Flat button helper class.
This is a helper class to generate a flat [Button] (see [member Button.flat]), creating a [ToolButton] is equivalent to:
[codeblock]
var btn = Button.new()
btn.flat = true
[/codeblock]
[StyleBox] used when the [ToolButton] is disabled.
[StyleBox] used when the [ToolButton] is focused. It is displayed over the current [StyleBox], so using [StyleBoxEmpty] will just disable the focus visual effect.
[Font] of the [ToolButton]'s text.
Default text [Color] of the [ToolButton].
Text [Color] used when the [ToolButton] is disabled.
Text [Color] used when the [ToolButton] is focused. Only replaces the normal text color of the button. Disabled, hovered, and pressed states take precedence over this color.
Text [Color] used when the [ToolButton] is being hovered.
Text [Color] used when the [ToolButton] is being pressed.
[StyleBox] used when the [ToolButton] is being hovered.
The horizontal space between [ToolButton]'s icon and text.
Default [StyleBox] for the [ToolButton].
[StyleBox] used when the [ToolButton] is being pressed.