qwt_widget_overlay.h

/******************************************************************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *
 * Modified by ChenZongYan in 2024 <czy.t@163.com>
 *   Summary of major modifications (see ChangeLog.md for full history):
 *   1. CMake build system & C++11 throughout.
 *   2. Core panner/ zoomer refactored:
 *        - QwtPanner → QwtCachePanner (pixmap-cache version)
 *        - New real-time QwtPlotPanner derived from QwtPicker.
 *   3. Zoomer supports multi-axis.
 *   4. Parasite-plot framework:
 *        - QwtFigure, QwtPlotParasiteLayout, QwtPlotTransparentCanvas,
 *        - QwtPlotScaleEventDispatcher, built-in pan/zoom on axis.
 *   5. New picker: QwtPlotSeriesDataPicker (works with date axis).
 *   6. Raster & color-map extensions:
 *        - QwtGridRasterData (2-D table + interpolation)
 *        - QwtLinearColorMap::stopColors(), stopPos() API rename.
 *   7. Bar-chart: expose pen/brush control.
 *   8. Amalgamated build: single QwtPlot.h / QwtPlot.cpp pair in src-amalgamate.
 *****************************************************************************/
 
#ifndef QWT_WIDGET_OVERLAY_H
#define QWT_WIDGET_OVERLAY_H
 
#include "qwt_global.h"
#include <qwidget.h>
 
class QPainter;
class QRegion;
 
class QWT_EXPORT QwtWidgetOverlay : public QWidget
{
    Q_OBJECT
public:
    enum MaskMode
    {
        NoMask,
 
        MaskHint,
 
        AlphaMask
    };
 
    enum RenderMode
    {
        AutoRenderMode,
 
        CopyAlphaMask,
 
        DrawOverlay
    };
 
    // Constructor with parent widget
    explicit QwtWidgetOverlay(QWidget*);
    // Destructor
    ~QwtWidgetOverlay() override;
 
    // Set the mask mode for the overlay
    void setMaskMode(MaskMode);
    // Get the current mask mode
    MaskMode maskMode() const;
 
    // Set the render mode for the overlay
    void setRenderMode(RenderMode);
    // Get the current render mode
    RenderMode renderMode() const;
 
    // Event filter for parent widget resize events
    virtual bool eventFilter(QObject*, QEvent*) override;
 
public Q_SLOTS:
    void updateOverlay();
 
protected:
    virtual void paintEvent(QPaintEvent*) override;
    virtual void resizeEvent(QResizeEvent*) override;
 
    virtual QRegion maskHint() const;
 
    virtual void drawOverlay(QPainter* painter) const = 0;
 
private:
    void updateMask();
    void draw(QPainter*) const;
 
private:
    QWT_DECLARE_PRIVATE(QwtWidgetOverlay)
};
 
#endif