Cut geometry

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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
// Copyright 2018 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.

import UIKit
import ArcGIS

class CutGeometryViewController: UIViewController {
    // MARK: Storyboard views

    /// The map view managed by the view controller.
    @IBOutlet var mapView: AGSMapView! {
        didSet {
            // Create a map with a topographic basemap.
            mapView.map = AGSMap(basemapStyle: .arcGISTopographic)
            // Add the graphics overlays to the map view.
            mapView.graphicsOverlays.addObjects(from: [lakeGraphicsOverlay, cutGraphicsOverlay])
            // Set viewpoint to the extent of the Lake Superior graphics overlay.
            mapView.setViewpointGeometry(lakeSuperiorPolygonGraphic.geometry!)
        }
    }

    // MARK: Instance properties

    /// A Boolean value indicating whether the geometry is cut.
    var isGeometryCut = false

    /// A polygon representing the area of Lake Superior.
    var lakeSuperiorPolygonGraphic: AGSGraphic {
        lakeGraphicsOverlay.graphics.firstObject as! AGSGraphic
    }

    /// A polyline representing the Canada/USA border.
    var borderPolylineGraphic: AGSGraphic {
        lakeGraphicsOverlay.graphics.lastObject as! AGSGraphic
    }

    /// A graphics overlay containing the Lake Superior polygon and border line.
    let lakeGraphicsOverlay: AGSGraphicsOverlay = {
        let lakeSuperiorPolygonGraphic: AGSGraphic = {
            // Create an array of points that represents Lake Superior (polygon).
            // Use the same spatial reference as the underlying base map.
            let points = [
                AGSPoint(x: -10254374.668616, y: 5908345.076380, spatialReference: .webMercator()),
                AGSPoint(x: -10178382.525314, y: 5971402.386779, spatialReference: .webMercator()),
                AGSPoint(x: -10118558.923141, y: 6034459.697178, spatialReference: .webMercator()),
                AGSPoint(x: -9993252.729399, y: 6093474.872295, spatialReference: .webMercator()),
                AGSPoint(x: -9882498.222673, y: 6209888.368416, spatialReference: .webMercator()),
                AGSPoint(x: -9821057.766387, y: 6274562.532928, spatialReference: .webMercator()),
                AGSPoint(x: -9690092.583250, y: 6241417.023616, spatialReference: .webMercator()),
                AGSPoint(x: -9605207.742329, y: 6206654.660191, spatialReference: .webMercator()),
                AGSPoint(x: -9564786.389509, y: 6108834.986367, spatialReference: .webMercator()),
                AGSPoint(x: -9449989.747500, y: 6095091.726408, spatialReference: .webMercator()),
                AGSPoint(x: -9462116.153346, y: 6044160.821855, spatialReference: .webMercator()),
                AGSPoint(x: -9417652.665244, y: 5985145.646738, spatialReference: .webMercator()),
                AGSPoint(x: -9438671.768711, y: 5946341.148031, spatialReference: .webMercator()),
                AGSPoint(x: -9398250.415891, y: 5922088.336339, spatialReference: .webMercator()),
                AGSPoint(x: -9419269.519357, y: 5855797.317714, spatialReference: .webMercator()),
                AGSPoint(x: -9467775.142741, y: 5858222.598884, spatialReference: .webMercator()),
                AGSPoint(x: -9462924.580403, y: 5902686.086985, spatialReference: .webMercator()),
                AGSPoint(x: -9598740.325877, y: 5884092.264688, spatialReference: .webMercator()),
                AGSPoint(x: -9643203.813979, y: 5845287.765981, spatialReference: .webMercator()),
                AGSPoint(x: -9739406.633691, y: 5879241.702350, spatialReference: .webMercator()),
                AGSPoint(x: -9783061.694736, y: 5922896.763395, spatialReference: .webMercator()),
                AGSPoint(x: -9844502.151022, y: 5936640.023354, spatialReference: .webMercator()),
                AGSPoint(x: -9773360.570059, y: 6019099.583107, spatialReference: .webMercator()),
                AGSPoint(x: -9883306.649729, y: 5968977.105610, spatialReference: .webMercator()),
                AGSPoint(x: -9957681.938918, y: 5912387.211662, spatialReference: .webMercator()),
                AGSPoint(x: -10055501.612742, y: 5871965.858842, spatialReference: .webMercator()),
                AGSPoint(x: -10116942.069028, y: 5884092.264688, spatialReference: .webMercator()),
                AGSPoint(x: -10111283.079633, y: 5933406.315128, spatialReference: .webMercator()),
                AGSPoint(x: -10214761.742852, y: 5888134.399970, spatialReference: .webMercator()),
                AGSPoint(x: -10254374.668616, y: 5901877.659929, spatialReference: .webMercator())
            ]

