/*
 * Project: MoleCuilder
 * Description: creates and alters molecular systems
 * Copyright (C)  2010 University of Bonn. All rights reserved.
 * Please see the LICENSE file or "Copyright notice" in builder.cpp for details.
 */

/*
 * GLMoleculeView.cpp
 *
 *  Created on: Aug 1, 2010
 *      Author: heber
 */

// include config.h
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "GLMoleculeView.hpp"
#include <GL/glu.h>
#include <QtGui/qslider.h>
#include <QtGui/qevent.h>

#include "ui_dialoglight.h"

#include "CodePatterns/MemDebug.hpp"

#include <iostream>
#include <boost/shared_ptr.hpp>

#include "LinearAlgebra/Line.hpp"
#include "atom.hpp"
#include "Bond/bond.hpp"
#include "element.hpp"
#include "molecule.hpp"
#include "periodentafel.hpp"
#include "World.hpp"

#if defined(Q_CC_MSVC)
#pragma warning(disable:4305) // init: truncation from const double to float
#endif


GLMoleculeView::GLMoleculeView(QWidget *parent) :
  QGLWidget(parent), Observer("GLMoleculeView"), X(Vector(1,0,0)), Y(Vector(0,1,0)), Z(Vector(0,0,1))
{
    xRot = yRot = zRot = 0.0;    // default object rotation
    scale = 5.;      // default object scale
    object = 0;
    LightPosition[0] = 0.0f;
    LightPosition[1] = 2.0f;
    LightPosition[2] = 2.0f;
    LightPosition[3] = 0.0f;
    LightDiffuse[0] = 0.5f;
    LightDiffuse[1] = 0.5f;
    LightDiffuse[2] = 0.5f;
    LightDiffuse[3] = 0.0f;
    LightAmbient[0] = 0.0f;
    LightAmbient[1] = 0.0f;
    LightAmbient[2] = 0.0f;
    LightAmbient[3] = 0.0f;

    SelectionColor[0] = 0;
    SelectionColor[1] = 128;
    SelectionColor[2] = 128;

    MultiViewEnabled = true;

    isSignaller = false;

    World::getInstance().signOn(this);
}

/** Destructor of GLMoleculeView.
 * Free's the CallList.
 */
GLMoleculeView::~GLMoleculeView()
{
    makeCurrent();
    glDeleteLists( object, 1 );

    World::getInstance().signOff(this);
}

/** Paints the conents of the OpenGL window.
 * Clears the GL buffers, enables lighting and depth.
 * Window is either quartered (if GLMoleculeView::MultiViewEnabled) and xy, xz, yz planar views
 * are added. Uses the CallList, constructed during InitializeGL().
 */
void GLMoleculeView::paintGL()
{
  Vector spot;

  glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glShadeModel(GL_SMOOTH);            // Enable Smooth Shading
  glEnable(GL_LIGHTING);              // Enable Light One
  glEnable(GL_DEPTH_TEST);            // Enables Depth Testing
  glDepthFunc(GL_LEQUAL);              // The Type Of Depth Testing To Do
  glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);      // Really Nice Perspective Calculations

  // 3d viewport
  if (MultiViewEnabled)
    glViewport( 0, 0, (GLint)width/2, (GLint)height/2 );
  else
    glViewport( 0, 0, (GLint)width, (GLint)height );
  glMatrixMode( GL_PROJECTION );
  glLoadIdentity();
  glFrustum( -1.0, 1.0, -1.0, 1.0, 1.0, 50.0 );
  glMatrixMode( GL_MODELVIEW );
  glLoadIdentity();

  // calculate point of view and direction
  glTranslated(position[0],position[1],position[2]);
  glTranslated(0.0, 0.0, -scale);
  glRotated(xRot, 1.0, 0.0, 0.0);
  glRotated(yRot, 0.0, 1.0, 0.0);
  glRotated(zRot, 0.0, 0.0, 1.0);

  // render scene
  glCallList(object);

  // enable light
  glLightfv(GL_LIGHT1, GL_AMBIENT, LightAmbient);       // Setup The Ambient Light
  glLightfv(GL_LIGHT1, GL_DIFFUSE, LightDiffuse);       // Setup The Diffuse Light
  glLightfv(GL_LIGHT1, GL_POSITION,LightPosition);      // Position The Light
  glEnable(GL_LIGHT1);              // Enable Light One

  if (MultiViewEnabled) {
    // xy view port
    glViewport( (GLint)width/2, 0, (GLint)width/2, (GLint)height/2 );
    glMatrixMode( GL_PROJECTION );
    glLoadIdentity();
    glScalef(1./scale, 1./scale,1./scale);
    glOrtho(0, width/2, 0, height/2, 0,0);
    glMatrixMode( GL_MODELVIEW );
    glLoadIdentity();

