record in
the database and that is what I will use in the dragged data object
associated with the wxDropSource(). But my example here only drags the node
name and reports it via the print statement when it is dropped, but does
nothing to alter the tree. Gotta walk before I can run.

So take a look at the wiki in a couple of hours to see my new example that
does selective drag-and-drop of nodes within a wxTreeCtrl.

Hope this makes things clearer.

David

···

-----Original Message-----
From: Paul Yeager [mailto:pyeager@tektone.net]
Sent: Tuesday, September 16, 2003 2:28 PM
To: wxPython-users@lists.wxwindows.org
Subject: Re: [wxPython-users] Drag and Drop Feedback

David:

I have been struggling with drag and drop myself, so I read your message
with interest.

Naturally, I immediately tried to run the demo you attached. It
presented a tree display which seemed quite functional, other than that
it does not seem to respond to drag attempts at all. It issues "invalid
tree item" messages for each attempt.

In what sort of environment are you working? What OS, Python, and
wxWindows versions are you using?

Are you interested in dragging items within the tree, or dropping items
from other applications, or both?

I do note that in MainWindow.OnBeginDrag(), you are creating and
converting some data, but I do not see where you associate that data
with a node on the tree. Could this be significant? In a real
application, would this not happen before a drag and drop operation
commenced?

Best Regards

Paul Yeager
TekTone Sound & Signal Mfg., Inc.

David Woods wrote:

Hello all,

I am trying to implement some subtle drag-and-drop behavior, and am stuck

on

the issue of providing feedback to the user during the drag about whether
their drop will succeed.

Am I right in thinking that there is no way to look at the contents of a
wxCustomDataObject from within the wxPyDropTarget's OnDragOver method?

See, I'm trying to implement a series of behaviors in my application that
get triggered by dragging wxTreeCtrl nodes around. The various Node Types
can only be dropped on some nodes, not others, in ways that are meaningful,
and I have implemented drag-and-drop feedback in other programming

languages

in such a way that my users can see whether the drop will be meaningful
before they let go. (This feedback is pretty important given how my app is
designed.) I've done it by comparing characteristics of the data being
dragged to the characteristics of the potential drop target. However, I
can't seem to access anything about the data being dragged until the drop
has occurred in wxPython.

By way of illustration, I've attached a small app. It shows a tree with
several "Series" nodes and several "Collection" nodes, and at present, I've
got the feedback mechanism working so that only "Collection" nodes will
accept data drops. What I want is to alter the wxPyDropTarget's OnDragOver
method so that "Collections" only receive data picked up from the "Series"
part of the tree and that "Series" can accepts only "Collection" drops.

My actual application has many more node types and much more complex data
acceptance rules. Any suggestions for how I can extract the dragged data
characteristics would be greatly appreciated.

David Woods, Ph.D.
Wisconsin Center for Education Research
University of Wisconsin, Madison
http://www.transana.org

------------------------------------------------------------------------

from wxPython import wx
import cPickle

class MainWindow(wx.wxDialog):
  """ This window displays a variety of GUI Widgets. """
  def __init__(self,parent,id,title):
     wx.wxDialog.__init__(self,parent,-4, title, size = (320,600),

style=wx.wxDEFAULT_FRAME_STYLE|wx.wxNO_FULL_REPAINT_ON_RESIZE)

     self.SetBackgroundColour(wx.wxWHITE)

     lay = wx.wxLayoutConstraints()
     lay.top.SameAs(self, wx.wxTop, 10)
     lay.centreX.SameAs(self, wx.wxCentreX)
     lay.height.AsIs()
     lay.width.AsIs()
     self.tree = wx.wxTreeCtrl(self, -1, size=(300, 530),

style=wx.wxTR_HAS_BUTTONS)

     self.tree.SetConstraints(lay)

     lay = wx.wxLayoutConstraints()
     lay.top.SameAs(self, wx.wxBottom, -25)
     lay.centreX.SameAs(self, wx.wxCentreX)
     lay.height.AsIs()
     lay.width.AsIs()
     btn = wx.wxButton(self, wx.wxID_OK, "OK")
     btn.SetConstraints(lay)

     self.treeroot = self.tree.AddRoot('Transana Database')

     self.seriesroot = self.tree.AppendItem(self.treeroot, 'Series')

     item = self.tree.AppendItem(self.seriesroot, 'Series 1')

     item = self.tree.AppendItem(self.seriesroot, 'Series 2')

     item = self.tree.AppendItem(self.seriesroot, 'Series 3')

     self.collectionsroot = self.tree.AppendItem(self.treeroot,

'Collections')

     item = self.tree.AppendItem(self.collectionsroot, 'Collection 1')

     item = self.tree.AppendItem(self.collectionsroot, 'Collection 2')

     item = self.tree.AppendItem(self.collectionsroot, 'Collection 3')

     self.tree.Expand(self.treeroot)
     self.tree.Expand(self.seriesroot)
     self.tree.Expand(self.collectionsroot)

