Change viewpoint

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
// Copyright 2016 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.

using System;
using System.Collections.Generic;
using System.Linq;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.UI.Controls;
using Foundation;
using UIKit;

namespace ArcGISRuntime.Samples.ChangeViewpoint
{
    [Register("ChangeViewpoint")]
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        name: "Change viewpoint",
        category: "MapView",
        description: "Set the map view to a new viewpoint.",
        instructions: "The map view has several methods for setting its current viewpoint. Select a viewpoint from the UI to see the viewpoint changed using that method.",
        tags: new[] { "animate", "extent", "pan", "rotate", "scale", "view", "zoom" })]
    public class ChangeViewpoint : UIViewController
    {
        // Hold references to UI controls.
        private MapView _myMapView;
        private UISegmentedControl _viewpointsButton;

        // Coordinates for London.
        private readonly MapPoint _londonCoords = new MapPoint(-13881.7678417696, 6710726.57374296, SpatialReferences.WebMercator);
        private const double LondonScale = 8762.7156655228955;

        // Coordinates for Redlands.
        private readonly Polygon _redlandsEnvelope = new Polygon(
            new List<MapPoint>
            {
                new MapPoint(-13049785.1566222, 4032064.6003424),
                new MapPoint(-13049785.1566222, 4040202.42595729),
                new MapPoint(-13037033.5780234, 4032064.6003424),
                new MapPoint(-13037033.5780234, 4040202.42595729)
            },
            SpatialReferences.WebMercator);

        // Coordinates for Edinburgh.
        private readonly Polygon _edinburghEnvelope = new Polygon(
            new List<MapPoint>
            {
                new MapPoint(-354262.156621384, 7548092.94093301),
                new MapPoint(-354262.156621384, 7548901.50684376),
                new MapPoint(-353039.164455303, 7548092.94093301),
                new MapPoint(-353039.164455303, 7548901.50684376)
            },
            SpatialReferences.WebMercator);

        public ChangeViewpoint()
        {
            Title = "Change viewpoint";
        }

        private void Initialize()
        {
            // Show a topographic basemap.
            _myMapView.Map = new Map(BasemapStyle.ArcGISTopographic);
        }

        private async void ViewpointButton_ValueChanged(object sender, EventArgs e)
        {
            try
            {
                switch (_viewpointsButton.SelectedSegment)
                {
                    case 0:
                        // Set Viewpoint using Redlands envelope defined above and a padding of 20.
                        await _myMapView.SetViewpointGeometryAsync(_redlandsEnvelope, 20);
                        break;
                    case 1:
                        // Set Viewpoint so that it is centered on the London coordinates defined above.
                        await _myMapView.SetViewpointCenterAsync(_londonCoords);

                        // Set the Viewpoint scale to match the specified scale.
                        await _myMapView.SetViewpointScaleAsync(LondonScale);
                        break;
                    case 2:
                        // Navigate to full extent of the first base layer before animating to specified geometry.
                        await _myMapView.SetViewpointAsync(new Viewpoint(_myMapView.Map.Basemap.BaseLayers.First().FullExtent));

                        // Create a new Viewpoint using the specified geometry.
                        Viewpoint viewpoint = new Viewpoint(_edinburghEnvelope);

                        // Set Viewpoint of MapView to the Viewpoint created above and animate to it using a timespan of 5 seconds.
                        await _myMapView.SetViewpointAsync(viewpoint, TimeSpan.FromSeconds(5));
                        break;
                }
            }
            catch (Exception ex)
            {
                new UIAlertView("Error", ex.ToString(), (IUIAlertViewDelegate) null, "OK", null).Show();
            }

            // Reset the segment button.
            _viewpointsButton.SelectedSegment = -1;
        }

        public override void ViewDidLoad()
        {
            base.ViewDidLoad();
            Initialize();
        }

        public override void LoadView()
        {
            // Create the views.
            View = new UIView { BackgroundColor = ApplicationTheme.BackgroundColor };

            _myMapView = new MapView();
            _myMapView.TranslatesAutoresizingMaskIntoConstraints = false;

            _viewpointsButton = new UISegmentedControl("Geometry", "Center & Scale", "Animate")
            {
                BackgroundColor = ApplicationTheme.BackgroundColor,
                TranslatesAutoresizingMaskIntoConstraints = false,
                // Clean up borders of segmented control - avoid corner pixels.
                ClipsToBounds = true,
                Layer = {CornerRadius = 5}
            };

            // Add the views.
            View.AddSubviews(_myMapView, _viewpointsButton);

            // Lay out the views.
            NSLayoutConstraint.ActivateConstraints(new[]
            {
                _myMapView.TopAnchor.ConstraintEqualTo(View.TopAnchor),
                _myMapView.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor),
                _myMapView.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor),
                _myMapView.BottomAnchor.ConstraintEqualTo(View.BottomAnchor),

                _viewpointsButton.LeadingAnchor.ConstraintEqualTo(View.LayoutMarginsGuide.LeadingAnchor),
                _viewpointsButton.TrailingAnchor.ConstraintEqualTo(View.LayoutMarginsGuide.TrailingAnchor),
                _viewpointsButton.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor, 8)
            });
        }

        public override void ViewWillAppear(bool animated)
        {
            base.ViewWillAppear(animated);

            // Subscribe to events.
            _viewpointsButton.ValueChanged += ViewpointButton_ValueChanged;
        }

        public override void ViewDidDisappear(bool animated)
        {
            base.ViewDidDisappear(animated);

            // Unsubscribe from events, per best practice.
            _viewpointsButton.ValueChanged -= ViewpointButton_ValueChanged;
        }
    }
}