X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Flist.cpp;h=5493947c566b025df46b6aebbe26f865f3432f3f;hb=878faa0c9283ee1e6e5e67b6ea1324cc52385742;hp=4ce35e266f4418accb2b9b2716480dc1451f20ad;hpb=df07e8f3e239b146cbc458d3cbd69758e590d255;p=libs%2Fgltk.git

diff --git a/source/list.cpp b/source/list.cpp
index 4ce35e2..5493947 100644
--- a/source/list.cpp
+++ b/source/list.cpp
@@ -1,5 +1,9 @@
+#include <msp/core/raii.h>
+#include <msp/debug/demangle.h>
 #include <msp/gl/matrix.h>
 #include <msp/gl/meshbuilder.h>
+#include <msp/input/keys.h>
+#include <msp/strings/format.h>
 #include "graphic.h"
 #include "list.h"
 #include "part.h"
@@ -12,6 +16,11 @@ using namespace std;
 namespace Msp {
 namespace GLtk {
 
+incompatible_data::incompatible_data(const type_info &ti):
+	logic_error("expected "+Debug::demangle(ti.name()))
+{ }
+
+
 List::List():
 	data(new BasicListData<string>),
 	own_data(true)
@@ -28,9 +37,21 @@ List::List(ListData &d):
 
 void List::init()
 {
+	input_type = INPUT_NAVIGATION;
+
+	item_factory = 0;
+	view_mode = LIST;
 	sel_index = -1;
-	first = 0;
+	focus_index = -1;
+	first_row = 0;
 	max_scroll = 0;
+	view_rows = 5;
+	view_columns = 5;
+	items_part = 0;
+	ignore_slider_change = false;
+	dragging = false;
+	drag_start_x = 0;
+	drag_start_y = 0;
 
 	observer = new DataObserver(*this);
 
@@ -41,55 +62,56 @@ void List::init()
 
 List::~List()
 {
+	delete item_factory;
 	delete observer;
 	if(own_data)
 		delete data;
 }
 
-void List::autosize()
+void List::autosize_special(const Part &part, Geometry &ageom) const
 {
-	autosize_rows(5);
-}
-
-void List::autosize_rows(unsigned n)
-{
-	if(!style)
-		return;
-
-	Widget::autosize();
-
-	if(const Part *items_part = style->get_part("items"))
+	if(part.get_name()=="items")
 	{
-		const Sides &margin = items_part->get_margin();
+		const Sides &margin = part.get_margin();
 
-		unsigned max_w = 0;
-		unsigned total_h = 0;
-		for(unsigned i=0; (i<n && i<items.size()); ++i)
+		unsigned items_w = 0;
+		unsigned items_h = 0;
+		for(unsigned i=0; i<items.size(); ++i)
 		{
-			items[i]->autosize();
-			const Geometry &igeom = items[i]->get_geometry();
-			max_w = max(max_w, igeom.w);
-			total_h += igeom.h;
+			Geometry igeom;
+			items[i]->autosize(igeom);
+			items_w = max(items_w, igeom.w);
+			items_h = max(items_h, igeom.h);
 		}
 
-		if(items.size()<n)
-			total_h = total_h*n/items.size();
+		if(view_mode==GRID)
+		{
+			unsigned r = view_rows;
+			unsigned c = view_columns;
+			if(r==0 && c==0)
+				r = sqrt(items.size());
+			if(r==0)
+				r = (items.size()+c-1)/c;
+			if(c==0)
+				c = (items.size()+r-1)/r;
+			items_w *= c;
+			items_h *= r;
+		}
+		else
+			items_h *= (view_rows==0 ? items.size() : view_rows);
 
-		geom.w = max(geom.w, max_w+margin.left+margin.right);
-		geom.h = max(geom.h, total_h+margin.top+margin.bottom);
+		ageom.w = max(ageom.w, items_w+margin.left+margin.right);
+		ageom.h = max(ageom.h, items_h+margin.top+margin.bottom);
 	}
-
-	check_view_range();
-	rebuild();
-}
-
-void List::autosize_all()
-{
-	autosize_rows(data->size());
+	else if(part.get_name()=="slider")
+		autosize_child(slider, part, ageom);
 }
 
 void List::set_data(ListData &d)
 {
+	if(item_factory)
+		item_factory->set_data(d);
+
 	delete observer;
 	if(own_data)
 		delete data;
@@ -98,170 +120,425 @@ void List::set_data(ListData &d)
 	own_data = false;
 	observer = new DataObserver(*this);
 