     # Define the Begin Drag Event
     wx.EVT_TREE_BEGIN_DRAG(self.tree, self.tree.GetId(),

self.OnBeginDrag)

     # Define the Drop Target
     dt = TestDropTarget(self.tree)
     self.tree.SetDropTarget(dt)

     self.Layout()
     self.SetAutoLayout(wx.true)

     self.ShowModal()
     self.Destroy()

  def OnBeginDrag(self, event):
     """ Left Mouse Button initiates "Drag" for Clips (Sort Order, Copy,

Move) and Keywords (Assign) """

     # Items in the tree are not automatically selected with a left click.
     # We must select the item that is initially clicked manually!!
     # We do this by looking at the screen point clicked and applying the

tree's HitTest method

     sel_item, flags = self.tree.HitTest(event.GetPoint())
     self.tree.SelectItem(sel_item)

     tempStr = "%s" % (self.tree.GetItemText(sel_item))

     # Determine what Item is being "dragged", and grab it's data
     print "A node called %s is being dragged" % (tempStr)

     # Create a custom Data Type for Drag and Drop
     ddd = TestDragDropData()
     ddd.SetSource(tempStr)

     pddd = cPickle.dumps(ddd, 1)

     # Now convert it to a wxCustomDataObject for dragging and dropping
     cdo = wx.wxCustomDataObject(wx.wxCustomDataFormat('TransanaData'))
     cdo.SetData(pddd)

     # Now put the CustomDataObject into a DataObjectComposite
     tdo = wx.wxDataObjectComposite()
     tdo.Add(cdo)

     # Create a DropSource Object
     tds = wx.wxDropSource(self)
     # Associate the Data with the Drop Source Object
     tds.SetData(tdo)
     # Initiate the Drag Operation
     dragResult = tds.DoDragDrop(wx.true)

     if dragResult == wx.wxDragCopy:
         print "Result indicated successful copy"
     elif dragResult == wx.wxDragMove:
         print "Result indicated successful move"
     else:
         print "Result indicated failed drop"

class TestDragDropData(object):
  def __init__(self):
     self.SourceText = ''
     self.DestText = ''

  def __repr__(self):
     return "SourceText = '%s', DestText = '%s'" % (self.SourceText,

self.DestText)

  def SetSource(self, txt):
     self.SourceText = txt

  def SetDest(self, txt):
     self.DestText = txt

class TestDropTarget(wx.wxPyDropTarget):
  def __init__(self, tree):
     wx.wxPyDropTarget.__init__(self)
     self.tree = tree

     # specify the data to accept
     self.df = wx.wxCustomDataFormat('TransanaData')
     self.cdo = wx.wxCustomDataObject(self.df)
     self.SetDataObject(self.cdo)

  def OnEnter(self, x, y, d):
     print "OnEnter %s, %s, %s" % (x, y, d)
     return d

  def OnLeave(self):
     print "OnLeave"
     pass

  def OnDrop(self, x, y):
       print "Drop: x=%s, y=%s" % (x, y)
       (id, flag) = self.tree.HitTest((x, y))
       tempStr = self.tree.GetItemText(id)
       print "Dropped on %s." % tempStr
       return(wx.true)

  def OnDragOver(self, x, y, d):
# print "OnDragOver %s, %s, %s" % (x, y, d)
     # Determine Source Characteristics
# if self.GetData():
# data = cPickle.loads(self.cdo.GetData())
# print data

     # Determine Destination Characteristics
     (id, flag) = self.tree.HitTest((x, y))
     tempStr = self.tree.GetItemText(id)

     if (tempStr[0:10] == 'Collection'): # and (data.SourceText[0:7] ==

'Series'):

        return d
     else:
        return wx.wxDragNone

  def OnData(self, x, y, d):
     print "OnData %s, %s, %s" % (x, y, d)
     if self.GetData():
        data = cPickle.loads(self.cdo.GetData())
        print "Drop Data = '%s'" % (data)
        data.SetDest('Set in Destination') # data is a COPY of the data,

not the original, so this has no effect

     if d == wx.wxDragCopy:
         print "OnData Result indicated successful copy"
     elif d == wx.wxDragMove:
         print "OnData Result indicated successful move"
     else:
         print "OnData Result indicated failed drop"
     return d

class MyApp(wx.wxApp):
  def OnInit(self):
     frame = MainWindow(None, -1, "Drag and Drop Test")
     self.SetTopWindow(frame)
     return wx.true

app = MyApp(0)
app.MainLoop()

