Set max extent

View on GitHub
Sample viewer app

Limit the view of a map to a particular area.

Image of set max extent

Use case

When showing map information relevant to only a certain area, you may wish to constrain the user's ability to pan or zoom away.

How to use the sample

The application loads with a map whose maximum extent has been set to the borders of Colorado. Note that you won't be able to pan far from the Colorado border or zoom out beyond the minimum scale set by the max extent. Use the toggle switch to disable the max extent to freely pan/zoom around the map.

How it works

  1. Create an AGSMap object.
  2. Create an envelop of the extent.
  3. Set the envelope to the map's maxExtent property.
  4. Set the map to an AGSMapView object.
  5. Set maxExtent to nil to disable the maximum extent of the map.

Relevant API

  • AGSEnvelope
  • AGSMap

Tags

extent, limit panning, map, mapview, max extent, zoom

Sample Code

SetMaxExtentViewController.swift
Use dark colors for code blocksCopy
                                                                   
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
// Copyright 2022 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
//
//   https://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 SetMaxExtentViewController: UIViewController {
    // MARK: Storyboard views

    /// The map view managed by the view controller.
    @IBOutlet var mapView: AGSMapView! {
        didSet {
            mapView.map = makeMap()
            // The graphics overlay used to show the extent envelope graphic.
            let graphicsOverlay = AGSGraphicsOverlay()
            graphicsOverlay.graphics.add(AGSGraphic(
                geometry: extentEnvelope,
                symbol: AGSSimpleLineSymbol(style: .dash, color: .red, width: 5)
            ))
            mapView.graphicsOverlays.add(graphicsOverlay)
        }
    }

    // MARK: Properties

    /// The envelope that represents the max extent.
    let extentEnvelope = AGSEnvelope(
        xMin: -12139393.2109,
        yMin: 4438148.7816,
        xMax: -11359277.5124,
        yMax: 5012444.0468,
        spatialReference: .webMercator()
    )

    // MARK: Methods

    /// Create a map.
    func makeMap() -> AGSMap {
        // Create a map with the streets basemap focused on Colorado.
        let map = AGSMap(basemapStyle: .arcGISStreets)
        // Set the map's max extent to an envelope of Colorado's northwest
        // and southeast corners.
        map.maxExtent = extentEnvelope
        return map
    }

    @IBAction func extentSwitchValueChanged(_ sender: UISwitch) {
        mapView.map!.maxExtent = sender.isOn ? extentEnvelope : nil
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Add the source code button item to the right of navigation bar.
        (navigationItem.rightBarButtonItem as? SourceCodeBarButtonItem)?.filenames = ["SetMaxExtentViewController"]
    }
}

Your browser is no longer supported. Please upgrade your browser for the best experience. See our browser deprecation post for more details.