AndroidViewBinding.kt
/*
* Copyright 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.compose.ui.viewinterop
import android.content.Context
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.FrameLayout
import androidx.compose.runtime.Composable
import androidx.compose.runtime.remember
import androidx.compose.ui.Modifier
import androidx.compose.ui.node.Ref
import androidx.viewbinding.ViewBinding
/**
* Composes an Android layout resource in the presence of [ViewBinding]. The binding is obtained
* from the [factory] block, which will be called exactly once to obtain the [ViewBinding]
* to be composed, and it is also guaranteed to be invoked on the UI thread.
* Therefore, in addition to creating the [ViewBinding], the block can also be used
* to perform one-off initializations and [View] constant properties' setting.
* The [update] block can be run multiple times (on the UI thread as well) due to recomposition,
* and it is the right place to set [View] properties depending on state. When state changes,
* the block will be reexecuted to set the new properties. Note the block will also be ran once
* right after the [factory] block completes.
*
* @sample androidx.compose.ui.samples.AndroidViewBindingSample
*
* @param factory The block creating the [ViewBinding] to be composed.
* @param modifier The modifier to be applied to the layout.
* @param update The callback to be invoked after the layout is inflated.
*/
@Composable
fun <T : ViewBinding> AndroidViewBinding(
factory: (inflater: LayoutInflater, parent: ViewGroup, attachToParent: Boolean) -> T,
modifier: Modifier = Modifier,
update: T.() -> Unit = {}
) {
val viewBindingRef = remember { Ref<T>() }
val viewBlock: (Context) -> View = remember {
{ context ->
val inflater = LayoutInflater.from(context)
val viewBinding = factory(inflater, FrameLayout(context), false)
viewBindingRef.value = viewBinding
viewBinding.root
}
}
AndroidView(
factory = viewBlock,
modifier = modifier,
update = { viewBindingRef.value?.update() }
)
}