------------------------------------------------------------------------

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-users-unsubscribe@lists.wxwindows.org
For additional commands, e-mail: wxPython-users-help@lists.wxwindows.org

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-users-unsubscribe@lists.wxwindows.org
For additional commands, e-mail: wxPython-users-help@lists.wxwindows.org

Paul_Yeager · September 16, 2003, 11:12pm

I tried the TreeCtrl Drag and Drop code on the wxPython wiki, and got the same result - the tree appears to be properly displayed, but drag and drop does not work. The SelectItem method in OnBeginDrag is issuing a "invalid tree item" error message.

Why is this happening? I am running RedHat 2.4.7, Python 2.3, and wxPython 2.4.1.2.

I have also noticed that the Drga and Drop code that I have working in the above environment does not work with Window$ 98, Python 2.3, and wxPython 2.4.1.2. Anyone have any idea why?

David Woods wrote:

···

I'll try to take your questions in order:

Naturally, I immediately tried to run the demo you attached. It
presented a tree display which seemed quite functional, other than that
it does not seem to respond to drag attempts at all. It issues "invalid
tree item" messages for each attempt.

The sample I attached does not accept outside data. Since I am trying to
figure out selective dragging between tree nodes of different types, that
example allows you to drag any tree node and drop it only on the
"Collection" nodes. It doesn't accept any other kind of data. I can't seem
to get the "invalid tree item" message you mention, so am not sure what you
are referring to there. Could that be platform-related?

In what sort of environment are you working? What OS, Python, and
wxWindows versions are you using?

OS is Windows 2000. Python is version 2.2. wxPython version is 2.4.1.2.

Are you interested in dragging items within the tree, or dropping items

from other applications, or both?

My particular interest is dragging within the tree only, at least until I
get it figured out. In my application, I use the tree control to represent
a hierarchical data structure, and use drag-and-drop within the tree to
implement a variety of different data manipulations. For example, you can
copy data between parallel nodes, which will trigger the copying of records
in the database and the corresponding addition of nodes in the tree. You
can also drag one type of node onto another as a way of signalling that the
one should be "applied to" the other, which would trigger a new record in
the database that would not be reflected in the tree because it's not a
relationship that is represented visually. So I need to know what kind of
node is being dragged and what kind of node is receiving the drop, and I
need to provide feedback to the user about when drops are legal and when
they aren't. So what I'm working on as a simplified example, which you see
the first iteration of, is something with "series" nodes and "collection"
nodes, and I am trying to enable the dragging of series nodes only onto
collection nodes and the dragging of collection nodes only onto series
nodes. I figure once I've got that figured out, I can develop everything I
need to to write that part of my application. I've got an example finished
that implements the drag-drop behavior and user feedback I want, which I
will post to the wxPython wiki (under wxTreeCtrl) within the next few hours.

I do note that in MainWindow.OnBeginDrag(), you are creating and
converting some data, but I do not see where you associate that data
with a node on the tree. Could this be significant? In a real
application, would this not happen before a drag and drop operation
commenced?

In this simplified example, the only data I'm interested in dragging is the
node's name, which is what gets sent (as tempStr) to SetData() in the
OnBeginDrag() method. When I implement this for real, I have a data
structure attached to each tree node that identifies the proper record in
the database and that is what I will use in the dragged data object
associated with the wxDropSource(). But my example here only drags the node
name and reports it via the print statement when it is dropped, but does
nothing to alter the tree. Gotta walk before I can run.

So take a look at the wiki in a couple of hours to see my new example that
does selective drag-and-drop of nodes within a wxTreeCtrl.

Hope this makes things clearer.

David

-----Original Message-----
From: Paul Yeager [mailto:pyeager@tektone.net]
Sent: Tuesday, September 16, 2003 2:28 PM
To: wxPython-users@lists.wxwindows.org
Subject: Re: [wxPython-users] Drag and Drop Feedback

David:

I have been struggling with drag and drop myself, so I read your message
with interest.

Naturally, I immediately tried to run the demo you attached. It
presented a tree display which seemed quite functional, other than that
it does not seem to respond to drag attempts at all. It issues "invalid
tree item" messages for each attempt.

In what sort of environment are you working? What OS, Python, and
wxWindows versions are you using?

Are you interested in dragging items within the tree, or dropping items
from other applications, or both?

I do note that in MainWindow.OnBeginDrag(), you are creating and
converting some data, but I do not see where you associate that data
with a node on the tree. Could this be significant? In a real
application, would this not happen before a drag and drop operation
commenced?

