Jetpack Compose中使用自定义Chart

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Jetpack Compose中使用Chart

前言

Jetpack Compose 中没有好用的Chart，这里就自定义Chart，能根据项目需求自定义样式。

BarChart

带分组

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import android.graphics.Paint
import androidx.compose.foundation.Canvas
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.CornerRadius
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.graphics.Brush
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.nativeCanvas
import com.xhkjedu.zxs_android.utils.extension.output
import kotlin.math.ceil

@Composable
fun ZBarChartWithGroup(
    labelArr: List<String> = listOf("一星", "二星", "三星", "四星", "五星"),
    groupNameArr: List<String> = listOf("做题数", "做对数"),
    data: List<List<Float>> = listOf(
        listOf(30f, 20f),
        listOf(50f, 30f),
        listOf(40f, 10f),
        listOf(60f, 20f),
        listOf(20f, 5f),
    ),
    colorArr: List<Color> = listOf(
        Color.Blue,
        Color.Green,
        Color.Yellow,
        Color.Magenta,
        Color.Cyan,
        Color.Gray,
        Color.LightGray,
        Color.DarkGray,
        Color.Black
    ),
    yAxisSegments: Int = 5, // Y轴分段数量
    showYLine: Boolean = true
) {
    Canvas(modifier = Modifier.fillMaxSize()) {
        val canvasWidth = size.width
        val canvasHeight = size.height

        // 边距
        val padding = 40f // 增加左 padding 以容纳Y轴标签
        val groupNameHeight = 20f
        val innerWidth = canvasWidth - padding
        val innerHeight = canvasHeight - padding * 2 - groupNameHeight
        val groupWidth = (innerWidth / labelArr.size)

        // 计算每个柱子的宽度
        val barWidth = ((groupWidth / groupNameArr.size) * 0.8f).coerceIn(8f, 20f)

        // 找到最大值用于比例计算
        val maxValue = data.maxOfOrNull { it.maxOrNull() ?: 1f } ?: 1f
        // 向上取整到最接近的整十数，使Y轴更美观
        val roundedMax = ceil(maxValue / 10) * 10f

        // 绘制坐标轴
        // X轴
        drawLine(
            start = Offset(padding, canvasHeight - padding),
            end = Offset(canvasWidth - padding, canvasHeight - padding),
            color = Color.LightGray,
            strokeWidth = 1f
        )
        if (showYLine) {
            // Y轴
            drawLine(
                start = Offset(padding, padding),
                end = Offset(padding, canvasHeight - padding),
                color = Color.LightGray,
                strokeWidth = 1f
            )
        }

        //绘制group
        val groupSpace = 30f
        val groupRectWith = 20f
        val groupNameWidth = groupNameArr.maxOf { it.length } * 16f + groupRectWith
        val groupNameStartX =
            (canvasWidth - groupNameWidth * groupNameArr.size - groupSpace * (groupNameArr.size - 1)) / 2f
        groupNameArr.forEachIndexed { index, groupName ->
            val groupNameX = groupNameStartX + index * (groupNameWidth + groupSpace)
            val y = canvasHeight - 10f
            val groupColor = colorArr[index]

            drawRoundRect(
                brush = Brush.linearGradient(
                    colors = listOf(groupColor.copy(0.4f), groupColor),
                    start = Offset.Zero,
                    end = Offset(0f, size.height) // 垂直
                ),
                topLeft = Offset(groupNameX, y),
                size = Size(20f, 20f),
                cornerRadius = CornerRadius(4f, 4f)
            )

            drawContext.canvas.nativeCanvas.drawText(
                groupName,
                groupNameX + groupRectWith + 8f,
                y + 14f,
                Paint().apply {
                    textSize = 14f
                    color = android.graphics.Color.BLACK
                    textAlign = Paint.Align.LEFT
                }
            )
        }


        // 绘制Y轴刻度、网格线和数值
        val segmentValue = roundedMax / yAxisSegments
        for (i in 0..yAxisSegments) {
            val value = i * segmentValue
            val y = canvasHeight - padding - (value / roundedMax) * innerHeight

            // 绘制网格线
            drawLine(
                start = Offset(padding, y),
                end = Offset(canvasWidth - padding, y),
                color = Color.LightGray,
                strokeWidth = 1f,
                alpha = 0.5f
            )

