FragmentInsetsComposeView

FragmentInsetsComposeView.kt

/*
 * Copyright 2021 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
 *
 *      https://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 dev.chrisbanes.accompanist.insets

import android.content.Context
import android.util.AttributeSet
import android.view.ViewGroup
import android.view.WindowInsets
import android.widget.FrameLayout
import androidx.compose.runtime.Composable
import androidx.compose.ui.platform.ComposeView

/**
 * A huge giant hack to help with https://github.com/chrisbanes/accompanist/issues/155.
 *
 * At the moment Compose will layout on the first [onMeasure] call. Now for fragments, they usually
 * will not receive [WindowInsets] (via [dispatchApplyWindowInsets] until the
 * second (or third) [onMeasure]. This creates the flicker.
 *
 * This class can be used in place of [ComposeView]. It ignores any [onMeasure] calls
 * until we've received some insets. This is dangerous though, as a view may never receive any
 * [WindowInsets] for valid reasons. To try and combat that, there's a limit to how many
 * [onMeasure] calls can be ignored.
 */
class FragmentInsetsComposeView @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = 0
) : FrameLayout(context, attrs, defStyleAttr) {
    private var measureCalls = 0
    private var applyInsetsRequested = false

    @Suppress("DEPRECATION")
    override fun requestFitSystemWindows() {
        applyInsetsRequested = true
        super.requestFitSystemWindows()
    }

    override fun dispatchApplyWindowInsets(insets: WindowInsets?): WindowInsets {
        return super.dispatchApplyWindowInsets(insets).also {
            applyInsetsRequested = false
        }
    }

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        if (measureCalls < MAXIMUM_ONMEASURE_IGNORED && applyInsetsRequested) {
            setMeasuredDimension(
                MeasureSpec.getSize(widthMeasureSpec),
                MeasureSpec.getSize(heightMeasureSpec)
            )
        } else {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec)
        }

        measureCalls++
    }

    val composeView: ComposeView = ComposeView(context)

    init {
        addView(
            composeView,
            ViewGroup.LayoutParams.MATCH_PARENT,
            ViewGroup.LayoutParams.MATCH_PARENT
        )
    }

    /**
     * Set the Jetpack Compose UI content for this view.
     *
     * @see [ComposeView.setContent].
     */
    fun setContent(content: @Composable () -> Unit) = composeView.setContent(content)

    companion object {
        private const val MAXIMUM_ONMEASURE_IGNORED = 5
    }
}

Sample.kt

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.compose.runtime.Providers
import androidx.fragment.app.Fragment
import dev.chrisbanes.accompanist.insets.FragmentInsetsComposeView
import dev.chrisbanes.accompanist.insets.LocalWindowInsets
import dev.chrisbanes.accompanist.insets.ViewWindowInsetObserver

class MyFragment : Fragment() {
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View = FragmentInsetsComposeView(requireContext()).apply {
        layoutParams = ViewGroup.LayoutParams(
            ViewGroup.LayoutParams.MATCH_PARENT,
            ViewGroup.LayoutParams.MATCH_PARENT
        )

        val windowInsets = ViewWindowInsetObserver(this).start(consumeWindowInsets = false)

        setContent {
            Providers(
                LocalWindowInsets provides windowInsets
            ) {
                // content
            }
        }
    }
}

Providers has been renamed to CompositionLocalProvider
https://developer.android.com/jetpack/androidx/releases/compose-runtime