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//$Id: treemodel_dnd.cc 836 2007-05-09 03:02:38Z jjongsma $ -*- c++ -*-
/* gtkmm example Copyright (C) 2002 gtkmm development team
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "treemodel_dnd.h"
#include <iostream>
TreeModel_Dnd::TreeModel_Dnd()
{
//We can't just call Gtk::TreeModel(m_Columns) in the initializer list
//because m_Columns does not exist when the base class constructor runs.
//And we can't have a static m_Columns instance, because that would be
//instantiated before the gtkmm type system.
//So, we use this method, which should only be used just after creation:
set_column_types(m_Columns);
}
Glib::RefPtr<TreeModel_Dnd> TreeModel_Dnd::create()
{
return Glib::RefPtr<TreeModel_Dnd>( new TreeModel_Dnd() );
}
bool
TreeModel_Dnd::row_draggable_vfunc(const Gtk::TreeModel::Path& path) const
{
// Make the value of the "draggable" column determine whether this row can
// be dragged:
//TODO: Add a const version of get_iter to TreeModel:
TreeModel_Dnd* unconstThis = const_cast<TreeModel_Dnd*>(this);
const_iterator iter = unconstThis->get_iter(path);
//const_iterator iter = get_iter(path);
if(iter)
{
Row row = *iter;
bool is_draggable = row[m_Columns.m_col_draggable];
return is_draggable;
}
return Gtk::TreeStore::row_draggable_vfunc(path);
}
bool
TreeModel_Dnd::row_drop_possible_vfunc(const Gtk::TreeModel::Path& dest,
const Gtk::SelectionData& selection_data) const
{
//Make the value of the "receives drags" column determine whether a row can be
//dragged into it:
//dest is the path that the row would have after it has been dropped:
//But in this case we are more interested in the parent row:
Gtk::TreeModel::Path dest_parent = dest;
bool dest_is_not_top_level = dest_parent.up();
if(!dest_is_not_top_level || dest_parent.empty())
{
//The user wants to move something to the top-level.
//Let's always allow that.
}
else
{
//Get an iterator for the row at this path:
//We must unconst this. This should not be necessary with a future version
//of gtkmm.
//TODO: Add a const version of get_iter to TreeModel:
TreeModel_Dnd* unconstThis = const_cast<TreeModel_Dnd*>(this);
const_iterator iter_dest_parent = unconstThis->get_iter(dest_parent);
//const_iterator iter_dest_parent = get_iter(dest);
if(iter_dest_parent)
{
Row row = *iter_dest_parent;
bool receives_drags = row[m_Columns.m_col_receivesdrags];
return receives_drags;
}
}
//You could also examine the row being dragged (via selection_data)
//if you must look at both rows to see whether a drop should be allowed.
//You could use
//TODO: Add const version of get_from_selection_data(): Glib::RefPtr<const
//Gtk::TreeModel> refThis = Glib::RefPtr<const Gtk::TreeModel>(this);
//
//Glib::RefPtr<Gtk::TreeModel> refThis =
//Glib::RefPtr<Gtk::TreeModel>(const_cast<TreeModel_Dnd*>(this));
//refThis->reference(); //, true /* take_copy */)
//Gtk::TreeModel::Path path_dragged_row;
//Gtk::TreeModel::Path::get_from_selection_data(selection_data, refThis,
//path_dragged_row);
return Gtk::TreeStore::row_drop_possible_vfunc(dest, selection_data);
}
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