With below function you can set shadow for text (label or i think edittext)
B4X:
Sub SetTextShadow(pView As View, pRadius As Float, pDx As Float, pDy As Float, pColor As Int)
Dim ref As Reflector
ref.Target = pView
ref.RunMethod4("setShadowLayer", Array As Object(pRadius, pDx, pDy, pColor), Array As String("java.lang.float", "java.lang.float", "java.lang.float", "java.lang.int"))
End Sub