Feature layer time offset

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
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
// 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.

using Esri.ArcGISRuntime;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.UI.Controls;
using Foundation;
using System;
using UIKit;

namespace ArcGISRuntime.Samples.FeatureLayerTimeOffset
{
    [Register("FeatureLayerTimeOffset")]
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        name: "Feature layer time offset",
        category: "MapView",
        description: "Display a time-enabled feature layer with a time offset.",
        instructions: "When the sample loads, you'll see hurricane tracks visualized in red and blue. The red hurricane tracks occurred 10 days before the tracks displayed in blue. Adjust the slider to move the interval to visualize how storms progress over time.",
        tags: new[] { "change", "range", "time", "time extent", "time offset", "time-aware", "time-enabled" })]
    public class FeatureLayerTimeOffset : UIViewController
    {
        // Hold references to UI controls.
        private MapView _myMapView;
        private UILabel _timeLabel;
        private UISlider _timeSlider;

        // Hold the feature layer URI.
        private readonly Uri _featureLayerUri = new Uri("https://sampleserver6.arcgisonline.com/arcgis/rest/services/Hurricanes/MapServer/0");

        // Hold a reference to the original time extent.
        private TimeExtent _originalExtent;

        public FeatureLayerTimeOffset()
        {
            Title = "Feature layer time offset";
        }

        private async void Initialize()
        {
            // Create new Map with oceans basemap.
            Map myMap = new Map(BasemapStyle.ArcGISOceans);

            // Create the hurricanes feature layer once.
            FeatureLayer noOffsetLayer = new FeatureLayer(_featureLayerUri);

            // Apply a blue dot renderer to distinguish hurricanes without offsets.
            SimpleMarkerSymbol blueDot = new SimpleMarkerSymbol(SimpleMarkerSymbolStyle.Circle, System.Drawing.Color.Blue, 10);
            noOffsetLayer.Renderer = new SimpleRenderer(blueDot);

            // Add the non-offset layer to the map.
            myMap.OperationalLayers.Add(noOffsetLayer);

            // Create the offset hurricanes feature layer.
            FeatureLayer withOffsetLayer = new FeatureLayer(_featureLayerUri);

            // Apply a red dot renderer to distinguish these hurricanes from the non-offset hurricanes.
            SimpleMarkerSymbol redDot = new SimpleMarkerSymbol(SimpleMarkerSymbolStyle.Circle, System.Drawing.Color.Red, 10);
            withOffsetLayer.Renderer = new SimpleRenderer(redDot);

            // Apply the time offset (red hurricane dots will be from 10 days before the current extent).
            withOffsetLayer.TimeOffset = new TimeValue(10, Esri.ArcGISRuntime.ArcGISServices.TimeUnit.Days);

            // Add the layer to the map.
            myMap.OperationalLayers.Add(withOffsetLayer);

            // Apply the Map to the MapView.
            _myMapView.Map = myMap;

            try
            {
                // Ensure the no offset layer is loaded.
                await noOffsetLayer.LoadAsync();

                // Store a reference to the original time extent.
                _originalExtent = noOffsetLayer.FullTimeExtent;

                // Update the time extent set on the map.
                UpdateTimeExtent();
            }
            catch (Exception e)
            {
                new UIAlertView("Error", e.ToString(), (IUIAlertViewDelegate)null, "OK", null).Show();
            }
        }

        private void TimeSlider_ValueChanged(object sender, EventArgs e)
        {
            UpdateTimeExtent();
        }

        private void UpdateTimeExtent()
        {
            // Check that the original extent has loaded.
            if (_originalExtent == null) return;

            // Get the value of the slider.
            double value = _timeSlider.Value;

            // Calculate the number of days that value corresponds to.
            // 1. Get the interval.
            TimeSpan interval = _originalExtent.EndTime - _originalExtent.StartTime;

            // 2. Store the interval as days.
            double days = interval.TotalDays;

            // 3. Scale the interval by the value from the slider.
            double desiredInterval = value * days;

            // 4. Create a new TimeSpan.
            TimeSpan newOffset = new TimeSpan((int)desiredInterval, 0, 0, 0);

            // Determine the new starting offset.
            DateTime newStart = _originalExtent.StartTime.DateTime.Add(newOffset);

            // Determine the new ending offset.
            DateTime newEnd = newStart.AddDays(10);

            // Reset the new DateTimeOffset if it is outside of the extent.
            if (newEnd > _originalExtent.EndTime)
            {
                newEnd = _originalExtent.EndTime.DateTime;
            }

            // Do nothing if out of bounds.
            if (newEnd < newStart)
            {
                return;
            }

            // Apply the new extent.
            _myMapView.TimeExtent = new TimeExtent(newStart, newEnd);

            // Update the label.
            _timeLabel.Text = $"{newStart:MMM d} - {newEnd:MMM d}";
        }

