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// 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 ClipGeometryViewController: UIViewController {
// MARK: Storyboard views
/// The map view managed by the view controller.
@IBOutlet var mapView: AGSMapView! {
didSet {
// Create a map with a topographic basemap.
mapView.map = AGSMap(basemapStyle: .arcGISTopographic)
// Add the graphics overlays to the map view.
mapView.graphicsOverlays.addObjects(from: [coloradoGraphicsOverlay, envelopesGraphicsOverlay, clippedGraphicsOverlay])
// Set the viewpoint to the extent of the Colorado geometry.
mapView.setViewpointGeometry(coloradoGraphic.geometry!, padding: 100)
}
}
// MARK: Instance properties
/// A Boolean value indicating whether the geometries are clipped.
private var geometriesAreClipped = false
/// The unclipped graphic of Colorado.
private var coloradoGraphic: AGSGraphic {
coloradoGraphicsOverlay.graphics.firstObject as! AGSGraphic
}
/// The overlay for displaying the graphic of Colorado.
private let coloradoGraphicsOverlay: AGSGraphicsOverlay = {
// An envelope approximating the boundary of Colorado.
let coloradoGeometry = AGSEnvelope(
xMin: -11362327.128340,
yMin: 5012861.290274,
xMax: -12138232.018408,
yMax: 4441198.773776,
spatialReference: .webMercator()
)
// A semi-transparent blue color for the fill.
let fillColor = UIColor.blue.withAlphaComponent(0.2)
// The fill symbol for displaying Colorado.
let fillSymbol = AGSSimpleFillSymbol(
style: .solid,
color: fillColor,
outline: AGSSimpleLineSymbol(style: .solid, color: .blue, width: 2)
)
// Create a graphic from the geometry and symbol representing Colorado.
let coloradoGraphic = AGSGraphic(geometry: coloradoGeometry, symbol: fillSymbol)
// Create a graphics overlay.
let coloradoGraphicsOverlay = AGSGraphicsOverlay()
// Add the Colorado graphic to its overlay.
coloradoGraphicsOverlay.graphics.add(coloradoGraphic)
return coloradoGraphicsOverlay
}()
/// The graphics overlay containing clipped graphics.
private let clippedGraphicsOverlay = AGSGraphicsOverlay()
/// The overlay for displaying the other envelopes.
private let envelopesGraphicsOverlay: AGSGraphicsOverlay = {
// An envelope outside Colorado.
let outsideEnvelope = AGSEnvelope(
xMin: -11858344.321294,
yMin: 5147942.225174,
xMax: -12201990.219681,
yMax: 5297071.577304,
spatialReference: .webMercator()
)
// An envelope intersecting Colorado.
let intersectingEnvelope = AGSEnvelope(
xMin: -11962086.479298,
yMin: 4566553.881363,
xMax: -12260345.183558,
yMax: 4332053.378376,
spatialReference: .webMercator()
)
// An envelope inside Colorado.
let containedEnvelope = AGSEnvelope(
xMin: -11655182.595204,
yMin: 4741618.772994,
xMax: -11431488.567009,
yMax: 4593570.068343,
spatialReference: .webMercator()
)
// A dotted red outline symbol.
let redOutline = AGSSimpleLineSymbol(style: .dot, color: .red, width: 3)
// The envelopes in the order we want to display them.
let envelopes = [outsideEnvelope, intersectingEnvelope, containedEnvelope]
// The graphics for the envelopes with the red outline symbol.
let graphics = envelopes.map { AGSGraphic(geometry: $0, symbol: redOutline) }
let envelopesOverlay = AGSGraphicsOverlay()
// Add the graphics to the overlay.
envelopesOverlay.graphics.addObjects(from: graphics)
return envelopesOverlay
}()
// MARK: Actions
/// Clip geometries and add resulting graphics.
private func clipGeometries() {
// Hides the Colorado graphic.
coloradoGraphic.isVisible = false
let coloradoGeometry = coloradoGraphic.geometry!
let coloradoSymbol = coloradoGraphic.symbol!
// Clip Colorado's geometry to each envelope.
let clippedGraphics: [AGSGraphic] = envelopesGraphicsOverlay.graphics.map { graphic in
let envelope = (graphic as! AGSGraphic).geometry as! AGSEnvelope
// Use the geometry engine to create a new geometry for the area of
// Colorado that overlaps the given envelope.
let clippedGeometry = AGSGeometryEngine.clipGeometry(coloradoGeometry, with: envelope)
// Create and return the clipped graphic from the clipped geometry
// if there is an overlap.
return AGSGraphic(geometry: clippedGeometry, symbol: coloradoSymbol)
}
// Add the clipped graphics.
clippedGraphicsOverlay.graphics.addObjects(from: clippedGraphics)
}
/// Remove all clipped graphics.
private func reset() {
clippedGraphicsOverlay.graphics.removeAllObjects()
coloradoGraphic.isVisible = true
}
@IBAction func clipGeometry(_ sender: UIBarButtonItem) {
geometriesAreClipped ? reset() : clipGeometries()
geometriesAreClipped.toggle()
// Set button title based on whether the geometries are clipped.
sender.title = geometriesAreClipped ? "Reset" : "Clip"
}
// MARK: UIViewController
override func viewDidLoad() {
super.viewDidLoad()
// Add the source code button item to the right of navigation bar.
(navigationItem.rightBarButtonItem as! SourceCodeBarButtonItem).filenames = ["ClipGeometryViewController"]
}
}