    // calculate point of view and direction
    view = position;
    spot = Vector(0.,0.,scale);
    top = Vector(0.,1.,0.);
    gluLookAt(
        spot[0], spot[1], spot[2],
        view[0], view[1], view[2],
        top[0], top[1], top[2]);

    // enable light
    glLightfv(GL_LIGHT1, GL_AMBIENT, LightAmbient);       // Setup The Ambient Light
    glLightfv(GL_LIGHT1, GL_DIFFUSE, LightDiffuse);       // Setup The Diffuse Light
    glLightfv(GL_LIGHT1, GL_POSITION,LightPosition);      // Position The Light
    glEnable(GL_LIGHT1);              // Enable Light One

    // render scene
    glCallList(object);

    // xz viewport
    glViewport( 0, (GLint)height/2, (GLint)width/2, (GLint)height/2 );
    glMatrixMode( GL_PROJECTION );
    glLoadIdentity();
    glScalef(1./scale, 1./scale,1./scale);
    glOrtho(0, width/2, 0, height/2, 0,0);
    glMatrixMode( GL_MODELVIEW );
    glLoadIdentity();

    // calculate point of view and direction
    view = position;
    spot = Vector(0.,scale,0.);
    top = Vector(1.,0.,0.);
    gluLookAt(
        spot[0], spot[1], spot[2],
        view[0], view[1], view[2],
        top[0], top[1], top[2]);

    // enable light
    glLightfv(GL_LIGHT1, GL_AMBIENT, LightAmbient);       // Setup The Ambient Light
    glLightfv(GL_LIGHT1, GL_DIFFUSE, LightDiffuse);       // Setup The Diffuse Light
    glLightfv(GL_LIGHT1, GL_POSITION,LightPosition);      // Position The Light
    glEnable(GL_LIGHT1);              // Enable Light One

    // render scene
    glCallList(object);

    //yz viewport
    glViewport( (GLint)width/2, (GLint)height/2, (GLint)width/2, (GLint)height/2 );
    glMatrixMode( GL_PROJECTION );
    glLoadIdentity();
    glScalef(1./scale, 1./scale,1./scale);
    glOrtho(0, width/2, 0, height/2, 0,0);
    glMatrixMode( GL_MODELVIEW );
    glLoadIdentity();

    // calculate point of view and direction
    view= position;
    spot = Vector(scale,0.,0.);
    top = Vector(0.,1.,0.);
    gluLookAt(
        spot[0], spot[1], spot[2],
        view[0], view[1], view[2],
        top[0], top[1], top[2]);

    // enable light
    glLightfv(GL_LIGHT1, GL_AMBIENT, LightAmbient);       // Setup The Ambient Light
    glLightfv(GL_LIGHT1, GL_DIFFUSE, LightDiffuse);       // Setup The Diffuse Light
    glLightfv(GL_LIGHT1, GL_POSITION,LightPosition);      // Position The Light
    glEnable(GL_LIGHT1);              // Enable Light One

    // render scene
    glCallList(object);
  }
  //CoordinatesBar->setText( QString ("X: %1, Y: %2, Z: %3").arg(position[0]).arg(position[1]).arg(position[2]) );
}

//void polarView{GLdouble distance, GLdouble twist,
//   GLdouble elevation, GLdouble azimuth)
//{
//      glTranslated(0.0, 0.0, -distance);
//      glRotated(-twist, 0.0, 0.0, 1.0);
//      glRotated(-elevation, 1.0, 0.0, 0.0);
//      glRotated(azimuth, 0.0, 0.0, 1.0);
//}

