/* Copyright 2005 Nicholas Bishop
 * 
 * This file is part of SharpConstruct.
 *
 * SharpConstruct 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.
 *
 * SharpConstruct 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 SharpConstruct; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include "Slider.hh"
#include "Utilities.h"
#include <gtkmm/adjustment.h>
#include <gtkmm/style.h>
#include <cmath>

#include <iostream>

using SharpConstruct::GInterface::Slider;

Slider::Slider()
: start_( 0 ), snap_( true ), in_slide_( false )
{
	show();

	get_adjustment()->set_lower( -100 );
	get_adjustment()->set_upper( 100 );
}

Slider::Slider( const double l, const double h )
: start_( 0 ), snap_( true ), in_slide_( false )
{
	show();

	get_adjustment()->set_lower( l );
	get_adjustment()->set_upper( h );
}

double Slider::Start() const
{
	return start_;
}

bool Slider::Snap() const
{
	return snap_;
}

double Slider::Range() const
{
	return get_adjustment()->get_upper() -
		get_adjustment()->get_lower();
}

bool Slider::InSlide() const
{
	return in_slide_;
}

Slider::SliderSignal& Slider::SignalStart()
{
	return signal_start_;
}
Slider::SliderSignal& Slider::SignalContinue()
{
	return signal_continue_;
}
Slider::SliderSignal& Slider::SignalEnd()
{
	return signal_end_;
}

bool Slider::on_button_press_event( GdkEventButton* e )
{
	mouse_down_x_ = e->x + get_allocation().get_x();
	start_slide_();

	queue_draw();

	return true;
}

bool Slider::on_button_release_event( GdkEventButton* e )
{
	end_slide_();

	queue_draw();

	return true;
}

bool Slider::on_expose_event( GdkEventExpose* e )
{
	Glib::RefPtr< Gtk::Style > style( Gtk::Style::create() );

	const Glib::RefPtr< Gdk::Window > wnd( get_window() );
	const Gdk::Rectangle area( get_allocation() );

	Gtk::StateType state( sensitive() ? Gtk::STATE_ACTIVE :
			      Gtk::STATE_INSENSITIVE );

	const int x( area.get_x() );
	const int y( area.get_y() );
	const int w( get_width() );
	const int h( get_height() );

	get_style()->paint_box( wnd, state, Gtk::SHADOW_IN, area,
				*this, "trough", x, y + 7, w, h - 14 );

	const int x1( amount_to_loc_( Start() ) );
	const int x2( amount_to_loc_( get_value() ) );
	int start_x( x1 ), width( x2 - x1 );

	if( x1 > x2 )
	{
		start_x = x2;
		width = x1 - x2;
	}

	// Make sure the button is visible
	if( width < 10 )
	    width = 10;

	Gtk::StateType mstate( Gtk::STATE_NORMAL );
	int mx, my;
	get_pointer( mx, my );
	if( in_slide_ )
		mstate = Gtk::STATE_ACTIVE;
	else if( mx < get_width() && my < get_height() )
		mstate = Gtk::STATE_PRELIGHT;

	get_style()->paint_slider( wnd, mstate, Gtk::SHADOW_OUT,
				   area, *this, "hscale", start_x, y, width, h,
				   Gtk::ORIENTATION_HORIZONTAL );

	Glib::RefPtr< Pango::Layout > layout( Pango::Layout::create
					      ( get_pango_context() ) );
	layout->set_alignment( Pango::ALIGN_RIGHT );
	layout->set_text( Glib::Ascii::dtostr( lround( get_value() ) ) );
	get_style()->paint_layout( wnd, Gtk::STATE_PRELIGHT, true,
				   area, *this, "hscale", get_width() / 2 + x,
				   y + 1, layout );

	return true;
}

bool Slider::on_motion_notify_event( GdkEventMotion* e )
{
	if( in_slide_ )
	{
		int mx, my;
		Gdk::ModifierType mask;
		get_window()->get_pointer( mx, my, mask );

		const Gdk::Rectangle area( get_allocation() );
		if( my < area.get_y() - 100 ||
		    my > area.get_y() + area.get_height() + 100 )
		{
			set_value( original_ );
		}
		else
		{
			const int delta( mx - mouse_down_x_ );
			set_value( loc_to_amount_
				   ( amount_to_loc_( original_ ) + delta ) );
		}

		continue_slide_();
	}

	queue_draw();

	return true;
}

void Slider::on_realize()
{
	Range::on_realize();
	add_events( Gdk::EXPOSURE_MASK | Gdk::POINTER_MOTION_MASK |
		    Gdk::POINTER_MOTION_HINT_MASK );
}

void Slider::on_size_request( Gtk::Requisition* r )
{
	*r = Gtk::Requisition();
	r->height = 20;
}

void Slider::start_slide_()
{
	SignalStart().emit( get_value() );

	original_ = get_value();
	in_slide_ = true;
}

void Slider::continue_slide_()
{
	SignalContinue().emit( get_value() );
}

void Slider::end_slide_()
{
	in_slide_ = false;

	if( get_value() != original_ )
		SignalEnd().emit( get_value() );

	if( Snap() )
		set_value( Start() );
}

int Slider::amount_to_loc_( const double a ) const
{
	return ( get_width() * ( a - get_adjustment()->get_lower() ) ) / Range()
		+ get_allocation().get_x();
}

double Slider::loc_to_amount_( const int l ) const
{
	return ( Range() * ( l - get_allocation().get_x() ) ) / get_width()
		+ get_adjustment()->get_lower();
}