/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
 *            knob.cc
 *
 *  Thu Feb 28 07:37:27 CET 2013
 *  Copyright 2013 Bent Bisballe Nyeng
 *  deva@aasimon.org
 ****************************************************************************/

/*
 *  This file is part of DrumGizmo.
 *
 *  DrumGizmo 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.
 *
 *  DrumGizmo 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 DrumGizmo; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */
#include "knob.h"

#include "painter.h"

#include <hugin.hpp>
#include <stdio.h>

// M_PI is not defined in math.h if __STRICT_ANSI__ is defined.
#ifdef __STRICT_ANSI__
#undef __STRICT_ANSI__
#endif
#include <math.h>

namespace GUI {

Knob::Knob(Widget *parent)
	: Widget(parent)
	, img_knob(":knob.png")
{
	state = up;

	maximum = 1.0;
	minimum = 0.0;

	currentValue = minimum;

	mouse_offset_x = 0;
}

void Knob::setValue(float value)
{
	internalSetValue(value);
}

float Knob::value()
{
	return currentValue;
}

void Knob::scrollEvent(ScrollEvent* scrollEvent)
{
	float value = currentValue - (scrollEvent->delta / 200.0);
	internalSetValue(value);
}

void Knob::mouseMoveEvent(MouseMoveEvent* mouseMoveEvent)
{
	if(state == down)
	{
		if(mouse_offset_x == (mouseMoveEvent->x + (-1 * mouseMoveEvent->y)))
		{
			return;
		}

		float dval =
			mouse_offset_x - (mouseMoveEvent->x + (-1 * mouseMoveEvent->y));
		float value = currentValue - (dval / 300.0);

		internalSetValue(value);

		mouse_offset_x = mouseMoveEvent->x + (-1 * mouseMoveEvent->y);
	}
}

void Knob::keyEvent(KeyEvent* keyEvent)
{
	if(keyEvent->direction != Direction::up)
	{
		return;
	}

	float value = currentValue;
	switch(keyEvent->keycode) {
	case Key::up:
		value += 0.01;
		break;
	case Key::down:
		value -= 0.01;
		break;
	case Key::right:
		value += 0.01;
		break;
	case Key::left:
		value -= 0.01;
		break;
	case Key::home:
		value = 0;
		break;
	case Key::end:
		value = 1;
		break;
	default:
		break;
	}

	internalSetValue(value);
}

void Knob::buttonEvent(ButtonEvent* buttonEvent)
{
	if(buttonEvent->direction == Direction::down)
	{
		state = down;
		mouse_offset_x = buttonEvent->x + (-1 * buttonEvent->y);
	}

	if(buttonEvent->direction == Direction::up)
	{
		state = up;
		mouse_offset_x = buttonEvent->x + (-1 * buttonEvent->y);
		clicked();
	}
}

void Knob::repaintEvent(RepaintEvent* repaintEvent)
{
	int diameter = (width()>height()?height():width());
	int radius = diameter / 2;
	int center_x = width() / 2;
	int center_y = height() / 2;

	Painter p(*this);

	p.clear();
	p.drawImageStretched(0, 0, img_knob, diameter, diameter);

	char buf[64];
	sprintf(buf, "%.2f", currentValue * maximum);
	p.drawText(center_x - font.textWidth(buf) / 2 + 1,
	           center_y + font.textHeight(buf) / 2 + 1, font, buf);

	// Make it start from 20% and stop at 80%
	double padval = currentValue * 0.8 + 0.1;

	double from_x = sin((-1 * padval + 1) * 2 * M_PI) * radius * 0.6;
	double from_y = cos((-1 * padval + 1) * 2 * M_PI) * radius * 0.6;

	double to_x = sin((-1 * padval + 1) * 2 * M_PI) * radius * 0.8;
	double to_y = cos((-1 * padval + 1) * 2 * M_PI) * radius * 0.8;

	// Draw "fat" line by drawing 9 lines with moved start/ending points.
	p.setColour(Colour(1, 0, 0, 1));
	for(int _x = -1; _x < 2; _x++)
	{
		for(int _y = -1; _y < 2; _y++)
		{
			p.drawLine(from_x + center_x + _x,
			           from_y + center_y + _y,
			           to_x + center_x + _x,
			           to_y + center_y + _y);
		}
	}
}

void Knob::internalSetValue(float value)
{
	if(value < minimum)
	{
	  value = minimum;
	}

	if(value > maximum)
	{
		value = maximum;
	}

	if(value == currentValue)
	{
		return;
	}

	currentValue = value;
	valueChangedNotifier(currentValue);
	repaintEvent(nullptr);
}

} // GUI::