Display device location with NMEA data sources

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
// [WriteFile Name=DisplayDeviceLocationWithNmeaDataSources, Category=Maps]
// [Legal]
// Copyright 2021 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
import Esri.ArcGISExtras 1.1

Rectangle {
    id: rootRectangle
    clip: true
    width: 800
    height: 600

    property bool nmeaSimulationActive: false
    property var mockNmeaData: []

    MapView {
        id: mapView
        anchors.fill: parent

        Component.onCompleted: {
            // Set the focus on MapView to initially enable keyboard navigation
            forceActiveFocus();
        }

        Map {
            id: map
            Basemap {
                initStyle: Enums.BasemapStyleArcGISNavigation
            }
            ViewpointCenter {
                Point {
                    x: -117.191
                    y: 34.0306
                    spatialReference: SpatialReference { wkid: 4326 }
                }
                targetScale: 100000
            }
        }

        // Create the NemaLocationDataSource to push NMEA sentences to
        locationDisplay.dataSource: NmeaLocationDataSource {
            id: nmeaLocationDataSource
            receiverSpatialReference: SpatialReference { wkid: 4326 }
        }
        locationDisplay.autoPanMode: Enums.LocationDisplayAutoPanModeRecenter
    }

    Button {
        id: button
        anchors {
            horizontalCenter: parent.horizontalCenter
            bottom: parent.bottom
            margins: 25
        }
        width: 200
        text: nmeaSimulationActive ? "RESET" : "START"
        onClicked: {
            nmeaSimulationActive = !nmeaSimulationActive;
            if (nmeaSimulationActive)
                startSimulation();
            else
                endSimulation();
        }
    }

    FileFolder {
        id: mockNmeaDataFile
        path: ":/Samples/Maps/DisplayDeviceLocationWithNmeaDataSources/redlands.nmea"
        Component.onCompleted: {
            // Load simulated NMEA sentences to display for sample
            readFile(path)
            .toString()
            .split("\n")
            .forEach(
                 (line) => {
                     // In this simulated data stream, blocks of NMEA sentences start with $GPGGA (which provides the device's position)
                     if (line.startsWith("$GPGGA"))
                         mockNmeaData.push(line + "\n");

                     // Additional sentences that provide information such as direction and velocity follow and are separated by line breaks
                     else
                         mockNmeaData[mockNmeaData.length-1] += (line + "\n");
                 });
        }
    }

    // This timer is used to simulate NMEA sentences being received at regular intervals
    Timer {
        id: timer
        interval: 1000
        repeat: true
        property var count: 0
        onTriggered: {
            try {
                // In a non-simulated scenario, incoming NMEA sentences from a serial port or bluetooth device would be pushed to the location data source in real time
                // NMEA sentences can be pushed individually or in multiple lines separated by line breaks
                // Sentences pass information such as direction, velocity, and location and are grouped together to provide detailed information about a user's position
                nmeaLocationDataSource.pushData(mockNmeaData[count]);
            } catch(err) {
                console.log("Unable to push: " + mockNmeaData[count]);
                console.log(err);
            }

            count++;
            if (count >= mockNmeaData.length)
                count = 0;
        }
    }

    function startSimulation() {
        // Enable receiving NMEA location data from external device
        nmeaLocationDataSource.start();

        // Display the user's location
        mapView.locationDisplay.start();

        // Begin simulated data stream
        timer.count = 0;
        timer.start();
    }

    function endSimulation() {
        // End simulated data stream
        timer.stop();

        // Stop displaying the user's location
        mapView.locationDisplay.stop();

        // Stop receiving location data
        nmeaLocationDataSource.stop();
    }
}