Handle nonsensical inputs in pattern generator

import com.google.android.gms.maps.model.Dot

import com.google.android.gms.maps.model.Gap

import com.google.android.gms.maps.model.PatternItem

import kotlin.math.max

fun PatternItem.getName(): String = when (this) {

    is Dash -> "dash${this.length}"

/**

 * Name of pattern, to identify it after it is added to map

 */

fun List<PatternItem>.getName(color: Int, strokeWidth: Float, skew: Float = 1f) = joinToString("-") {

fun List<PatternItem>.getName(color: Int, strokeWidth: Float, skew: Float = 1f) = if (isEmpty()) {

    "solid-${color}"

} else {joinToString("-") {

        it.getName()

    } + "-${color}-width${strokeWidth}-skew${skew}"

}

/**

 * Gets width that a bitmap for this pattern item would have if the pattern's bitmap

    val width = getWidth(strokeWidth, skew).toInt()

    val height = (strokeWidth * skew).toInt() // avoids squished image bugs

    // For empty list or nonsensical input (zero-width items)

    if (width == 0 || height == 0) {

        val nonZeroHeight = max(1f, strokeWidth)

        return Bitmap.createBitmap(1, nonZeroHeight.toInt(), Bitmap.Config.ARGB_8888).also {

            Canvas(it).drawRect(0f, 0f, nonZeroHeight, nonZeroHeight, paint)

        }

    }

    val bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)

    val canvas = Canvas(bitmap)

            it.lineWidth = strokeWidth / map.dpiFactor

            (strokePattern ?: listOf(Dash(1f))).let { pattern ->

            (strokePattern ?: emptyList()).let { pattern ->

                val bitmapName = pattern.getName(strokeColor, strokeWidth)

                map.addBitmap(bitmapName, pattern.makeBitmap(strokeColor, strokeWidth))

                line.annotation?.linePattern = bitmapName