Fix camera settings item blinking (EXPOSUREAPP-6337)

[mtwalli]

• With the introduction of intervalFlow in CheckIns screen causes a refresh every second, when Camera item is displayed it had blinking effect to avoid that this PR create only one item lazily
• Fix typo

[d4rken]

Works for me, as the CameraItem was only instantiated once in init. The other solution would be to use HasPayloadDiffer.

[mtwalli]

Works for me, as the CameraItem was only instantiated once in init. The other solution would be to use HasPayloadDiffer.

I did try it as :

 override fun diffPayload(old: Any, new: Any): Any? = null

did not work for me , not sure if this how it should be ?

[d4rken]

did not work for me , not sure if this how it should be ?

You need to return a non-null value.

cwa-app-android/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/util/lists/diffutil/SmartDiffUtil.kt

Lines 24 to 39 in c9cabdc

	class AsyncDiffer<T : HasStableId>(
	adapter: RecyclerView.Adapter<*>,
	compareItem: (T, T) -> Boolean = { i1, i2 -> i1.stableId == i2.stableId },
	compareItemContent: (T, T) -> Boolean = { i1, i2 -> i1 == i2 },
	determinePayload: (T, T) -> Any? = { i1, i2 ->
	when {
	i1 is HasPayloadDiffer && i1::class == i2::class -> i1.diffPayload(i1, i2)
	else -> null
	}
	}
	) {
	private val callback = object : DiffUtil.ItemCallback<T>() {
	override fun areItemsTheSame(oldItem: T, newItem: T): Boolean = compareItem(oldItem, newItem)
	override fun areContentsTheSame(oldItem: T, newItem: T): Boolean = compareItemContent(oldItem, newItem)
	override fun getChangePayload(oldItem: T, newItem: T): Any? = determinePayload(oldItem, newItem)
	}

Other cards we have use this pattern:

cwa-app-android/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/submission/ui/homecards/TestErrorCard.kt

Lines 34 to 36 in c9cabdc

	) : TestResultItem, HasPayloadDiffer {
	override fun diffPayload(old: Any, new: Any): Any? = if (old::class == new::class) new else null
	}

then

cwa-app-android/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/submission/ui/homecards/TestErrorCard.kt

Lines 22 to 29 in c9cabdc

	override val onBindData: HomeSubmissionStatusCardErrorBinding.(
	item: Item,
	payloads: List<Any>
	) -> Unit = { item, payloads ->
	val curItem = payloads.filterIsInstance<Item>().singleOrNull() ?: item
	itemView.setOnClickListener { curItem.onDeleteTest(item) }
	showTestAction.setOnClickListener { itemView.performClick() }
	}

The idea being that we want to replace any stale on-click listeners that may reference something that no longer exists due to recreation on lifecycle events. Not sure if it's necessary in this case, but using the payload mechanism tells the RecyclerView that we will take care of any layout that is necessary, so you may be able to just return Any() as payload diff.

[mtwalli]

did not work for me , not sure if this how it should be ?

You need to return a non-null value.

cwa-app-android/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/util/lists/diffutil/SmartDiffUtil.kt

Lines 24 to 39 in c9cabdc

	class AsyncDiffer<T : HasStableId>(
	adapter: RecyclerView.Adapter<*>,
	compareItem: (T, T) -> Boolean = { i1, i2 -> i1.stableId == i2.stableId },
	compareItemContent: (T, T) -> Boolean = { i1, i2 -> i1 == i2 },
	determinePayload: (T, T) -> Any? = { i1, i2 ->
	when {
	i1 is HasPayloadDiffer && i1::class == i2::class -> i1.diffPayload(i1, i2)
	else -> null
	}
	}
	) {
	private val callback = object : DiffUtil.ItemCallback<T>() {
	override fun areItemsTheSame(oldItem: T, newItem: T): Boolean = compareItem(oldItem, newItem)
	override fun areContentsTheSame(oldItem: T, newItem: T): Boolean = compareItemContent(oldItem, newItem)
	override fun getChangePayload(oldItem: T, newItem: T): Any? = determinePayload(oldItem, newItem)
	}

Other cards we have use this pattern:

cwa-app-android/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/submission/ui/homecards/TestErrorCard.kt

Lines 34 to 36 in c9cabdc

	) : TestResultItem, HasPayloadDiffer {
	override fun diffPayload(old: Any, new: Any): Any? = if (old::class == new::class) new else null
	}

then

cwa-app-android/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/submission/ui/homecards/TestErrorCard.kt

Lines 22 to 29 in c9cabdc

	override val onBindData: HomeSubmissionStatusCardErrorBinding.(
	item: Item,
	payloads: List<Any>
	) -> Unit = { item, payloads ->
	val curItem = payloads.filterIsInstance<Item>().singleOrNull() ?: item
	itemView.setOnClickListener { curItem.onDeleteTest(item) }
	showTestAction.setOnClickListener { itemView.performClick() }
	}

The idea being that we want to replace any stale on-click listeners that may reference something that no longer exists due to recreation on lifecycle events. Not sure if it's necessary in this case, but using the payload mechanism tells the RecyclerView that we will take care of any layout that is necessary, so you may be able to just return Any() as payload diff.

In this case , current solution is sufficient, item does not change and click listener does not any data

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

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0.0% Duplication

[harambasicluka]

@mtwalli how do I get this card? Tried it on an Xiamoi Mi (Android 9) and Oneplus 6t (Android 10) by clicking deny in the scanning screen.

[harambasicluka]

@mtwalli how do I get this card? Tried it on an Xiamoi Mi (Android 9) and Oneplus 6t (Android 10) by clicking deny in the scanning screen.

Ok found it, you have deny once and then the second time you get asked if you don't want to be asked again.

Works on both devices :)