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#include "GraphWidget.h"
#include "Edge.h"
#include "Node.h"

#include <QtGui>

#include <cpPlugins/Interface/Workspace.h>

#include <math.h>

GraphWidget::GraphWidget( QWidget* parent )
  : QGraphicsView( parent ),
    timerId( 0 ),
    m_Workspace( NULL )
{
  QGraphicsScene* scene = new QGraphicsScene( this );
  scene->setItemIndexMethod( QGraphicsScene::NoIndex );
  // TODO: scene->setSceneRect( -200, -200, 400, 400 );
  this->setScene( scene );
  /* TODO
     this->setCacheMode(CacheBackground);
     this->setViewportUpdateMode(BoundingRectViewportUpdate);
     this->setRenderHint(QPainter::Antialiasing);
     this->setTransformationAnchor(AnchorUnderMouse);
     this->scale(qreal(0.8), qreal(0.8));
     this->setMinimumSize(400, 400);
     this->setWindowTitle( tr("Elastic Nodes") );
  */

  /*
    Node *node1 = new Node(this);
    Node *node2 = new Node(this);
    Node *node3 = new Node(this);
    Node *node4 = new Node(this);
    centerNode = new Node(this);
    Node *node6 = new Node(this);
    Node *node7 = new Node(this);
    Node *node8 = new Node(this);
    Node *node9 = new Node(this);
    scene->addItem(node1);
    scene->addItem(node2);
    scene->addItem(node3);
    scene->addItem(node4);
    scene->addItem(centerNode);
    scene->addItem(node6);
    scene->addItem(node7);
    scene->addItem(node8);
    scene->addItem(node9);
    scene->addItem(new Edge(node1, node2));
    scene->addItem(new Edge(node2, node3));
    scene->addItem(new Edge(node2, centerNode));
    scene->addItem(new Edge(node3, node6));
    scene->addItem(new Edge(node4, node1));
    scene->addItem(new Edge(node4, centerNode));
    scene->addItem(new Edge(centerNode, node6));
    scene->addItem(new Edge(centerNode, node8));
    scene->addItem(new Edge(node6, node9));
    scene->addItem(new Edge(node7, node4));
    scene->addItem(new Edge(node8, node7));
    scene->addItem(new Edge(node9, node8));

    node1->setPos(-50, -50);
    node2->setPos(0, -50);
    node3->setPos(50, -50);
    node4->setPos(-50, 0);
    centerNode->setPos(0, 0);
    node6->setPos(50, 0);
    node7->setPos(-50, 50);
    node8->setPos(0, 50);
    node9->setPos(50, 50);
  */
}

// -------------------------------------------------------------------------
cpPlugins::Interface::Workspace* GraphWidget::
workspace( )
{
  return( this->m_Workspace );
}

// -------------------------------------------------------------------------
const cpPlugins::Interface::Workspace* GraphWidget::
workspace( ) const
{
  return( this->m_Workspace );
}

// -------------------------------------------------------------------------
void GraphWidget::
setWorkspace( cpPlugins::Interface::Workspace* ws )
{
  if( this->m_Workspace == ws )
    return;
  this->m_Workspace = ws;
  QGraphicsScene* scene = this->scene( );

  // Create graph
  this->m_Graph = TGraph::New( );

  // Add vertices
  auto vIt = this->m_Workspace->GetGraph( )->BeginVertices( );
  auto vIt_end = this->m_Workspace->GetGraph( )->EndVertices( );
  for( ; vIt != vIt_end; ++vIt )
  {
    std::string label = vIt->second->GetName( ) + std::string( "\n" );
    label += vIt->second->GetClassName( );

    Node* node = new Node( this, label );
    this->m_Graph->InsertVertex( vIt->first, node );
    scene->addItem( node );

  } // rof

  // Add edges
  auto rIt = this->m_Workspace->GetGraph( )->BeginEdgesRows( );
  auto rIt_end = this->m_Workspace->GetGraph( )->EndEdgesRows( );
  for( ; rIt != rIt_end; ++rIt )
  {
    Node* a = this->m_Graph->GetVertex( rIt->first );
    if( a == NULL )
      continue;
    auto cIt = rIt->second.begin( );
    for( ; cIt != rIt->second.end( ); ++cIt )
    {
      Node* b = this->m_Graph->GetVertex( cIt->first );
      if( b == NULL )
        continue;
      Edge* e = new Edge( a, b );
      this->m_Graph->AddConnection( rIt->first, cIt->first, e );
      scene->addItem( e );

