/*
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   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, or (at your option)
   any later version.

   ### File Specific:
   main-programmer: Benjamin Grauer
   co-programmer: ...
*/

#define DEBUG_SPECIAL_MODULE DEBUG_MODULE_GUI

#include "glgui_slider.h"
#include "event_def.h"

#include "glgui_handler.h"

namespace OrxGui
{

  /**
   * @brief standard constructor
   */
  GLGuiSlider::GLGuiSlider ()
  {
    this->init();

  }


  /**
   * @brief standard deconstructor
   */
  GLGuiSlider::~GLGuiSlider()
  {}

  /**
   * @brief initializes the GUI-element
   */
  void GLGuiSlider::init()
  {

    this->setClassID(CL_GLGUI_SLIDER, "GLGuiSlider");

    this->setClickable( );
    this->setFocusable( );

    this->_value = 0.0;
    this->_minValue = 0.0;
    this->_maxValue = 1.0;
    this->_step = 0.1;
    this->_sliderWidth = 5.0;
    this->grabbed = false;

    this->setSize2D(100, 30);
    this->resize();
  }

  /**
   * @param value the new Value.
   * @note will automatically be set between max() and min()
   */
  void GLGuiSlider::setValue(float value)
  {
    if (value < this->min())
      this->_value = min();
    else if (value > max())
      this->_value = max();
    else
      this->_value = value;
    emit(valueChanged(this->_value));
  }

  /**
   * @param minimum the minumum of the range.
   *
   * @note will rearange value if necessary and will not be made bigger than max()
   */
  void GLGuiSlider::setMin(float minimum)
  {
    if (minimum <= max())
    {
      this->_minValue = minimum;
      emit(rangeChanged(this->_minValue, this->_maxValue));
    }
    if (this->value() < this->min())
      this->setValue(this->min());
  }


  /**
   * @param maximum the maximum of the range.
   *
   * @note will rearange value if necessary and will not be made smaller than min()
   */
  void GLGuiSlider::setMax(float maximum)
  {
    if (maximum >= min())
    {
      this->_maxValue = maximum;
      emit(rangeChanged(this->_minValue, this->_maxValue));
    }
    if (this->value() > this->max())
      this->setValue(this->max());
  }

  /**
   * @param minimum the minimum
   * @param maximum the maximum
   *
   * @see setMax
   * @see setMin
   */
  void GLGuiSlider::setRange(float minimum, float maximum)
  {
    if (minimum < maximum)
    {
      this->_minValue = minimum;
      this->_maxValue = maximum;
      emit(rangeChanged(this->_minValue, this->_maxValue));
    }
    if (this->value() < this->min())
      this->setValue(this->min());
    else if (this->value() > this->max())
      this->setValue(this->max());
  }

  /**
   * @brief sets the stepSize
   */
  void GLGuiSlider::setStep(float step)
  {
    this->_step = step;
  }

  /**
   * @brief makes one step into the minus direction
   */
  void GLGuiSlider::stepMinus()
  {
    this->setValue(value() - step());
  }

  /**
   * @brief makes one step into the minus direction
   */
  void GLGuiSlider::stepPlus()
  {
    this->setValue(value() + step());
  }

  /**
   * @brief resizes the Slider, and through this Synchronizes the GUI-size.
   */
  void GLGuiSlider::resize()
  {
    GLGuiWidget::resize();
    this->frontRect().setTopLeft(this->borderLeft(), this->getSizeY2D()/2.0 - 2.0);
    this->frontRect().setSize(this->getSizeX2D() - borderLeft() - borderRight(), 4.0);
  }

  /**
   * @brief handle the clicked event.
   * @param pos the position the Click occured (from the topleft corner out)
   */
  void GLGuiSlider::clicking(const Vector2D& pos)
  {
    GLGuiWidget::clicking(pos);

    float sliderPosition = this->sliderPosition();
    if (sliderPosition > pos.x + this->_sliderWidth)
      this->setValue(this->value() - this->step());

    else if (sliderPosition < pos.x - this->_sliderWidth)
      this->setValue(this->value() + this->step());
    else
      this->grabbed = true;
  }

  void GLGuiSlider::releasing(const Vector2D& pos)
  {
    GLGuiWidget::releasing(pos);
    this->grabbed = false;
  }

  void GLGuiSlider::removedFocus()
  {
    GLGuiWidget::removedFocus();
    this->grabbed = false;
  }

  /**
   * @returns the current SliderPosition calculated from the current value and the Silders' size.
   */
  float GLGuiSlider::sliderPosition() const
  {
    return (this->_value - this->_minValue)/( this->_maxValue - this->_minValue) *
           (this->getSizeX2D() - (borderLeft() + borderRight() + 2.0*_sliderWidth)) +
           (borderLeft() +_sliderWidth);
  }

  /**
   * @param position the position relative from the left border.
   * @returns the Value at the given position.
   */
  float GLGuiSlider::sliderValue(float position) const
  {
    return (position - (borderLeft()+_sliderWidth)) / (this->getSizeX2D() - (borderLeft() + borderRight() + 2.0*_sliderWidth))
           *( this->_maxValue - this->_minValue) +
           this->_minValue ;
  }

  void GLGuiSlider::tick(float dt)
  {
  }

  /**
   * @brief draws the GLGuiSlider
   */
  void GLGuiSlider::draw() const
  {
    this->beginDraw();
    GLGuiWidget::draw();

    this->frontMaterial().select();
    this->drawRect(this->frontRect());

    this->drawRect(Rect2D(this->sliderPosition()-_sliderWidth/2.0, 0*this->borderTop(), _sliderWidth, this->getSizeY2D() - (borderTop() + borderBottom()) ));

    this->endDraw();
  }


  bool GLGuiSlider::processEvent( const Event& event )
  {
    if (this->grabbed && event.type == EV_MOUSE_MOTION)
    {
      this->setValue(sliderValue(GLGuiHandler::getInstance()->cursorPositionRel(this).x));
      return true;
    }
    else if (event.bPressed)
    {
      if (event.type == SDLK_LEFT)
      {
        this->stepMinus();
        return true;
      }
      else if (event.type == SDLK_RIGHT)
      {
        this->stepPlus();
        return true;
      }
    }
    return false;
  }
}