Qt 5.9 | Qt Data Visualization | Textured Surface Example | custominputhandler.cpp Example File

Qt 5.9.9 Reference Documentation

# custominputhandler.cpp Example File

texturesurface/custominputhandler.cpp

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      ** Contact: https://www.qt.io/licensing/
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      ** This file is part of the Qt Data Visualization module of the Qt Toolkit.
      **
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      #include "custominputhandler.h"

      #include <QtDataVisualization/Q3DCamera>
      #include <QtCore/qmath.h>

      CustomInputHandler::CustomInputHandler(QAbstract3DGraph *graph, QObject *parent) :
          Q3DInputHandler(parent),
          m_highlight(0),
          m_mousePressed(false),
          m_state(StateNormal),
          m_axisX(0),
          m_axisZ(0),
          m_speedModifier(20.0f)
      {
          // Connect to the item selection signal from graph
          connect(graph, &QAbstract3DGraph::selectedElementChanged, this,
                  &CustomInputHandler::handleElementSelected);
      }

      void CustomInputHandler::mousePressEvent(QMouseEvent *event, const QPoint &mousePos)
      {
          if (Qt::LeftButton == event->button()) {
              m_highlight->setVisible(false);
              m_mousePressed = true;
          }
          Q3DInputHandler::mousePressEvent(event, mousePos);
      }

      void CustomInputHandler::wheelEvent(QWheelEvent *event)
      {
          float delta = float(event->delta());

          m_axisXMinValue += delta;
          m_axisXMaxValue -= delta;
          m_axisZMinValue += delta;
          m_axisZMaxValue -= delta;
          checkConstraints();

          float y = (m_axisXMaxValue - m_axisXMinValue) * m_aspectRatio;

          m_axisX->setRange(m_axisXMinValue, m_axisXMaxValue);
          m_axisY->setRange(100.0f, y);
          m_axisZ->setRange(m_axisZMinValue, m_axisZMaxValue);
      }

      void CustomInputHandler::mouseMoveEvent(QMouseEvent *event, const QPoint &mousePos)
      {
          // Check if we're trying to drag axis label
          if (m_mousePressed && m_state != StateNormal) {
              setPreviousInputPos(inputPosition());
              setInputPosition(mousePos);
              handleAxisDragging();
          } else {
              Q3DInputHandler::mouseMoveEvent(event, mousePos);
          }
      }

      void CustomInputHandler::mouseReleaseEvent(QMouseEvent *event, const QPoint &mousePos)
      {
          Q3DInputHandler::mouseReleaseEvent(event, mousePos);
          m_mousePressed = false;
          m_state = StateNormal;
      }

      void CustomInputHandler::handleElementSelected(QAbstract3DGraph::ElementType type)
      {
          switch (type) {
          case QAbstract3DGraph::ElementAxisXLabel:
              m_state = StateDraggingX;
              break;
          case QAbstract3DGraph::ElementAxisZLabel:
              m_state = StateDraggingZ;
              break;
          default:
              m_state = StateNormal;
              break;
          }
      }

      void CustomInputHandler::handleAxisDragging()
      {
          float distance = 0.0f;

          // Get scene orientation from active camera
          float xRotation = scene()->activeCamera()->xRotation();

          // Calculate directional drag multipliers based on rotation
          float xMulX = qCos(qDegreesToRadians(xRotation));
          float xMulY = qSin(qDegreesToRadians(xRotation));
          float zMulX = qSin(qDegreesToRadians(xRotation));
          float zMulY = qCos(qDegreesToRadians(xRotation));

          // Get the drag amount
          QPoint move = inputPosition() - previousInputPos();

          // Adjust axes
          switch (m_state) {
          case StateDraggingX:
              distance = (move.x() * xMulX - move.y() * xMulY) * m_speedModifier;
              m_axisXMinValue -= distance;
              m_axisXMaxValue -= distance;
              if (m_axisXMinValue < m_areaMinValue) {
                  float dist = m_axisXMaxValue - m_axisXMinValue;
                  m_axisXMinValue = m_areaMinValue;
                  m_axisXMaxValue = m_axisXMinValue + dist;
              }
              if (m_axisXMaxValue > m_areaMaxValue) {
                  float dist = m_axisXMaxValue - m_axisXMinValue;
                  m_axisXMaxValue = m_areaMaxValue;
                  m_axisXMinValue = m_axisXMaxValue - dist;
              }
              m_axisX->setRange(m_axisXMinValue, m_axisXMaxValue);
              break;
          case StateDraggingZ:
              distance = (move.x() * zMulX + move.y() * zMulY) * m_speedModifier;
              m_axisZMinValue += distance;
              m_axisZMaxValue += distance;
              if (m_axisZMinValue < m_areaMinValue) {
                  float dist = m_axisZMaxValue - m_axisZMinValue;
                  m_axisZMinValue = m_areaMinValue;
                  m_axisZMaxValue = m_axisZMinValue + dist;
              }
              if (m_axisZMaxValue > m_areaMaxValue) {
                  float dist = m_axisZMaxValue - m_axisZMinValue;
                  m_axisZMaxValue = m_areaMaxValue;
                  m_axisZMinValue = m_axisZMaxValue - dist;
              }
              m_axisZ->setRange(m_axisZMinValue, m_axisZMaxValue);
              break;
          default:
              break;
          }
      }

      void CustomInputHandler::checkConstraints()
      {
          if (m_axisXMinValue < m_areaMinValue)
              m_axisXMinValue = m_areaMinValue;
          if (m_axisXMaxValue > m_areaMaxValue)
              m_axisXMaxValue = m_areaMaxValue;
          // Don't allow too much zoom in
          if ((m_axisXMaxValue - m_axisXMinValue) < m_axisXMinRange) {
              float adjust = (m_axisXMinRange - (m_axisXMaxValue - m_axisXMinValue)) / 2.0f;
              m_axisXMinValue -= adjust;
              m_axisXMaxValue += adjust;
          }

          if (m_axisZMinValue < m_areaMinValue)
              m_axisZMinValue = m_areaMinValue;
          if (m_axisZMaxValue > m_areaMaxValue)
              m_axisZMaxValue = m_areaMaxValue;
          // Don't allow too much zoom in
          if ((m_axisZMaxValue - m_axisZMinValue) < m_axisZMinRange) {
              float adjust = (m_axisZMinRange - (m_axisZMaxValue - m_axisZMinValue)) / 2.0f;
              m_axisZMinValue -= adjust;
              m_axisZMaxValue += adjust;
          }
      }