            // 绘制Y轴刻度值
            drawContext.canvas.nativeCanvas.drawText(
                value.toInt().toString(),
                padding - 10,
                y + 10,
                Paint().apply {
                    textSize = 14f
                    color = android.graphics.Color.GRAY
                    textAlign = Paint.Align.RIGHT
                }
            )
        }


        val startX = padding
        if (data.size == labelArr.size) {
            // 绘制每个柱子和顶部数值
            labelArr.forEachIndexed { labelIndex, label ->
                val groupX = startX + labelIndex * groupWidth
                // 绘制X轴标签
                drawContext.canvas.nativeCanvas.drawText(
                    label,
                    groupX + groupWidth / 2,
                    canvasHeight - padding + 24,
                    Paint().apply {
                        textSize = 14f
                        color = android.graphics.Color.GRAY
                        textAlign = Paint.Align.CENTER
                    }
                )

                data.get(labelIndex).forEachIndexed { groupIndex, barValue ->
                    val barColor = colorArr[groupIndex]
                    // 计算柱子高度（按比例）
                    val barHeight = (barValue / roundedMax) * innerHeight
                    val barSpace = 10f
                    val barLeftSpace =
                        (groupWidth - barWidth * groupNameArr.size - barSpace * (groupNameArr.size - 1)) / 2
                    // 计算柱子位置
                    val barX = groupX + barLeftSpace + barSpace * groupIndex + barWidth * groupIndex
                    val y = canvasHeight - padding - barHeight

                    // 绘制柱子
                    drawRoundRect(
                        brush = Brush.linearGradient(
                            colors = listOf(barColor.copy(0.4f), barColor),
                            start = Offset.Zero,
                            end = Offset(0f, size.height) // 垂直
                        ),
                        topLeft = Offset(barX, y),
                        size = Size(barWidth, barHeight),
                        cornerRadius = CornerRadius(barWidth / 2, barWidth / 2)
                    )

                    // 在柱顶绘制数值
                    drawContext.canvas.nativeCanvas.drawText(
                        barValue.output(),
                        barX + barWidth / 2,
                        y - 10,
                        Paint().apply {
                            textSize = 14f
                            color = android.graphics.Color.BLACK
                            textAlign = Paint.Align.CENTER
                        }
                    )
                }
            }
        }
    }
}

雷达图

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import android.graphics.Paint
import androidx.compose.foundation.Canvas
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.drawscope.DrawScope
import androidx.compose.ui.graphics.drawscope.Stroke
import androidx.compose.ui.graphics.nativeCanvas
import androidx.compose.ui.graphics.toArgb
import androidx.compose.ui.unit.dp
import kotlin.math.*

@Composable
fun ZRadarChart(
    data: List<Float>,
    valueLabelArr: List<String> = listOf(),
    labels: List<String>,
    gridLevels: Int = 5,
    strokeColor: Color = Color(0xFF2196F3),
    textColor: Color = Color.Gray,
    labelSizeSp: Float = 12f
) {
    require(labels.size == data.size) { "Labels and values must have the same size" }
    require(labels.size >= 3) { "At least 3 axes are required" }
    var maxValue = data.maxOrNull() ?: 1.0f
    maxValue *= 1.1f
    val vLabelArr = mutableListOf<String>()
    if (valueLabelArr.size != data.size) {
        vLabelArr.addAll(data.map { getFloatStr(it) })
    } else {
        vLabelArr.clear()
        vLabelArr.addAll(valueLabelArr)
    }

    Canvas(modifier = Modifier.fillMaxSize()) {
        val radius = (size.minDimension / 2f) * 0.8f
        val center = Offset(size.width / 2, size.height / 2)

        val axisCount = data.size
        val angleStep = (2 * PI).toFloat() / axisCount

        // Draw grid lines (concentric polygons)
        for (level in 1..gridLevels) {
            drawPolygon(
                center,
                radius * level / gridLevels,
                axisCount,
                angleStep,
                color = Color.LightGray.copy(alpha = 0.3f)
            )
        }

        drawGridLines(
            center,
            radius,
            axisCount,
            angleStep,
            color = Color.LightGray.copy(alpha = 0.3f)
        )

        // Draw filled area
        val dataPoints = getDataPoints(center, radius, data, maxValue, angleStep)

        // Draw outline
        drawPolygonOutline(dataPoints, strokeColor)


        val labelPoints = getLabelPoints(center, radius, data, maxValue, angleStep)
        for ((index, offset) in labelPoints.withIndex()) {
            drawLabelCenter(offset, vLabelArr[index], textColor, 8f)
        }

