compose/foundation/foundation/integration-tests/foundation-demos/src/main/java/androidx/compose/foundation/demos/text/TailFollowingTextField.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.foundation.demos.text

import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.requiredHeight
import androidx.compose.foundation.text.BasicTextField
import androidx.compose.runtime.Composable
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clipToBounds
import androidx.compose.ui.layout.Layout
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.Constraints
import androidx.compose.ui.unit.constrainWidth
import androidx.compose.ui.unit.dp
import kotlin.math.min

@Preview
@Composable
fun TailFollowingTextFieldDemo() {
    Column {
        val hstate = rememberSaveable {
            mutableStateOf("abc def ghi jkl mno pqr stu vwx yz")
        }
        HorizontalTailFollowingTextField(
            value = hstate.value,
            onValueChange = { hstate.value = it },
            modifier = Modifier
                .then(demoTextFieldModifiers)
                .fillMaxWidth()
                .clipToBounds()
        )

        val vstate = rememberSaveable {
            mutableStateOf("a\nb\nc\nd\ne\nf\ng\nh")
        }
        VerticalTailFollowintTextField(
            value = vstate.value,
            onValueChange = { vstate.value = it },
            modifier = Modifier
                .then(demoTextFieldModifiers)
                .fillMaxWidth()
                .requiredHeight(120.dp)
                .clipToBounds()
        )
    }
}

@Composable
private fun HorizontalTailFollowingTextField(
    value: String,
    onValueChange: (String) -> Unit,
    modifier: Modifier,
    textStyle: TextStyle = TextStyle(fontSize = fontSize8)
) {
    Layout(
        content = @Composable {
            BasicTextField(
                value = value,
                onValueChange = onValueChange,
                textStyle = textStyle
            )
        },
        modifier = modifier
    ) { measurable, constraints ->

        val p = measurable[0].measure(
            Constraints(
                minWidth = 0,
                maxWidth = Constraints.Infinity,
                minHeight = constraints.minHeight,
                maxHeight = constraints.maxHeight
            )
        )

        val width = constraints.constrainWidth(p.width)
        val xOffset = min(0, constraints.maxWidth - p.width)

        layout(width, p.height) {
            p.placeRelative(xOffset, 0)
        }
    }
}

@Composable
private fun VerticalTailFollowintTextField(
    value: String,
    onValueChange: (String) -> Unit,
    modifier: Modifier,
    textStyle: TextStyle = TextStyle(fontSize = fontSize8)
) {
    Layout(
        content = @Composable {
            BasicTextField(
                value = value,
                onValueChange = onValueChange,
                textStyle = textStyle
            )
        },
        modifier = modifier
    ) { measurable, constraints ->

        val p = measurable[0].measure(
            Constraints(
                minWidth = constraints.minWidth,
                maxWidth = constraints.maxWidth,
                minHeight = 0,
                maxHeight = Constraints.Infinity
            )
        )

        val height = min(p.height, constraints.maxHeight)
        val yOffset = min(0, constraints.maxHeight - p.height)

        layout(p.width, height) {
            p.placeRelative(0, yOffset)
        }
    }
}