/** Make a sphere.
 * \param x position
 * \param radius radius
 * \param color[3] color rgb values
 */
void GLMoleculeView::makeSphere(const Vector &x, double radius, const unsigned char color[3])
{
  float blueMaterial[] = { 255./(float)color[0], 255./(float)color[1], 255./(float)color[2], 1 };  // need to recast from [0,255] with integers into [0,1] with floats
  GLUquadricObj* q = gluNewQuadric ();
  gluQuadricOrientation(q, GLU_OUTSIDE);

  std::cout << "Setting sphere at " << x << " with color r"
      << (int)color[0] << ",g" << (int)color[1] << ",b" << (int)color[2] << "." << endl;

  glPushMatrix();
  glTranslatef( x[0], x[1], x[2]);
//  glRotatef( xRot, 1.0, 0.0, 0.0);
//  glRotatef( yRot, 0.0, 1.0, 0.0);
//  glRotatef( zRot, 0.0, 0.0, 1.0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blueMaterial);
  gluSphere (q, (GLdouble)radius, 10, 10);
  glPopMatrix();
}

/** Make a cylinder.
 * \param x origin
 * \param y direction
 * \param radius thickness
 * \param height length
 * \color[3] color rgb values
 */
void GLMoleculeView::makeCylinder(const Vector &x, const Vector &y, double radius, double height, const unsigned char color[3])
{
  float blueMaterial[] = { 255./(float)color[0], 255./(float)color[1], 255./(float)color[2], 1 };
  GLUquadricObj* q = gluNewQuadric ();
  gluQuadricOrientation(q, GLU_OUTSIDE);
  Vector a,b;
  Vector OtherAxis;
  double alpha;
  a = x - y;
  // construct rotation axis
  b = a;
  b.VectorProduct(Z);
  Line axis(zeroVec, b);
  // calculate rotation angle
  alpha = a.Angle(Z);
  // construct other axis to check right-hand rule
  OtherAxis = b;
  OtherAxis.VectorProduct(Z);
  // assure right-hand rule for the rotation
  if (a.ScalarProduct(OtherAxis) < MYEPSILON)
    alpha = M_PI-alpha;
  // check
  Vector a_rotated = axis.rotateVector(a, alpha);
  std::cout << "Setting cylinder from "// << x << " to " << y
      << a << " to " << a_rotated << " around " << b << " by " << alpha/M_PI*180. << ", respectively, "
      << " with color r"
      << (int)color[0] << ",g" << (int)color[1] << ",b" << (int)color[2] << "." << endl;

  glPushMatrix();
  glTranslatef( x[0], x[1], x[2]);
  glRotatef( alpha/M_PI*180., b[0], b[1], b[2]);
  glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blueMaterial);
  gluCylinder (q, (GLdouble)radius, (GLdouble)radius, (GLdouble)height, 10, 10);
  glPopMatrix();
}

/** Defines the display CallList.
 * Goes through all molecules and their atoms and adds spheres for atoms and cylinders
 * for bonds. Heeds GLMoleculeView::SelectedAtom and GLMoleculeView::SelectedMolecule.
 */
void GLMoleculeView::initializeGL()
{
  double x[3] = {-1, 0, -10};
  unsigned char white[3] = {255,255,255};
  Vector Position, OtherPosition;
  QSize window = size();
  width = window.width();
  height = window.height();
  std::cout << "Setting width to " << width << " and height to " << height << std::endl;
  GLfloat shininess[] = { 0.0 };
  GLfloat specular[] = { 0, 0, 0, 1 };
  glClearColor(0.0f, 0.0f, 0.0f, 0.0f);     // Let OpenGL clear to black
  object = glGenLists(1);
  glNewList( object, GL_COMPILE );
  glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);
  glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, shininess);

  const std::vector<molecule*> &molecules = World::getInstance().getAllMolecules();

  if (molecules.size() > 0) {
    for (std::vector<molecule*>::const_iterator Runner = molecules.begin();
        Runner != molecules.end();
        Runner++) {
      for (molecule::const_iterator atomiter = (*Runner)->begin();
          atomiter != (*Runner)->end();
          ++atomiter) {
        // create atom
        const element *ptr = (*atomiter)->getType();
        boost::shared_ptr<Vector> MolCenter((*Runner)->DetermineCenterOfGravity());
        Position = (*atomiter)->getPosition() - *MolCenter;
        const unsigned char* color = NULL;
        if ((World::getInstance().isSelected(*atomiter)) || (World::getInstance().isSelected((*Runner))))
          color = SelectionColor;
        else
          color = ptr->getColor();
        makeSphere(Position, ptr->getVanDerWaalsRadius()*0.25, color);