        // Draw labels
        for (i in labels.indices) {
            val label = labels[i]
            val angle = (i * angleStep)
            var textOffset = calculateLabelPosition(center, radius, angle)

            val textWidth = getTextWidth(label, labelSizeSp)
            if (textOffset.x < center.x) {
                textOffset -= Offset(textWidth + 26f, 0f)
            } else {
                textOffset += Offset(26f, 0f)
            }
            textOffset += Offset(0f, labelSizeSp / 2 * density)
            drawLabel(textOffset, label, textColor, labelSizeSp)
        }
    }
}

fun getFloatStr(num: Float): String {
    if (num.toInt() - num == 0f) {
        return num.toInt().toString()
    } else {
        return num.toString()
    }
}

private fun DrawScope.drawPolygon(
    center: Offset,
    radius: Float,
    sides: Int,
    angleStep: Float,
    color: Color
) {
    val path = androidx.compose.ui.graphics.Path().apply {
        moveTo(center.x + radius * cos(-angleStep), center.y + radius * sin(-angleStep))
        for (i in 0 until sides) {
            lineTo(
                center.x + radius * cos(i * angleStep - angleStep),
                center.y + radius * sin(i * angleStep - angleStep)
            )
        }
        close()
    }
    drawPath(path, color, style = Stroke(width = 1.dp.toPx()))
}

private fun DrawScope.drawGridLines(
    center: Offset,
    radius: Float,
    sides: Int,
    angleStep: Float,
    color: Color
) {
    val path = androidx.compose.ui.graphics.Path().apply {

        for (i in 0 until sides) {
            moveTo(center.x, center.y)
            lineTo(
                center.x + radius * cos(i * angleStep),
                center.y + radius * sin(i * angleStep)
            )
        }
        close()
    }
    drawPath(path, color, style = Stroke(width = 1.dp.toPx()))
}

private fun getDataPoints(
    center: Offset,
    radius: Float,
    data: List<Float>,
    maxValue: Float,
    angleStep: Float
): List<Offset> {
    return data.mapIndexed { index, value ->
        val ratio = min(value / maxValue, 1f)
        val angle = index * angleStep
        center + Offset(
            (ratio * radius * cos(angle)),
            (ratio * radius * sin(angle))
        )
    }
}

private fun getLabelPoints(
    center: Offset,
    radius: Float,
    data: List<Float>,
    maxValue: Float,
    angleStep: Float
): List<Offset> {
    return data.mapIndexed { index, value ->
        val ratio = min(value / maxValue, 1f)
        val angle = index * angleStep
        center + Offset(
            ((ratio * radius + 12f) * cos(angle)),
            ((ratio * radius + 12f) * sin(angle))
        )
    }
}

private fun DrawScope.drawPolygonOutline(
    points: List<Offset>,
    color: Color
) {
    if (points.size < 2) return
    val path = androidx.compose.ui.graphics.Path().apply {
        moveTo(points[0].x, points[0].y)
        points.forEach { lineTo(it.x, it.y) }
        close()
    }
    drawPath(path, color, style = Stroke(width = 2f))
}

private fun calculateLabelPosition(center: Offset, radius: Float, angle: Float): Offset {
    return center + Offset((radius) * cos(angle), (radius) * sin(angle))
}

private fun DrawScope.getTextWidth(text: String, textSizeSp: Float): Float {
    val paint = android.graphics.Paint().apply {
        this.textSize = textSizeSp * density  // 转换为 px
        typeface = android.graphics.Typeface.DEFAULT
    }
    return paint.measureText(text)  // 返回 px 单位的宽度
}

private fun DrawScope.drawLabel(offset: Offset, label: String, color: Color, textSize: Float) {
    val paint = androidx.compose.ui.graphics.Paint().asFrameworkPaint().apply {
        this.color = color.toArgb()
        this.textSize = textSize * density
        typeface = android.graphics.Typeface.DEFAULT_BOLD
    }
    drawContext.canvas.nativeCanvas.drawText(label, offset.x, offset.y, paint)
}


private fun DrawScope.drawLabelCenter(
    offset: Offset,
    label: String,
    color: Color,
    textSize: Float
) {
    val paint = androidx.compose.ui.graphics.Paint().asFrameworkPaint().apply {
        this.color = color.toArgb()
        this.textSize = textSize * density
        typeface = android.graphics.Typeface.DEFAULT
        textAlign = Paint.Align.CENTER
    }
    val fontMetrics = paint.fontMetrics
    val drawY = offset.y - (fontMetrics.ascent + fontMetrics.descent) / 2
    drawContext.canvas.nativeCanvas.drawText(label, offset.x, drawY, paint)
}

调用示例

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val data = listOf(70f, 80f, 60f, 90f, 30f, 70f, 80f)
val valueLabelArr = data.map { ZTimeUtils.formatSecondsToMinutesAndSeconds(it.toInt()) }
val labels = listOf(
    "教材同步练",
    "我的任务",
    "学习资料",
    "错题本",
    "AI测评",
    "知识图谱",
    "知识点专练"
)

Box(
    modifier = Modifier
    .fillMaxWidth()
    .height(300.dp)
    .padding(16.dp),
    contentAlignment = androidx.compose.ui.Alignment.Center
) {
    ZRadarChart(data = data, labels = labels, valueLabelArr = valueLabelArr)
}