如何有拖和下降和GTK3分类GtkTreeView？(How to have drag-and-dr

我移植liblarch ，处理向无环图一库，从PyGTK的（GTK2）到PyGObject内省（GTK3）。 我跑进与GtkTreeView的问题。

该应用程序使用liblarch需要由列进行排序GtkTreeView但在同一时间，用户可以拖动和拖放行，在另一行移动行。 对于我不得不手动处理dnd_data_get()和dnd_data_receive()这是完全没问题。

没有为GtkTreeView最小的设置，其中的PyGTK下工作。 行进行排序，并且用户可以移动行。

#!/usr/bin/python
# -*- coding: utf-8 -*-

import gtk

window = gtk.Window()
window.set_size_request(300, 200)
window.connect('delete_event', lambda w,e: gtk.main_quit())

# Define Liblarch Tree

store = gtk.TreeStore(str, str)
store.insert(None, -1, ["A", "Task A"])
store.insert(None, -1, ["B", "Task B"])
store.insert(None, -1, ["C", "Task C"])
d_parent = store.insert(None, -1, ["D", "Task D"])
store.insert(d_parent, -1, ["E", "Task E"])

# Define TreeView in similar way as it happens in GTG/Liblarch_gtk
tv = gtk.TreeView()

col = gtk.TreeViewColumn()
col.set_title("Title")
render_text = gtk.CellRendererText()
col.pack_start(render_text, expand=True)
col.add_attribute(render_text, 'markup', 1)
col.set_resizable(True)
col.set_expand(True)
col.set_sort_column_id(0)
tv.append_column(col)
tv.set_property("expander-column", col)

treemodel = store

def _sort_func(model, iter1, iter2):
    """ Sort two iterators by function which gets node objects.
    This is a simple wrapper which prepares node objects and then
    call comparing function. In other case return default value -1
    """
    node_a = model.get_value(iter1, 0)
    node_b = model.get_value(iter2, 0)
    if node_a and node_b:
        sort = cmp(node_a, node_b)
    else:
        sort = -1
    return sort

treemodel.set_sort_func(1, _sort_func)
tv.set_model(treemodel)

def on_child_toggled(treemodel2, path, iter, param=None):
    """ Expand row """
    if not tv.row_expanded(path):
        tv.expand_row(path, True)

treemodel.connect('row-has-child-toggled', on_child_toggled)

tv.set_search_column(1)
tv.set_property("enable-tree-lines", False)
tv.set_rules_hint(False)


#### Drag and drop stuff

dnd_internal_target = ''
dnd_external_targets = {}

def on_drag_fail(widget, dc, result):
    print "Failed dragging", widget, dc, result

def __init_dnd():
    """ Initialize Drag'n'Drop support

    Firstly build list of DND targets:
        * name
        * scope - just the same widget / same application
        * id

    Enable DND by calling enable_model_drag_dest(), 
    enable_model-drag_source()

    It didnt use support from gtk.Widget(drag_source_set(),
    drag_dest_set()). To know difference, look in PyGTK FAQ:
    http://faq.pygtk.org/index.py?file=faq13.033.htp&req=show
    """
    #defer_select = False

    if dnd_internal_target == '':
        error = 'Cannot initialize DND without a valid name\n'
        error += 'Use set_dnd_name() first'
        raise Exception(error)

    dnd_targets = [(dnd_internal_target, gtk.TARGET_SAME_WIDGET, 0)]
    for target in dnd_external_targets:
        name = dnd_external_targets[target][0]
        dnd_targets.append((name, gtk.TARGET_SAME_APP, target))

    tv.enable_model_drag_source( gtk.gdk.BUTTON1_MASK,
        dnd_targets, gtk.gdk.ACTION_DEFAULT | gtk.gdk.ACTION_MOVE)

    tv.enable_model_drag_dest(\
        dnd_targets, gtk.gdk.ACTION_DEFAULT | gtk.gdk.ACTION_MOVE)


def on_drag_data_get(treeview, context, selection, info, timestamp):
    """ Extract data from the source of the DnD operation.

    Serialize iterators of selected tasks in format 
    <iter>,<iter>,...,<iter> and set it as parameter of DND """
    print "on_drag_data_get(", treeview, context, selection, info, timestamp

    treeselection = treeview.get_selection()
    model, paths = treeselection.get_selected_rows()
    iters = [model.get_iter(path) for path in paths]
    iter_str = ','.join([model.get_string_from_iter(iter) for iter in iters])
    selection.set(dnd_internal_target, 0, iter_str)
    print "Sending", iter_str

def on_drag_data_received(treeview, context, x, y, selection, info,\
                          timestamp):
    """ Handle a drop situation.

