- Qt 6.6
- Qt Graphs
- Graph Gallery
- Qt Graphs | Commercial or GPLv3

# Graph Gallery

     // Copyright (C) 2023 The Qt Company Ltd.
     // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

     #include "axesinputhandler.h"
     #include <QtCore/qmath.h>

     AxesInputHandler::AxesInputHandler(QAbstract3DGraph *graph, QObject *parent) :
         Q3DInputHandler(parent)
     {
         // Connect to the item selection signal from graph
         connect(graph, &QAbstract3DGraph::selectedElementChanged, this,
                 &AxesInputHandler::handleElementSelected);
     }

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

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

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

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

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

         // 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();

         // Flip the effect of y movement if we're viewing from below
         float yMove = (yRotation < 0) ? -move.y() : move.y();

         // Adjust axes
         switch (m_state) {
         case StateDraggingX:
             distance = (move.x() * xMulX - yMove * xMulY) / m_speedModifier;
             m_axisX->setRange(m_axisX->min() - distance, m_axisX->max() - distance);
             break;
         case StateDraggingZ:
             distance = (move.x() * zMulX + yMove * zMulY) / m_speedModifier;
             m_axisZ->setRange(m_axisZ->min() + distance, m_axisZ->max() + distance);
             break;
         case StateDraggingY:
             distance = move.y() / m_speedModifier; // No need to use adjusted y move here
             m_axisY->setRange(m_axisY->min() + distance, m_axisY->max() + distance);
             break;
         default:
             break;
         }
     }