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How to drag a graphic with ArcGIS Runtime SDK for iOS
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// | |
// ViewController.swift | |
// TestDrag | |
// | |
// Created by Nicholas Furness on 11/10/17. | |
// Copyright © 2017 Esri. All rights reserved. | |
// | |
import ArcGIS | |
class ViewController: UIViewController { | |
@IBOutlet weak var mapView: AGSMapView! { | |
didSet { | |
// Set the map to center on NYC | |
mapView.map = AGSMap(basemapType: .topographicVector, latitude: 40.73, longitude: -73.99, levelOfDetail: 14) | |
mapView.graphicsOverlays.add(draggableOverlay) | |
// We'll be the touchDelegate to handle the dragging | |
mapView.touchDelegate = self | |
} | |
} | |
lazy var draggableOverlay:AGSGraphicsOverlay = { | |
let overlay = AGSGraphicsOverlay() | |
// Add a single point to the graphics overlay | |
let pt = AGSPoint(x: -73.99, y: 40.73, spatialReference: AGSSpatialReference.wgs84()) | |
let symbol = AGSSimpleMarkerSymbol(style: .triangle, color: UIColor.red, size: 20) | |
let graphic = AGSGraphic(geometry: pt, symbol: symbol, attributes: ["Name": "Draggable Graphic"]) | |
overlay.graphics.add(graphic) | |
return overlay | |
}() | |
// Track the graphic we're dragging | |
var graphicBeingDragged:AGSGraphic? | |
override func viewDidLoad() { | |
super.viewDidLoad() | |
// Do any additional setup after loading the view, typically from a nib. | |
} | |
override func didReceiveMemoryWarning() { | |
super.didReceiveMemoryWarning() | |
// Dispose of any resources that can be recreated. | |
} | |
} | |
// Handle the drag | |
extension ViewController: AGSGeoViewTouchDelegate { | |
func geoView(_ geoView: AGSGeoView, didTouchDownAtScreenPoint screenPoint: CGPoint, mapPoint: AGSPoint, completion: @escaping (Bool) -> Void) { | |
// When the user touches the map, let's figure out if they tapped the graphic - if so, don't pan the map around but | |
// start dragging that graphic. | |
geoView.identify(draggableOverlay, screenPoint: screenPoint, tolerance: 40, returnPopupsOnly: false) { identifyResult in | |
if let nearbyGraphicToDrag = identifyResult.graphics.first { | |
// We want to start dragging this graphic | |
// We would disconnect the graphic from the GPS location at this point and go into "Manual placement" mode so to speak. | |
// Track the graphic. By setting the opacity, we make it easier to precisely place the graphic using the default magnifier. | |
self.draggableOverlay.opacity = 0.3 | |
self.graphicBeingDragged = nearbyGraphicToDrag | |
// Tell the ArcGIS Runtime that we're handling interaction for the time being. | |
completion(true) | |
} else { | |
// We didn't tap a graphic - the Runtime should handle interactions. | |
completion(false) | |
} | |
} | |
} | |
func geoView(_ geoView: AGSGeoView, didTouchDragToScreenPoint screenPoint: CGPoint, mapPoint: AGSPoint) { | |
guard let graphic = graphicBeingDragged else { | |
// Sanity Check: Nothing being dragged - we shouldn't be here | |
print("Unexpected drag event") | |
return | |
} | |
// Just move the graphic to follow the drag | |
graphic.geometry = mapPoint | |
} | |
func geoView(_ geoView: AGSGeoView, didTouchUpAtScreenPoint screenPoint: CGPoint, mapPoint: AGSPoint) { | |
guard let graphic = graphicBeingDragged else { | |
// Sanity Check: Nothing being dragged - we shouldn't be here | |
print("Unexpected touch up event") | |
return | |
} | |
// Move the graphic to its final position. | |
graphic.geometry = mapPoint | |
// Stop tracking the graphic now | |
graphicBeingDragged = nil | |
self.draggableOverlay.opacity = 1 | |
} | |
} |
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