    First of all, we need to get id of node which should accept
    all draged nodes as their new children. If there is no node,
    drop to root node.

    Deserialize iterators of dragged nodes (see self.on_drag_data_get())
    Info parameter determines which target was used:
        * info == 0 => internal DND within this TreeView
        * info > 0 => external DND

    In case of internal DND we just use Tree.move_node().
    In case of external DND we call function associated with that DND
    set by self.set_dnd_external()
    """
    print "on_drag_data_received", treeview, context, x, y, selection, info, timestamp

    model = treeview.get_model()
    destination_iter = None
    destination_tid = None
    drop_info = treeview.get_dest_row_at_pos(x, y)
    if drop_info:
        path, position = drop_info
        destination_iter = model.get_iter(path)
        if destination_iter:
            destination_tid = model.get_value(destination_iter, 0)

    # Get dragged iter as a TaskTreeModel iter
    # If there is no selected task (empty selection.data), 
    # explictly skip handling it (set to empty list)
    if selection.data == '':
        iters = []
    else:
        iters = selection.data.split(',')

    dragged_iters = []
    for iter in iters:
        print "Info", info
        if info == 0:
            try:
                dragged_iters.append(model.get_iter_from_string(iter))
            except ValueError:
                #I hate to silently fail but we have no choice.
                #It means that the iter is not good.
                #Thanks shitty gtk API for not allowing us to test the string
                print "Shitty iter", iter
                dragged_iter = None

        elif info in dnd_external_targets and destination_tid:
            f = dnd_external_targets[info][1]

            src_model = context.get_source_widget().get_model()
            dragged_iters.append(src_model.get_iter_from_string(iter))


    for dragged_iter in dragged_iters:
        if info == 0:
            if dragged_iter and model.iter_is_valid(dragged_iter):
                dragged_tid = model.get_value(dragged_iter, 0)
                try:
                    row = []
                    for i in range(model.get_n_columns()):
                        row.append(model.get_value(dragged_iter, i))
                    #tree.move_node(dragged_tid, new_parent_id=destination_tid)
                    print "move_after(%s, %s) ~ (%s, %s)" % (dragged_iter, destination_iter, dragged_tid, destination_tid)
                    #model.move_after(dragged_iter, destination_iter)
                    model.insert(destination_iter, -1, row)
                    model.remove(dragged_iter)
                except Exception, e:
                    print 'Problem with dragging: %s' % e
        elif info in dnd_external_targets and destination_tid:    
            source = src_model.get_value(dragged_iter,0)
            # Handle external Drag'n'Drop
            f(source, destination_tid)


dnd_internal_target = 'gtg/task-iter-str'
__init_dnd()
tv.connect('drag_data_get', on_drag_data_get)
tv.connect('drag_data_received', on_drag_data_received)
tv.connect('drag_failed', on_drag_fail)

window.add(tv)
window.show_all()

tv.expand_all()
gtk.main()

# vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4

我移植这个脚本到PyGObject（GTK3）。 我的代码：

#!/usr/bin/python
# -*- coding: utf-8 -*-

from gi.repository import Gtk, Gdk

window = Gtk.Window()
window.set_size_request(300, 200)
window.connect('delete_event', lambda w,e: Gtk.main_quit())

# Define Liblarch Tree

store = Gtk.TreeStore(str, str)
store.insert(None, -1, ["A", "Task A"])
store.insert(None, -1, ["B", "Task B"])
store.insert(None, -1, ["C", "Task C"])
d_parent = store.insert(None, -1, ["D", "Task D"])
store.insert(d_parent, -1, ["E", "Task E"])