+	for(vector<Item *>::iterator i=items.begin(); i!=items.end(); ++i)
+		delete *i;
+	items.clear();
+	unsigned n_items = data->size();
+	for(unsigned i=0; i<n_items; ++i)
+	{
+		Item *item = create_item(i);
+		items.push_back(item);
+	}
+
 	items_changed();
 }
 
 void List::items_changed()
 {
-	check_view_range();
 	signal_autosize_changed.emit();
-	reposition_items();
+	mark_rebuild();
 }
 
 List::Item *List::create_item(unsigned index)
 {
-	return new BasicItem(data->get_string(index));
+	Item *item = 0;
+	if(item_factory)
+		item = item_factory->create_item(index);
+	else
+		item = new BasicItem(data->get_string(index));
+	if(static_cast<int>(index)==sel_index)
+		item->set_active(true);
+	add(*item);
+	item->autosize();
+	item->signal_autosize_changed.connect(sigc::bind(sigc::mem_fun(this, &List::item_autosize_changed), item));
+	return item;
+}
+
+void List::set_view_size(unsigned s)
+{
+	set_view_size(s, s);
+}
+
+void List::set_view_size(unsigned r, unsigned c)
+{
+	view_rows = r;
+	view_columns = c;
+	signal_autosize_changed.emit();
+}
+
+void List::set_view_all()
+{
+	set_view_size(0);
 }
 
 void List::set_selected_index(int i)
 {
-	if(i>static_cast<int>(data->size()))
+	if(i>=static_cast<int>(data->size()))
 		throw out_of_range("List::set_selected_index");
 
+	if(i==sel_index || (i<0 && sel_index<0))
+		return;
+
 	if(sel_index>=0)
 		items[sel_index]->set_active(false);
 	if(i<0)
+	{
 		sel_index = -1;
+		focus_index = -1;
+		set_input_focus(0);
+		signal_selection_cleared.emit();
+	}
 	else
 	{
 		sel_index = i;
+		focus_index = i;
 		items[sel_index]->set_active(true);
+		if(state&FOCUS)
+			set_input_focus(items[focus_index]);
 		signal_item_selected.emit(sel_index);
 	}
 }
 
+void List::set_selected_item(Widget *item)
+{
+	for(unsigned i=rows[first_row].first; (i<items.size() && items[i]->is_visible()); ++i)
+		if(item==items[i])
+			return set_selected_index(i);
+}
+
+void List::rebuild_special(const Part &part)
+{
+	if(part.get_name()=="slider")
+		reposition_child(slider, part);
+	else if(part.get_name()=="items")
+	{
+		SetFlag flag(ignore_slider_change);
+		reposition_items(true);
+		unsigned old_first_row = first_row;
+		unsigned old_max_scroll = max_scroll;
+		check_view_range();
+		if(first_row!=old_first_row || max_scroll!=old_max_scroll)
+			reposition_items(false);
+	}
+
+	Widget::rebuild_special(part);
+}
+
 void List::render_special(const Part &part, GL::Renderer &renderer) const
 {
 	if(part.get_name()=="items")
 	{
-		for(unsigned i=first; (i<items.size() && items[i]->is_visible()); ++i)
+		for(unsigned i=rows[first_row].first; (i<items.size() && items[i]->is_visible()); ++i)
 			items[i]->render(renderer);
 	}
 	else if(part.get_name()=="slider")
 		slider.render(renderer);
 }
 
