// QT widget embedding a ROOT TCanvas.
// From B. Bellenot:
//   https://root.cern.ch/phpBB3/viewtopic.php?f=3&t=19524&sid=2483d853ca550cebba166ca147332e5d&p=83521#p83634

// SimViewer headers
#include "QRootCanvas.h"

#include "SmartLog.h"

// QT headers
#include <QPushButton>
#include <QLayout>
#include <QTimer>
#include <QPaintEvent>
#include <QResizeEvent>
#include <QMouseEvent>
#include <QMessageBox>

// ROOT headers
#include <TCanvas.h>
#include <TVirtualX.h>

#include <iostream>
QRootCanvas::QRootCanvas(QWidget *parent) :
    QWidget(parent, Qt::Widget), fCanvas(NULL) {
  // QRootCanvas constructor.

  // set options needed to properly update the canvas when resizing the widget
  // and to properly handle context menus and mouse move events
  setAttribute(Qt::WA_PaintOnScreen, true);
  setAttribute(Qt::WA_OpaquePaintEvent, true);
  setMinimumSize(10, 10);
  setUpdatesEnabled(kFALSE);
  setMouseTracking(kTRUE);

  // register the QWidget in TVirtualX, giving its native window id
  int wid = gVirtualX->AddWindow((ULong_t) winId(), 10, 10);
  // create the ROOT TCanvas, giving as argument the QWidget registered id
  SmartLog::MuteOutput();
  fCanvas = new TCanvas("Root Canvas", width(), height(), wid);
  SmartLog::UnmuteOutput();

  // Connect the Root slot
  fCanvas->Connect("RangeAxisChanged()", "QRootCanvas", this, "emitChangeRangeAxis()");
}

QRootCanvas::~QRootCanvas() {
  // QRootCanvas destructor.
  fCanvas->Disconnect();
  delete fCanvas;
}

void QRootCanvas::mouseMoveEvent(QMouseEvent *e) {
  // Handle mouse move events.

  if (fCanvas) {
    if (e->buttons() & Qt::LeftButton) {
      fCanvas->HandleInput(kButton1Motion, e->x(), e->y());
    }
    else if (e->buttons() & Qt::MidButton) {
      fCanvas->HandleInput(kButton2Motion, e->x(), e->y());
    }
    else if (e->buttons() & Qt::RightButton) {
      fCanvas->HandleInput(kButton3Motion, e->x(), e->y());
    }
    else {
      fCanvas->HandleInput(kMouseMotion, e->x(), e->y());
    }
  }
}

void QRootCanvas::mousePressEvent(QMouseEvent *e) {
  // Handle mouse button press events.

  if (fCanvas) {
    switch (e->button()) {
    case Qt::LeftButton:
      fCanvas->HandleInput(kButton1Down, e->x(), e->y());
      break;
    case Qt::MidButton:
      fCanvas->HandleInput(kButton2Down, e->x(), e->y());
      break;
    case Qt::RightButton:
      // does not work properly on Linux...
      // ...adding setAttribute(Qt::WA_PaintOnScreen, true)
      // seems to cure the problem
      fCanvas->HandleInput(kButton3Down, e->x(), e->y());
      break;
    default:
      break;
    }
  }
}

void QRootCanvas::mouseReleaseEvent(QMouseEvent *e) {
  // Handle mouse button release events.

  if (fCanvas) {
    switch (e->button()) {
    case Qt::LeftButton:
      fCanvas->HandleInput(kButton1Up, e->x(), e->y());
      break;
    case Qt::MidButton:
      fCanvas->HandleInput(kButton2Up, e->x(), e->y());
      break;
    case Qt::RightButton:
      // does not work properly on Linux...
      // ...adding setAttribute(Qt::WA_PaintOnScreen, true)
      // seems to cure the problem
      fCanvas->HandleInput(kButton3Up, e->x(), e->y());
      break;
    default:
      break;
    }
  }
}

void QRootCanvas::resizeEvent(QResizeEvent *) {
  // Handle resize events.

  if (fCanvas) {
    fCanvas->Resize();
    fCanvas->Update();
  }
}

void QRootCanvas::paintEvent(QPaintEvent *) {
  // Handle paint events.

  if (fCanvas) {
    fCanvas->Resize();
    fCanvas->Update();
  }
}

void QRootCanvas::emitRangeAxisChanged(){
  emit rangeAxisChanged();
}

//------------------------------------------------------------------------------