#include "mycustomplot.h"

#include <QGesture>
#include <QGestureEvent>
#include <QGestureRecognizer>

MyCustomPlot::MyCustomPlot(QWidget* parent) : QCustomPlot(parent)
{
 grabGesture(Qt::PinchGesture);
 installEventFilter(this);
}

bool MyCustomPlot::event(QEvent *event)
{
 if(event->type() == QEvent::Gesture)
 {
 QGestureEvent* gEvent = static_cast<QGestureEvent*>(event);
 QGesture* gesture = gEvent->gesture(Qt::PinchGesture);
 if(!gesture)
 return QCustomPlot::event(event);
 if(!interactions().testFlag(QCP::iRangeZoom))
 return QCustomPlot::event(event);
 QPinchGesture* pinchGesture = static_cast<QPinchGesture *>(gesture);
 if(!handlePinchGesture(pinchGesture))
 return QCustomPlot::event(event);
 event->accept();
 return true;
 }
 return QCustomPlot::event(event);
}

bool MyCustomPlot::eventFilter(QObject *watched, QEvent *event)
{
 // eventFilter doesn't work on the mouseEvent of layerables
 // so this eventFilter should be installed on the QCustomPlot object,
 // and treat "mMouseEventLayerable" as "watched"
 if(event->type() == QEvent::MouseMove)
 {
 QCPAxis* axis = qobject_cast<QCPAxis*>(mMouseEventLayerable);
 if(axis)
 {
 // if iRangeDrag is not set, return true(filter it out)
 return !interactions().testFlag(QCP::iRangeDrag);
 }
 }
 return QCustomPlot::eventFilter(watched, event);
}

bool MyCustomPlot::handlePinchGesture(QPinchGesture* pinchGesture)
{
 auto state = pinchGesture->state();
 // record the scale center
 if(state == Qt::GestureStarted)
 {
 // disable the drag interaction
 // The drag interaction will affect the scaleRange() there.
 // The mouseMoveEvent() of QCPAxisRect will test the iRangeDrag flag.
 // The mouseMoveEvent() of QCPAxis will not test the iRangeDrag flag, so I need some extra code in MyCustomPlot::eventFilter()
 m_iRangeDragEnabled = interactions().testFlag(QCP::iRangeDrag);
 setInteraction(QCP::iRangeDrag, false);

 QPointF pinchCenter = mapFromGlobal(pinchGesture->centerPoint().toPoint());
 foreach(QCPLayerable* candidate, layerableListAt(pinchCenter, false))
 {
 QCPAxis* axis = qobject_cast<QCPAxis*>(candidate);
 QCPAxisRect* rect = qobject_cast<QCPAxisRect*>(candidate);
 // pinch on axis, detect it first
 if(axis && axis->axisRect()->rangeZoom().testFlag(axis->orientation()) && axis->axisRect()->rangeZoomAxes(axis->orientation()).contains(axis))
 {
 qDebug() << "on axis";
 m_axisScaleCenterList.insert(axis, axis->pixelToCoord(axis->orientation() == Qt::Horizontal ? pinchCenter.x() : pinchCenter.y()));
 break; // necessary, since the QCPAxisRcet contains the QCPAxis
 }
 // pinch on rect
 else if(rect)
 {
 qDebug() << "on rect";
 QPointF pinchDirection = pinchGesture->centerPoint() - pinchGesture->hotSpot();
 qreal pinchTan = (pinchDirection.x() == 0) ? 572958 : qAbs(pinchDirection.y() / pinchDirection.x());
 Qt::Orientations pinchOrientations;
 if(pinchTan < 2.74) // ~70 degree
 pinchOrientations |= Qt::Horizontal;
 if(pinchTan > 0.364) // ~20 degree
 pinchOrientations |= Qt::Vertical;
 Qt::Orientations rangeZoom = rect->rangeZoom();
 if(rangeZoom.testFlag(Qt::Horizontal) && pinchOrientations.testFlag(Qt::Horizontal))
 {
 foreach(QCPAxis* it, rect->rangeZoomAxes(Qt::Horizontal))
 {
 m_axisScaleCenterList.insert(it, it->pixelToCoord(pinchCenter.x()));
 }
 }
 if(rangeZoom.testFlag(Qt::Vertical) && pinchOrientations.testFlag(Qt::Vertical))
 {
 foreach(QCPAxis* it, rect->rangeZoomAxes(Qt::Vertical))
 {
 m_axisScaleCenterList.insert(it, it->pixelToCoord(pinchCenter.y()));
 }
 }
 break;
 }
 }
 }
 // scale
 else if(state == Qt::GestureUpdated)
 {
 for(auto it = m_axisScaleCenterList.begin(); it != m_axisScaleCenterList.end(); ++it)
 {
 it.key()->scaleRange(1.0 / pinchGesture->scaleFactor(), it.value());
 }
 replot(rpQueuedReplot);
 }
 else if(state == Qt::GestureFinished)
 {
 setInteraction(QCP::iRangeDrag, m_iRangeDragEnabled);
 m_axisScaleCenterList.clear();
 replot();
 }
 return true;
}