# Define TreeView in similar way as it happens in GTG/Liblarch_gtk
tv = Gtk.TreeView()

col = Gtk.TreeViewColumn()
col.set_title("Title")
render_text = Gtk.CellRendererText()
col.pack_start(render_text, expand=True)
col.add_attribute(render_text, 'markup', 1)
col.set_resizable(True)
col.set_expand(True)
col.set_sort_column_id(0)
tv.append_column(col)
tv.set_property("expander-column", col)

treemodel = store

def _sort_func(model, iter1, iter2):
    """ Sort two iterators by function which gets node objects.
    This is a simple wrapper which prepares node objects and then
    call comparing function. In other case return default value -1
    """
    node_a = model.get_value(iter1, 0)
    node_b = model.get_value(iter2, 0)
    if node_a and node_b:
        sort = cmp(node_a, node_b)
    else:
        sort = -1
    return sort

treemodel.set_sort_func(1, _sort_func)
tv.set_model(treemodel)

def on_child_toggled(treemodel2, path, iter, param=None):
    """ Expand row """
    if not tv.row_expanded(path):
        tv.expand_row(path, True)

treemodel.connect('row-has-child-toggled', on_child_toggled)

tv.set_search_column(1)
tv.set_property("enable-tree-lines", False)
tv.set_rules_hint(False)


#### Drag and drop stuff

dnd_internal_target = ''
dnd_external_targets = {}

def on_drag_fail(widget, dc, result):
    print "Failed dragging", widget, dc, result

def __init_dnd():
    """ Initialize Drag'n'Drop support

    Firstly build list of DND targets:
        * name
        * scope - just the same widget / same application
        * id

    Enable DND by calling enable_model_drag_dest(), 
    enable_model-drag_source()

    It didnt use support from Gtk.Widget(drag_source_set(),
    drag_dest_set()). To know difference, look in PyGTK FAQ:
    http://faq.pygtk.org/index.py?file=faq13.033.htp&req=show
    """
    #defer_select = False

    if dnd_internal_target == '':
        error = 'Cannot initialize DND without a valid name\n'
        error += 'Use set_dnd_name() first'
        raise Exception(error)

    dnd_targets = [(dnd_internal_target, Gtk.TargetFlags.SAME_WIDGET, 0)]
    for target in dnd_external_targets:
        name = dnd_external_targets[target][0]
        dnd_targets.append((name, Gtk.TARGET_SAME_APP, target))

    tv.enable_model_drag_source( Gdk.ModifierType.BUTTON1_MASK,
        dnd_targets, Gdk.DragAction.DEFAULT | Gdk.DragAction.MOVE)

    tv.enable_model_drag_dest(\
        dnd_targets, Gdk.DragAction.DEFAULT | Gdk.DragAction.MOVE)


def on_drag_data_get(treeview, context, selection, info, timestamp):
    """ Extract data from the source of the DnD operation.

    Serialize iterators of selected tasks in format 
    <iter>,<iter>,...,<iter> and set it as parameter of DND """
    print "on_drag_data_get(", treeview, context, selection, info, timestamp

    treeselection = treeview.get_selection()
    model, paths = treeselection.get_selected_rows()
    iters = [model.get_iter(path) for path in paths]
    iter_str = ','.join([model.get_string_from_iter(iter) for iter in iters])
    selection.set(dnd_internal_target, 0, iter_str)
    print "Sending", iter_str

def on_drag_data_received(treeview, context, x, y, selection, info,\
                          timestamp):
    """ Handle a drop situation.

    First of all, we need to get id of node which should accept
    all draged nodes as their new children. If there is no node,
    drop to root node.

    Deserialize iterators of dragged nodes (see self.on_drag_data_get())
    Info parameter determines which target was used:
        * info == 0 => internal DND within this TreeView
        * info > 0 => external DND

    In case of internal DND we just use Tree.move_node().
    In case of external DND we call function associated with that DND
    set by self.set_dnd_external()
    """
    print "on_drag_data_received", treeview, context, x, y, selection, info, timestamp

    model = treeview.get_model()
    destination_iter = None
    destination_tid = None
    drop_info = treeview.get_dest_row_at_pos(x, y)
    if drop_info:
        path, position = drop_info
        destination_iter = model.get_iter(path)
        if destination_iter:
            destination_tid = model.get_value(destination_iter, 0)

