Click the button in any position, show a list of menu
// 1. Create view model, including title and image name.
let arrowMenuViewModel0 = DPArrowMenuViewModel(title: "Find Teachers",
imageName: "iconProfessionalTeacherSemiBlack")
let arrowMenuViewModel1 = DPArrowMenuViewModel(title: "Find Language Partners",
imageName: "iconUserFriendsSemiBlack24")
viewModels.append(arrowMenuViewModel0)
viewModels.append(arrowMenuViewModel1)
// 2. Bind action, when user selects one of them
DPArrowMenu.show(view, viewModels: viewModels, done: { index in
print(index)
}) {
print("cancel")
}