/*
    Copyright (C) 2006 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.

    $Id: fastmeter.h 570 2006-06-07 21:21:21Z sampo $
*/


#include <iostream>
#include "gtkmm2ext/pixfader.h"
#include "gtkmm2ext/keyboard.h"
#include "gtkmm2ext/rgb_macros.h"
#include "gtkmm2ext/utils.h"

using namespace Gtkmm2ext;
using namespace Gtk;
using namespace std;

#define CORNER_RADIUS 4
#define FADER_RESERVE (2*CORNER_RADIUS)

PixFader::PixFader (
	Glib::RefPtr<Gdk::Pixbuf> belt,
	Glib::RefPtr<Gdk::Pixbuf> belt_desensitised,
	Gtk::Adjustment& adj,
	int orientation,
	int fader_length
	)
	: adjustment (adj),
	  _orien(orientation)
{
#if 0
	pixbuf[NORMAL] = belt;
	pixbuf[DESENSITISED] = belt_desensitised;
#endif
	
	pattern = 0;
	shine_pattern = 0;
	
	_hovering = false;
	dragging = false;
	default_value = adjustment.get_value();
	last_drawn = -1;

	view.x = 0;
	view.y = 0;

	if (orientation == VERT) {
		view.width = girth = 24;
	} else {
		view.height = girth = 24;
	}

	set_fader_length (fader_length);

	add_events (Gdk::BUTTON_PRESS_MASK|Gdk::BUTTON_RELEASE_MASK|Gdk::POINTER_MOTION_MASK|Gdk::SCROLL_MASK|Gdk::ENTER_NOTIFY_MASK|Gdk::LEAVE_NOTIFY_MASK);

	adjustment.signal_value_changed().connect (mem_fun (*this, &PixFader::adjustment_changed));
	adjustment.signal_changed().connect (mem_fun (*this, &PixFader::adjustment_changed));

#if 0
	for (int i = 0; i < STATES; ++i) {
		Cairo::Format format;
			
		if (pixbuf[i]->get_has_alpha()) {
			format = Cairo::FORMAT_ARGB32;
		} else {
			format = Cairo::FORMAT_RGB24;
		}

		belt_surface[i] = Cairo::ImageSurface::create (format, pixbuf[i]->get_width(), pixbuf[i]->get_height());
		belt_context[i] = Cairo::Context::create (belt_surface[i]);
		Gdk::Cairo::set_source_pixbuf (belt_context[i], pixbuf[i], 0.0, 0.0);
		belt_context[i]->paint();
	}
#endif
	
        left_r = 0;
        left_g = 0;
        left_b = 0;

        right_r = 0;
        right_g = 0;
        right_b = 0;
}

PixFader::~PixFader ()
{
}

void
PixFader::set_border_colors (uint32_t left, uint32_t right)
{
        int r, g, b;
        UINT_TO_RGB(left, &r, &g, &b);
        left_r = r/255.0;
        left_g = g/255.0;
        left_b = b/255.0;
        UINT_TO_RGB(right, &r, &g, &b);
        right_r = r/255.0;
        right_g = g/255.0;
        right_b = b/255.0;
}

void
PixFader::create_patterns ()
{
	Gdk::Color c = get_style()->get_fg (get_state());
    float r, g, b;
	r = c.get_red_p ();
	g = c.get_green_p ();
	b = c.get_blue_p ();

 	if (_orien == VERT) {
		pattern = cairo_pattern_create_linear (0.0, 0.0, get_width(), 0);
		cairo_pattern_add_color_stop_rgba (pattern, 0, r*0.8,g*0.8,b*0.8, 1.0);
		cairo_pattern_add_color_stop_rgba (pattern, 1, r*0.6,g*0.6,b*0.6, 1.0);

