Convex hull

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
/*
 * Copyright 2020 Esri
 *
 * 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.esri.arcgisruntime.sample.convexhull

import android.graphics.Color
import android.os.Bundle
import android.view.MotionEvent
import android.widget.Button
import androidx.appcompat.app.AppCompatActivity
import com.esri.arcgisruntime.ArcGISRuntimeEnvironment
import com.esri.arcgisruntime.geometry.GeometryEngine
import com.esri.arcgisruntime.geometry.GeometryType
import com.esri.arcgisruntime.geometry.Multipoint
import com.esri.arcgisruntime.geometry.Point
import com.esri.arcgisruntime.geometry.PointCollection
import com.esri.arcgisruntime.mapping.ArcGISMap
import com.esri.arcgisruntime.mapping.BasemapStyle
import com.esri.arcgisruntime.mapping.view.DefaultMapViewOnTouchListener
import com.esri.arcgisruntime.mapping.view.Graphic
import com.esri.arcgisruntime.mapping.view.GraphicsOverlay
import com.esri.arcgisruntime.mapping.view.MapView
import com.esri.arcgisruntime.sample.convexhull.databinding.ActivityMainBinding
import com.esri.arcgisruntime.symbology.SimpleFillSymbol
import com.esri.arcgisruntime.symbology.SimpleLineSymbol
import com.esri.arcgisruntime.symbology.SimpleMarkerSymbol

class MainActivity : AppCompatActivity() {

    private val activityMainBinding by lazy {
        ActivityMainBinding.inflate(layoutInflater)
    }

    private val mapView: MapView by lazy {
        activityMainBinding.mapView
    }

    private val createButton: Button by lazy {
        activityMainBinding.createButton
    }

    private val resetButton: Button by lazy {
        activityMainBinding.resetButton
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(activityMainBinding.root)

        // authentication with an API key or named user is required to access basemaps and other
        // location services
        ArcGISRuntimeEnvironment.setApiKey(BuildConfig.API_KEY)

        // create an array list to store points
        val inputPoints = arrayListOf<Point>()

        // create a symbol and graphic to represent single points
        val pointSymbol = SimpleMarkerSymbol(SimpleMarkerSymbol.Style.CIRCLE, Color.RED, 10F)
        val pointGraphic = Graphic().apply { symbol = pointSymbol }

        // create a graphic for the convex hull consisting of a line and empty interior
        val lineSymbol = SimpleLineSymbol(SimpleLineSymbol.Style.SOLID, Color.BLUE, 3F)
        val fillSymbol =
            SimpleFillSymbol(SimpleFillSymbol.Style.NULL, Color.TRANSPARENT, lineSymbol)
        val convexHullGraphic = Graphic()

        // create a graphics overlay and add the graphics to it
        val graphicsOverlay = GraphicsOverlay()
        graphicsOverlay.graphics.addAll(listOf(pointGraphic, convexHullGraphic))

        mapView.apply {
            // set the map to a topographic basemap
            map = ArcGISMap(BasemapStyle.ARCGIS_TOPOGRAPHIC)
            // add the graphics overlay to the map
            graphicsOverlays.add(graphicsOverlay)

            onTouchListener = object : DefaultMapViewOnTouchListener(this@MainActivity, mapView) {
                override fun onSingleTapConfirmed(e: MotionEvent): Boolean {
                    // get the tapped point and convert it to a screen point
                    val point = android.graphics.Point(e.x.toInt(), e.y.toInt())
                    val convertedPoint = mapView.screenToLocation(point)

                    // add the new point to the list and recreate the graphic representing the input points
                    inputPoints.add(convertedPoint)
                    val multiPoint = Multipoint(PointCollection(inputPoints))
                    pointGraphic.geometry = multiPoint

                    if (inputPoints.isNotEmpty()) {
                        createButton.isEnabled = true
                        resetButton.isEnabled = true
                    }

                    return super.onSingleTapConfirmed(e)
                }
            }
        }

        // create the convex hull when the button is pressed
        createButton.setOnClickListener {
            // normalize the points for panning beyond the meridian
            val normalizedPoints = GeometryEngine.normalizeCentralMeridian(pointGraphic.geometry)
            // create a convex hull from the points
            val convexHull = GeometryEngine.convexHull(normalizedPoints)
            // the convex hull's geometry may be a point or polyline if the number of points is less than 3
            convexHullGraphic.symbol = when (convexHull.geometryType) {
                GeometryType.POINT -> pointSymbol
                GeometryType.POLYLINE -> lineSymbol
                GeometryType.POLYGON -> fillSymbol
                else -> null
            }
            // set the convex hull graphic to display the new geometry
            convexHullGraphic.geometry = convexHull
            // disable the button
            createButton.isEnabled = false
        }

        // clear the points and graphics and disable the buttons when reset is tapped
        resetButton.setOnClickListener {
            inputPoints.clear()
            pointGraphic.geometry = null
            convexHullGraphic.geometry = null
            resetButton.isEnabled = false
            createButton.isEnabled = false
        }
    }

    override fun onResume() {
        super.onResume()
        mapView.resume()
    }

    override fun onPause() {
        mapView.pause()
        super.onPause()
    }

    override fun onDestroy() {
        mapView.dispose()
        super.onDestroy()
    }
}