Best Regards

Paul Yeager
TekTone Sound & Signal Mfg., Inc.

David Woods wrote:

Hello all,

I am trying to implement some subtle drag-and-drop behavior, and am stuck


on

the issue of providing feedback to the user during the drag about whether
their drop will succeed.

Am I right in thinking that there is no way to look at the contents of a
wxCustomDataObject from within the wxPyDropTarget's OnDragOver method?

See, I'm trying to implement a series of behaviors in my application that
get triggered by dragging wxTreeCtrl nodes around. The various Node Types
can only be dropped on some nodes, not others, in ways that are meaningful,
and I have implemented drag-and-drop feedback in other programming


languages

in such a way that my users can see whether the drop will be meaningful
before they let go. (This feedback is pretty important given how my app is
designed.) I've done it by comparing characteristics of the data being
dragged to the characteristics of the potential drop target. However, I
can't seem to access anything about the data being dragged until the drop
has occurred in wxPython.

By way of illustration, I've attached a small app. It shows a tree with
several "Series" nodes and several "Collection" nodes, and at present, I've
got the feedback mechanism working so that only "Collection" nodes will
accept data drops. What I want is to alter the wxPyDropTarget's OnDragOver
method so that "Collections" only receive data picked up from the "Series"
part of the tree and that "Series" can accepts only "Collection" drops.

My actual application has many more node types and much more complex data
acceptance rules. Any suggestions for how I can extract the dragged data
characteristics would be greatly appreciated.

David Woods, Ph.D.
Wisconsin Center for Education Research
University of Wisconsin, Madison
http://www.transana.org

------------------------------------------------------------------------

from wxPython import wx

import cPickle

class MainWindow(wx.wxDialog):
""" This window displays a variety of GUI Widgets. """
def __init__(self,parent,id,title):
    wx.wxDialog.__init__(self,parent,-4, title, size = (320,600),


style=wx.wxDEFAULT_FRAME_STYLE|wx.wxNO_FULL_REPAINT_ON_RESIZE)

    self.SetBackgroundColour(wx.wxWHITE)

    lay = wx.wxLayoutConstraints()
    lay.top.SameAs(self, wx.wxTop, 10)
    lay.centreX.SameAs(self, wx.wxCentreX)
    lay.height.AsIs()
    lay.width.AsIs()
    self.tree = wx.wxTreeCtrl(self, -1, size=(300, 530),


style=wx.wxTR_HAS_BUTTONS)

    self.tree.SetConstraints(lay)

    lay = wx.wxLayoutConstraints()
    lay.top.SameAs(self, wx.wxBottom, -25)
    lay.centreX.SameAs(self, wx.wxCentreX)
    lay.height.AsIs()
    lay.width.AsIs()
    btn = wx.wxButton(self, wx.wxID_OK, "OK")
    btn.SetConstraints(lay)

    self.treeroot = self.tree.AddRoot('Transana Database')

    self.seriesroot = self.tree.AppendItem(self.treeroot, 'Series')

    item = self.tree.AppendItem(self.seriesroot, 'Series 1')

    item = self.tree.AppendItem(self.seriesroot, 'Series 2')

    item = self.tree.AppendItem(self.seriesroot, 'Series 3')

    self.collectionsroot = self.tree.AppendItem(self.treeroot,


'Collections')

    item = self.tree.AppendItem(self.collectionsroot, 'Collection 1')

    item = self.tree.AppendItem(self.collectionsroot, 'Collection 2')

    item = self.tree.AppendItem(self.collectionsroot, 'Collection 3')

    self.tree.Expand(self.treeroot)
    self.tree.Expand(self.seriesroot)
    self.tree.Expand(self.collectionsroot)

    # Define the Begin Drag Event
    wx.EVT_TREE_BEGIN_DRAG(self.tree, self.tree.GetId(),


self.OnBeginDrag)

    # Define the Drop Target
    dt = TestDropTarget(self.tree)
    self.tree.SetDropTarget(dt)

    self.Layout()
    self.SetAutoLayout(wx.true)

    self.ShowModal()
    self.Destroy()

def OnBeginDrag(self, event):
    """ Left Mouse Button initiates "Drag" for Clips (Sort Order, Copy,


Move) and Keywords (Assign) """

    # Items in the tree are not automatically selected with a left click.
    # We must select the item that is initially clicked manually!!
    # We do this by looking at the screen point clicked and applying the


tree's HitTest method

    sel_item, flags = self.tree.HitTest(event.GetPoint())
    self.tree.SelectItem(sel_item)

    tempStr = "%s" % (self.tree.GetItemText(sel_item))