		shine_pattern = cairo_pattern_create_linear (0.0, 0.0, 15, 0);
		cairo_pattern_add_color_stop_rgba (shine_pattern, 0, 1,1,1,0.0);
		cairo_pattern_add_color_stop_rgba (shine_pattern, 0.2, 1,1,1,0.3);
		cairo_pattern_add_color_stop_rgba (shine_pattern, 0.5, 1,1,1,0.0);
		cairo_pattern_add_color_stop_rgba (shine_pattern, 1, 1,1,1,0.0);
	} else {
		float rheight = get_height();
	
		pattern = cairo_pattern_create_linear (0.0, 0.0, 0.0, rheight);
		cairo_pattern_add_color_stop_rgba (pattern, 0, r*0.8,g*0.8,b*0.8, 1.0);
		cairo_pattern_add_color_stop_rgba (pattern, 1, r*0.6,g*0.6,b*0.6, 1.0);

		shine_pattern = cairo_pattern_create_linear (0.0, 0.0, 0.0, rheight);
		cairo_pattern_add_color_stop_rgba (shine_pattern, 0, 1,1,1,0.0);
		cairo_pattern_add_color_stop_rgba (shine_pattern, 0.2, 1,1,1,0.3);
		cairo_pattern_add_color_stop_rgba (shine_pattern, 0.5, 1,1,1,0.0);
		cairo_pattern_add_color_stop_rgba (shine_pattern, 1, 1,1,1,0.0);
	}

	if ( !_text.empty()) {
		_layout->get_pixel_size (_text_width, _text_height);
	} else {
		_text_width = 0;
		_text_height = 0;
	}
	c = get_style()->get_text (get_state());
	text_r = c.get_red_p ();
	text_g = c.get_green_p ();
	text_b = c.get_blue_p ();
}

bool
PixFader::on_expose_event (GdkEventExpose* ev)
{
	Cairo::RefPtr<Cairo::Context> context = get_window()->create_cairo_context();
	cairo_t* cr = context->cobj();

	if (!pattern) {
		create_patterns();
	}
	
//	int const pi = get_sensitive() ? NORMAL : DESENSITISED;
	
	int ds = display_span ();

	float w = get_width();
	float h = get_height();
	float radius = CORNER_RADIUS;

	/* black border */

	cairo_set_source_rgb (cr, 0,0,0);
	cairo_rectangle (cr, 0, 0, w, h);
	cairo_fill (cr);

	/* draw active box */

	if (_orien == VERT) {
		if (ds > h - FADER_RESERVE)
			ds = h - FADER_RESERVE;

		cairo_set_source (cr, pattern);
		Gtkmm2ext::rounded_rectangle (cr, 1, 1+ds, w-2, h-(1+ds)-1, radius-1.5);
		cairo_fill (cr);

//		cairo_set_source (cr, shine_pattern);
//		Gtkmm2ext::rounded_rectangle (cr, 2, ds, w-4, h-(1+ds)-1, radius-1.5);
//		cairo_fill (cr);
	} else {
		if (ds < FADER_RESERVE)
			ds = FADER_RESERVE;

		cairo_set_source (cr, pattern);
		Gtkmm2ext::rounded_rectangle (cr, 1, 1, ds-1, h-2, radius-1.5);
		cairo_fill (cr);

//		cairo_set_source (cr, shine_pattern);
//		Gtkmm2ext::rounded_rectangle (cr, 2, 3, ds-1, 15, radius-1.5);
//		cairo_fill (cr);
	}
	
	/* draw the unity-position line if it's not at either end*/
	if (unity_loc > 0) {
		if ( _orien == VERT && unity_loc < h ) {
					context->set_line_width (1); 
					context->set_source_rgb (0.0, 1.0, 0.0);
					context->move_to (1, unity_loc);
					context->line_to (girth, unity_loc);
					context->stroke ();
		} else if ( unity_loc < w ){
					context->set_line_width (1); 
					context->set_source_rgb (0.0, 1.0, 0.0);
					context->move_to (unity_loc, 1);
					context->line_to (unity_loc, girth);
					context->stroke ();
		}
	}
	
	if ( !_text.empty() ) {

		cairo_new_path (cr);	

