# Copyright 2008 Kevin Ryde # This file is part of Gtk2-Ex-TreeModelFilter-DragDest. # # Gtk2-Ex-TreeModelFilter-DragDest is free software; you can redistribute it # and/or modify it under the terms of the GNU General Public License as # published by the Free Software Foundation; either version 3, or (at your # option) any later version. # # Gtk2-Ex-TreeModelFilter-DragDest 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 Gtk2-Ex-TreeModelFilter-DragDest. If not, see # . package Gtk2::Ex::TreeModelFilter::DragDest; use strict; use warnings; use Gtk2; use Carp; our $VERSION = 1; use constant DEBUG => 0; # gtk_tree_drag_dest_row_drop_possible # gtk_tree_drag_dest_drag_data_received # # The two funcs are delegated to the child model the same way, just the # method used when found differs. # sub ROW_DROP_POSSIBLE { push @_, 'row_drop_possible'; goto &_drop; } sub DRAG_DATA_RECEIVED { push @_, 'drag_data_received'; goto &_drop; } sub _drop { my ($self, $path, $sel, $method) = @_; if (DEBUG) { print "Filter::DragDest ",uc($method)," to path=", $path->to_string," type=",$sel->type->name,"\n"; if ($sel->type->name eq 'GTK_TREE_MODEL_ROW') { my ($src_model, $src_path) = $sel->get_row_drag_data; print " src_model=$src_model src_path=", $src_path->to_string,", has DragDest=", $src_model->isa('Gtk2::TreeDragDest')?"yes":"no", "\n"; }} # See if there's a TreeDragDest capable child. Do this before building a # child path, since path conversions can be expensive. # my $submodel = $self; for (;;) { $submodel = $submodel->get_model || do { if (DEBUG) { print " no TreeDragDest child\n"; } return; }; if ($submodel->isa('Gtk2::TreeDragDest')) { last; } if (! $submodel->isa('Gtk2::TreeModelFilter')) { if (DEBUG) { print " no TreeDragDest child\n"; } return; } } # Same again, building $subpath. # $submodel = $self; my $subpath = $path; for (;;) { $subpath = _path_to_child_path_or_end ($submodel, $subpath) || do { if (DEBUG) { print " no subpath\n"; } return 0; }; $submodel = $submodel->get_model or return; # oops, wasn't this ok in the loop above! if ($submodel->isa('Gtk2::TreeDragDest')) { last; } if (! $submodel->isa('Gtk2::TreeModelFilter')) { return; # oops, wasn't this ok in the loop above! } } if (DEBUG) { print " drop on $submodel, path=",$subpath->to_string,"\n"; } my $ret = $submodel->$method ($subpath, $sel); if (DEBUG) { print " ", $ret?"yes":"no","\n"; } return $ret; } sub _path_to_child_path_or_end { my ($self, $path) = @_; my $subpath = $self->convert_path_to_child_path ($path); if (! $subpath) { $path = $path->copy; if ($path->up) { $subpath = $self->convert_path_to_child_path ($path); if ($subpath) { my $model = $self->get_model; my $subiter = ($subpath->get_depth == 0 ? undef : $model->get_iter ($subpath)); my $n = $model->iter_n_children ($subiter); if (DEBUG) { print " follow to end of subpath=", $subpath->to_string||'none'," n=$n\n"; } $subpath->append_index ($n); } } } return $subpath; } 1; __END__ =head1 NAME Gtk2::Ex::TreeModelFilter::DragDest -- drag destination mix-in for TreeModelFilter subclasses =head1 SYNOPSIS package MyNewFilterModel; use Gtk2; use base 'Gtk2::Ex::TreeModelFilter::DragDest'; use Glib::Object::Subclass Gtk2::TreeModelFilter::, interfaces => [ 'Gtk2::TreeDragDest' ]; =head1 DESCRIPTION C provides the following two functions to implement the C interface in a sub-class of C. ROW_DROP_POSSIBLE DRAG_DATA_RECEIVED They're designed as a multiple-inheritance mix-in, so you put C in your C<@ISA>, then add C to the C in your C (or C). For simple filter draggability you'll probably find C enough, but C lets you add draggability to sub-sub-classes of TreeModelFilter. =head2 Drop The drop strategy is simply to delegate to the filter's C. If it's not a TreeDragDest, but is another C, then its C is tried, and so downwards to the first TreeDragDest capable child. The destination path position is converted as necessary. If the drag source is the filter itself (which is usual for say dragging in a C) then the source row ends up being from the first non-filter child model. The above drop stragegy ends up on that same child, which is important for instance for a C since it only allows drags within itself. =head1 OTHER NOTES There's probably no reason C itself couldn't do this sort of drop, but as of Gtk 2.12 it doesn't. Perhaps by the time you read this it will, and you won't need this code. If your filter's "visible" function decides a newly dropped row shouldn't appear then the drop still works, but it'll look to the user like the source just disappeared. That might be confusing; or if the destination is some designated "hidden track" then it be what you want. =head1 SEE ALSO L, L =head1 HOME PAGE L =head1 COPYRIGHT Copyright 2008 Kevin Ryde Gtk2-Ex-TreeModelFilter-DragDest is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. Gtk2-Ex-TreeModelFilter-DragDest 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 Gtk2-Ex-TreeModelFilter-DragDest. If not, see L. =cut