#include <QDebug>
#include <QGraphicsScene>
#include <QWheelEvent>
#include <QGraphicsItem>
#include <QGenericMatrix>
#include <QApplication>
#include <math.h>

#include "MyGraphicsView.h"

MyGraphicsView::MyGraphicsView(QWidget* iQWidget):
QGraphicsView(iQWidget),
Mode(SELECTION),
ZoomBox(NULL),
Panning(false),
MaxZoomFactor(100)
{
   Q_INIT_RESOURCE(MyGraphicsView);
   Scene = new QGraphicsScene(this);
   Scene->setItemIndexMethod(QGraphicsScene::NoIndex);
   setScene(Scene);

   setCacheMode(CacheBackground);
   setViewportUpdateMode(BoundingRectViewportUpdate);
   setRenderHint(QPainter::Antialiasing);
   setHorizontalScrollBarPolicy( Qt::ScrollBarAlwaysOff );
   setVerticalScrollBarPolicy( Qt::ScrollBarAlwaysOff );

   setResizeAnchor(AnchorViewCenter);

   setSceneRect(0,0,500,500);

   scale(qreal(1.0), qreal(1.0));
   setWindowTitle(tr("QT Graphics View Test"));

   //Add Control Buttons
   ControlPanelBackground = scene()->addRect(QRectF(size().width() - 100,0,100,5),QPen(),QBrush(QColor(255,255,255, 0)));
   ControlPanelBackground->setZValue(1);
   QWidget *ControlFrame =  new QWidget();
   ControlFrame->setMinimumWidth(60);
   ControlFrame->setMinimumHeight(28);
   ModeButtonGroup = new QButtonGroup(ControlFrame);

   ControlFrame->setLayout(new QHBoxLayout());
   ControlFrame->layout()->setSpacing(0);
   ControlFrame->layout()->setMargin(0);

   ButtonSelect =  new QPushButton(ControlFrame);
   ButtonSelect->setText("Select");
   ButtonSelect->setMinimumHeight(24);
   ButtonSelect->setCheckable(true);
   ButtonSelect->setChecked(true);
   ControlFrame->layout()->addWidget(ButtonSelect);
   ModeButtonGroup->addButton(ButtonSelect);
   ButtonZoom =  new QPushButton(ControlFrame);
   ButtonZoom->setText("Zoom");
   ButtonZoom->setMinimumHeight(24);
   ButtonZoom->setCheckable(true);
   ControlFrame->layout()->addWidget(ButtonZoom);
   ModeButtonGroup->addButton(ButtonZoom);

   ((QHBoxLayout *)ControlFrame->layout())->addSpacing(6);

   ButtonFitToView =  new QPushButton(ControlFrame);
   ButtonFitToView->setText("Zoom to Max");
   ButtonFitToView->setMinimumHeight(24);
   ControlFrame->layout()->addWidget(ButtonFitToView);

   FrameGraphics = scene()->addWidget(ControlFrame);
   FrameGraphics->setParentItem(ControlPanelBackground);
   ControlPanelBackground->setRect(FrameGraphics->boundingRect());

   connect(ButtonSelect, SIGNAL(clicked()), this, SLOT(vModeSelected()));
   connect(ButtonZoom, SIGNAL(clicked()), this, SLOT(vModeSelected()));
   connect(ButtonFitToView, SIGNAL(clicked()), this, SLOT(vFullExtents()));

   PixmapItem = Scene->addPixmap(QPixmap(":/new/prefix1/apple.png"));
   PixmapItem->setPos(100, 100);

   scaleView(1.0);
}

MyGraphicsView::~MyGraphicsView()
{
}

void MyGraphicsView::vModeSelected()
{
   QAbstractButton *_pButton = ModeButtonGroup->checkedButton();
   if (_pButton == ButtonSelect)
   {
      vSetMode(SELECTION);
   }
   else if (_pButton == ButtonZoom)
   {
      vSetMode(ZOOM_BOX);
   }

   emit vOnModeChanged(getMode());
}

// SETTING THE CURSORS FOR EACH MODE
// THIS IS TRIGGERED FROM THE BUTTONS INSIDE THE GRAPHICS VIEW
void MyGraphicsView::vSetMode(ModeEnum a_Mode)
{
   Mode = a_Mode;

   // MUST BE CALLED SO THAT THE CURSOR CAN BE CHANGED BACK TO THE ARROW ONCE WE'VE CHANGED
   // IT TO THE CUSTOM CURSOR
   this->unsetCursor();

   if (a_Mode == SELECTION)
   {
      viewport()->setCursor(Qt::ArrowCursor);
      ButtonSelect->setChecked(true);
   }
   else if (a_Mode == ZOOM_BOX)
   {
      QCursor *_pCursor = new QCursor(QPixmap(":/new/prefix1/zoom.png"));
      viewport()->setCursor(*_pCursor);
      setCursor(*_pCursor);
      ButtonZoom->setChecked(true);
   }

   // NEEDED TO ENSURE THAT THE CURSOR IS ACTUALLY CHANGED
   setDragMode(QGraphicsView::ScrollHandDrag);
   setDragMode(QGraphicsView::NoDrag);
}

//  SETTING THE CURSOR FROM A TRIGGER OUTSIDE THE GRAPHICS VIEW
//  THIS IS CALLED FROM THE BUTTON ABOVE THE VIEW
void MyGraphicsView::vStartHiddenMode()
{
     TempMode = Mode;

     vSetMode(QUERY);
     QCursor *_pCursor = new QCursor(QPixmap(":/new/prefix1/pencil.png"));
     viewport()->setCursor(*_pCursor);
     setCursor(*_pCursor);
     setFocus();
}













void MyGraphicsView::vFullExtents()
{
   QRectF unity = matrix().mapRect(QRectF(0, 0, 1, 1));
   scaleView(1 / unity.width());
}