        // create bonds
        const BondList &bonds = (*atomiter)->getListOfBonds();
        for (BondList::const_iterator bonditer = bonds.begin();
            bonditer != bonds.end();
            ++bonditer) {
          if ((*bonditer)->leftatom->getId() == (*atomiter)->getId()) {
            Position = (*bonditer)->leftatom->getPosition() - *MolCenter;
            OtherPosition = (*bonditer)->rightatom->getPosition() - *MolCenter;
            const double distance = sqrt(Position.DistanceSquared(OtherPosition))/2.;
            const unsigned char *color1 = (*bonditer)->leftatom->getType()->getColor();
            const unsigned char *color2 = (*bonditer)->rightatom->getType()->getColor();
            makeCylinder(Position, OtherPosition, 0.1, distance, color1);
            makeCylinder(OtherPosition, Position, 0.1, distance, color2);
          }
        }
      }
    }
  } else {
    makeSphere( x,1, white);
  }
  glEndList();
}


/* ================================== SLOTS ============================== */

/** Initializes some public variables.
 * \param *ptr pointer to QLabel statusbar
 */
void GLMoleculeView::init(QLabel *ptr)
{
  StatusBar = ptr;
}

/** Initializes the viewport statusbar.
 * \param *ptr pointer to QLabel for showing view pointcoordinates.
 */
void GLMoleculeView::initCoordinates(QLabel *ptr)
{
  CoordinatesBar = ptr;
}

/** Slot to be called when to initialize GLMoleculeView::MolData.
 */
void GLMoleculeView::createView( )
{
  initializeGL();
  updateGL();
}

/** Slot of window is resized.
 * Copies new width and height to GLMoleculeView::width and GLMoleculeView::height and calls updateGL().
 * \param w new width of window
 * \param h new height of window
 */
void GLMoleculeView::resizeGL( int w, int h )
{
  width = w;
  height = h;
  updateGL();
}

/** Sets x rotation angle.
 * sets GLMoleculeView::xRot and calls updateGL().
 * \param degrees new rotation angle in degrees
 */
void GLMoleculeView::setXRotation( int degrees )
{
  xRot = (GLfloat)(degrees % 360);
  updateGL();
}


/** Sets y rotation angle.
 * sets GLMoleculeView::yRot and calls updateGL().
 * \param degrees new rotation angle in degrees
 */
void GLMoleculeView::setYRotation( int degrees )
{
  yRot = (GLfloat)(degrees % 360);
  updateGL();
}


/** Sets z rotation angle.
 * sets GLMoleculeView::zRot and calls updateGL().
 * \param degrees new rotation angle in degrees
 */
void GLMoleculeView::setZRotation( int degrees )
{
  zRot = (GLfloat)(degrees % 360);
  updateGL();
}

/** Sets the scale of the scene.
 * sets GLMoleculeView::scale and calls updateGL().
 * \param distance distance divided by 100 is the new scale
 */
void GLMoleculeView::setScale( int distance )
{
  scale = (GLfloat)(distance / 100.);
  updateGL();
}

/** Update the ambient light.
 * \param light[4] light strength per axis and position (w)
 */
void GLMoleculeView::setLightAmbient( int *light )
{
  for(int i=0;i<4;i++)
    LightAmbient[i] = light[i];
  updateGL();
}

/** Update the diffuse light.
 * \param light[4] light strength per axis and position (w)
 */
void GLMoleculeView::setLightDiffuse( int *light )
{
  for(int i=0;i<4;i++)
    LightDiffuse[i] = light[i];
  updateGL();
}

/** Update the position of light.
 * \param light[4] light strength per axis and position (w)
 */
void GLMoleculeView::setLightPosition( int *light )
{
  for(int i=0;i<4;i++)
    LightPosition[i] = light[i];
  updateGL();
}

/** Toggles the boolean GLMoleculeView::MultiViewEnabled.
 * Flips the boolean and calls updateGL().
 */
void GLMoleculeView::toggleMultiViewEnabled ( )
{
  MultiViewEnabled = !MultiViewEnabled;
  cout << "Setting MultiView to " << MultiViewEnabled << "." << endl;
  updateGL();
}