+bool List::key_press(unsigned key, unsigned mod)
+{
+	if(key==Input::KEY_UP && mod==MOD_CTRL)
+		move_focus(NAV_UP, false);
+	else if(key==Input::KEY_DOWN && mod==MOD_CTRL)
+		move_focus(NAV_DOWN, false);
+	else
+		return false;
+
+	return true;
+}
+
 void List::button_press(int x, int y, unsigned btn)
 {
-	Container::button_press(x, y, btn);
-	if(click_focus && btn==1)
+	if(btn==4 || btn==5)
+	{
+		unsigned change = 3;
+		if(btn==4)
+		{
+			change = min(first_row, change);
+			slider.set_value(max_scroll-(first_row-change));
+		}
+		else if(btn==5)
+		{
+			change = min(max_scroll-first_row, change);
+			slider.set_value(max_scroll-(first_row+change));
+		}
+	}
+	else
+	{
+		Container::button_press(x, y, btn);
+		if(click_focus && btn==1)
+			set_selected_item(click_focus);
+	}
+}
+
+void List::touch_press(int x, int y, unsigned finger)
+{
+	if(finger==0)
+	{
+		dragging = true;
+		drag_start_x = x;
+		drag_start_y = y;
+	}
+}
+
+void List::touch_release(int x, int y, unsigned finger)
+{
+	if(finger==0)
+	{
+		int dx = x-drag_start_x;
+		int dy = y-drag_start_y;
+		if(dx*dx+dy*dy<25)
+		{
+			Container::touch_press(drag_start_x, drag_start_y, finger);
+			if(touch_focus)
+				set_selected_item(touch_focus);
+			Container::touch_motion(x, y, finger);
+			Container::touch_release(x, y, finger);
+		}
+		dragging = false;
+	}
+}
+
+void List::touch_motion(int, int y, unsigned finger)
+{
+	if(finger==0 && !items.empty() && dragging)
 	{
-		for(unsigned i=first; (i<items.size() && items[i]->is_visible()); ++i)
-			if(click_focus==items[i])
+		int dy = y-drag_start_y;
+		if(dy>0 && first_row<max_scroll)
+		{
+			int row_h = rows[first_row].height;
+			if(dy>row_h)
 			{
-				set_selected_index(i);
-				break;
+				drag_start_y += row_h;
+				slider.set_value(max_scroll-(first_row+1));
 			}
+		}
+		else if(dy<0 && first_row>0)
+		{
+			int row_h = rows[first_row-1].height;
+			if(-dy>row_h)
+			{
+				drag_start_y -= row_h;
+				slider.set_value(max_scroll-(first_row-1));
+			}
+		}
 	}
 }
 
-void List::on_geometry_change()
+void List::focus_in()
 {
-	reposition_slider();
-	reposition_items();
+	Container::focus_in();
+	if(focus_index>=0 && items[focus_index]->is_visible())
+		set_input_focus(items[focus_index]);
+	else
+	{
+		if(sel_index>=0 && items[sel_index]->is_visible())
+			set_focus_index(sel_index);
+		else if(!items.empty())
+			set_focus_index(rows[first_row].first);
+	}
+}
+
+bool List::navigate(Navigation nav)
+{
+	if((nav==NAV_UP || nav==NAV_DOWN || ((nav==NAV_LEFT || nav==NAV_RIGHT) && view_mode==GRID)) && !items.empty())
+		move_focus(nav, true);
+	else if(nav==NAV_ACTIVATE)
+		set_selected_index(focus_index);
+	else
+		return false;
 
-	check_view_range();
+	return true;
 }
 
 void List::on_style_change()
 {
-	if(!style)
-		return;
+	items_part = (style ? style->get_part("items") : 0);
+}
 
-	reposition_slider();
-	reposition_items();
+void List::move_focus(Navigation nav, bool select)
+{
+	if(nav==NAV_UP && view_mode==GRID)
+	{
+		unsigned row = item_index_to_row(focus_index);
+		if(row>0)
+			set_focus_index(rows[row-1].first+focus_index-rows[row].first);
+		else
+			set_focus_index(0);
+	}
+	else if(nav==NAV_DOWN && view_mode==GRID)
+	{
+		unsigned row = item_index_to_row(focus_index);
+		if(row+1<rows.size())
+			set_focus_index(rows[row+1].first+focus_index-rows[row].first);
+		else
+			set_focus_index(items.size()-1);
+	}
+	else if(nav==NAV_UP || (nav==NAV_LEFT && view_mode==GRID))
+	{
+		if(focus_index>0)
+			set_focus_index(focus_index-1);
+	}
+	else if(nav==NAV_DOWN || (nav==NAV_RIGHT && view_mode==GRID))
+	{
+		if(static_cast<unsigned>(focus_index+1)<items.size())
+			set_focus_index(focus_index+1);
+	}
 
-	check_view_range();
+	if(select)
+		set_selected_index(focus_index);
 }
 
-void List::reposition_slider()
+void List::set_focus_index(int i)
 {
-	if(!style)
-		return;
-
-	if(const Part *slider_part = style->get_part("slider"))
+	focus_index = i;
+	if(focus_index>=0)
 	{
-		Geometry sgeom = slider_part->get_geometry();
-		slider_part->get_alignment().apply(sgeom, geom, slider_part->get_margin());
-		slider.set_geometry(sgeom);
+		scroll_to_focus();
+		if(state&FOCUS)
+			set_input_focus(items[focus_index]);
 	}
 }
 
