Wie Drag-and-Drop und sortiert GtkTreeView in GTK3?

Question

Ich portiere liblarch, eine Bibliothek für die Handhabung von gerichteten azyklischen Graphen, von PyGTK (GTK2) zu PyGObject Introspektion (GTK3). Ich bin auf das Problem mit GtkTreeView gestoßen.

Die App, die liblarch verwendet, muss GtkTreeView nach einer Spalte sortieren, aber gleichzeitig kann der Benutzer Zeilen ziehen und ablegen, eine Zeile unter eine andere Zeile verschieben. Dazu musste ich manuell dnd_data_get() und dnd_data_receive() verarbeiten, was völlig in Ordnung ist.

Es gibt das minimale Setup für GtkTreeView, das unter PyGTK funktioniert. Zeilen werden sortiert und der Benutzer kann Zeilen verschieben.

#!/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 

Ich portierte dieses Skript in PyGObject (GTK3). Mein Code:

#!/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 

Ich bin nicht in der Lage dnd_data_receive() richtig zu behandeln, in denen es entweder nicht hervorgerufen wird oder keine Daten empfangen werden. Es schlägt fehl, immer mit dem folgenden Rückruf + seine Parameter:

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> 

Meine Frage: Wie Port, um das erste Skript pygobject (GTK3) so GtkTreeView sortiert werden können und in den gleichen Zeitreihen können sein Drag & fallen gelassen? Wie ändere ich die Handhabung von Drag-and-Drop-Callbacks, um das Drag-and-Drop-Verfahren korrekt auszuführen?

Answer 1

Erstens scheint der Fehler, den Sie erhalten, mit der Version von PyGObject zusammenhängen. Ich gebe ähnliche Fehlerinformationen wieder, bevor ich meinen Laptop mit der neuesten Ubuntu 13.04 Beta neu installiere. Aber nach der Aktualisierung ändert sich der Fehler-Callback um so etwas wie

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' 

Es gibt nur zwei kleine Probleme:

• der erste Parameter von SelectionData.set() scheint nur sein Gtk.gdk.Atom aber keine Zeichenfolge, die das in pygtk angibt.
• SelectionData hat keine 'Daten'-Attribute, sondern stattdessen eine Methode' get_data() '.

Ein Arbeitscodeausschnitt unten aufgeführten

#!/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 

den Unterschied zwischen dem Snippet oben mit dem in Ihrer Frage ist

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(',') 

Außerdem gibt es ein weiteres Beispiel für GTK + 3-Version Drag & Drop von TreeView in einem anderen Thread: unresponsive drag and drop in pygobject

Answer 2

GTG ist ein großartiges Stück Software! Aber es ist viel zu langsam, zumindest auf meinem Computer. Also habe ich eine C++ - Bibliothek geschrieben, die ein gerichteter azyklischer Graph mit einem Gtk :: TreeView anzeigt, und ich habe den Quellcode von LibLarch sehr oft untersucht.

Soweit ich weiß, teilen Python- und C++ - Bindungen von GTK die gleiche Beschränkung, von GTK selbst kommend (ich habe einmal im GTK-Quellcode gesucht, um genau zu finden, warum es so funktioniert): Wenn Sie von ziehen-und -Drop und Sortierung, Drag-and-Drop wird nicht funktionieren. Ich biete drei Dinge, die Sie dagegen tun können:

1. einen Patch zu GTK Stellen, die dnd begrenzt, wenn das Sortieren aktiviert ist, anstatt sie vollständig blockiert

2. Implementieren von selbst zu sortieren. Ganz einfach: Beginnen Sie mit dem Laden Ihrer Daten in eine sortierte Baumansicht. Ziehen Sie nun die gezogene Zeile jedes Mal, wenn der Benutzer die Position zieht und ablegt, mithilfe der Sortierfunktion an die neue Position. Aber lass die GTK-Sortierung ab.

3. Dies kann zusätzlich zu 2 getan werden, es ist ein GUI-Design-Problem: In GtkTreeView können Sie ein Element zwischen Geschwisterelemente einfügen, was in sortierten Bäumen nicht viel Sinn macht. In Bezug auf die Benutzeroberfläche ist es besser zu erlauben, nur ON-Zeilen fallenzulassen, nicht zwischen ihnen. Beispiel: Nautilus list-view funktioniert so. Die Lösung überschreibt den TreeView-DragData_received() -Standard-Handler oder besser als das im Hinblick auf Wartbarkeit: Senden Sie Ihrem Modell einen Hinweis aus der Ansicht, der dem Modell mitteilt, ob die Drop-Position ON oder BEFORE ist. Wenn die Position vor, stellen Sie Ihren Baum des drop_possible() virtuelle Überschreibung false zurück, und dann sehen Sie nicht die der Baumansicht „können Sie hier fallen“ didplay“, so dass Sie eine sauberere GUI erhalten.

2 und 3 ist, was ich in C++ mache, sollten Sie in Python leicht tun können :)

Auch eine Anmerkung zu Option 1: GtktreeView (oder war GtkTreeStore? Ich habe vergessen) blockiert einfach jeden Tropfen, wenn Sortieren ist Wenn jemand nur das repariert (du ... oder ich ...), oder schreibt zumindest eine abgeleitete Ansichtsklasse, wir haben eine saubere Standard-GUI für sortierte Bäume mit dnd-Unterstützung.