Example.kt

import android.graphics.Typeface
import androidx.compose.runtime.Composable
import androidx.compose.runtime.remember
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp
import com.patrykandpatrick.vico.compose.cartesian.CartesianChartHost
import com.patrykandpatrick.vico.compose.cartesian.axis.rememberAxisLabelComponent
import com.patrykandpatrick.vico.compose.cartesian.axis.rememberAxisLineComponent
import com.patrykandpatrick.vico.compose.cartesian.axis.rememberStartAxis
import com.patrykandpatrick.vico.compose.cartesian.fullWidth
import com.patrykandpatrick.vico.compose.cartesian.layer.rememberColumnCartesianLayer
import com.patrykandpatrick.vico.compose.cartesian.rememberCartesianChart
import com.patrykandpatrick.vico.compose.cartesian.rememberVicoScrollState
import com.patrykandpatrick.vico.compose.common.of
import com.patrykandpatrick.vico.core.cartesian.CartesianDrawContext
import com.patrykandpatrick.vico.core.cartesian.HorizontalLayout
import com.patrykandpatrick.vico.core.cartesian.axis.AxisPosition
import com.patrykandpatrick.vico.core.cartesian.axis.HorizontalAxis
import com.patrykandpatrick.vico.core.cartesian.data.CartesianChartModelProducer
import com.patrykandpatrick.vico.core.cartesian.data.CartesianValueFormatter
import com.patrykandpatrick.vico.core.cartesian.data.columnSeries
import com.patrykandpatrick.vico.core.common.Dimensions
import com.patrykandpatrick.vico.core.common.VerticalPosition
import com.patrykandpatrick.vico.core.common.component.LineComponent
import com.patrykandpatrick.vico.core.common.component.TextComponent
import java.time.LocalTime
import java.time.format.DateTimeFormatter
import kotlin.random.Random

private class BottomAxis(
    label: TextComponent,
    private val labelPredicate: CartesianDrawContext.(Float) -> Boolean,
    line: LineComponent,
) : HorizontalAxis<AxisPosition.Horizontal.Bottom>(AxisPosition.Horizontal.Bottom) {

    init {
        this.label = label
        valueFormatter = Companion.valueFormatter
        axisLine = line
        guideline
    }

    override fun drawBehindChart(context: CartesianDrawContext) {
        with(context) {
            val baseCanvasX =
                (if (isLtr) bounds.left else bounds.right) - horizontalScroll +
                    horizontalDimensions.startPadding * layoutDirectionMultiplier
            val maxLabelHeight = (bounds.height() - axisThickness / 2).toInt()
            val labelCanvasY = bounds.top + axisThickness
            val labelX = buildList {
                var x = chartValues.minX
                while (x <= chartValues.maxX) {
                    if (labelPredicate(x)) add(x)
                    x += chartValues.xStep
                }
            }
            labelX.forEachIndexed { index, x ->
                val text = valueFormatter.format(value = x, chartValues = chartValues, verticalAxisPosition = null)
                var canvasX =
                    baseCanvasX +
                        (x - chartValues.minX) / chartValues.xStep *
                            horizontalDimensions.xSpacing *
                            layoutDirectionMultiplier
                if (index == 0 || index == labelX.lastIndex) {
                    val width = label?.getWidth(context = this, text = text, height = maxLabelHeight) ?: 0f
                    canvasX =
                        if (isLtr && index == 0 || !isLtr && index == labelX.lastIndex) {
                            canvasX.coerceAtLeast(bounds.left + width / 2)
                        } else {
                            canvasX.coerceAtMost(bounds.right - width / 2)
                        }
                }
                label?.drawText(
                    context = this,
                    text = text,
                    textX = canvasX,
                    textY = labelCanvasY,
                    verticalPosition = VerticalPosition.Bottom,
                    maxTextHeight = maxLabelHeight,
                    rotationDegrees = labelRotationDegrees,
                )
            }
            axisLine?.drawHorizontal(
                context = context,
                left = chartBounds.left,
                right = chartBounds.right,
                centerY = bounds.top + axisThickness / 2,
            )
        }
    }

    private companion object {
        val dateTimeFormatter: DateTimeFormatter = DateTimeFormatter.ofPattern("hh:mm a")
        val valueFormatter = CartesianValueFormatter { x, _, _ -> dateTimeFormatter.format(LocalTime.of(x.toInt(), 0)) }
    }
}

@Composable
private fun rememberBottomAxis(labelPredicate: CartesianDrawContext.(Float) -> Boolean): BottomAxis {
    val label = rememberAxisLabelComponent(padding = Dimensions.of(vertical = 2.dp), typeface = Typeface.DEFAULT)
    val line = rememberAxisLineComponent()
    return remember(label, line) { BottomAxis(label, labelPredicate, line) }
}

@Preview(showBackground = true)
@Composable
private fun Example() {
    val modelProducer = remember {
        CartesianChartModelProducer.build {
            columnSeries { series(x = List(48) { it / 2f }, y = List(48) { (Random.nextFloat() + 1) / 2 }) }
        }
    }
    CartesianChartHost(
        chart =
            rememberCartesianChart(
                rememberColumnCartesianLayer(spacing = 2.dp),
                startAxis =
                    rememberStartAxis(label = rememberAxisLabelComponent(typeface = Typeface.DEFAULT), tick = null),
                bottomAxis = rememberBottomAxis { it % 6f == 0f || it == 23f },
            ),
        modelProducer = modelProducer,
        scrollState = rememberVicoScrollState(scrollEnabled = false),
        horizontalLayout = HorizontalLayout.fullWidth(scalableStartPadding = 2.dp, scalableEndPadding = 2.dp),
    )
}