IndustrialKnob.h

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/*
 * SPDX-FileCopyrightText: 2026 Paolo Sereno <paolomsereno@gmail.com>
 *
 * SPDX-License-Identifier: MIT
 */
 
#pragma once
 
#include <QtIndustrialWidgets/qtindustrialwidgets_global.h>
#include <QtWidgets/QWidget>
#include <QtGui/QColor>
#include <memory>
 
namespace QtIndustrialWidgets {
 
class IndustrialKnobPrivate;
 
class QTINDUSTRIALWIDGETS_EXPORT IndustrialKnob : public QWidget
{
    Q_OBJECT
 
    Q_PROPERTY(double minimum READ minimum WRITE setMinimum NOTIFY rangeChanged)
    Q_PROPERTY(double maximum READ maximum WRITE setMaximum NOTIFY rangeChanged)
    Q_PROPERTY(double value READ value WRITE setValue NOTIFY valueChanged)
    Q_PROPERTY(double step READ step WRITE setStep NOTIFY appearanceChanged)
    Q_PROPERTY(int precision READ precision WRITE setPrecision NOTIFY appearanceChanged)
    Q_PROPERTY(QString unit READ unit WRITE setUnit NOTIFY appearanceChanged)
    Q_PROPERTY(double startAngle READ startAngle WRITE setStartAngle NOTIFY appearanceChanged)
    Q_PROPERTY(double spanAngle READ spanAngle WRITE setSpanAngle NOTIFY appearanceChanged)
    Q_PROPERTY(int majorTicks READ majorTicks WRITE setMajorTicks NOTIFY appearanceChanged)
    Q_PROPERTY(int minorTicks READ minorTicks WRITE setMinorTicks NOTIFY appearanceChanged)
    Q_PROPERTY(KnobMode mode READ mode WRITE setMode NOTIFY modeChanged)
    Q_PROPERTY(int discreteSteps READ discreteSteps WRITE setDiscreteSteps NOTIFY appearanceChanged)
    Q_PROPERTY(bool trackVisible READ isTrackVisible WRITE setTrackVisible NOTIFY appearanceChanged)
    Q_PROPERTY(bool valueDisplayVisible READ isValueDisplayVisible WRITE setValueDisplayVisible NOTIFY appearanceChanged)
    Q_PROPERTY(QColor knobColor READ knobColor WRITE setKnobColor NOTIFY appearanceChanged)
    Q_PROPERTY(QColor pointerColor READ pointerColor WRITE setPointerColor NOTIFY appearanceChanged)
    Q_PROPERTY(QColor scaleColor READ scaleColor WRITE setScaleColor NOTIFY appearanceChanged)
    Q_PROPERTY(QColor trackColor READ trackColor WRITE setTrackColor NOTIFY appearanceChanged)
    Q_PROPERTY(QColor textColor READ textColor WRITE setTextColor NOTIFY appearanceChanged)
 
public:
    enum class KnobMode {
        Continuous, 
        Discrete    
    };
    Q_ENUM(KnobMode)
 
    
    explicit IndustrialKnob(QWidget *parent = nullptr);
    ~IndustrialKnob() override;
 
    [[nodiscard]] double minimum() const;
    [[nodiscard]] double maximum() const;
    [[nodiscard]] double value() const;
    [[nodiscard]] double step() const;
    [[nodiscard]] int precision() const;
    [[nodiscard]] QString unit() const;
    [[nodiscard]] double startAngle() const;
    [[nodiscard]] double spanAngle() const;
    [[nodiscard]] int majorTicks() const;
    [[nodiscard]] int minorTicks() const;
    [[nodiscard]] KnobMode mode() const;
    [[nodiscard]] int discreteSteps() const;
    [[nodiscard]] bool isTrackVisible() const;
    [[nodiscard]] bool isValueDisplayVisible() const;
 
    [[nodiscard]] QColor knobColor() const;
    [[nodiscard]] QColor pointerColor() const;
    [[nodiscard]] QColor scaleColor() const;
    [[nodiscard]] QColor trackColor() const;
    [[nodiscard]] QColor textColor() const;
 
    [[nodiscard]] QSize sizeHint() const override;
    [[nodiscard]] QSize minimumSizeHint() const override;
 
public Q_SLOTS:
    void setValue(double value);
    void setMinimum(double min);
    void setMaximum(double max);
    void setRange(double min, double max);
    void setStep(double step);
    void setPrecision(int precision);
    void setUnit(const QString &unit);
    void setStartAngle(double angle);
    void setSpanAngle(double span);
    void setMajorTicks(int count);
    void setMinorTicks(int count);
    void setMode(KnobMode mode);
    void setDiscreteSteps(int steps);
    void setTrackVisible(bool visible);
    void setValueDisplayVisible(bool visible);
 
    void setKnobColor(const QColor &color);
    void setPointerColor(const QColor &color);
    void setScaleColor(const QColor &color);
    void setTrackColor(const QColor &color);
    void setTextColor(const QColor &color);
 
Q_SIGNALS:
    void valueChanged(double value);
    void rangeChanged(double min, double max);
    void modeChanged(KnobMode mode);
    void appearanceChanged();
 
protected:
    void paintEvent(QPaintEvent *event) override;
    void resizeEvent(QResizeEvent *event) override;
    void changeEvent(QEvent *event) override;
    void mousePressEvent(QMouseEvent *event) override;
    void mouseMoveEvent(QMouseEvent *event) override;
    void mouseReleaseEvent(QMouseEvent *event) override;
    void wheelEvent(QWheelEvent *event) override;
    void keyPressEvent(QKeyEvent *event) override;
 
private:
    void invalidateCache();
    void renderStaticScale(const QSize &size);
    [[nodiscard]] double valueToAngle(double val) const;
    [[nodiscard]] double angleToValue(double angle) const;
    void updateValueFromPoint(const QPointF &pos);
 
    std::unique_ptr<IndustrialKnobPrivate> d_ptr;
    Q_DECLARE_PRIVATE(IndustrialKnob)
};
 
} // namespace QtIndustrialWidgets