/** Launch a dialog to configure the lights.
 */
void GLMoleculeView::createDialogLight()
{
//  Ui_DialogLight *Lights = new Ui_DialogLight();
//  if (Lights == NULL)
//    return;
//  // Set up the dynamic dialog here
//  QLineEdit *Field = NULL;
//  Field = Lights->findChild<QLineEdit *>("LightPositionX");
//  if (Field) Field->setText( QString("%1").arg(LightPosition[0]) );
//  Field = Lights->findChild<QLineEdit *>("LightPositionY");
//  if (Field) Field->setText( QString("%1").arg(LightPosition[1]) );
//  Field = Lights->findChild<QLineEdit *>("LightPositionZ");
//  if (Field) Field->setText( QString("%1").arg(LightPosition[2]) );
//  Field = Lights->findChild<QLineEdit *>("LightPositionW");
//  if (Field) Field->setText( QString("%1").arg(LightPosition[3]) );
//
//  Field = Lights->findChild<QLineEdit *>("LightDiffuseX");
//  if (Field) Field->setText( QString("%1").arg(LightDiffuse[0]) );
//  Field = Lights->findChild<QLineEdit *>("LightDiffuseY");
//  if (Field) Field->setText( QString("%1").arg(LightDiffuse[1]) );
//  Field = Lights->findChild<QLineEdit *>("LightDiffuseZ");
//  if (Field) Field->setText( QString("%1").arg(LightDiffuse[2]) );
//  Field = Lights->findChild<QLineEdit *>("LightDiffuseW");
//  if (Field) Field->setText( QString("%1").arg(LightDiffuse[3]) );
//
//  Field = Lights->findChild<QLineEdit *>("LightAmbientX");
//  if (Field) Field->setText( QString("%1").arg(LightAmbient[0]) );
//  Field = Lights->findChild<QLineEdit *>("LightAmbientY");
//  if (Field) Field->setText( QString("%1").arg(LightAmbient[1]) );
//  Field = Lights->findChild<QLineEdit *>("LightAmbientZ");
//  if (Field) Field->setText( QString("%1").arg(LightAmbient[2]) );
//  Field = Lights->findChild<QLineEdit *>("LightAmbientW");
//  if (Field) Field->setText( QString("%1").arg(LightAmbient[3]) );
//
//  if ( Lights->exec() ) {
//    //cout << "User accepted.\n";
//    // The user accepted, act accordingly
//    Field = Lights->findChild<QLineEdit *>("LightPositionX");
//    if (Field) LightPosition[0] = Field->text().toDouble();
//    Field = Lights->findChild<QLineEdit *>("LightPositionY");
//    if (Field) LightPosition[1] = Field->text().toDouble();
//    Field = Lights->findChild<QLineEdit *>("LightPositionZ");
//    if (Field) LightPosition[2] = Field->text().toDouble();
//    Field = Lights->findChild<QLineEdit *>("LightPositionW");
//    if (Field) LightPosition[3] = Field->text().toDouble();
//
//    Field = Lights->findChild<QLineEdit *>("LightDiffuseX");
//    if (Field) LightDiffuse[0] = Field->text().toDouble();
//    Field = Lights->findChild<QLineEdit *>("LightDiffuseY");
//    if (Field) LightDiffuse[1] = Field->text().toDouble();
//    Field = Lights->findChild<QLineEdit *>("LightDiffuseZ");
//    if (Field) LightDiffuse[2] = Field->text().toDouble();
//    Field = Lights->findChild<QLineEdit *>("LightDiffuseW");
//    if (Field) LightDiffuse[3] = Field->text().toDouble();
//
//    Field = Lights->findChild<QLineEdit *>("LightAmbientX");
//    if (Field) LightAmbient[0] = Field->text().toDouble();
//    Field = Lights->findChild<QLineEdit *>("LightAmbientY");
//    if (Field) LightAmbient[1] = Field->text().toDouble();
//    Field = Lights->findChild<QLineEdit *>("LightAmbientZ");
//    if (Field) LightAmbient[2] = Field->text().toDouble();
//    Field = Lights->findChild<QLineEdit *>("LightAmbientW");
//    if (Field) LightAmbient[3] = Field->text().toDouble();
//    updateGL();
//  } else {
//    //cout << "User reclined.\n";
//  }
//  delete(Lights);
}