    # Determine what Item is being "dragged", and grab it's data
    print "A node called %s is being dragged" % (tempStr)

    # Create a custom Data Type for Drag and Drop
    ddd = TestDragDropData()
    ddd.SetSource(tempStr)

    pddd = cPickle.dumps(ddd, 1)

    # Now convert it to a wxCustomDataObject for dragging and dropping
    cdo = wx.wxCustomDataObject(wx.wxCustomDataFormat('TransanaData'))
    cdo.SetData(pddd)

    # Now put the CustomDataObject into a DataObjectComposite
    tdo = wx.wxDataObjectComposite()
    tdo.Add(cdo)

    # Create a DropSource Object
    tds = wx.wxDropSource(self)
    # Associate the Data with the Drop Source Object
    tds.SetData(tdo)
    # Initiate the Drag Operation
    dragResult = tds.DoDragDrop(wx.true)

    if dragResult == wx.wxDragCopy:
        print "Result indicated successful copy"
    elif dragResult == wx.wxDragMove:
        print "Result indicated successful move"
    else:
        print "Result indicated failed drop"

class TestDragDropData(object):
def __init__(self):
    self.SourceText = ''
    self.DestText = ''

def __repr__(self):
    return "SourceText = '%s', DestText = '%s'" % (self.SourceText,


self.DestText)

def SetSource(self, txt):
    self.SourceText = txt

def SetDest(self, txt):
    self.DestText = txt

class TestDropTarget(wx.wxPyDropTarget):
def __init__(self, tree):
    wx.wxPyDropTarget.__init__(self)
    self.tree = tree

    # specify the data to accept
    self.df = wx.wxCustomDataFormat('TransanaData')
    self.cdo = wx.wxCustomDataObject(self.df)
    self.SetDataObject(self.cdo)

def OnEnter(self, x, y, d):
    print "OnEnter %s, %s, %s" % (x, y, d)
    return d

def OnLeave(self):
    print "OnLeave"
    pass

def OnDrop(self, x, y):
      print "Drop: x=%s, y=%s" % (x, y)
      (id, flag) = self.tree.HitTest((x, y))
      tempStr = self.tree.GetItemText(id)
      print "Dropped on %s." % tempStr
      return(wx.true)

def OnDragOver(self, x, y, d):
# print "OnDragOver %s, %s, %s" % (x, y, d)
    # Determine Source Characteristics
# if self.GetData():
# data = cPickle.loads(self.cdo.GetData())
# print data

    # Determine Destination Characteristics
    (id, flag) = self.tree.HitTest((x, y))
    tempStr = self.tree.GetItemText(id)

    if (tempStr[0:10] == 'Collection'): # and (data.SourceText[0:7] ==


'Series'):

       return d
    else:
       return wx.wxDragNone

def OnData(self, x, y, d):
    print "OnData %s, %s, %s" % (x, y, d)
    if self.GetData():
       data = cPickle.loads(self.cdo.GetData())
       print "Drop Data = '%s'" % (data)
       data.SetDest('Set in Destination') # data is a COPY of the data,


not the original, so this has no effect

    if d == wx.wxDragCopy:
        print "OnData Result indicated successful copy"
    elif d == wx.wxDragMove:
        print "OnData Result indicated successful move"
    else:
        print "OnData Result indicated failed drop"
    return d

class MyApp(wx.wxApp):
def OnInit(self):
    frame = MainWindow(None, -1, "Drag and Drop Test")
    self.SetTopWindow(frame)
    return wx.true

app = MyApp(0)
app.MainLoop()

------------------------------------------------------------------------

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-users-unsubscribe@lists.wxwindows.org
For additional commands, e-mail: wxPython-users-help@lists.wxwindows.org

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-users-unsubscribe@lists.wxwindows.org
For additional commands, e-mail: wxPython-users-help@lists.wxwindows.org

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-users-unsubscribe@lists.wxwindows.org
For additional commands, e-mail: wxPython-users-help@lists.wxwindows.org

David_Woods4 · September 17, 2003, 2:54pm

Okay, I've now tried the code on Mac OS-X using wxPythonMac 2.4.1.2 under
MacPython 2.3, and I get the same error message as you report under Linux.

It appears to me that the event.GetPoint() method in the wxTreeCtrl's
OnBeginDrag() method is not working. On my Mac, it returns (0, 0) rather
than the current mouse position. Since that is not the correct spot on the
window, the wxTreeCtrl's HitTest method does not return the id for one of
the tree nodes, so the SelectItem() method reports, accurately, that it has
received an invalid tree item.

So it looks like event.GetPoint() is broken and that's the source of the
problem.

