Display your location history on the map.
Use case
You can track device location history and display it as lines and points on the map. The history can be used to visualize how the user moved through the world, to retrace their steps, or to create new feature geometry. An unmapped trail, for example, could be added to the map using this technique.
How to use the sample
Click 'Start tracking' to start tracking your location, which will appear as points on the map. A line will connect the points for easier visualization. Click 'Stop tracking' to stop updating the location history. This sample uses a simulated data source to allow the sample to be useful on desktop/non-mobile devices. To track a user's real position, use the DefaultLocationDataSource instead.
How it works
- If necessary, request location permission from the operating system.
- Create a graphics overlay to show each point and another graphics overlay for displaying the route line.
- Create a
SimulatedLocationDataSourceand initialize it with a polyline. Start theSimulatedLocationDataSourceto begin receiving location updates.- NOTE: To track a user's real position, use
DefaultLocationDataSourceinstead.
- NOTE: To track a user's real position, use
- Connect to the
LocationDisplay'sLocationChangedsignal to handle location updates. - Every time the location updates, store that location, display a point on the map, and re-create the route line.
Relevant API
- Location.position
- LocationDisplay.autoPanMode
- LocationDisplay.dataSource
- LocationDisplay.locationChanged
- MapView.locationDisplay
- SimulatedLocationDataSource
About the data
A custom set of points is used to create a Polyline and initialize a SimulatedLocationDataSource. This simulated location data source enables easier testing and allows the sample to be used on devices without an actively updating GPS signal.
Tags
bread crumb, breadcrumb, GPS, history, movement, navigation, real-time, trace, track, trail
Sample Code
ShowLocationHistory.qml
// [WriteFile Name=ShowLocationHistory, Category=Maps]
// [Legal]
// Copyright 2020 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.
// [Legal]
import QtQuick 2.6
import QtQuick.Controls 2.2
import Esri.ArcGISRuntime 100.15
Rectangle {
id: rootRectangle
clip: true
width: 800
height: 600
readonly property int initialZoomScale: 8000
property bool trackingEnabled: false
property Point lastPosition: null
// add a mapView component
MapView {
anchors.fill: parent
Map {
Basemap {
initStyle: Enums.BasemapStyleArcGISDarkGray
}
}
// set initial viewpoint near UCLA, Los Angeles
ViewpointCenter {
Point {
x: -13185535.98
y: 4037766.28
}
targetScale: initialZoomScale
}
Button {
id: button
text: trackingEnabled ? "Stop tracking" : "Start tracking"
anchors.horizontalCenter: parent.horizontalCenter
width: 200
onClicked: trackingEnabled =! trackingEnabled
}
SimulationParameters {
id: simulationParameters
velocity: 30
}
locationDisplay {
dataSource: SimulatedLocationDataSource {
id: simulatedLocationDataSource
Component.onCompleted: {
setLocationsWithPolylineAndParameters(polyline, simulationParameters);
simulatedLocationDataSource.start();
}
}
initialZoomScale: initialZoomScale
}
// if tracking is enabled then show location history
locationDisplay.onLocationChanged: {
if (!trackingEnabled)
return;
// clear old route
locationHistoryLineOverlay.graphics.clear();
if (lastPosition !== null) {
polylineBuilder.addPoint(lastPosition);
locationHistoryOverlay.graphics.append(ArcGISRuntimeEnvironment.createObject("Graphic", {geometry: lastPosition}));
}
// update last position
lastPosition = locationDisplay.location.position;
// update the polyline
locationHistoryLineOverlay.graphics.append(ArcGISRuntimeEnvironment.createObject("Graphic", {geometry: polylineBuilder.geometry}));
}
Component.onCompleted: {
// Set the focus on MapView to initially enable keyboard navigation
forceActiveFocus();
locationDisplay.autoPanMode = Enums.LocationDisplayAutoPanModeRecenter;
}
Polyline {
id: polyline
json: {"paths":[[[-13185646.046666779,4037971.5966668758],[-13185586.780000051,4037827.6633333955],