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

void MyGraphicsView::resizeEvent(QResizeEvent *event)
{
   setSceneRect(0,0, this->width(), this->height());
   this->setBackgroundBrush(QBrush(QColor(26, 51, 71)));

   int wNewSizeWidth = event->size().width();
   int wNewSizeHeight = event->size().height();

   int _width = size().width();
   QPoint wPointScreen(_width <= 250 ? 0 : _width- 250,5);
   QPointF wPointScene = mapToScene(wPointScreen);

   qreal ActualFactor = matrix().mapRect(QRectF(0, 0, 1, 1)).width();

   if(ControlPanelBackground)
   {
      ControlPanelBackground->setPos(wPointScene);
      ControlPanelBackground->setScale(1/ActualFactor);
   }
}

void MyGraphicsView::mousePressEvent(QMouseEvent *a_MouseEvent)
{
   // Since the map should drag on the middle mouse, we make QGraphicsView believe that left button is pressed
   if(a_MouseEvent->button() == Qt::MidButton)
   {
      Panning = true;
      setDragMode(QGraphicsView::ScrollHandDrag);
      QMouseEvent* _Event = new QMouseEvent(a_MouseEvent->type(),a_MouseEvent->pos(),Qt::LeftButton,(a_MouseEvent->buttons() | Qt::MidButton),a_MouseEvent->modifiers());
      QGraphicsView::mousePressEvent(_Event);
      return;
   }

   Panning = false;
   if(a_MouseEvent->button() == Qt::LeftButton && (Mode == ZOOM_BOX))
   {
      if(ZoomBox == NULL)
      {
         QPen wPen;
         wPen.setColor(QColor("Red"));
         wPen.setStyle(Qt::DashLine);
         ZoomBox = Scene->addRect(0,0,0,0,wPen);
      }

      ZoomX = a_MouseEvent->x();
      ZoomY = a_MouseEvent->y();

      ZoomBox->setRect(ZoomX, ZoomY,0,0);
   }
   else if(a_MouseEvent->button() == Qt::LeftButton && Mode == QUERY)
   {
      double _Lat, _Lon;
      int _ScreenX = a_MouseEvent->x();
      int _ScreenY = a_MouseEvent->y();
   }

   QGraphicsView::mousePressEvent(a_MouseEvent);
}

void MyGraphicsView::mouseReleaseEvent(QMouseEvent *a_MouseEvent)
{
   // Since the view should drag on the middle mouse, we make QGraphicsView believe that left button is released
   if(a_MouseEvent->button() == Qt::MidButton)
   {
      Panning = false;
      QMouseEvent* _Event = new QMouseEvent(a_MouseEvent->type(),a_MouseEvent->pos(),Qt::LeftButton,(a_MouseEvent->buttons() | Qt::MidButton),a_MouseEvent->modifiers());
      QGraphicsView::mouseReleaseEvent(_Event);
      setDragMode(QGraphicsView::NoDrag);
      return;
   }

   //  Once we release the mouse in the query mode we turn it off and return to the previous mode.
   if (a_MouseEvent->button() == Qt::LeftButton && Mode == QUERY)
   {
      vSetMode(TempMode);
   }

   if(ZoomBox && Mode == ZOOM_BOX)
   {
      Scene->removeItem(ZoomBox);
      delete ZoomBox;
      ZoomBox = NULL;
   }
   setDragMode(QGraphicsView::NoDrag);
   QGraphicsView::mouseReleaseEvent(a_MouseEvent);
}

void MyGraphicsView::mouseMoveEvent(QMouseEvent * a_MouseEvent)
{
   if(ZoomBox && (Mode == ZOOM_BOX))
   {
      int _ScreenX = a_MouseEvent->x();
      int _ScreenY = a_MouseEvent->y();

      double _x = ZoomX;
      double _y = ZoomY;
      double _x2 = _x;
      double _y2 = _y;
      double _width, _height;
      _height = _ScreenY - _y;
      _width = _ScreenX - _x;

      ZoomBox->setRect(_x2,_y2,_width, _height);
   }

   QGraphicsView::mouseMoveEvent(a_MouseEvent);
}


void MyGraphicsView::mouseDoubleClickEvent( QMouseEvent *event )
{
   if(Mode != SELECTION)
   {
      mousePressEvent(event);
   }
   else
   {
      QGraphicsView::mouseDoubleClickEvent(event);
   }
}

void MyGraphicsView::scaleView(qreal scaleFactor)
{
   QRectF _Rect = matrix().mapRect(QRectF(0, 0, 1, 1));
   qreal _ActualFactor = matrix().mapRect(QRectF(0, 0, 1, 1)).width();
   qreal _NewFactor = matrix().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width();

   // Limit zoom factor to 50...
   if(_NewFactor>MaxZoomFactor)
   {
      return;
   }

   scale(scaleFactor, scaleFactor);

   int _width = size().width();
   QPoint wPointScreen(_width <= 250 ? 0 : _width- 250,5);
   QPointF wPointScene = mapToScene(wPointScreen);

   qreal ActualFactor = matrix().mapRect(QRectF(0, 0, 1, 1)).width();

   if(ControlPanelBackground)
   {
      ControlPanelBackground->setPos(wPointScene);
      ControlPanelBackground->setScale(1/ActualFactor);
   }
}