-void List::reposition_items()
+void List::item_autosize_changed(Item *item)
 {
-	if(!style)
+	item->autosize();
+	signal_autosize_changed.emit();
+	mark_rebuild();
+}
+
+void List::reposition_items(bool record_rows)
+{
+	if(!items_part)
 		return;
 
-	if(const Part *items_part = style->get_part("items"))
+	if(record_rows)
 	{
-		const Sides &margin = items_part->get_margin();
-		unsigned w = geom.w-margin.left-margin.right;
-		unsigned y = geom.h-margin.top;
-		for(unsigned i=0; i<items.size(); ++i)
+		rows.clear();
+		rows.push_back(0);
+	}
+
+	const Sides &margin = items_part->get_margin();
+	unsigned view_w = geom.w-min(geom.w, margin.left+margin.right);
+	unsigned x = 0;
+	unsigned y = 0;
+	unsigned row_h = 0;
+	for(unsigned i=0; i<items.size(); ++i)
+	{
+		const Geometry &igeom = items[i]->get_geometry();
+
+		if(view_mode!=GRID || (x>0 && x+igeom.w>view_w))
 		{
-			if(i<first || !y)
-				items[i]->set_visible(false);
-			else
+			x = 0;
+			if(y)
+				y -= row_h;
+			if(record_rows && i>0)
 			{
-				Geometry igeom = items[i]->get_geometry();
-				if(igeom.h+margin.bottom<=y)
-				{
-					items[i]->set_visible(true);
-					y -= igeom.h;
-					igeom.x = margin.left;
-					igeom.y = y;
-					igeom.w = w;
-					items[i]->set_geometry(igeom);
-				}
-				else
-				{
-					items[i]->set_visible(false);
-					y = 0;
-				}
+				rows.back().height = row_h;
+				rows.push_back(i);
 			}
+			row_h = 0;
 		}
+
+		if(first_row<rows.size() && i==rows[first_row].first)
+			y = geom.h-min(geom.h, margin.top);
+
+		if(!y)
+			items[i]->set_visible(false);
+		else if(igeom.h+margin.bottom<=y)
+		{
+			items[i]->set_visible(true);
+			unsigned iw = (view_mode==GRID ? igeom.w : view_w);
+			items[i]->set_geometry(Geometry(margin.left+x, y-igeom.h, iw, igeom.h));
+		}
+		else
+		{
+			for(unsigned j=rows.back().first; j<=i; ++j)
+				items[j]->set_visible(false);
+			y = 0;
+		}
+
+		x += igeom.w;
+		row_h = max(row_h, igeom.h);
 	}
+
+	if(record_rows)
+		rows.back().height = row_h;
 }
 
-void List::check_view_range()
+unsigned List::last_to_first_row(unsigned last) const
 {
-	if(!style)
-		return;
+	if(!items_part)
+		return last;
 
-	unsigned h = geom.h;
-	if(const Part *items_part = style->get_part("items"))
-	{
-		const Sides &margin = items_part->get_margin();
-		h -= margin.top+margin.bottom;
-	}
+	const Sides &margin = items_part->get_margin();
+	unsigned view_h = geom.h-min(geom.h, margin.top+margin.bottom);
 
-	max_scroll = items.size();
-	for(unsigned i=items.size(); i-->0; )
+	unsigned items_h = 0;
+	for(unsigned i=last; i<rows.size(); --i)
 	{
-		unsigned ih = items[i]->get_geometry().h;
-		if(ih<=h)
-		{
-			h -= ih;
-			--max_scroll;
-		}
+		items_h += rows[i].height;
+		if(items_h>view_h)
+			return min(i+1, last);
 	}
 