[-13185514.813333312,4037709.1299999417],[-13185569.846666701,4037522.8633330846],
[-13185591.01333339,4037378.9299996048],[-13185629.113333428,4037283.6799995075],
[-13185770.93000024,4037425.4966663187],[-13185821.730000293,4037546.146666442],
[-13185880.996667018,4037704.8966666036],[-13185948.730000421,4037874.2300001099],
[-13185974.130000448,4037946.1966668498],[-13186120.180000596,4037958.896666863],
[-13186264.113334076,4037984.296666889],[-13186336.080000836,4038001.2300002342],
[-13186314.91333415,4037757.8133333195],[-13186272.580000773,4037560.9633331187],
[-13186187.913334005,4037463.59666635],[-13186431.33000092,4037404.3299996229],
[-13186676.863334503,4037290.0299995062],[-13187625.130002158,4038589.6633341513],
[-13187333.030001862,4038756.8800009824],[-13187091.730001617,4038617.1800008402],
[-13186791.163334643,4038805.5633343654],[-13186721.313334571,4038801.3300010278],
[-13186833.49666802,4038195.9633337436],[-13186977.677439401,4037699.8176972247],
[-13186784.921301765,4037820.4541915278],[-13186749.517113185,4038150.8932846226],
[-13186649.860878762,4038288.5762400767],[-13186556.760975549,4038323.9804286221],
[-13186472.839936033,4038481.3323777127],[-13186373.183701571,4038489.1999751539],
[-13186344.335844241,4038242.6819215398],[-13186126.665647998,4038308.245233661],
[-13185814.584282301,4038358.0733508728],[-13185651.987268206,4038116.8003622484],
[-13185203.534213299,4038048.6145176427],[-13184576.748949422,4038150.8932845518],
[-13184251.55492135,4037833.5668537691],[-13184146.653621957,4037524.1080205571],
[-13183949.963685593,4037621.1417224966],[-13183687.71043711,4037781.1162040718],
[-13183480.530370807,4037875.5273735262],[-13182307.629999243,4037859.7460188437],
[-13181376.039484169,4037820.9297473822],[-13180716.162869323,4038364.3575478429],
[-13180182.439136729,4038810.7446696493],[-13178474.523192419,4040237.2426458625],
[-13178321.134040033,4039740.6894803117],[-13177958.020228144,4039140.1550991111],
[-13177073.512224896,4037459.5898928214],[-13177757.842101147,4037589.9384406791],
[-13178386.308314031,4037799.427178307],[-13180095.012208173,4037811.6550856642],
[-13180126.165447287,4036845.9046731163],[-13179806.844746364,4036324.0879179495],
[-13180928.361354485,4035887.9425703473],[-13181598.155995468,4035428.432293402],
[-13182984.47513606,4034447.105261297],[-13182229.264383668,4033222.8051626245],
[-13182058.735615831,4033339.8690072047],[-13181939.035180708,4033691.2477038498],
[-13182116.65518121,4033861.1450956347],[-13181792.305615077,4034085.1007484416],
[-13182027.845180977,4034467.3698799671],[-13181877.254310986,4034644.9898804692],
[-13181630.130832028,4034517.5668366305],[-13181386.868657427,4034424.8955320208],
[-13181228.555178719,4034652.7124891868],[-13181379.14604871,4034942.3103160923],
[-13181267.168222306,4035189.4337950516],[-13181074.103004368,4035015.6750989081],
[-13180807.673003616,4034934.5877073747],[-13180618.469090037,4034814.8872722536],
[-13180599.162568243,4035374.7764042714],[-13181047.073873857,4035494.476839392],
[-13181317.365178969,4035413.3894478586],[-13180765.198655669,4035143.0981427468],
[-13180328.871263131,4034892.1133594285],[-13180270.951697765,4035258.9372735149],
[-13180325.009958787,4035718.4324922049],[-13180707.279090302,4035695.2646660525],
[-13181413.897788007,4035536.9511873648],[-13181618.54691902,4035807.2424924765],
[-13181884.976919774,4036065.949884512],[-13182159.129529245,4035861.3007534989],
[-13182174.57474668,4035668.2355355616],[-13182417.83692128,4035664.374231203],
[-13182784.660835361,4035409.5281435261],[-13182997.032575091,4035255.0759691764],
[-13182618.624747934,4034679.7416197238]]],
"spatialReference":{"latestWkid":3857,"wkid":102100}}
}
GraphicsOverlay {
id: locationHistoryLineOverlay
SimpleRenderer {
SimpleLineSymbol {
color: "lime"
style: Enums.SimpleLineSymbolStyleSolid
width: 2
}
}
}
GraphicsOverlay {
id: locationHistoryOverlay
SimpleRenderer {
SimpleMarkerSymbol {
color: "red"
style: Enums.SimpleMarkerSymbolStyleCircle
size: 3
}
}
}
}
PolylineBuilder {
id: polylineBuilder
spatialReference: SpatialReference { wkid: 3857 }
}
}