Polygon.kt

// Copyright 2021 Google LLC
//
// 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 com.google.maps.android.compose

import androidx.compose.runtime.Composable
import androidx.compose.runtime.ReusableComposeNode
import androidx.compose.runtime.currentComposer
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.toArgb
import com.google.android.gms.maps.model.JointType
import com.google.android.gms.maps.model.LatLng
import com.google.android.gms.maps.model.PatternItem
import com.google.android.gms.maps.model.Polygon
import com.google.maps.android.ktx.addPolygon

internal class PolygonNode(
    val polygon: Polygon,
    var onPolygonClick: (Polygon) -> Unit
) : MapNode {
    override fun onRemoved() {
        polygon.remove()
    }
}

/**
 * A composable for a polygon on the map.
 *
 * @param points the points comprising the vertices of the polygon
 * @param clickable boolean indicating if the polygon is clickable or not
 * @param fillColor the fill color of the polygon
 * @param geodesic specifies whether to draw each segment as a geodesic
 * @param holes the holes for the polygon
 * @param strokeColor the stroke color of the polygon
 * @param strokeJointType the joint type for all vertices of the polygon's outline
 * @param strokePattern the stroke pattern for the polygon's outline
 * @param strokeWidth specifies the polygon's stroke width, in display pixels
 * @param tag optional tag to associate wiht the polygon
 * @param visible the visibility of the polygon
 * @param zIndex the z-index of the polygon
 * @param onClick a lambda invoked when the polygon is clicked
 */
@Composable
@GoogleMapComposable
public fun Polygon(
    points: List<LatLng>,
    clickable: Boolean = false,
    fillColor: Color = Color.Black,
    geodesic: Boolean = false,
    holes: List<List<LatLng>> = emptyList(),
    strokeColor: Color = Color.Black,
    strokeJointType: Int = JointType.DEFAULT,
    strokePattern: List<PatternItem>? = null,
    strokeWidth: Float = 10f,
    tag: Any? = null,
    visible: Boolean = true,
    zIndex: Float = 0f,
    onClick: (Polygon) -> Unit = {}
) {
    val mapApplier = currentComposer.applier as MapApplier?
    ReusableComposeNode<PolygonNode, MapApplier>(
        factory = {
            val polygon = mapApplier?.map?.addPolygon {
                addAll(points)
                clickable(clickable)
                fillColor(fillColor.toArgb())
                geodesic(geodesic)
                for (hole in holes) {
                    addHole(hole)
                }
                strokeColor(strokeColor.toArgb())
                strokeJointType(strokeJointType)
                strokePattern(strokePattern)
                strokeWidth(strokeWidth)
                visible(visible)
                zIndex(zIndex)
            } ?: error("Error adding polygon")
            polygon.tag = tag
            PolygonNode(polygon, onClick)
        },
        update = {
            update(onClick) { this.onPolygonClick = it }

            set(points) { this.polygon.points = it }
            set(clickable) { this.polygon.isClickable = it }
            set(fillColor) { this.polygon.fillColor = it.toArgb() }
            set(geodesic) { this.polygon.isGeodesic = it }
            set(holes) { this.polygon.holes = it }
            set(strokeColor) { this.polygon.strokeColor = it.toArgb() }
            set(strokeJointType) { this.polygon.strokeJointType = it }
            set(strokePattern) { this.polygon.strokePattern = it }
            set(strokeWidth) { this.polygon.strokeWidth = it }
            set(tag) { this.polygon.tag = it }
            set(visible) { this.polygon.isVisible = it }
            set(zIndex) { this.polygon.zIndex = it }
        }
    )
}