David Woods
Wisconsin Center for Education Research
University of Wisconsin, Madison

···

-----Original Message-----
From: Paul Yeager [mailto:pyeager@tektone.net]
Sent: Tuesday, September 16, 2003 6:13 PM
To: wxPython-users@lists.wxwindows.org
Subject: [wxPython-users] Drag and Drop Problems

I tried the TreeCtrl Drag and Drop code on the wxPython wiki, and got
the same result - the tree appears to be properly displayed, but drag
and drop does not work. The SelectItem method in OnBeginDrag is issuing
a "invalid tree item" error message.

Why is this happening? I am running RedHat 2.4.7, Python 2.3, and
wxPython 2.4.1.2.

I have also noticed that the Drga and Drop code that I have working in
the above environment does not work with Window$ 98, Python 2.3, and
wxPython 2.4.1.2. Anyone have any idea why?

David Woods wrote:

I'll try to take your questions in order:

Naturally, I immediately tried to run the demo you attached. It
presented a tree display which seemed quite functional, other than that
it does not seem to respond to drag attempts at all. It issues "invalid
tree item" messages for each attempt.

The sample I attached does not accept outside data. Since I am trying to
figure out selective dragging between tree nodes of different types, that
example allows you to drag any tree node and drop it only on the
"Collection" nodes. It doesn't accept any other kind of data. I can't

seem

to get the "invalid tree item" message you mention, so am not sure what you
are referring to there. Could that be platform-related?

In what sort of environment are you working? What OS, Python, and
wxWindows versions are you using?

OS is Windows 2000. Python is version 2.2. wxPython version is 2.4.1.2.

Are you interested in dragging items within the tree, or dropping items

from other applications, or both?

My particular interest is dragging within the tree only, at least until I
get it figured out. In my application, I use the tree control to represent
a hierarchical data structure, and use drag-and-drop within the tree to
implement a variety of different data manipulations. For example, you can
copy data between parallel nodes, which will trigger the copying of records
in the database and the corresponding addition of nodes in the tree. You
can also drag one type of node onto another as a way of signalling that the
one should be "applied to" the other, which would trigger a new record in
the database that would not be reflected in the tree because it's not a
relationship that is represented visually. So I need to know what kind of
node is being dragged and what kind of node is receiving the drop, and I
need to provide feedback to the user about when drops are legal and when
they aren't. So what I'm working on as a simplified example, which you see
the first iteration of, is something with "series" nodes and "collection"
nodes, and I am trying to enable the dragging of series nodes only onto
collection nodes and the dragging of collection nodes only onto series
nodes. I figure once I've got that figured out, I can develop everything I
need to to write that part of my application. I've got an example finished
that implements the drag-drop behavior and user feedback I want, which I
will post to the wxPython wiki (under wxTreeCtrl) within the next few

hours.

I do note that in MainWindow.OnBeginDrag(), you are creating and
converting some data, but I do not see where you associate that data
with a node on the tree. Could this be significant? In a real
application, would this not happen before a drag and drop operation
commenced?

In this simplified example, the only data I'm interested in dragging is the
node's name, which is what gets sent (as tempStr) to SetData() in the
OnBeginDrag() method. When I implement this for real, I have a data
structure attached to each tree node that identifies the proper record in
the database and that is what I will use in the dragged data object
associated with the wxDropSource(). But my example here only drags the

node

name and reports it via the print statement when it is dropped, but does
nothing to alter the tree. Gotta walk before I can run.

So take a look at the wiki in a couple of hours to see my new example that
does selective drag-and-drop of nodes within a wxTreeCtrl.

Hope this makes things clearer.

David

-----Original Message-----
From: Paul Yeager [mailto:pyeager@tektone.net]
Sent: Tuesday, September 16, 2003 2:28 PM
To: wxPython-users@lists.wxwindows.org
Subject: Re: [wxPython-users] Drag and Drop Feedback

David:

I have been struggling with drag and drop myself, so I read your message
with interest.

Naturally, I immediately tried to run the demo you attached. It
presented a tree display which seemed quite functional, other than that
it does not seem to respond to drag attempts at all. It issues "invalid
tree item" messages for each attempt.

In what sort of environment are you working? What OS, Python, and
wxWindows versions are you using?

Are you interested in dragging items within the tree, or dropping items
from other applications, or both?

I do note that in MainWindow.OnBeginDrag(), you are creating and
converting some data, but I do not see where you associate that data
with a node on the tree. Could this be significant? In a real
application, would this not happen before a drag and drop operation
commenced?

Best Regards

Paul Yeager
TekTone Sound & Signal Mfg., Inc.

David Woods wrote:

Hello all,

I am trying to implement some subtle drag-and-drop behavior, and am stuck

on

the issue of providing feedback to the user during the drag about whether
their drop will succeed.