/** Slot for event of pressed mouse button.
 * Switch discerns between buttons and stores position of event in GLMoleculeView::LeftButtonPos,
 * GLMoleculeView::MiddleButtonPos or GLMoleculeView::RightButtonPos.
 * \param *event structure containing information of the event
 */
void GLMoleculeView::mousePressEvent(QMouseEvent *event)
{
  std::cout << "MousePressEvent." << endl;
  QPoint *pos = NULL;
  switch (event->button()) {  // get the right array
    case Qt::LeftButton:
      pos = &LeftButtonPos;
      std::cout << "Left Button" << endl;
      break;
    case Qt::MidButton:
      pos = &MiddleButtonPos;
      std::cout << "Middle Button" << endl;
      break;
    case Qt::RightButton:
      pos = &RightButtonPos;
      std::cout << "Right Button" << endl;
      break;
    default:
      break;
  }
  if (pos) {    // store the position
    pos->setX(event->pos().x());
    pos->setY(event->pos().y());
    std::cout << "Stored src position is (" << pos->x() << "," << pos->y() << ")." << endl;
  } else {
    std::cout << "pos is NULL." << endl;
  }
}

/** Slot for event of pressed mouse button.
 * Switch discerns between buttons:
 * -# Left Button: Rotates the view of the GLMoleculeView, relative to GLMoleculeView::LeftButtonPos.
 * -# Middle Button: nothing
 * -# Right Button: Shifts the selected molecule or atom, relative to GLMoleculeView::RightButtonPos.
 * \param *event structure containing information of the event
 */
void GLMoleculeView::mouseReleaseEvent(QMouseEvent *event)
{
  std::cout << "MouseReleaseEvent." << endl;
  QPoint *srcpos = NULL;
  QPoint destpos = event->pos();
  int Width = (MultiViewEnabled) ? width/2 : width;
  int Height = (MultiViewEnabled) ? height/2 : height;
  std::cout << "Received dest position is (" << destpos.x() << "," << destpos.y() << ")." << endl;
  switch (event->button()) {  // get the right array
    case Qt::LeftButton:  // LeftButton rotates the view
      srcpos = &LeftButtonPos;
      std::cout << "Left Button" << endl;
      if (srcpos) {    // subtract the position and act
        std::cout << "Stored src position is (" << srcpos->x() << "," << srcpos->y() << ")." << endl;
        destpos -= *srcpos;
        std::cout << "Resulting diff position is (" << destpos.x() << "," << destpos.y() << ")." << endl;
        std::cout << "Width and Height are " << Width << "," << Height << "." << endl;

        int pos = (int)floor((double)srcpos->x()/(double)Width) + ((int)floor((double)srcpos->y()/(double)Height))*2;
        if ((MultiViewEnabled) && (pos != 2)) { // means four regions, and we are in a shifting one
          // switch between three regions
          // decide into which of the four screens the initial click has been made
          std::cout << "Position is " << pos << "." << endl;
          switch(pos) {
            case 0:  // lower left = xz
              position[0] += -destpos.y()/100.;
              position[2] += destpos.x()/100.;
              break;
            case 1: // lower right = yz
              position[1] += -destpos.y()/100.;
              position[2] += -destpos.x()/100.;
              break;
            case 2:  // upper left = projected
              std::cout << "This is impossible: Shifting in the projected region, we should rotate!." << endl;
              break;
            case 3:  // upper right = xy
              position[0] += destpos.x()/100.;
              position[1] += -destpos.y()/100.;
              break;
            default:
              std::cout << "click was not in any of the four regions." << endl;
              break;
          }
          updateGL();
        } else { // we are in rotation region
          QWidget *Parent = parentWidget();
          QSlider *sliderX = Parent->findChild<QSlider *>("sliderX");
          QSlider *sliderY = Parent->findChild<QSlider *>("sliderY");
          std::cout << sliderX << " and " << sliderY << endl;
          if (sliderX) {
            int xrange = sliderX->maximum() - sliderX->minimum();
            double xValue = ((destpos.x() + Width) % Width);
            xValue *= (double)xrange/(double)Width;
            xValue += sliderX->value();
            int xvalue = (int) xValue % xrange;
            std::cout << "Setting x to " << xvalue << " within range " << xrange << "." << endl;
            setXRotation(xvalue);
            sliderX->setValue(xvalue);
          } else {
            std::cout << "sliderX is NULL." << endl;
          }
          if (sliderY) {
            int yrange = sliderY->maximum() - sliderY->minimum();
            double yValue = ((destpos.y() + Height) % Height);
            yValue *= (double)yrange/(double)Height;
            yValue += sliderY->value();
            int yvalue = (int) yValue % yrange;
            std::cout << "Setting y to " << yvalue << " within range " << yrange << "." << endl;
            setYRotation(yvalue);
            sliderY->setValue(yvalue);
          } else {
            std::cout << "sliderY is NULL." << endl;
          }
        }
      } else {
        std::cout << "srcpos is NULL." << endl;
      }
      break;

