add new code for generic select next/previous row ops in a treeview

git-svn-id: svn://localhost/ardour2/branches/3.0@7849 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 224 insertions, 0 deletions

diff --git a/libs/gtkmm2ext/treeutils.cc b/libs/gtkmm2ext/treeutils.cc
new file mode 100644
index 0000000000..c81e03faea
--- /dev/null
+++ b/libs/gtkmm2ext/treeutils.cc
@@ -0,0 +1,224 @@
+/*
+    Copyright (C) 2010 Paul Davis
+
+    This program 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 2 of the License, or
+    (at your option) any later version.
+
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include "gtkmm2ext/treeutils.h"
+
+using namespace Glib;
+using namespace Gtk;
+
+void
+Gtkmm2ext::treeview_select_one (RefPtr<TreeSelection> selection, RefPtr<TreeModel> model, TreeView& view,
+                                TreeIter iter, TreePath path, TreeViewColumn* col)
+{
+        if (!view.row_expanded (path)) {
+                // cerr << "!! selecting a row that isn't expanded! " << path.to_string() << endl;
+        }
+
+        selection->unselect_all ();
+        view.set_cursor (path, *col, true);
+}
+
+void
+Gtkmm2ext::treeview_select_previous (TreeView& view, RefPtr<TreeModel> model, TreeViewColumn* col)
+{
+	RefPtr<TreeSelection> selection = view.get_selection();
+	TreeView::Selection::ListHandle_Path rows = selection->get_selected_rows ();
+
+	if (selection->count_selected_rows() == 0 || !col || model->children().size() < 2) {
+		return;
+	}
+
+	TreeView::Selection::ListHandle_Path::iterator i = rows.begin();
+        TreeModel::Path start = *i;
+        TreePath prev = start;
+        TreeIter iter;
+
+        iter = model->get_iter (prev);
+
+        if (iter == model->children().begin()) {
+
+                /* at the start, go to the end */
+
+                TreeIter x = iter;
+                while (iter != model->children().end()) {
+                        x = iter;
+                        iter++;
+                }
+
+                /* "x" is now an iterator for the last row */
+
+                iter = x;
+                prev = model->get_path (iter);
+
+        } else {
+                
+                prev.prev();
+        }
+
+        if (prev == start) {
+                /* can't go back, go up */
+
+                if (!prev.empty()) {
+                        prev.up ();
+                }
+        }
+
+        iter = model->get_iter (prev);
+
+        if (iter) {
+
+                treeview_select_one (selection, model, view, iter, prev, col);
+
+        } else {
+
+                /* can't move to previous, so restart at selected and move up the tree */
+
+                prev = start;
+                prev.up ();
+
+                if (!prev.empty()) {
+                        iter = model->get_iter (prev);
+
+                        if (!iter) {
+                                /* can't move up the tree*/
+                                return;
+                        } else {
+                                /* moved up from child to parent, now move to ??? */
+                                prev.prev();
+                        }
+
+                        iter = model->get_iter (prev);
+                }
+                
+                if (iter) {
+                        treeview_select_one (selection, model, view, iter, prev, col);
+                } else {
+
+                        /* we could not forward, so wrap around to the first row */
+
+                        /* grr: no nice way to get an iter for the 
+                           last row, because there is no operator--
+                           for TreeIter
+                        */
+
+                        TreeIter x = model->children().begin();
+                        TreeIter px = x;
+                        while (x != model->children().end()) {
+                                px = x;
+                                x++;
+                        }
+                        prev = model->get_path (px);
+                        treeview_select_one (selection, model, view, px, prev, col);
+                }
+        }
+}
+
+void
+Gtkmm2ext::treeview_select_next (TreeView& view, RefPtr<TreeModel> model, TreeViewColumn* col)
+{
+	RefPtr<TreeSelection> selection = view.get_selection();
+	TreeView::Selection::ListHandle_Path rows = selection->get_selected_rows ();
+
+	if (selection->count_selected_rows() == 0 || !col || model->children().size() < 2) {
+		return;
+	}
+
+        /* start with the last selected row, not the first */
+
+	TreeView::Selection::ListHandle_Path::iterator i = rows.begin();
+	TreeView::Selection::ListHandle_Path::iterator p = i;
+
+        /* get the last selected row */
+
+        while (i != rows.end()) {
+                p = i;
+                ++i;
+        }
+
+        TreeModel::Path start = *p;
+        TreePath next = start;
+        TreeIter iter;
+
+        /* if the row we intend to start from has children but it is not expanded,
+           do not try to go down.
+        */
+
+        iter = model->get_iter (start);
+
+        TreeRow row = (*iter);
+        bool down_allowed = true;
+
+        if (!row.children().empty()) {
+                TreePath tp = model->get_path (iter);
+
+                if (!view.row_expanded (tp)) {
+                        down_allowed = false;
+                }
+        }
+
+        start = next;
+
+        if (down_allowed) {
+                next.down ();
+                TreeIter iter = model->get_iter (next);
+                if (!iter) {
+                        /* can't go down, so move to next */
+                        next = start;
+                        next.next ();
+                }
+        } else {
+                next.next ();
+        }
+
+        iter = model->get_iter (next);
+
+        if (iter) {
+
+                treeview_select_one (selection, model, view, iter, next, col);
+
+        } else {
+
+                /* can't move down/next, so restart at selected and move up the tree */
+
+                next = start;
+                next.up ();
+
+                if (!next.empty()) {
+                        iter = model->get_iter (next);
+
+                        if (!iter) {
+                                /* can't move up the tree*/
+                                return;
+                        } else {
+                                /* moved up from child to parent, now move to next */
+                                next.next();
+                        }
+
+                        iter = model->get_iter (next);
+                }
+                
+                if (iter) {
+                        treeview_select_one (selection, model, view, iter, next, col);
+                } else {
+                        /* we could not forward, so wrap around to the first row */
+                        next = model->get_path (model->children().begin());
+                        treeview_select_one (selection, model, view, model->children().begin(), next, col);
+                }
+        }
+}