Paintable.invalidateSize

Called by implementations of [gdk.paintable.Paintable] to invalidate their size.

As long as the size is not invalidated, paintable must return the same values for its intrinsic width, height and aspect ratio.

This function will emit the signalGdk.Paintable::invalidate-size signal.

If a paintable reports the [gdk.types.PaintableFlags.Size] flag, it must not call this function.