    case Qt::MidButton: // MiddleButton has no function so far
      srcpos = &MiddleButtonPos;
      std::cout << "Middle Button" << endl;
      if (srcpos) {    // subtract the position and act
        QWidget *Parent = parentWidget();
        QSlider *sliderZ = Parent->findChild<QSlider *>("sliderZ");
        QSlider *sliderScale = Parent->findChild<QSlider *>("sliderScale");
        std::cout << sliderZ << " and " << sliderScale << endl;
        std::cout << "Stored src position is (" << srcpos->x() << "," << srcpos->y() << ")." << endl;
        destpos -= *srcpos;
        std::cout << "Resulting diff position is (" << destpos.x() << "," << destpos.y() << ")." << endl;
        std::cout << "Width and Height are " << Width << "," << Height << "." << endl;
        if (sliderZ) {
          int xrange = sliderZ->maximum() - sliderZ->minimum();
          double xValue = ((destpos.x() + Width) % Width);
          xValue *= (double)xrange/(double)Width;
          xValue += sliderZ->value();
          int xvalue = (int) xValue % xrange;
          std::cout << "Setting x to " << xvalue << " within range " << xrange << "." << endl;
          setZRotation(xvalue);
          sliderZ->setValue(xvalue);
        } else {
          std::cout << "sliderZ is NULL." << endl;
        }
        if (sliderScale) {
          int yrange = sliderScale->maximum() - sliderScale->minimum();
          double yValue = ((destpos.y() + Height) % Height);
          yValue *= (double)yrange/(double)Height;
          yValue += sliderScale->value();
          int yvalue = (int) yValue % yrange;
          std::cout << "Setting y to " << yvalue << " within range " << yrange << "." << endl;
          setScale(yvalue);
          sliderScale->setValue(yvalue);
        } else {
          std::cout << "sliderScale is NULL." << endl;
        }
      } else {
        std::cout << "srcpos is NULL." << endl;
      }
      break;
      break;

    case Qt::RightButton:  // RightButton moves eitstdher the selected molecule or atom
      srcpos = &RightButtonPos;
      std::cout << "Right Button" << endl;
      if (srcpos) {    // subtract the position and act
        std::cout << "Stored src position is (" << srcpos->x() << "," << srcpos->y() << ")." << endl;
        destpos -= *srcpos;
        std::cout << "Resulting diff position is (" << destpos.x() << "," << destpos.y() << ")." << endl;
        std::cout << "Width and Height are " << Width << "," << Height << "." << endl;
        if (MultiViewEnabled) {
          // which vector to change
          Vector SelectedPosition;
          const std::vector<atom*> &SelectedAtoms = World::getInstance().getSelectedAtoms();
          const std::vector<molecule*> &SelectedMolecules = World::getInstance().getSelectedMolecules();
          if (SelectedMolecules.size()) {
            if (SelectedAtoms.size())
              SelectedPosition = (*SelectedAtoms.begin())->getPosition();
            else
              SelectedPosition = (*(*SelectedMolecules.begin())->begin())->getPosition();
          }
          // decide into which of the four screens the initial click has been made
          int pos = (int)floor((double)srcpos->x()/(double)Width) + ((int)floor((double)srcpos->y()/(double)Height))*2;
          if (!SelectedPosition.IsZero()) {
            std::cout << "Position is " << pos << "." << endl;
            switch(pos) {
              case 0:  // lower left = xz
                SelectedPosition[0] += -destpos.y()/100.;
                SelectedPosition[2] += destpos.x()/100.;
                break;
              case 1: // lower right = yz
                SelectedPosition[1] += -destpos.y()/100.;
                SelectedPosition[2] += -destpos.x()/100.;
                break;
              case 2:  // upper left = projected
                SelectedPosition[0] += destpos.x()/100.;
                SelectedPosition[1] += destpos.y()/100.;
                SelectedPosition[2] += destpos.y()/100.;
                break;
              case 3:  // upper right = xy
                SelectedPosition[0] += destpos.x()/100.;
                SelectedPosition[1] += -destpos.y()/100.;
                break;
              default:
                std::cout << "click was not in any of the four regions." << endl;
                break;
            }
          } else {
            std::cout << "Nothing selected." << endl;
          }
          // update Tables
          if (SelectedMolecules.size()) {
            isSignaller = true;
            if (SelectedAtoms.size())
              emit notifyAtomChanged( (*SelectedMolecules.begin()), (*SelectedAtoms.begin()), AtomPosition);
            else
              emit notifyMoleculeChanged( (*SelectedMolecules.begin()), MoleculePosition );
          }
          // update graphic
          initializeGL();
          updateGL();
        } else {
          cout << "MultiView is not enabled." << endl;
        }
      } else {
        cout << "srcpos is NULL." << endl;
      }
  break;