            // Create a polygon from the array of points.
            let polygon = AGSPolygon(points: points)

            // Create a blue border line symbol with a stroke weight of 4 for
            // the Lake Superior polygon.
            let lineSymbol = AGSSimpleLineSymbol(style: .solid, color: .blue, width: 4)

            // Create a semi transparent blue fill symbol using the red
            // border line symbol for the Lake Superior polygon.
            let fillSymbol = AGSSimpleFillSymbol(style: .solid, color: #colorLiteral(red: 0, green: 0, blue: 1, alpha: 0.1), outline: lineSymbol)

            // Create and return a graphic using the polyline and fill symbol
            // for the border polyline.
            return AGSGraphic(geometry: polygon, symbol: fillSymbol)
        }()

        let borderPolylineGraphic: AGSGraphic = {
            // Create an array of points that represents a cut line.
            let points = [
                AGSPoint(x: -9981328.687124, y: 6111053.281447, spatialReference: .webMercator()),
                AGSPoint(x: -9946518.044066, y: 6102350.620682, spatialReference: .webMercator()),
                AGSPoint(x: -9872545.427566, y: 6152390.920079, spatialReference: .webMercator()),
                AGSPoint(x: -9838822.617103, y: 6157830.083057, spatialReference: .webMercator()),
                AGSPoint(x: -9446115.050097, y: 5927209.572793, spatialReference: .webMercator()),
                AGSPoint(x: -9430885.393759, y: 5876081.440801, spatialReference: .webMercator()),
                AGSPoint(x: -9415655.737420, y: 5860851.784463, spatialReference: .webMercator())
            ]

            // Create a polyline from the array of points.
            let polyline = AGSPolyline(points: points)

            // Create a red border line symbol with a stroke weight of 5.
            let lineSymbol = AGSSimpleLineSymbol(style: .dot, color: .red, width: 5)

            // Create and return a graphic using the polyline and line symbol
            // for the border polyline.
            return AGSGraphic(geometry: polyline, symbol: lineSymbol, attributes: nil)
        }()

        // Create a graphics overlay.
        let overlay = AGSGraphicsOverlay()
        // Add the Lake Superior graphics to the overlay.
        overlay.graphics.addObjects(from: [lakeSuperiorPolygonGraphic, borderPolylineGraphic])
        return overlay
    }()

    /// The graphics overlay containing cut graphics.
    let cutGraphicsOverlay = AGSGraphicsOverlay()

    // MARK: Actions

    /// Cut geometry and add resulting graphics.
    func cutGeometry() {
        // Cut the Lake Superior polygon using the border polyline.
        guard let parts = AGSGeometryEngine.cut(lakeSuperiorPolygonGraphic.geometry!, withCutter: borderPolylineGraphic.geometry as! AGSPolyline),
              parts.count == 2,
              let firstPart = parts.first,
              let secondPart = parts.last else {
            return
        }
        // Create the graphics for the Canadian and USA sides of Lake Superior.
        let canadaSideGraphic = AGSGraphic(geometry: firstPart, symbol: AGSSimpleFillSymbol(style: .backwardDiagonal, color: .green, outline: nil))
        let usaSideGraphic = AGSGraphic(geometry: secondPart, symbol: AGSSimpleFillSymbol(style: .forwardDiagonal, color: .yellow, outline: nil))
        // Add the graphics to the graphics overlay.
        cutGraphicsOverlay.graphics.addObjects(from: [canadaSideGraphic, usaSideGraphic])
    }

    /// Removes all cut graphics.
    func reset() {
        cutGraphicsOverlay.graphics.removeAllObjects()
    }

    @IBAction func cutGeometryWithPolyline(_ sender: UIBarButtonItem) {
        isGeometryCut ? reset() : cutGeometry()
        isGeometryCut.toggle()
        // Set button title based on whether the geometry is cut.
        sender.title = isGeometryCut ? "Reset" : "Cut"
    }

    // MARK: UIViewController

    override func viewDidLoad() {
        super.viewDidLoad()
        // Add the source code button item to the right of navigation bar.
        (navigationItem.rightBarButtonItem as! SourceCodeBarButtonItem).filenames = ["CutGeometryViewController"]
    }
}