void MyCustomPlot::setDarkStyle(bool enabled)
{
 QPen tmpPen[3];
 QColor tmpColor;
 QBrush tmpBrush[2];

 QLinearGradient plotGradient;
 QLinearGradient axisRectGradient;
 if(enabled)
 {
 // from https://www.qcustomplot.com/index.php/demos/styleddemo
 plotGradient.setStart(0, 0);
 plotGradient.setFinalStop(0, 350);
 plotGradient.setColorAt(0, QColor(80, 80, 80));
 plotGradient.setColorAt(1, QColor(50, 50, 50));
 axisRectGradient.setStart(0, 0);
 axisRectGradient.setFinalStop(0, 350);
 axisRectGradient.setColorAt(0, QColor(80, 80, 80));
 axisRectGradient.setColorAt(1, QColor(30, 30, 30));

 tmpPen[0] = QPen(Qt::white, 1);
 tmpPen[1] = QPen(QColor(140, 140, 140), 1, Qt::DotLine);
 tmpPen[2] = Qt::NoPen;
 tmpColor = Qt::white;
 tmpBrush[0] = plotGradient;
 tmpBrush[1] = axisRectGradient;
 }
 else
 {
 // from qcustomplot.cpp(2.1.1)
 tmpPen[0] = QPen(Qt::black, 0, Qt::SolidLine, Qt::SquareCap);
 tmpPen[1] = QPen(QColor(200, 200, 200), 0, Qt::DotLine);
 tmpPen[2] = QPen(QColor(200, 200, 200), 0, Qt::SolidLine);
 tmpColor = Qt::black;
 tmpBrush[0] = QBrush(Qt::white, Qt::SolidPattern);
 tmpBrush[1] = Qt::NoBrush;
 }
 xAxis->setBasePen(tmpPen[0]);
 yAxis->setBasePen(tmpPen[0]);
 xAxis->setTickPen(tmpPen[0]);
 yAxis->setTickPen(tmpPen[0]);
 xAxis->setSubTickPen(tmpPen[0]);
 yAxis->setSubTickPen(tmpPen[0]);
 xAxis->setTickLabelColor(tmpColor);
 yAxis->setTickLabelColor(tmpColor);
 xAxis->grid()->setPen(tmpPen[1]);
 yAxis->grid()->setPen(tmpPen[1]);
// xAxis->grid()->setSubGridPen(QPen(QColor(80, 80, 80), 1, Qt::DotLine));
// yAxis->grid()->setSubGridPen(QPen(QColor(80, 80, 80), 1, Qt::DotLine));
// xAxis->grid()->setSubGridVisible(true);
// yAxis->grid()->setSubGridVisible(true);
 xAxis->grid()->setZeroLinePen(tmpPen[2]);
 yAxis->grid()->setZeroLinePen(tmpPen[2]);
 setBackground(tmpBrush[0]);
 axisRect()->setBackground(tmpBrush[1]);

 xAxis->setUpperEnding(QCPLineEnding::esSpikeArrow);
 yAxis->setUpperEnding(QCPLineEnding::esSpikeArrow);
}