/*
   ui/listview.cc
   This file is part of the Osirion project and is distributed under
   the terms of the GNU General Public License version 2
*/

#include "ui/listview.h"

namespace ui
{

ListView::ListView(Widget *parent) : Widget(parent)
{
	listview_scroll = 0.0f;
	listview_selecteditem = 0;
	
	set_label("listview");
	set_border(true);
	set_background(true);
	
	listview_scrollbar = new ScrollBar(this);
	listview_scrollbar->set_background(false);
	listview_scrollbar->set_border(false);
}

ListView::~ListView()
{
}

void ListView::set_scroll(float scroll)
{
	listview_scroll = scroll;
	if (listview_scroll < 0)
		listview_scroll = 0;
	
	// calculate maximal scroll size
	float nb_items = 0;
	for (Children::iterator it = children().begin(); it != children().end(); ++it) {
		if ((*it) != static_cast<Widget *>(listview_scrollbar)) {
			nb_items += 1.0f;
		}	
	}
	if (nb_items > 0.0f) {
		nb_items -= 1.0f;
	}
	if (listview_scroll > nb_items) {
		listview_scroll = nb_items;
	}
}

void ListView::inc_scroll(float scroll)
{
	set_scroll(listview_scroll + scroll);
}

void ListView::dec_scroll(float scroll)
{
	set_scroll(listview_scroll - scroll);
}
	
void ListView::resize()
{
	listview_scrollbar->set_size(font()->height(), height());
	listview_scrollbar->set_location(width() - listview_scrollbar->width(), 0);
	
	float total_height = 0;
	float visible_height = 0;
	float nb_items = 0;
	
	// reposition all children within the container
	for (Children::iterator it = children().begin(); it != children().end(); ++it) {
		if ((*it) != static_cast<Widget *>(listview_scrollbar)) {
			(*it)->set_width(width() - listview_scrollbar->width());
			
			if (nb_items - listview_scroll < 0) {
				// child widget is invisible
				(*it)->hide();
			} else if ((visible_height + (*it)->height()) > height()) {
				// child widget is invisible
				(*it)->hide();
			} else {
				// child widget is visible
				(*it)->show();
				(*it)->set_location(0, visible_height);
				visible_height += (*it)->height();
			}
			
			total_height += (*it)->height();
			nb_items += 1.0f;
			
		}
	}
	
	if (total_height > height()) {
		if (nb_items > 0.0f)
			nb_items -= 1.0f;
		listview_scrollbar->set_range(0.0f, nb_items);
		listview_scrollbar->set_value(listview_scroll);
		listview_scrollbar->show();
	} else {
		for (Children::iterator it = children().begin(); it != children().end(); ++it) {
			if ((*it) != static_cast<Widget *>(listview_scrollbar)) {
				(*it)->set_width(width());
			}
		}
		listview_scrollbar->hide();
	}
}

void ListView::deselect()
{
	listview_selecteditem = 0;
}

void ListView::select(ListItem *item)
{
	if (!item || is_child(item)) {
		listview_selecteditem = item;
	}
}

void ListView::clear()
{
	listview_scroll = 0;
	listview_selecteditem = 0;
	remove_children();
	
	listview_scrollbar = new ScrollBar(this);
	listview_scrollbar->set_background(false);
	listview_scrollbar->set_border(false);
	listview_scrollbar->set_range(0.0f, 0.0f);
	listview_scrollbar->set_value(listview_scroll);
}

ListItem *ListView::add_item(const std::string & text)
{
	return new ui::ListItem(this, text.c_str());
}

bool ListView::on_emit(Widget *sender, const Event event, void *data)
{
	if (sender == listview_scrollbar) {
		if (event == Widget::EventScrollBarChanged)  {
			listview_scroll = listview_scrollbar->value();
			resize();
		}
		return true;
		
	} else if ((sender->parent() == this) && (event == Widget::EventListItemClicked)) {
		listview_selecteditem = static_cast<ListItem *>(sender);
		emit(EventListViewChanged);
		return true;
	}
	
	return false;
}

bool ListView::on_mousewheel(const math::Vector2f & direction)
{
	if (direction.y() > 0 )
	{
		dec_scroll(1.0f);
		resize();
		return true;
	} 
	else if (direction.y() < 0) 
	{
		inc_scroll(1.0f);
		resize();

		return true;
	}
	return false;
}

bool compare_listitems_ascending(const Widget *first, const Widget *second)
{
	const ListItem *firstitem = dynamic_cast<const ListItem *>(first);
	const ListItem *seconditem = dynamic_cast<const ListItem *>(second);
	
	if (!firstitem)
		return true;
	else if (!seconditem)
		return false;
	
	if (firstitem->sortkey() < seconditem->sortkey()) {
		return true;
	} else if (firstitem->sortkey() > seconditem->sortkey()) {
		return false;
	} else {
		return (firstitem->sortkey().length() < seconditem->sortkey().length());
	}
}


bool compare_listitems_descending(const Widget *first, const Widget *second)
{
	const ListItem *firstitem = dynamic_cast<const ListItem *>(first);
	const ListItem *seconditem = dynamic_cast<const ListItem *>(second);

	if (!firstitem)
		return true;
	else if (!seconditem)
		return false;
	
	if (firstitem->sortkey() < seconditem->sortkey()) {
		return false;
	} else if (firstitem->sortkey() > seconditem->sortkey()) {
		return true;
	} else {
		return (firstitem->sortkey().length() > seconditem->sortkey().length());
	}
}

void ListView::sort(bool ascending)
{
	if (ascending) {
		children().sort(compare_listitems_ascending);
	} else {
		children().sort(compare_listitems_descending);
	}
}

}