    # Get dragged iter as a TaskTreeModel iter
    # If there is no selected task (empty selection.data), 
    # explictly skip handling it (set to empty list)
    if selection.data == '':
        iters = []
    else:
        iters = selection.data.split(',')

    dragged_iters = []
    for iter in iters:
        print "Info", info
        if info == 0:
            try:
                dragged_iters.append(model.get_iter_from_string(iter))
            except ValueError:
                #I hate to silently fail but we have no choice.
                #It means that the iter is not good.
                #Thanks shitty Gtk API for not allowing us to test the string
                print "Shitty iter", iter
                dragged_iter = None

        elif info in dnd_external_targets and destination_tid:
            f = dnd_external_targets[info][1]

            src_model = context.get_source_widget().get_model()
            dragged_iters.append(src_model.get_iter_from_string(iter))


    for dragged_iter in dragged_iters:
        if info == 0:
            if dragged_iter and model.iter_is_valid(dragged_iter):
                dragged_tid = model.get_value(dragged_iter, 0)
                try:
                    row = []
                    for i in range(model.get_n_columns()):
                        row.append(model.get_value(dragged_iter, i))
                    #tree.move_node(dragged_tid, new_parent_id=destination_tid)
                    print "move_after(%s, %s) ~ (%s, %s)" % (dragged_iter, destination_iter, dragged_tid, destination_tid)
                    #model.move_after(dragged_iter, destination_iter)
                    model.insert(destination_iter, -1, row)
                    model.remove(dragged_iter)
                except Exception, e:
                    print 'Problem with dragging: %s' % e
        elif info in dnd_external_targets and destination_tid:    
            source = src_model.get_value(dragged_iter,0)
            # Handle external Drag'n'Drop
            f(source, destination_tid)


dnd_internal_target = 'gtg/task-iter-str'
__init_dnd()
tv.connect('drag_data_get', on_drag_data_get)
tv.connect('drag_data_received', on_drag_data_received)
tv.connect('drag_failed', on_drag_fail)

window.add(tv)
window.show_all()

tv.expand_all()
Gtk.main()

# vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4

我不能够处理dnd_data_receive()正确的地方要么不诱发或不接收数据。 它总是失败，出现以下回调+它的参数：

Failed dragging <TreeView object at 0xeb4370 (GtkTreeView at 0xf742a0)> <gtk.gdk.X11DragContext object at 0xf351e0 (GdkX11DragContext at 0xf96ca0)> <enum GTK_DRAG_RESULT_NO_TARGET of type GtkDragResult>

我的问题： 如何端口第一个脚本来PyGObject（GTK3），所以GtkTreeView可以进行排序，并在同一时间行可以拖和下降？ 如何改变处理拖动和拖放回调正确处理拖和下降？

Answer 1:

首先，你的错误似乎与PyGObject的版本。 我之前做重现类似的错误信息重新安装我的笔记本电脑与最新的Ubuntu 13.04测试版。 但升级后，错误回调变为像

on_drag_data_get( <TreeView object at 0x1765870 (GtkTreeView at 0x19120a0)> <gtk.gdk.X11DragContext object at 0x1765aa0 (GdkX11DragContext at 0x1988820)> <GtkSelectionData at 0x7fffb106b760> 0 21962912
Traceback (most recent call last):
  File "dnd_gtk3_org.py", line 116, in on_drag_data_get
    selection.set(dnd_internal_target, 0, iter_str)
  File "/usr/lib/python2.7/dist-packages/gi/types.py", line 113, in function
    return info.invoke(*args, **kwargs)
TypeError: argument type: Expected Gdk.Atom, but got str
on_drag_data_received <TreeView object at 0x1765870 (GtkTreeView at 0x19120a0)> <gtk.gdk.X11DragContext object at 0x1765be0 (GdkX11DragContext at 0x1988940)> 45 77 <GtkSelectionData at 0x7fffb106b6e0> 0 21962912
Traceback (most recent call last):
  File "dnd_gtk3_org.py", line 151, in on_drag_data_received
    if selection.data == '':
AttributeError: 'SelectionData' object has no attribute 'data'

只有两个小问题：

• 第一个参数SelectionData.set()似乎只能是Gtk.gdk.Atom但不是指定的字符串作为PyGTK的。
• SelectionData没有data的属性，但有一个get_data()方法来代替。

一个工作的代码片段如下

#!/usr/bin/python
# -*- coding: utf-8 -*-

from gi.repository import Gtk, Gdk

window = Gtk.Window()
window.set_size_request(300, 200)
window.connect('delete_event', Gtk.main_quit)

# Define Liblarch Tree

store = Gtk.TreeStore(str, str)
store.insert(None, -1, ["A", "Task A"])
store.insert(None, -1, ["B", "Task B"])
store.insert(None, -1, ["C", "Task C"])
d_parent = store.insert(None, -1, ["D", "Task D"])
store.insert(d_parent, -1, ["E", "Task E"])

