| name | ui-leanback |
| description | Trigger: TV UI & Media Clients. Implementing Leanback-compliant interfaces, handling D-pad focus, View Binding, and Glide image loading. |
UI Leanback & Media Client Standards
View Binding Implementation
Mandatory for all new UI and refactors. Replaces findViewById.
In Activities
private lateinit var binding: ActivityExampleBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityExampleBinding.inflate(layoutInflater)
setContentView(binding.root)
}
In Fragments
private var _binding: FragmentExampleBinding? = null
private val binding get() = _binding!!
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
_binding = FragmentExampleBinding.inflate(inflater, container, false)
return binding.root
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
Handling Includes
val progressBinding = IncludeLoadingProgressBinding.bind(binding.root)
Image Loading with Glide
Standard for all image loading and caching.
Glide.with(context)
.load(url)
.placeholder(R.drawable.default_video_still)
.error(R.drawable.default_error)
.into(binding.imageView)
Animations (XML Only)
MotionLayout is prohibited. Use XML animations in res/anim.
Example Fade In (res/anim/fade_in.xml)
<alpha xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="@android:anim/accelerate_interpolator"
android:fromAlpha="0.0" android:toAlpha="1.0"
android:duration="300" />
Focus Effects (D-pad Navigation)
Non-negotiable for TV UI. Provide clear visual feedback.
Scale-up on Focus
view.setOnFocusChangeListener { v, hasFocus ->
if (hasFocus) {
v.animate().scaleX(1.1f).scaleY(1.1f).setDuration(200).start()
} else {
v.animate().scaleX(1.0f).scaleY(1.0f).setDuration(200).start()
}
}
Alternatively, use a drawable selector with a border or background change.