Am I right in thinking that there is no way to look at the contents of a
wxCustomDataObject from within the wxPyDropTarget's OnDragOver method?

See, I'm trying to implement a series of behaviors in my application that
get triggered by dragging wxTreeCtrl nodes around. The various Node Types
can only be dropped on some nodes, not others, in ways that are

meaningful,

and I have implemented drag-and-drop feedback in other programming

languages

in such a way that my users can see whether the drop will be meaningful
before they let go. (This feedback is pretty important given how my app

is

designed.) I've done it by comparing characteristics of the data being
dragged to the characteristics of the potential drop target. However, I
can't seem to access anything about the data being dragged until the drop
has occurred in wxPython.

By way of illustration, I've attached a small app. It shows a tree with
several "Series" nodes and several "Collection" nodes, and at present,

I've

got the feedback mechanism working so that only "Collection" nodes will
accept data drops. What I want is to alter the wxPyDropTarget's

OnDragOver

method so that "Collections" only receive data picked up from the "Series"
part of the tree and that "Series" can accepts only "Collection" drops.

My actual application has many more node types and much more complex data
acceptance rules. Any suggestions for how I can extract the dragged data
characteristics would be greatly appreciated.

David Woods, Ph.D.
Wisconsin Center for Education Research
University of Wisconsin, Madison
http://www.transana.org

------------------------------------------------------------------------

from wxPython import wx

import cPickle

class MainWindow(wx.wxDialog):
""" This window displays a variety of GUI Widgets. """
def __init__(self,parent,id,title):
    wx.wxDialog.__init__(self,parent,-4, title, size = (320,600),

style=wx.wxDEFAULT_FRAME_STYLE|wx.wxNO_FULL_REPAINT_ON_RESIZE)

    self.SetBackgroundColour(wx.wxWHITE)

    lay = wx.wxLayoutConstraints()
    lay.top.SameAs(self, wx.wxTop, 10)
    lay.centreX.SameAs(self, wx.wxCentreX)
    lay.height.AsIs()
    lay.width.AsIs()
    self.tree = wx.wxTreeCtrl(self, -1, size=(300, 530),

style=wx.wxTR_HAS_BUTTONS)

    self.tree.SetConstraints(lay)

    lay = wx.wxLayoutConstraints()
    lay.top.SameAs(self, wx.wxBottom, -25)
    lay.centreX.SameAs(self, wx.wxCentreX)
    lay.height.AsIs()
    lay.width.AsIs()
    btn = wx.wxButton(self, wx.wxID_OK, "OK")
    btn.SetConstraints(lay)

    self.treeroot = self.tree.AddRoot('Transana Database')

    self.seriesroot = self.tree.AppendItem(self.treeroot, 'Series')

    item = self.tree.AppendItem(self.seriesroot, 'Series 1')

    item = self.tree.AppendItem(self.seriesroot, 'Series 2')

    item = self.tree.AppendItem(self.seriesroot, 'Series 3')

    self.collectionsroot = self.tree.AppendItem(self.treeroot,

'Collections')

    item = self.tree.AppendItem(self.collectionsroot, 'Collection 1')

    item = self.tree.AppendItem(self.collectionsroot, 'Collection 2')

    item = self.tree.AppendItem(self.collectionsroot, 'Collection 3')

    self.tree.Expand(self.treeroot)
    self.tree.Expand(self.seriesroot)
    self.tree.Expand(self.collectionsroot)

    # Define the Begin Drag Event
    wx.EVT_TREE_BEGIN_DRAG(self.tree, self.tree.GetId(),

self.OnBeginDrag)

    # Define the Drop Target
    dt = TestDropTarget(self.tree)
    self.tree.SetDropTarget(dt)

    self.Layout()
    self.SetAutoLayout(wx.true)

    self.ShowModal()
    self.Destroy()

def OnBeginDrag(self, event):
    """ Left Mouse Button initiates "Drag" for Clips (Sort Order, Copy,

Move) and Keywords (Assign) """

    # Items in the tree are not automatically selected with a left click.
    # We must select the item that is initially clicked manually!!
    # We do this by looking at the screen point clicked and applying the

tree's HitTest method

    sel_item, flags = self.tree.HitTest(event.GetPoint())
    self.tree.SelectItem(sel_item)

    tempStr = "%s" % (self.tree.GetItemText(sel_item))

    # Determine what Item is being "dragged", and grab it's data
    print "A node called %s is being dragged" % (tempStr)

    # Create a custom Data Type for Drag and Drop
    ddd = TestDragDropData()
    ddd.SetSource(tempStr)

    pddd = cPickle.dumps(ddd, 1)