-	if(first>max_scroll)
-		first = max_scroll;
+	return 0;
+}
+
+unsigned List::item_index_to_row(unsigned index) const
+{
+	for(unsigned i=0; i+1<rows.size(); ++i)
+		if(rows[i+1].first>index)
+			return i;
+	return rows.size()-1;
+}
+
+void List::check_view_range()
+{
+	if(!style)
+		return;
+
+	if(items.empty())
+		max_scroll = 0;
+	else
+		max_scroll = last_to_first_row(rows.size()-1);
+
+	if(first_row>max_scroll)
+		first_row = max_scroll;
 
 	slider.set_range(0, max_scroll);
-	slider.set_value(max_scroll-first);
+	slider.set_value(max_scroll-first_row);
+}
+
+void List::scroll_to_focus()
+{
+	if(focus_index<0 || items[focus_index]->is_visible())
+		return;
+
+	unsigned focus_row = item_index_to_row(static_cast<unsigned>(focus_index));
+	if(focus_row<first_row)
+		slider.set_value(max_scroll-focus_row);
+	else
+		slider.set_value(max_scroll-last_to_first_row(focus_row));
 }
 
 void List::slider_value_changed(double value)
 {
-	if(max_scroll>0)
+	if(max_scroll>0 && !ignore_slider_change)
 	{
-		first = max_scroll-static_cast<unsigned>(value);
-		reposition_items();
+		first_row = max_scroll-static_cast<unsigned>(value);
+		mark_rebuild();
 	}
 }
 
+void List::adjust_index(int &index, int pos, int change)
+{
+	if(index>pos)
+		index += change;
+	else if(index==pos)
+		index = (change>0 ? index+change : -1);
+}
+
 
 List::DataObserver::DataObserver(List &l):
 	list(l)
@@ -269,59 +546,71 @@ List::DataObserver::DataObserver(List &l):
 	list.data->signal_item_added.connect(sigc::mem_fun(this, &DataObserver::item_added));
 	list.data->signal_item_removed.connect(sigc::mem_fun(this, &DataObserver::item_removed));
 	list.data->signal_cleared.connect(sigc::mem_fun(this, &DataObserver::cleared));
-	list.data->signal_refresh_strings.connect(sigc::mem_fun(this, &DataObserver::refresh_strings));
+	list.data->signal_refresh_item.connect(sigc::mem_fun(this, &DataObserver::refresh_item));
 }
 
 void List::DataObserver::item_added(unsigned i)
 {
-	if(list.sel_index>=static_cast<int>(i))
-		++list.sel_index;
+	adjust_index(list.sel_index, i, 1);
+	adjust_index(list.focus_index, i, 1);
 
 	Item *item = list.create_item(i);
-	list.add(*item);
 	list.items.insert(list.items.begin()+i, item);
 	list.items_changed();
 }
 
 void List::DataObserver::item_removed(unsigned i)
 {
-	if(list.sel_index>static_cast<int>(i))
-		--list.sel_index;
-	else if(list.sel_index==static_cast<int>(i))
-		list.sel_index = -1;
+	bool had_selection = (list.sel_index>=0);
+	adjust_index(list.sel_index, i, -1);
+	adjust_index(list.focus_index, i, -1);
 
 	delete list.items[i];
 	list.items.erase(list.items.begin()+i);
 	list.items_changed();
+
+	if(had_selection && list.sel_index<0)
+		list.signal_selection_cleared.emit();
 }
 
 void List::DataObserver::cleared()
 {
 	list.sel_index = -1;
+	list.focus_index = -1;
 	for(vector<Item *>::iterator i=list.items.begin(); i!=list.items.end(); ++i)
 		delete *i;
 	list.items.clear();
 	list.items_changed();
+
+	list.signal_selection_cleared.emit();
 }
 
-void List::DataObserver::refresh_strings()
+void List::DataObserver::refresh_item(unsigned i)
 {
+	delete list.items[i];
+	// Avoid stale pointer while create_item is executing
+	list.items[i] = 0;
+	list.items[i] = list.create_item(i);
 	list.items_changed();
 }
 
 
-void List::Item::autosize()
+List::Item::Item()
 {
-	Widget::autosize();
+	input_type = INPUT_NAVIGATION;
+}
 
-	if(const Part *part = style->get_part("children"))
+void List::Item::autosize_special(const Part &part, Geometry &ageom) const
+{
+	if(part.get_name()=="children")
 	{
-		const Sides &margin = part->get_margin();
+		const Sides &margin = part.get_margin();
 		for(list<Child *>::const_iterator i=children.begin(); i!=children.end(); ++i)
 		{
-			const Geometry &cgeom = (*i)->widget->get_geometry();
-			geom.w = max(geom.w, cgeom.x+cgeom.w+margin.right);
-			geom.h = max(geom.h, cgeom.y+cgeom.h+margin.top);
+			Geometry cgeom;
+			(*i)->widget->autosize(cgeom);
+			ageom.w = max(ageom.w, cgeom.x+cgeom.w+margin.right);
+			ageom.h = max(ageom.h, cgeom.y+cgeom.h+margin.top);
 		}
 	}
 }
@@ -341,30 +630,101 @@ void List::Item::render_special(const Part &part, GL::Renderer &renderer) const
 }
 
