List transformations

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
173
174
175
176
177
178
179
180
181
182
// 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 ListTransformationsViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
    @IBOutlet var mapView: AGSMapView!
    @IBOutlet var tableView: UITableView!
    @IBOutlet var orderByMapExtent: UISwitch!

    var datumTransformations = [AGSDatumTransformation]()
    var defaultTransformation: AGSDatumTransformation?
    let graphicsOverlay = AGSGraphicsOverlay()
    var originalGeometry = AGSPoint(x: 538985.355, y: 177329.516, spatialReference: AGSSpatialReference(wkid: 27700))

    var projectedGraphic: AGSGraphic? {
        if graphicsOverlay.graphics.count > 1 {
            return graphicsOverlay.graphics.lastObject as? AGSGraphic
        } else {
            return nil
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        // Add the source code button item to the right of navigation bar.
        (self.navigationItem.rightBarButtonItem as! SourceCodeBarButtonItem).filenames = ["ListTransformationsViewController"]

        // Get MapView from layout and set a map into this view
        mapView.map = AGSMap(basemapStyle: .arcGISLightGrayBase)
        mapView.graphicsOverlays.add(graphicsOverlay)

        // add original graphic to overlay
        addGraphic(originalGeometry, color: .red, style: .square)

        mapView.map?.load { [weak self] (error) in
            if let error = error {
                print("map load error = \(error)")
            } else {
                self?.mapDidLoad()
            }
        }
    }

    func mapDidLoad() {
        mapView.setViewpoint(AGSViewpoint(center: originalGeometry, scale: 5000), duration: 2.0, completion: nil)

        // set the url for our projection engine data;
        setPEDataURL()
    }

    // add a graphic with the given geometry, color and style to the graphics overlay
    func addGraphic(_ geometry: AGSGeometry, color: UIColor, style: AGSSimpleMarkerSymbolStyle) {
        let sms = AGSSimpleMarkerSymbol(style: style, color: color, size: 15.0)
        graphicsOverlay.graphics.add(AGSGraphic(geometry: geometry, symbol: sms, attributes: nil))
    }

    // set up our datumTransformations array
    func setupTransformsList() {
        guard let map = mapView.map,
            let inputSR = originalGeometry.spatialReference,
            let outputSR = map.spatialReference else { return }

        // if orderByMapExtent is on, use the map extent when retrieving the transformations
        if orderByMapExtent.isOn {
            datumTransformations = AGSTransformationCatalog.transformationsBySuitability(withInputSpatialReference: inputSR, outputSpatialReference: outputSR, areaOfInterest: mapView.visibleArea?.extent)
        } else {
            datumTransformations = AGSTransformationCatalog.transformationsBySuitability(withInputSpatialReference: inputSR, outputSpatialReference: outputSR)
        }

        defaultTransformation = AGSTransformationCatalog.transformation(forInputSpatialReference: inputSR, outputSpatialReference: outputSR)

        // unselect selected row
        if let selectedIndexPath = tableView.indexPathForSelectedRow {
            tableView.deselectRow(at: selectedIndexPath, animated: true)
        }

        // remove projected graphic from overlay
        if let graphic = projectedGraphic {
            // we have the projected graphic, remove it (it's always the last one)
            graphicsOverlay.graphics.remove(graphic)
        }

        tableView.reloadData()
    }

    func setPEDataURL() {
        if let projectionEngineDataURL = FileManager.default
            .urls(for: .documentDirectory, in: .userDomainMask)
            .first?.appendingPathComponent("PEDataRuntime") {
            do {
                guard try projectionEngineDataURL.checkResourceIsReachable() else { return }

                // Normally, this method would be called immediately upon application startup before any other API method calls.
                // So usually it would be called from AppDelegate.application(_:didFinishLaunchingWithOptions:), but for the purposes
                // of this sample, we're calling it here.
                try AGSTransformationCatalog.setProjectionEngineDirectory(projectionEngineDataURL)
            } catch {
                print("Could not load projection engine data.  See the README file for instructions on adding PE data to your app.")
            }
        }

        setupTransformsList()
    }

    @IBAction func oderByMapExtentValueChanged(_ sender: Any) {
        setupTransformsList()
    }

    // MARK: - TableView data source

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return datumTransformations.count
    }

    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "DatumTransformCell", for: indexPath)
        // get the selected transformation
        let transformation = datumTransformations[indexPath.row]

        // disable selection if the transformation is missing files
        cell.isUserInteractionEnabled = !transformation.isMissingProjectionEngineFiles

        cell.textLabel?.text = transformation.name
        cell.detailTextLabel?.text = {
            if transformation.isMissingProjectionEngineFiles,
                // if we're missing the grid files, detail which ones
                let geographicTransformation = transformation as? AGSGeographicTransformation {
                let files = geographicTransformation.steps.flatMap { (step) -> [String] in
                    step.isMissingProjectionEngineFiles ? step.projectionEngineFilenames : []
                }
                return "Missing grid files: \(files.joined(separator: ", "))"
            } else {
                return ""
            }
        }()

        return cell
    }

    // MARK: - TableView delegates

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        guard let mapViewSR = mapView.spatialReference else { return }

        let selectedTransform = datumTransformations[indexPath.row]
        if let projectedGeometry = AGSGeometryEngine.projectGeometry(originalGeometry, to: mapViewSR, datumTransformation: selectedTransform) {
            // projectGeometry succeeded
            if let graphic = projectedGraphic {
                // we've already added the projected graphic
                graphic.geometry = projectedGeometry
            } else {
                // add projected graphic
                addGraphic(projectedGeometry, color: .blue, style: .cross)
            }
        } else {
            // If a transformation is missing grid files, then it cannot be
            // successfully used to project a geometry, and "projectGeometry" will return nil.
            // In that case, remove projected graphic
            if graphicsOverlay.graphics.count > 1 {
                graphicsOverlay.graphics.removeLastObject()
            }
        }
    }
}