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

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

            UIToolbar topToolbar = new UIToolbar { TranslatesAutoresizingMaskIntoConstraints = false };

            _myMapView = new MapView { TranslatesAutoresizingMaskIntoConstraints = false };

            _timeLabel = new UILabel();

            _timeSlider = new UISlider
            {
                MinValue = 0,
                MaxValue = 1,
                TranslatesAutoresizingMaskIntoConstraints = false
            };

            UIToolbar bottomToolbar = new UIToolbar();
            bottomToolbar.TranslatesAutoresizingMaskIntoConstraints = false;

            bottomToolbar.Items = new[]
            {
                new UIBarButtonItem { CustomView = _timeSlider, Width = 100 },
                new UIBarButtonItem(UIBarButtonSystemItem.FlexibleSpace),
                new UIBarButtonItem { CustomView = _timeLabel},
                new UIBarButtonItem(UIBarButtonSystemItem.FlexibleSpace),
            };

            UIStackView legendView = new UIStackView();
            legendView.TranslatesAutoresizingMaskIntoConstraints = false;
            legendView.Axis = UILayoutConstraintAxis.Horizontal;
            legendView.Spacing = 8;

            UIView redIcon = new UIView();
            redIcon.TranslatesAutoresizingMaskIntoConstraints = false;
            redIcon.BackgroundColor = UIColor.Red;
            redIcon.WidthAnchor.ConstraintEqualTo(16).Active = true;
            redIcon.HeightAnchor.ConstraintEqualTo(16).Active = true;
            redIcon.ClipsToBounds = true;
            redIcon.Layer.CornerRadius = 8;
            legendView.AddArrangedSubview(redIcon);

            UILabel _redLabel = new UILabel
            {
                Text = "Offset 10 days",
                TextColor = UIColor.Red,
                TranslatesAutoresizingMaskIntoConstraints = false
            };
            legendView.AddArrangedSubview(_redLabel);

            UIView spacer = new UIView();
            spacer.TranslatesAutoresizingMaskIntoConstraints = false;
            spacer.SetContentCompressionResistancePriority((float)UILayoutPriority.DefaultLow, UILayoutConstraintAxis.Horizontal);
            legendView.AddArrangedSubview(spacer);

            UIView blueIcon = new UIView();
            blueIcon.BackgroundColor = UIColor.Blue;
            blueIcon.TranslatesAutoresizingMaskIntoConstraints = false;
            blueIcon.WidthAnchor.ConstraintEqualTo(16).Active = true;
            blueIcon.HeightAnchor.ConstraintEqualTo(16).Active = true;
            blueIcon.ClipsToBounds = true;
            blueIcon.Layer.CornerRadius = 8;
            legendView.AddArrangedSubview(blueIcon);

            UILabel _blueLabel = new UILabel
            {
                Text = "No offset",
                TextColor = UIColor.Blue,
                TranslatesAutoresizingMaskIntoConstraints = false
            };
            legendView.AddArrangedSubview(_blueLabel);

            // Add the views.
            View.AddSubviews(topToolbar, _myMapView, bottomToolbar);
            topToolbar.AddSubview(legendView);

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

                _myMapView.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor),
                _myMapView.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor),
                _myMapView.TopAnchor.ConstraintEqualTo(topToolbar.BottomAnchor),
                _myMapView.BottomAnchor.ConstraintEqualTo(bottomToolbar.TopAnchor),

                bottomToolbar.LeadingAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.LeadingAnchor),
                bottomToolbar.TrailingAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TrailingAnchor),
                bottomToolbar.BottomAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.BottomAnchor),

                legendView.LeftAnchor.ConstraintEqualTo(topToolbar.SafeAreaLayoutGuide.LeftAnchor, 8),
                legendView.RightAnchor.ConstraintEqualTo(topToolbar.SafeAreaLayoutGuide.RightAnchor, -8),
                legendView.TopAnchor.ConstraintEqualTo(topToolbar.SafeAreaLayoutGuide.TopAnchor, 8),
                legendView.BottomAnchor.ConstraintEqualTo(topToolbar.SafeAreaLayoutGuide.BottomAnchor, -8),

                redIcon.CenterYAnchor.ConstraintEqualTo(blueIcon.CenterYAnchor),
                blueIcon.CenterYAnchor.ConstraintEqualTo(topToolbar.CenterYAnchor),

                _timeLabel.WidthAnchor.ConstraintEqualTo(150),
                _timeSlider.WidthAnchor.ConstraintEqualTo(600),
            });
        }

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

            // Subscribe to events.
            _timeSlider.ValueChanged += TimeSlider_ValueChanged;
        }

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

            // Unsubscribe from events, per best practice.
            _timeSlider.ValueChanged -= TimeSlider_ValueChanged;
        }
    }
}