    default:
      break;
  }
}

/* ======================================== SLOTS ================================ */

/** Hear announcement of selected molecule.
 * \param *mol pointer to selected molecule
 */
void GLMoleculeView::hearMoleculeSelected(molecule *mol)
{
  if (isSignaller) { // if we emitted the signal, return
    isSignaller = false;
    return;
  }
  initializeGL();
  updateGL();
};

/** Hear announcement of selected atom.
 * \param *mol pointer to molecule containing atom
 * \param *Walker pointer to selected atom
 */
void GLMoleculeView::hearAtomSelected(molecule *mol, atom *Walker)
{
  if (isSignaller) { // if we emitted the signal, return
    isSignaller = false;
    return;
  }
  initializeGL();
  updateGL();
};

/** Hear announcement of changed molecule.
 * \param *mol pointer to changed molecule
 * \param type of change
 */
void GLMoleculeView::hearMoleculeChanged(molecule *mol, enum ChangesinMolecule type)
{
  if (isSignaller) { // if we emitted the signal, return
    isSignaller = false;
    return;
  }
  initializeGL();
  updateGL();
};

/** Hear announcement of changed atom.
 * \param *mol pointer to molecule containing atom
 * \param *Walker pointer to changed atom
 * \param type type of change
 */
void GLMoleculeView::hearAtomChanged(molecule *mol, atom *Walker, enum ChangesinAtom type)
{
  if (isSignaller) { // if we emitted the signal, return
    isSignaller = false;
    return;
  }
  initializeGL();
  updateGL();
};

/** Hear announcement of changed element.
 * \param *Runner pointer to changed element
 * \param type of change
 */
void GLMoleculeView::hearElementChanged(element *Runner, enum ChangesinElement type)
{
  if (isSignaller) { // if we emitted the signal, return
    isSignaller = false;
    return;
  }
  switch(type) {
    default:
    case ElementName:
    case ElementSymbol:
    case ElementMass:
    case ElementValence:
    case ElementZ:
      break;
    case ElementCovalent:
    case ElementVanderWaals:
      initializeGL();
      updateGL();
      break;
  }
};

/** Hear announcement of added molecule.
 * \param *mol pointer to added molecule
 */
void GLMoleculeView::hearMoleculeAdded(molecule *mol)
{
  if (isSignaller) { // if we emitted the signal, return
    isSignaller = false;
    return;
  }
  initializeGL();
  updateGL();
};

/** Hear announcement of added atom.
 * \param *mol pointer to molecule containing atom
 * \param *Walker pointer to added atom
 */
void GLMoleculeView::hearAtomAdded(molecule *mol, atom *Walker)
{
  if (isSignaller) { // if we emitted the signal, return
    isSignaller = false;
    return;
  }
  initializeGL();
  updateGL();
};

/** Hear announcement of removed molecule.
 * \param *mol pointer to removed molecule
 */
void GLMoleculeView::hearMoleculeRemoved(molecule *mol)
{
  if (isSignaller) { // if we emitted the signal, return
    isSignaller = false;
    return;
  }
  initializeGL();
  updateGL();
};

/** Hear announcement of removed atom.
 * \param *mol pointer to molecule containing atom
 * \param *Walker pointer to removed atom
 */
void GLMoleculeView::hearAtomRemoved(molecule *mol, atom *Walker)
{
  if (isSignaller) { // if we emitted the signal, return
    isSignaller = false;
    return;
  }
  initializeGL();
  updateGL();
};

void GLMoleculeView::update(Observable *publisher)
{
  initializeGL();
  updateGL();
}

/**
 * This method is called when a special named change
 * of the Observable occured
 */
void GLMoleculeView::recieveNotification(Observable *publisher, Notification_ptr notification)
{
  initializeGL();
  updateGL();
}

/**
 * This method is called when the observed object is destroyed.
 */
void GLMoleculeView::subjectKilled(Observable *publisher)
{

}