MouseOverWatcher

/*
  ==============================================================================

    MouseOverChecker.h
    Created: 13 Aug 2019 1:26:42pm
    Author:  Daniel Walz

  ==============================================================================
*/

#pragma once

class MouseOverChecker : public MouseListener
{
public:
    MouseOverChecker (Component& componentToWatch) : watchedComponent (componentToWatch)
    {
        watchedComponent.addMouseListener (this, true);
    }

    ~MouseOverChecker()
    {
        watchedComponent.removeMouseListener (this);
    }

    void mouseEnter (const MouseEvent&) override
    {
        if (mouseIsOver == false)
        {
            mouseIsOver = true;
            if (onMouseEnter != nullptr)
                onMouseEnter();
        }
    }

    void mouseExit (const MouseEvent&) override
    {
        if (mouseIsOver == true)
        {
            mouseIsOver = false;
            if (onMouseExit != nullptr)
                onMouseExit();
        }
    }

    std::function<void()> onMouseEnter;
    std::function<void()> onMouseExit;

private:
    Component& watchedComponent;

    bool mouseIsOver = false;
    
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MouseOverChecker);
};

// example usage:
/*
// members:
bool highlight = false;
MouseOverChecker overChecker {*this};

// in Constructor after all "addAndMakeVisible()" calls:
overChecker.onMouseEnter = [&]
{
    highlight = true;
    Timer::callAfterDelay (50, [this] { repaint(); });
};
overChecker.onMouseExit = [&]
{
    highlight = false;
    // the delay allows the mouseEnter of the other child to occur
    Timer::callAfterDelay (50, [this] { repaint(); });
};

// and use the "highlight" flag in your "paint()"
*/

Ah well, there are different views about that. It is a header, and I usually have the #include "JuceHeader.h" at the beginning of each cpp file. I aim for no includes in headers, but there are different opinions on that, I know...