# Define TreeView in similar way as it happens in GTG/Liblarch_gtk
tv = Gtk.TreeView()

col = Gtk.TreeViewColumn()
col.set_title("Title")
render_text = Gtk.CellRendererText()
col.pack_start(render_text, expand=True)
col.add_attribute(render_text, 'markup', 1)
col.set_resizable(True)
col.set_expand(True)
col.set_sort_column_id(0)
tv.append_column(col)
tv.set_property("expander-column", col)

treemodel = store

def _sort_func(model, iter1, iter2):
    """ Sort two iterators by function which gets node objects.
    This is a simple wrapper which prepares node objects and then
    call comparing function. In other case return default value -1
    """
    node_a = model.get_value(iter1, 0)
    node_b = model.get_value(iter2, 0)
    if node_a and node_b:
        sort = cmp(node_a, node_b)
    else:
        sort = -1
    return sort

treemodel.set_sort_func(1, _sort_func)
tv.set_model(treemodel)

def on_child_toggled(treemodel2, path, iter, param=None):
    """ Expand row """
    if not tv.row_expanded(path):
        tv.expand_row(path, True)

treemodel.connect('row-has-child-toggled', on_child_toggled)

tv.set_search_column(1)
tv.set_property("enable-tree-lines", False)
tv.set_rules_hint(False)


#### Drag and drop stuff

dnd_internal_target = ''
dnd_external_targets = {}

def on_drag_fail(widget, dc, result):
    print "Failed dragging", widget, dc, result

def __init_dnd():
    """ Initialize Drag'n'Drop support

    Firstly build list of DND targets:
        * name
        * scope - just the same widget / same application
        * id

    Enable DND by calling enable_model_drag_dest(), 
    enable_model-drag_source()

    It didnt use support from Gtk.Widget(drag_source_set(),
    drag_dest_set()). To know difference, look in PyGTK FAQ:
    http://faq.pygtk.org/index.py?file=faq13.033.htp&req=show
    """
    #defer_select = False

    if dnd_internal_target == '':
        error = 'Cannot initialize DND without a valid name\n'
        error += 'Use set_dnd_name() first'
        raise Exception(error)

    dnd_targets = [(dnd_internal_target, Gtk.TargetFlags.SAME_WIDGET, 0)]
    for target in dnd_external_targets:
        name = dnd_external_targets[target][0]
        dnd_targets.append((name, Gtk.TARGET_SAME_APP, target))

    tv.enable_model_drag_source( Gdk.ModifierType.BUTTON1_MASK,
        dnd_targets, Gdk.DragAction.DEFAULT | Gdk.DragAction.MOVE)

    tv.enable_model_drag_dest(\
        dnd_targets, Gdk.DragAction.DEFAULT | Gdk.DragAction.MOVE)


def on_drag_data_get(treeview, context, selection, info, timestamp):
    """ Extract data from the source of the DnD operation.

    Serialize iterators of selected tasks in format 
    <iter>,<iter>,...,<iter> and set it as parameter of DND """
    print "on_drag_data_get(", treeview, context, selection, info, timestamp

    treeselection = treeview.get_selection()
    model, paths = treeselection.get_selected_rows()
    iters = [model.get_iter(path) for path in paths]
    iter_str = ','.join([model.get_string_from_iter(iter) for iter in iters])
    selection.set(selection.get_target(), 0, iter_str)
    print "Sending", iter_str

def on_drag_data_received(treeview, context, x, y, selection, info,\
                          timestamp):
    """ Handle a drop situation.

    First of all, we need to get id of node which should accept
    all draged nodes as their new children. If there is no node,
    drop to root node.

    Deserialize iterators of dragged nodes (see self.on_drag_data_get())
    Info parameter determines which target was used:
        * info == 0 => internal DND within this TreeView
        * info > 0 => external DND

    In case of internal DND we just use Tree.move_node().
    In case of external DND we call function associated with that DND
    set by self.set_dnd_external()
    """
    print "on_drag_data_received", treeview, context, x, y, selection, info, timestamp

    model = treeview.get_model()
    destination_iter = None
    destination_tid = None
    drop_info = treeview.get_dest_row_at_pos(x, y)
    if drop_info:
        path, position = drop_info
        destination_iter = model.get_iter(path)
        if destination_iter:
            destination_tid = model.get_value(destination_iter, 0)

