Makes a JUCE component grayscale.

MonochromeEffect.h

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

    MonochromeEffect.h
    Created: 18 Feb 2018 6:47:14pm
    Author:  Tal@SoundRadix

  ==============================================================================
*/
#pragma once

#include "JuceHeader.h"

//==============================================================================
/**
 An effect filter that simple makes image monochrome.
 (This will only work on images/components that aren't opaque, of course).
 @see Component::setComponentEffect
 */
class MonochromeEffect  : public ImageEffectFilter
{
public:
    //==============================================================================
    /** Creates a default drop-shadow effect.
     To customise the shadow's appearance, use the setShadowProperties() method.
     @param backgroundColour (optional) - for some alpha values you might prefer a background (such as black).
     */
    MonochromeEffect(juce::Colour backgroundColour = juce::Colours::transparentBlack) { bgColour_ = backgroundColour; }

    /** Destructor. */
    ~MonochromeEffect() {}

    //==============================================================================
    /** @internal */
    void applyEffect (juce::Image& image, juce::Graphics& g, float scaleFactor, float alpha)
    {
        g.fillAll(bgColour_);
        image.desaturate();
        g.setOpacity (alpha);
        g.drawImageAt (image, 0, 0);
    }
private:
    //==============================================================================
    juce::Colour bgColour_;
    JUCE_LEAK_DETECTOR (MonochromeEffect)
};