Prevent drop to first row of TreeView

[jeffb]

I am trying to prevent drops to the first line of a treeview. My code is basically working, but I would like for the drag icon to change when I move over the first line to indicate that a drop is not permitted there. I set action to “0 to indicate that a drop will not be accepted” (as per documentation), but that setting does not affect the icon. Any suggestions?

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk, Gdk

class DragWindow(Gtk.Window):
    def __init__(self):
        super().__init__()
        self.set_default_size(300, 200)
        self.connect('destroy', Gtk.main_quit)

        hbox = Gtk.Box()
        hbox.set_orientation(Gtk.Orientation.HORIZONTAL)

        button = Gtk.Button.new_with_label('Label')
        hbox.pack_start(button, False, False, 0)

        model = Gtk.ListStore.new([str])
        treeview = Gtk.TreeView.new_with_model(model)
        model.append(('row 1',))
        model.append(('row 2',))

        label = Gtk.Label.new('drop in this column')
        label.show()

        renderer = Gtk.CellRendererText()
        renderer.set_alignment(0.5, 0.5)

        col = Gtk.TreeViewColumn('', renderer, text=0)
        col.set_widget(label)
        col.set_alignment(0.5)
        treeview.append_column(col)

        hbox.pack_end(treeview, True, True, 0)
        self.add(hbox)
        self.show_all()

        button.drag_source_set(
                Gdk.ModifierType.BUTTON1_MASK,
                [Gtk.TargetEntry.new('button', Gtk.TargetFlags.SAME_APP, 0)],
                Gdk.DragAction.COPY)
        treeview.enable_model_drag_dest(
                [Gtk.TargetEntry.new('button', Gtk.TargetFlags.SAME_APP, 0)],
                Gdk.DragAction.COPY)

        treeview.connect('drag-data-received', self.on_drag_data_received)
        treeview.connect('drag-motion', self.on_drag_motion)

    def on_drag_motion(self, treeview, context, x, y, time):
        dest_row = treeview.get_dest_row_at_pos(x, y)
        if dest_row is not None:
            path, position = dest_row
            if path == Gtk.TreePath.new_first() \
                    and position != Gtk.TreeViewDropPosition.AFTER:
                print('invalid position')
                Gdk.drag_status(context, 0, time)
                return False
            else:
                print('valid position')
                Gdk.drag_status(context, Gdk.DragAction.COPY, time)
                return True
        else:
            print('not in treeview')
            Gdk.drag_status(context, Gdk.DragAction.COPY, time)
            return True

    def on_drag_data_received(self, treeview, context, x, y, data, info, time):
        selection = treeview.get_selection()
        model = treeview.get_model()
        new_row = ('data',)
        dest_row = treeview.get_dest_row_at_pos(x, y)
        if dest_row is not None:
            path, position = dest_row
            if path == Gtk.TreePath.new_first() \
                    and position != Gtk.TreeViewDropPosition.AFTER:
                return

            dest_iter = model.get_iter(path)
            if position == Gtk.TreeViewDropPosition.BEFORE:
                drop_iter = model.insert_before(dest_iter, new_row)
            else:
                drop_iter = model.insert_after(dest_iter, new_row)
        else:
            drop_iter = model.append(new_row)

        selection.select_iter(drop_iter)


dragwindow = DragWindow()
Gtk.main()

[jeffb]

I found playqueue_treeview.set_drag_dest_row(path, position). It highlights the row of the current drop position. Documentation says that I should set path to None to remove the highlight. Unfortunately, the row below the drag remains highlighted. Is this feature broken, or am I doing something wrong?

One other question: When I reject a drop to the first position, how do I trigger the animation for an unsuccessful drop? context.finish(False, False, time) does not do it.