    # Get dragged iter as a TaskTreeModel iter
    # If there is no selected task (empty selection.data), 
    # explictly skip handling it (set to empty list)
    data = selection.get_data()
    if data == '':
        iters = []
    else:
        iters = data.split(',')

    dragged_iters = []
    for iter in iters:
        print "Info", info
        if info == 0:
            try:
                dragged_iters.append(model.get_iter_from_string(iter))
            except ValueError:
                #I hate to silently fail but we have no choice.
                #It means that the iter is not good.
                #Thanks shitty Gtk API for not allowing us to test the string
                print "Shitty iter", iter
                dragged_iter = None

        elif info in dnd_external_targets and destination_tid:
            f = dnd_external_targets[info][1]

            src_model = context.get_source_widget().get_model()
            dragged_iters.append(src_model.get_iter_from_string(iter))


    for dragged_iter in dragged_iters:
        if info == 0:
            if dragged_iter and model.iter_is_valid(dragged_iter):
                dragged_tid = model.get_value(dragged_iter, 0)
                try:
                    row = []
                    for i in range(model.get_n_columns()):
                        row.append(model.get_value(dragged_iter, i))
                    #tree.move_node(dragged_tid, new_parent_id=destination_tid)
                    print "move_after(%s, %s) ~ (%s, %s)" % (dragged_iter, destination_iter, dragged_tid, destination_tid)
                    #model.move_after(dragged_iter, destination_iter)
                    model.insert(destination_iter, -1, row)
                    model.remove(dragged_iter)
                except Exception, e:
                    print 'Problem with dragging: %s' % e
        elif info in dnd_external_targets and destination_tid:    
            source = src_model.get_value(dragged_iter,0)
            # Handle external Drag'n'Drop
            f(source, destination_tid)


dnd_internal_target = 'gtg/task-iter-str'
__init_dnd()
tv.connect('drag_data_get', on_drag_data_get)
tv.connect('drag_data_received', on_drag_data_received)
tv.connect('drag_failed', on_drag_fail)

window.add(tv)
window.show_all()

tv.expand_all()
Gtk.main()

# vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4

与一个在你的问题之间上述片段的差异是

116c116
<     selection.set(selection.get_target(), 0, iter_str)
---
>     selection.set(dnd_internal_target, 0, iter_str)
151,152c151
<     data = selection.get_data()
<     if data == '':
---
>     if selection.data == '':
155c154
<         iters = data.split(',')
---
>         iters = selection.data.split(',')

此外，还有为GTK + 3的版本将和降落另一个例子TreeView在另一个线程： 反应迟钝拖放在pygobject

Answer 2:

GTG是一个伟大的软件！ 但它过于缓慢，至少在我的电脑上。 所以，我一直在写这显示使用的Gtk :: TreeView的有向无环图的C ++库，我看了看LibLarch源代码了很多。

据我所知GTK的，Python和C ++绑定共享相同的限制，从GTK本身来（我曾经看着GTK源代码，找出究竟为什么它的工作原理类似）：如果你把拖和下降和排序，拖和下降将无法正常工作。 我提供的三件事情可以做：

1. 使补丁GTK时启用排序这限制了DND，而不是完全阻止它

2. 实现自己的排序。 它简单：你的数据加载到一个排序的树视图开始。 现在，每次用户拖放时，将拖行使用排序功能的新位置。 但离开GTK排序了。

3. 这可以另外做2，这是一个GUI设计问题：在GtkTreeView，你可以到同级项目，这并没有太大的意义在排序树之间插入项目。 在UI方面，最好只允许未落行，而不是它们之间。 例如：鹦鹉螺列表视图是这样工作的。 解决方法是，覆盖的TreeView drag_data_received（）默认的处理程序，或比可维护性方面更好：从告诉模型的下降位置是日或之前的观点发送您模型的提示。 如果位置之前，请对树的drop_possible（）虚拟重写返回false，然后你看不到TreeView的“你可以在这里放下”展架”，这样你会得到一个更清洁的GUI。

2和3是我在C ++中做了什么，你应该能够做到这一点在Python容易:)

此外，注：关于选项1：GtktreeView（或者是为GtkTreeStore我忘了吗？）简单地阻止任何下降，如果启用了排序。 如果有人只是修复了（你......或者我......），或至少写了一个派生视图类，我们将有一个默认的干净GUI与DND支持排序树。

文章来源: How to have drag-and-drop and sorted GtkTreeView in GTK3?