qcustomplot示例程序-axis-tags代码分析

axistag.h

/***************************************************************************
**                                                                        **
**  QCustomPlot, an easy to use, modern plotting widget for Qt            **
**  Copyright (C) 2011-2022 Emanuel Eichhammer                            **
**                                                                        **
**  This program is free software: you can redistribute it and/or modify  **
**  it under the terms of the GNU General Public License as published by  **
**  the Free Software Foundation, either version 3 of the License, or     **
**  (at your option) any later version.                                   **
**                                                                        **
**  This program is distributed in the hope that it will be useful,       **
**  but WITHOUT ANY WARRANTY; without even the implied warranty of        **
**  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         **
**  GNU General Public License for more details.                          **
**                                                                        **
**  You should have received a copy of the GNU General Public License     **
**  along with this program.  If not, see http://www.gnu.org/licenses/.   **
**                                                                        **
****************************************************************************
**           Author: Emanuel Eichhammer                                   **
**  Website/Contact: https://www.qcustomplot.com/                         **
**             Date: 06.11.22                                             **
**          Version: 2.1.1                                                **
****************************************************************************/

#ifndef AXISTAG_H
#define AXISTAG_H

#include <QObject>
#include "qcustomplot.h"

class AxisTag : public QObject
{
   
   
  Q_OBJECT
public:
  explicit AxisTag(QCPAxis *parentAxis);
  virtual ~AxisTag();
  
  // setters:
  void setPen(const QPen &pen);
  void setBrush(const QBrush &brush);
  void setText(const QString &text);
  
  // getters:
  QPen pen() const {
   
    return mLabel->pen(); }
  QBrush brush() const {
   
    return mLabel->brush(); }
  QString text() const {
   
    return mLabel->text(); }
  
  // other methods:
  void updatePosition(double value);
  
protected:
  QCPAxis *mAxis;
  QPointer<QCPItemTracer> mDummyTracer;
  QPointer<QCPItemLine> mArrow;
  QPointer<QCPItemText> mLabel;
};


#endif // AXISTAG_H

axistag.cpp

/***************************************************************************
**                                                                        **
**  QCustomPlot, an easy to use, modern plotting widget for Qt            **
**  Copyright (C) 2011-2022 Emanuel Eichhammer                            **
**                                                                        **
**  This program is free software: you can redistribute it and/or modify  **
**  it under the terms of the GNU General Public License as published by  **
**  the Free Software Foundation, either version 3 of the License, or     **
**  (at your option) any later version.                                   **
**                                                                        **
**  This program is distributed in the hope that it will be useful,       **
**  but WITHOUT ANY WARRANTY; without even the implied warranty of        **
**  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         **
**  GNU General Public License for more details.                          **
**                                                                        **
**  You should have received a copy of the GNU General Public License     **
**  along with this program.  If not, see http://www.gnu.org/licenses/.   **
**                                                                        **
****************************************************************************
**           Author: Emanuel Eichhammer                                   **
**  Website/Contact: https://www.qcustomplot.com/                         **
**             Date: 06.11.22                                             **
**          Version: 2.1.1                                                **
****************************************************************************/

#include "axistag.h"

AxisTag::AxisTag(QCPAxis *parentAxis) :
  QObject(parentAxis),
  mAxis(parentAxis)
{
   
   
  // The dummy tracer serves here as an invisible anchor which always sticks to the right side of
  // the axis rect
  mDummyTracer = new QCPItemTracer(mAxis->parentPlot());
  mDummyTracer->setVisible(false);
  mDummyTracer->position->setTypeX