    # Now convert it to a wxCustomDataObject for dragging and dropping
    cdo = wx.wxCustomDataObject(wx.wxCustomDataFormat('TransanaData'))
    cdo.SetData(pddd)

    # Now put the CustomDataObject into a DataObjectComposite
    tdo = wx.wxDataObjectComposite()
    tdo.Add(cdo)

    # Create a DropSource Object
    tds = wx.wxDropSource(self)
    # Associate the Data with the Drop Source Object
    tds.SetData(tdo)
    # Initiate the Drag Operation
    dragResult = tds.DoDragDrop(wx.true)

    if dragResult == wx.wxDragCopy:
        print "Result indicated successful copy"
    elif dragResult == wx.wxDragMove:
        print "Result indicated successful move"
    else:
        print "Result indicated failed drop"

class TestDragDropData(object):
def __init__(self):
    self.SourceText = ''
    self.DestText = ''

def __repr__(self):
    return "SourceText = '%s', DestText = '%s'" % (self.SourceText,

self.DestText)

def SetSource(self, txt):
    self.SourceText = txt

def SetDest(self, txt):
    self.DestText = txt

class TestDropTarget(wx.wxPyDropTarget):
def __init__(self, tree):
    wx.wxPyDropTarget.__init__(self)
    self.tree = tree

    # specify the data to accept
    self.df = wx.wxCustomDataFormat('TransanaData')
    self.cdo = wx.wxCustomDataObject(self.df)
    self.SetDataObject(self.cdo)

def OnEnter(self, x, y, d):
    print "OnEnter %s, %s, %s" % (x, y, d)
    return d

def OnLeave(self):
    print "OnLeave"
    pass

def OnDrop(self, x, y):
      print "Drop: x=%s, y=%s" % (x, y)
      (id, flag) = self.tree.HitTest((x, y))
      tempStr = self.tree.GetItemText(id)
      print "Dropped on %s." % tempStr
      return(wx.true)

def OnDragOver(self, x, y, d):
# print "OnDragOver %s, %s, %s" % (x, y, d)
    # Determine Source Characteristics
# if self.GetData():
# data = cPickle.loads(self.cdo.GetData())
# print data

    # Determine Destination Characteristics
    (id, flag) = self.tree.HitTest((x, y))
    tempStr = self.tree.GetItemText(id)

    if (tempStr[0:10] == 'Collection'): # and (data.SourceText[0:7] ==

'Series'):

       return d
    else:
       return wx.wxDragNone

def OnData(self, x, y, d):
    print "OnData %s, %s, %s" % (x, y, d)
    if self.GetData():
       data = cPickle.loads(self.cdo.GetData())
       print "Drop Data = '%s'" % (data)
       data.SetDest('Set in Destination') # data is a COPY of the data,

not the original, so this has no effect

    if d == wx.wxDragCopy:
        print "OnData Result indicated successful copy"
    elif d == wx.wxDragMove:
        print "OnData Result indicated successful move"
    else:
        print "OnData Result indicated failed drop"
    return d

class MyApp(wx.wxApp):
def OnInit(self):
    frame = MainWindow(None, -1, "Drag and Drop Test")
    self.SetTopWindow(frame)
    return wx.true

app = MyApp(0)
app.MainLoop()

------------------------------------------------------------------------

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-users-unsubscribe@lists.wxwindows.org
For additional commands, e-mail: wxPython-users-help@lists.wxwindows.org

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-users-unsubscribe@lists.wxwindows.org
For additional commands, e-mail: wxPython-users-help@lists.wxwindows.org

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-users-unsubscribe@lists.wxwindows.org
For additional commands, e-mail: wxPython-users-help@lists.wxwindows.org

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-users-unsubscribe@lists.wxwindows.org
For additional commands, e-mail: wxPython-users-help@lists.wxwindows.org

Robin · September 17, 2003, 7:21pm

David Woods wrote:

Okay, I've now tried the code on Mac OS-X using wxPythonMac 2.4.1.2 under
MacPython 2.3, and I get the same error message as you report under Linux.

It appears to me that the event.GetPoint() method in the wxTreeCtrl's
OnBeginDrag() method is not working. On my Mac, it returns (0, 0) rather
than the current mouse position. Since that is not the correct spot on the
window, the wxTreeCtrl's HitTest method does not return the id for one of
the tree nodes, so the SelectItem() method reports, accurately, that it has
received an invalid tree item.

So it looks like event.GetPoint() is broken and that's the source of the
problem.

Probably. Please enter a bug report about it.

As a workaround you can get the current position of the mouse in screen coordinants with wxGetMousePosition and then convert to client coordinants in the tree window.

···

--
Robin Dunn
Software Craftsman
http://wxPython.org Java give you jitters? Relax with wxPython!