		/* center text */
		cairo_move_to (cr, (get_width() - _text_width)/2.0, get_height()/2.0 - _text_height/2.0);

		cairo_set_source_rgba (cr, text_r, text_g, text_b, 0.9);
		pango_cairo_show_layout (cr, _layout->gobj());
	} 
	
//	if (Config->get_widget_prelight()) {  //pixfader does not have access to config
		if (_hovering) {
			Gtkmm2ext::rounded_rectangle (cr, 0, 0, get_width(), get_height(), 3);
			cairo_set_source_rgba (cr, 0.905, 0.917, 0.925, 0.2);
			cairo_fill (cr);
		}
//	}

	last_drawn = ds;

	return true;
}

void
PixFader::on_size_request (GtkRequisition* req)
{
	req->width = view.width;
	req->height = view.height;
}

void
PixFader::on_size_allocate (Gtk::Allocation& alloc)
{
	DrawingArea::on_size_allocate(alloc);
	if (_orien == VERT) {
		view.height = span = alloc.get_height();
	} else {
		view.width = span = alloc.get_width();
	}

	update_unity_position ();
	create_patterns();
	
	queue_draw ();
}

bool
PixFader::on_button_press_event (GdkEventButton* ev)
{
	if (ev->type != GDK_BUTTON_PRESS) {
		return true;
	}

	if (ev->button != 1 && ev->button != 2) {
		return false;
	}

	add_modal_grab ();
	grab_loc = (_orien == VERT) ? ev->y : ev->x;
	grab_start = (_orien == VERT) ? ev->y : ev->x;
	grab_window = ev->window;
	dragging = true;

	if (ev->button == 2) {
		set_adjustment_from_event (ev);
	}
	
	return true;
}

bool
PixFader::on_button_release_event (GdkEventButton* ev)
{
	double const ev_pos = (_orien == VERT) ? ev->y : ev->x;
	
	switch (ev->button) {
	case 1:
		if (dragging) {
			remove_modal_grab();
			dragging = false;

			if (!_hovering) {
				Keyboard::magic_widget_drop_focus();
				queue_draw ();
			}

			if (ev_pos == grab_start) {

				/* no motion - just a click */

				if (ev->state & Keyboard::TertiaryModifier) {
					adjustment.set_value (default_value);
				} else if (ev->state & Keyboard::GainFineScaleModifier) {
					adjustment.set_value (adjustment.get_lower());
				} else if ((_orien == VERT && ev_pos < span - display_span()) || (_orien == HORIZ && ev_pos > span - display_span())) {
					/* above the current display height, remember X Window coords */
					adjustment.set_value (adjustment.get_value() + adjustment.get_step_increment());
				} else {
					adjustment.set_value (adjustment.get_value() - adjustment.get_step_increment());
				}
			}

		} 
		break;
		
	case 2:
		if (dragging) {
			remove_modal_grab();
			dragging = false;
			set_adjustment_from_event (ev);
		}
		break;

	default:
		break;
	}

	return false;
}

bool
PixFader::on_scroll_event (GdkEventScroll* ev)
{
	double scale;
	bool ret = false;

	if (ev->state & Keyboard::GainFineScaleModifier) {
		if (ev->state & Keyboard::GainExtraFineScaleModifier) {
			scale = 0.01;
		} else {
			scale = 0.05;
		}
	} else {
		scale = 0.25;
	}

	if (_orien == VERT) {

		/* should left/right scroll affect vertical faders ? */

		switch (ev->direction) {

		case GDK_SCROLL_UP:
			adjustment.set_value (adjustment.get_value() + (adjustment.get_page_increment() * scale));
			ret = true;
			break;
		case GDK_SCROLL_DOWN:
			adjustment.set_value (adjustment.get_value() - (adjustment.get_page_increment() * scale));
			ret = true;
			break;
		default:
			break;
		}
	} else {

