Spatial operations

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
// Copyright 2017 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 SpatialOperationsViewController: UIViewController {
    // MARK: Storyboard view and properties

    /// The map view managed by the view controller.
    @IBOutlet var mapView: AGSMapView! {
        didSet {
            // Initialize map with basemap.
            mapView.map = AGSMap(basemapStyle: .arcGISTopographic)
            // Add the graphics overlay with two polygon graphics and the result graphic to map view.
            mapView.graphicsOverlays.add(makeGraphicsOverlay())
            // Set the map view's viewpoint.
            let center = AGSPoint(x: -13453, y: 6710127, spatialReference: .webMercator())
            mapView.setViewpointCenter(center, scale: 30000, completion: nil)
        }
    }

    /// The resulting graphic for the spatial operation.
    private var resultGraphic: AGSGraphic!

    private let polygon1: AGSGeometry = {
        // Create the polygon 1.
        let polygon = AGSPolygonBuilder(spatialReference: .webMercator())
        polygon.addPointWith(x: -13960, y: 6709400)
        polygon.addPointWith(x: -14660, y: 6710000)
        polygon.addPointWith(x: -13760, y: 6710730)
        polygon.addPointWith(x: -13300, y: 6710500)
        polygon.addPointWith(x: -13160, y: 6710100)
        return polygon.toGeometry()
    }()

    private let polygon2: AGSGeometry = {
        // The outer ring of polygon 2.
        let outerRing = AGSMutablePart(spatialReference: .webMercator())
        outerRing.addPointWith(x: -13060, y: 6711030)
        outerRing.addPointWith(x: -12160, y: 6710730)
        outerRing.addPointWith(x: -13160, y: 6709700)
        outerRing.addPointWith(x: -14560, y: 6710730)
        outerRing.addPointWith(x: -13060, y: 6711030)

        // The inner ring of polygon 2.
        let innerRing = AGSMutablePart(spatialReference: .webMercator())
        innerRing.addPointWith(x: -13060, y: 6710910)
        innerRing.addPointWith(x: -14160, y: 6710630)
        innerRing.addPointWith(x: -13160, y: 6709900)
        innerRing.addPointWith(x: -12450, y: 6710660)
        innerRing.addPointWith(x: -13060, y: 6710910)

        // Create polygon 2.
        let polygon = AGSPolygonBuilder(spatialReference: .webMercator())
        polygon.parts.add(outerRing)
        polygon.parts.add(innerRing)
        return polygon.toGeometry()
    }()

    /// An enum of spatial operations.
    private enum SpatialOperation: CaseIterable {
        case none, union, difference, symmetricDifference, intersection
        /// Human readable label strings for each spatial operation.
        var label: String {
            switch self {
            case .none: return "None"
            case .union: return "Union"
            case .difference: return "Difference"
            case .symmetricDifference: return "Symmetric Difference"
            case .intersection: return "Intersection"
            }
        }
    }
    /// The selected operation.
    private var selectedOperation = SpatialOperation.none

    // MARK: Methods

    func makeGraphicsOverlay() -> AGSGraphicsOverlay {
        // A black line symbol for borders of the graphics.
        let lineSymbol = AGSSimpleLineSymbol(style: .solid, color: .black, width: 1)
        // The blue fill symbol of polygon 1.
        let fillSymbol1 = AGSSimpleFillSymbol(style: .solid, color: .blue, outline: lineSymbol)
        // The graphic of polygon 1.
        let polygon1Graphic = AGSGraphic(geometry: polygon1, symbol: fillSymbol1)
        // The green fill symbol of polygon 2.
        let fillSymbol2 = AGSSimpleFillSymbol(style: .solid, color: .green, outline: lineSymbol)
        // The graphic of polygon 2.
        let polygon2Graphic = AGSGraphic(geometry: polygon2, symbol: fillSymbol2)

        // Using red fill symbol with black border for result graphic.
        let symbol = AGSSimpleFillSymbol(style: .solid, color: .red, outline: lineSymbol)
        let graphic = AGSGraphic(geometry: nil, symbol: symbol)
        resultGraphic = graphic

        // An overlay to display polygon graphics.
        let graphicsOverlay = AGSGraphicsOverlay()

        // Add graphics to graphics overlay.
        graphicsOverlay.graphics.addObjects(from: [polygon1Graphic, polygon2Graphic, graphic])
        return graphicsOverlay
    }

    private func performOperation(_ operation: SpatialOperation) {
        let resultGeometry: AGSGeometry?
        switch operation {
        case .none:
            resultGeometry = nil
        case .union:
            resultGeometry = AGSGeometryEngine.union(ofGeometry1: polygon1, geometry2: polygon2)!
        case .difference:
            resultGeometry = AGSGeometryEngine.difference(ofGeometry1: polygon1, geometry2: polygon2)!
        case .symmetricDifference:
            resultGeometry = AGSGeometryEngine.symmetricDifference(ofGeometry1: polygon1, geometry2: polygon2)!
        case .intersection:
            resultGeometry = AGSGeometryEngine.intersection(ofGeometry1: polygon1, geometry2: polygon2)!
        }
        // Update the geometry.
        resultGraphic.geometry = resultGeometry
    }

    @IBAction func chooseOperationBarButtonTapped(_ sender: UIBarButtonItem) {
        let selectedIndex = SpatialOperation.allCases.firstIndex(of: selectedOperation)

        let controller = OptionsTableViewController(labels: SpatialOperation.allCases.map { $0.label }, selectedIndex: selectedIndex) { [weak self] newIndex in
            guard let self = self else { return }
            let newOperation = SpatialOperation.allCases[newIndex]
            self.selectedOperation = newOperation
            // Perform the new spatial operation.
            self.performOperation(newOperation)
        }

        // Configure the options controller as a popover.
        controller.modalPresentationStyle = .popover
        controller.presentationController?.delegate = self
        controller.preferredContentSize = CGSize(width: 300, height: CGFloat(SpatialOperation.allCases.count) * 44)
        controller.popoverPresentationController?.barButtonItem = sender

        // Show the popover.
        present(controller, animated: true)
    }

    // MARK: UIViewController

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

// MARK: - UIAdaptivePresentationControllerDelegate

extension SpatialOperationsViewController: UIAdaptivePresentationControllerDelegate {
    func adaptivePresentationStyle(for controller: UIPresentationController, traitCollection: UITraitCollection) -> UIModalPresentationStyle {
        // Show presented controller as a popover even on small displays.
        return .none
    }
}