/* $Id: scrollpane.cpp 7120 2005-06-04 19:16:06Z ott $ */
/*
   Copyright (C) 2004 by Philippe Plantier <ayin@anathas.org>
   Part of the Battle for Wesnoth Project http://www.wesnoth.org

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License.
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY.

   See the COPYING file for more details.
*/

#include "../global.hpp"

#include <algorithm>

#include "scrollpane.hpp"

namespace {
class widget_finder {
public:
	widget_finder(gui::widget* w) : w_(w) {};

	bool operator()(const std::pair<int, gui::scrollpane::scrollpane_widget>& p)
	{
		if(p.second.w == w_)
			return true;
		return false;
	}
private:
	gui::widget* w_;
};
}

namespace gui {

scrollpane::scrollpane(CVideo &video) : scrollarea(video), border_(5)
{
	content_pos_.x = 0;
	content_pos_.y = 0;
	update_content_size();
	set_scroll_rate(40);
}

void scrollpane::clear()
{
	content_.clear();
	update_content_size();
}

void scrollpane::set_location(SDL_Rect const& rect)
{
	scrollarea::set_location(rect);
	set_shown_size(client_area().h);
	update_widget_positions();
}

void scrollpane::hide(bool value)
{
	for(widget_map::iterator itor = content_.begin(); itor != content_.end(); ++itor) {
		itor->second.w->hide(value);
	}
}

void scrollpane::add_widget(widget* w, int x, int y, int z_order)
{
	if (w == NULL)
		return;

	widget_map::iterator itor = std::find_if(content_.begin(), content_.end(), widget_finder(w));
	if (itor != content_.end())
		return;

	scrollpane_widget spw(w, x, y, z_order);

	w->set_clip_rect(client_area());
	content_.insert(std::pair<int, scrollpane_widget>(z_order, spw));

	position_widget(spw);

	// Recalculates the whole content size
	update_content_size();
}

void scrollpane::remove_widget(widget* w)
{
	widget_map::iterator itor = std::find_if(content_.begin(), content_.end(), widget_finder(w));

	if (itor != content_.end())
		content_.erase(itor);

	update_content_size();
}

void scrollpane::set_inner_location(const SDL_Rect& rect)
{
	for(widget_map::iterator itor = content_.begin(); itor != content_.end(); ++itor) {
		itor->second.w->set_clip_rect(client_area());
	}
}

void scrollpane::draw()
{
	//draws the scrollpane background
}

void scrollpane::scroll(int pos)
{
	if (pos == content_pos_.y)
		return;

	content_pos_.y = pos;
	update_widget_positions();
}

void scrollpane::update_widget_positions()
{

	widget_map::iterator itor;
	std::vector<bool> hidden(content_.size());
	int i = 0;
	for(itor = content_.begin(); itor != content_.end(); ++itor) {
		hidden[i++] = itor->second.w->hidden();
		itor->second.w->hide();
	}

	for(itor = content_.begin(); itor != content_.end(); ++itor) {
		position_widget(itor->second);
	}

	i = 0;
	for(itor = content_.begin(); itor != content_.end(); ++itor) {
		if (!hidden[i++])
			itor->second.w->hide(false);
	}

	set_dirty();
}

void scrollpane::position_widget(scrollpane_widget& spw)
{
	spw.w->set_location(spw.x + location().x + border_,
			spw.y + location().y - content_pos_.y + border_);
}

SDL_Rect scrollpane::client_area() const
{
	SDL_Rect res;

	res.x = location().x + border_;
	res.y = location().y + border_;
	res.w = location().w > 2 * border_ ? location().w - 2 * border_ : 0;
	res.h = location().h > 2 * border_ ? location().h - 2 * border_ : 0;

	return res;
}

void scrollpane::update_content_size()
{
	int maxx = 0;
	int maxy = 0;

	for(widget_map::iterator itor = content_.begin(); itor != content_.end(); ++itor) {
		if(itor->second.x + itor->second.w->width() > maxx) {
			maxx = itor->second.x + itor->second.w->width();
		}
		if(itor->second.y + itor->second.w->height() > maxy) {
			maxy = itor->second.y + itor->second.w->height();
		}
	}

	content_pos_.w = maxx;
	content_pos_.h = maxy;

	set_full_size(maxy);
	set_shown_size(client_area().h);

	set_dirty();
}

}