    } // rof

  } // rof
}

// -------------------------------------------------------------------------
void GraphWidget::
draw( )
{
  if( this->m_Workspace == NULL )
    return;
}

// -------------------------------------------------------------------------
void GraphWidget::itemMoved()
{
  if (!timerId)
    timerId = startTimer(1000 / 25);
}

void GraphWidget::keyPressEvent(QKeyEvent *event)
{
  switch (event->key()) {
  case Qt::Key_Up:
    centerNode->moveBy(0, -20);
    break;
  case Qt::Key_Down:
    centerNode->moveBy(0, 20);
    break;
  case Qt::Key_Left:
    centerNode->moveBy(-20, 0);
    break;
  case Qt::Key_Right:
    centerNode->moveBy(20, 0);
    break;
  case Qt::Key_Plus:
    zoomIn();
    break;
  case Qt::Key_Minus:
    zoomOut();
    break;
  case Qt::Key_Space:
  case Qt::Key_Enter:
    shuffle();
    break;
  default:
    QGraphicsView::keyPressEvent(event);
  }
}

void GraphWidget::timerEvent(QTimerEvent *event)
{
  Q_UNUSED(event);

  QList<Node *> nodes;
  foreach (QGraphicsItem *item, scene()->items()) {
    if (Node *node = qgraphicsitem_cast<Node *>(item))
      nodes << node;
  }

  foreach (Node *node, nodes)
    node->calculateForces();

  bool itemsMoved = false;
  foreach (Node *node, nodes) {
    if (node->advance())
      itemsMoved = true;
  }

  if (!itemsMoved) {
    killTimer(timerId);
    timerId = 0;
  }
}

void GraphWidget::wheelEvent(QWheelEvent *event)
{
  scaleView(pow((double)2, -event->delta() / 240.0));
}

void GraphWidget::drawBackground(QPainter *painter, const QRectF &rect)
{
  //Q_UNUSED(rect);

  // Shadow
  QRectF sceneRect = rect;//this->sceneRect();
  QRectF rightShadow(sceneRect.right(), sceneRect.top() + 5, 5, sceneRect.height());
  QRectF bottomShadow(sceneRect.left() + 5, sceneRect.bottom(), sceneRect.width(), 5);
  if (rightShadow.intersects(rect) || rightShadow.contains(rect))
    painter->fillRect(rightShadow, Qt::darkGray);
  if (bottomShadow.intersects(rect) || bottomShadow.contains(rect))
    painter->fillRect(bottomShadow, Qt::darkGray);

  // Fill
  QLinearGradient gradient(sceneRect.topLeft(), sceneRect.bottomRight());
  gradient.setColorAt(0, Qt::white);
  gradient.setColorAt(1, Qt::lightGray);
  painter->fillRect(rect.intersect(sceneRect), gradient);
  painter->setBrush(Qt::NoBrush);
  painter->drawRect(sceneRect);

#if !defined(Q_OS_SYMBIAN) && !defined(Q_WS_MAEMO_5)
  // Text
  QRectF textRect(sceneRect.left() + 4, sceneRect.top() + 4,
                  sceneRect.width() - 4, sceneRect.height() - 4);
  QString message(tr("Click and drag the nodes around, and zoom with the mouse "
                     "wheel or the '+' and '-' keys"));

  QFont font = painter->font();
  font.setBold(true);
  font.setPointSize(14);
  painter->setFont(font);
  painter->setPen(Qt::lightGray);
  painter->drawText(textRect.translated(2, 2), message);
  painter->setPen(Qt::black);
  painter->drawText(textRect, message);
#endif
}

void GraphWidget::scaleView(qreal scaleFactor)
{
  qreal factor = transform().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width();
  if (factor < 0.07 || factor > 100)
    return;

  scale(scaleFactor, scaleFactor);
}

void GraphWidget::shuffle()
{
  foreach (QGraphicsItem *item, scene()->items()) {
    if (qgraphicsitem_cast<Node *>(item))
      item->setPos(-150 + qrand() % 300, -150 + qrand() % 300);
  }
}

void GraphWidget::zoomIn()
{
  scaleView(qreal(1.2));
}

void GraphWidget::zoomOut()
{
  scaleView(1 / qreal(1.2));
}