我正在移植liblarch，一个用于处理有向无环图的库，从PyGTK（GTK2）到PyGObject内省（GTK3）。我遇到了GtkTreeView的问题。
使用liblarch的应用程序需要按列对GtkTreeView进行排序，但同时，用户可以拖放行，在另一行下移动一行。为此，我必须手动处理dnd_data_get()和dnd_data_receive()，这是完全可以的。
GtkTreeView的最小设置在PyGTK下运行。行已排序，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
我将此脚本移植到PyGObject（GTK3）中。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
我无法正确处理dnd_data_receive()无法引发或未收到任何数据的地方。它始终因以下回调及其参数而失败：
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：如何将第一个脚本移植到PyGObject（GTK3），以便可以对GtkTreeView进行排序，同时可以拖放行？如何更改处理拖动和 - -drop回调以正确处理拖放？
答案 0 :(得分：5)
首先，你得到的错误似乎与PyGObject的版本有关。在使用最新的Ubuntu 13.04测试版重新安装笔记本电脑之前，我会重现类似的错误信息。但升级后，错误回调会更改为
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：
SelectionData.set()的第一个参数似乎只能是Gtk.gdk.Atom，而不是指定在pygtk中的字符串。SelectionData没有data属性，而是使用get_data()方法。下面列出的工作代码段
#!/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
上面的代码段与您问题中的代码段之间的区别是
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，还有另一个例子是GTK + 3版本在另一个帖子中拖放TreeView：unresponsive drag and drop in pygobject
答案 1 :(得分：1)
GTG是一款非常棒的软件！但它太慢了，至少在我的电脑上。所以我一直在编写一个C ++库，它使用Gtk :: TreeView显示有向无环图，我查看了很多LibLarch源代码。
据我所知，GTK的Python和C ++绑定共享相同的限制，来自GTK本身（我曾经看过GTK源代码以找到它的工作原理）：如果你转向拖动 - 和 - 删除和排序，拖放将无法正常工作。我提供了三件你可以做的事情：
为GTK制作补丁，在启用排序时限制dnd，而不是完全阻止它
自己实施排序。很简单：首先将数据加载到排序的树视图中。现在，每次用户拖放时，使用排序功能将拖动的行移动到新位置。但是让GTK排除。
这可以在2之外完成，这是一个GUI设计问题：在GtkTreeView中，您可以在兄弟项目之间插入一个项目，这在排序树中没有多大意义。在UI方面，最好只允许删除ON行，而不是BETWEEN它们。示例：Nautilus list-view的工作原理如下。解决方案是覆盖TreeView drag_data_received（）默认处理程序，或者比可维护性更好：从模型中向模型发送提示，告诉模型放置位置是ON还是BEFORE。如果位置是BEFORE，让你的树的drop_possible（）虚拟覆盖返回false，然后你没有看到树视图的“你可以放在这里”didplay“，因此你得到一个更清晰的GUI。
2和3是我在C ++中所做的，你应该能够在Python中轻松实现这一点：）
另外，关于选项1的注释：GtktreeView（或者是GtkTreeStore？我忘了）只是在启用排序时阻止任何丢弃。如果有人只是修复了（你......或者我......），或者至少编写了一个派生的视图类，我们将为有dnd支持的排序树提供一个默认的干净GUI。