		/* up/down scrolls should definitely affect horizontal faders
		   because they are so much easier to use
		*/

		switch (ev->direction) {

		case GDK_SCROLL_RIGHT:
		case GDK_SCROLL_UP:
			adjustment.set_value (adjustment.get_value() + (adjustment.get_page_increment() * scale));
			ret = true;
			break;
		case GDK_SCROLL_LEFT:
		case GDK_SCROLL_DOWN:
			adjustment.set_value (adjustment.get_value() - (adjustment.get_page_increment() * scale));
			ret = true;
			break;
		default:
			break;
		}
	}
	return ret;
}

bool
PixFader::on_motion_notify_event (GdkEventMotion* ev)
{
	if (dragging) {
		double scale = 1.0;
		double const ev_pos = (_orien == VERT) ? ev->y : ev->x;
		
		if (ev->window != grab_window) {
			grab_loc = ev_pos;
			grab_window = ev->window;
			return true;
		}
		
		if (ev->state & Keyboard::GainFineScaleModifier) {
			if (ev->state & Keyboard::GainExtraFineScaleModifier) {
				scale = 0.05;
			} else {
				scale = 0.1;
			}
		}

		double const delta = ev_pos - grab_loc;
		grab_loc = ev_pos;

		double fract = (delta / span);

		fract = min (1.0, fract);
		fract = max (-1.0, fract);

		// X Window is top->bottom for 0..Y
		
		if (_orien == VERT) {
			fract = -fract;
		}

		adjustment.set_value (adjustment.get_value() + scale * fract * (adjustment.get_upper() - adjustment.get_lower()));
	}

	return true;
}

void
PixFader::adjustment_changed ()
{
	if (display_span() != last_drawn) {
		queue_draw ();
	}
}

/** @return pixel offset of the current value from the right or bottom of the fader */
int
PixFader::display_span ()
{
	float fract = (adjustment.get_value () - adjustment.get_lower()) / ((adjustment.get_upper() - adjustment.get_lower()));
	int ds;
	if (_orien == VERT) {
		ds = (int)floor ( span * (1.0 - fract));
	} else {
		ds = (int)floor (span * fract);
	}
	
	return ds;
}

void
PixFader::set_fader_length (int l)
{
	if (_orien == VERT) {
		view.height = span = l;
	} else {
		view.width = span = l;
	}

	update_unity_position ();

	queue_draw ();
}

void
PixFader::update_unity_position ()
{
	if (_orien == VERT) {
		unity_loc = (int) rint (view.height * (1 - (default_value / (adjustment.get_upper() - adjustment.get_lower())))) - 1;
	} else {
		unity_loc = (int) rint (default_value * view.width);
	}

	queue_draw ();
}

bool
PixFader::on_enter_notify_event (GdkEventCrossing*)
{
	_hovering = true;
	Keyboard::magic_widget_grab_focus ();
	queue_draw ();
	return false;
}

bool
PixFader::on_leave_notify_event (GdkEventCrossing*)
{
	if (!dragging) {
		_hovering = false;
		Keyboard::magic_widget_drop_focus();
		queue_draw ();
	}
	return false;
}

void
PixFader::set_adjustment_from_event (GdkEventButton* ev)
{
	double fract = (_orien == VERT) ? (1.0 - (ev->y / span)) : (ev->x / span);

	fract = min (1.0, fract);
	fract = max (0.0, fract);

	adjustment.set_value (fract * (adjustment.get_upper () - adjustment.get_lower ()));
}

void
PixFader::set_default_value (float d)
{
	default_value = d;
	update_unity_position ();
}

void
PixFader::set_text (const std::string& str)
{
	_text = str;

 	if (!_layout && !_text.empty()) {
		_layout = Pango::Layout::create (get_pango_context());
	} 

	if (_layout) {
		_layout->set_text (str);
	}

	queue_resize ();
}