Custom ViewGroup for advanced layouts

package com.example.myapp.ui.custom

import android.content.Context
import android.util.AttributeSet
import android.view.ViewGroup
import kotlin.math.max

class FlowLayout @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = 0
) : ViewGroup(context, attrs, defStyleAttr) {

    private var horizontalSpacing = 0
    private var verticalSpacing = 0

    init {
        context.obtainStyledAttributes(attrs, R.styleable.FlowLayout).apply {
            horizontalSpacing = getDimensionPixelSize(
                R.styleable.FlowLayout_horizontalSpacing, 0
            )
            verticalSpacing = getDimensionPixelSize(
                R.styleable.FlowLayout_verticalSpacing, 0
            )
            recycle()
        }
    }

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        val widthMode = MeasureSpec.getMode(widthMeasureSpec)
        val widthSize = MeasureSpec.getSize(widthMeasureSpec)
        val heightMode = MeasureSpec.getMode(heightMeasureSpec)
        val heightSize = MeasureSpec.getSize(heightMeasureSpec)

        var currentWidth = paddingLeft
        var currentHeight = paddingTop
        var maxLineHeight = 0

        for (i in 0 until childCount) {
            val child = getChildAt(i)
            if (child.visibility == GONE) continue

            measureChildWithMargins(
                child,
                widthMeasureSpec,
                0,
                heightMeasureSpec,
                0
            )

            val childWidth = child.measuredWidth
            val childHeight = child.measuredHeight
            val lp = child.layoutParams as MarginLayoutParams

            val childWidthWithMargins = childWidth + lp.leftMargin + lp.rightMargin
            val childHeightWithMargins = childHeight + lp.topMargin + lp.bottomMargin

            if (currentWidth + childWidthWithMargins + paddingRight > widthSize) {
                // Move to next line
                currentWidth = paddingLeft
                currentHeight += maxLineHeight + verticalSpacing
                maxLineHeight = 0
            }

            currentWidth += childWidthWithMargins + horizontalSpacing
            maxLineHeight = max(maxLineHeight, childHeightWithMargins)
        }

        currentHeight += maxLineHeight + paddingBottom

        val finalWidth = if (widthMode == MeasureSpec.EXACTLY) widthSize else currentWidth
        val finalHeight = if (heightMode == MeasureSpec.EXACTLY) heightSize else currentHeight

        setMeasuredDimension(finalWidth, finalHeight)
    }

    override fun onLayout(changed: Boolean, l: Int, t: Int, r: Int, b: Int) {
        var currentX = paddingLeft
        var currentY = paddingTop
        var maxLineHeight = 0
        val width = r - l

        for (i in 0 until childCount) {
            val child = getChildAt(i)
            if (child.visibility == GONE) continue

            val childWidth = child.measuredWidth
            val childHeight = child.measuredHeight
            val lp = child.layoutParams as MarginLayoutParams

            val childWidthWithMargins = childWidth + lp.leftMargin + lp.rightMargin

            if (currentX + childWidthWithMargins + paddingRight > width) {
                // Move to next line
                currentX = paddingLeft
                currentY += maxLineHeight + verticalSpacing
                maxLineHeight = 0
            }

            val left = currentX + lp.leftMargin
            val top = currentY + lp.topMargin
            val right = left + childWidth
            val bottom = top + childHeight

            child.layout(left, top, right, bottom)

            currentX += childWidthWithMargins + horizontalSpacing
            maxLineHeight = max(maxLineHeight, childHeight + lp.topMargin + lp.bottomMargin)
        }
    }

    override fun generateDefaultLayoutParams(): LayoutParams {
        return MarginLayoutParams(
            LayoutParams.WRAP_CONTENT,
            LayoutParams.WRAP_CONTENT
        )
    }

    override fun generateLayoutParams(attrs: AttributeSet?): LayoutParams {
        return MarginLayoutParams(context, attrs)
    }

    override fun generateLayoutParams(p: LayoutParams?): LayoutParams {
        return MarginLayoutParams(p)
    }

    override fun checkLayoutParams(p: LayoutParams?): Boolean {
        return p is MarginLayoutParams
    }
}