OptionalfillTooltip label for the Fill button.
OptionalgapGap in pixels between the object's bottom edge and the menu.
OptionallineTooltip label for the Line button.
OptionalnoTooltip label for the "no color / transparent" swatch.
Called when delete is clicked.
Called when duplicate is clicked.
Called when a swatch is clicked. color is null when the user picks
the "transparent" option, allowing the caller to clear that property.
Colors offered as swatches in the Fill / Line popovers.
The Fabric canvas to observe selection/transform events on.