BR: DrawableButton draws background when it shouldn't

General JUCE discussion
1

This seems like a mistake…

The docs for DrawableButton::ButtonStyle give the impression that a DrawableButton’s background will be filled in only when the styles ‘ImageOnButtonBackground’ and ‘ImageOnButtonBackgroundOriginalSize’ are used.

https://docs.juce.com/master/classDrawableButton.html#a7da653337d7329405ef9865cc35f612e

The DrawableButton::paintButton gives the impression that it is decided in that function whether the background is drawn:

    if (shouldDrawButtonBackground())
        lf.drawButtonBackground (g, *this,
                                 findColour (getToggleState() ? TextButton::buttonOnColourId
                                                              : TextButton::buttonColourId),
                                 shouldDrawButtonAsHighlighted, shouldDrawButtonAsDown);
    else
        lf.drawDrawableButton (g, *this, shouldDrawButtonAsHighlighted, shouldDrawButtonAsDown);

However, the ‘else’ branch goes to LookAndFeel_V2::drawDrawableButton which proceeds to fill the background for toggled-on buttons regardless:

g.fillAll (button.findColour (toggleState ? DrawableButton::backgroundOnColourId
                                          : DrawableButton::backgroundColourId));

So then, one is forced to use LnF to get rid of the background.

I would suggest removing the background fill from the drawDrawableButton.