 
-List::BasicItem::BasicItem(const string &text):
-	label(text)
+void List::SimpleItem::on_style_change()
 {
-	add(label);
+	if(!style || children.empty())
+		return;
+
+	Widget *child = children.front()->widget;
+	child->autosize();
+	if(const Part *part = style->get_part("children"))
+	{
+		const Sides &margin = part->get_margin();
+		child->set_position(margin.left, margin.bottom);
+	}
+}
+
+
+void List::MultiColumnItem::check_widths(vector<unsigned> &widths) const
+{
+	if(widths.size()<children.size())
+		widths.resize(children.size(), 0);
+
+	unsigned n = 0;
+	for(list<Child *>::const_iterator i=children.begin(); i!=children.end(); ++i, ++n)
+	{
+		Geometry cgeom;
+		(*i)->widget->autosize(cgeom);
+		// TODO invent a better way to specify spacings
+		widths[n] = max(widths[n], cgeom.w+8);
+	}
 }
 
-void List::BasicItem::on_style_change()
+void List::MultiColumnItem::set_widths(const vector<unsigned> &widths)
 {
 	if(!style)
 		return;
 
-	label.autosize();
-	if(const Part *part = style->get_part("children"))
+	const Part *part = style->get_part("children");
+	if(!part)
+		return;
+
+	const Sides &margin = part->get_margin();
+	int x = margin.left;
+	unsigned n = 0;
+	for(list<Child *>::const_iterator i=children.begin(); i!=children.end(); ++i, ++n)
 	{
-		const Sides &margin = part->get_margin();
-		label.set_position(margin.left, margin.bottom);
+		(*i)->widget->set_position(x, margin.bottom);
+		x += widths[n];
 	}
 }
 
+void List::MultiColumnItem::on_style_change()
+{
+	if(!style)
+		return;
+
+	for(std::list<Child *>::const_iterator i=children.begin(); i!=children.end(); ++i)
+		(*i)->widget->autosize();
+
+	vector<unsigned> widths;
+	List *list = static_cast<List *>(parent);
+	for(vector<Item *>::const_iterator i=list->items.begin(); i!=list->items.end(); ++i)
+		if(*i!=this)
+			if(MultiColumnItem *mci = dynamic_cast<MultiColumnItem *>(*i))
+				mci->check_widths(widths);
+
+	vector<unsigned> self_widths(widths);
+	check_widths(self_widths);
+	bool update_all = false;
+	for(unsigned i=0; (!update_all && i<widths.size() && i<self_widths.size()); ++i)
+		update_all = self_widths[i]>widths[i];
+
+	if(update_all)
+	{
+		for(vector<Item *>::const_iterator i=list->items.begin(); i!=list->items.end(); ++i)
+			if(MultiColumnItem *mci = dynamic_cast<MultiColumnItem *>(*i))
+				mci->set_widths(self_widths);
+	}
+
+	set_widths(self_widths);
+}
+
+
+List::BasicItem::BasicItem(const string &text):
+	label(text)
+{
+	add(label);
+}
+
 
 List::Loader::Loader(List &l):
 	DataFile::DerivedObjectLoader<List, Widget::Loader>(l)
 {
 	add("item", &Loader::item);
+	add("view_mode", &List::view_mode);
+	add("view_size", &List::view_rows);
+	add("view_size", &List::view_rows, &List::view_columns);
 }
 
 void List::Loader::item(const string &v)
@@ -372,5 +732,17 @@ void List::Loader::item(const string &v)
 	dynamic_cast<BasicListData<string> &>(*obj.data).append(v);
 }
 
+
+void operator>>(const LexicalConverter &conv, List::ViewMode &vm)
+{
+	const string &str = conv.get();
+	if(str=="LIST")
+		vm = List::LIST;
+	else if(str=="GRID")
+		vm = List::GRID;
+	else
+		throw lexical_error(format("conversion of '%s' to List::ViewMode", str));
+}
+
 } // namespace GLtk
 } // namespace Msp