1/****************************************************************************
2**
3** Copyright (C) 2019 Julian Sherollari <jdotsh@gmail.com>
4** Copyright (C) 2019 The Qt Company Ltd.
5** Contact: https://www.qt.io/licensing/
6**
7** This file is part of the examples of the Qt Toolkit.
8**
9** $QT_BEGIN_LICENSE:BSD$
10** Commercial License Usage
11** Licensees holding valid commercial Qt licenses may use this file in
12** accordance with the commercial license agreement provided with the
13** Software or, alternatively, in accordance with the terms contained in
14** a written agreement between you and The Qt Company. For licensing terms
15** and conditions see https://www.qt.io/terms-conditions. For further
16** information use the contact form at https://www.qt.io/contact-us.
17**
18** BSD License Usage
19** Alternatively, you may use this file under the terms of the BSD license
20** as follows:
21**
22** "Redistribution and use in source and binary forms, with or without
23** modification, are permitted provided that the following conditions are
24** met:
25** * Redistributions of source code must retain the above copyright
26** notice, this list of conditions and the following disclaimer.
27** * Redistributions in binary form must reproduce the above copyright
28** notice, this list of conditions and the following disclaimer in
29** the documentation and/or other materials provided with the
30** distribution.
31** * Neither the name of The Qt Company Ltd nor the names of its
32** contributors may be used to endorse or promote products derived
33** from this software without specific prior written permission.
34**
35**
36** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
37** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
38** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
39** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
40** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
42** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
43** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
44** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
45** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
46** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
47**
48** $QT_END_LICENSE$
49**
50****************************************************************************/
51
52#include <QApplication>
53#include <QQmlApplicationEngine>
54#include <QDebug>
55#include <QFile>
56#include <QJsonDocument>
57#include <QVariantMap>
58#include <QQmlContext>
59#include <QtLocation/private/qgeojson_p.h>
60#include <QGeoCircle>
61#include <QGeoPath>
62#include <QGeoPolygon>
63#include <QtLocation/private/qdeclarativegeomapitemview_p.h>
64#include <QtLocation/private/qdeclarativegeomapquickitem_p.h>
65#include <QtLocation/private/qdeclarativecirclemapitem_p.h>
66#include <QtLocation/private/qdeclarativepolylinemapitem_p.h>
67#include <QtLocation/private/qdeclarativepolygonmapitem_p.h>
68#include <QtLocation/private/qdeclarativerectanglemapitem_p.h>
69#include <QJsonObject>
70#include <QJsonArray>
71#include <QFileInfo>
72#include <QtCore/qobjectdefs.h>
73#ifdef Q_OS_ANDROID
74#include <QtAndroid>
75#endif
76
77class extractor
78{
79public:
80 extractor();
81
82 static bool hasProperties(QQuickItem *item)
83 {
84 QVariant props = item->property(name: "props");
85 return !props.isNull();
86 }
87
88 static bool isFeatureCollection(QQuickItem *item)
89 {
90 QVariant geoJsonType = item->property(name: "geojsonType");
91 return geoJsonType.toString() == QStringLiteral("FeatureCollection");
92 }
93
94 static bool isGeoJsonEntry(QQuickItem *item)
95 {
96 QVariant geoJsonType = item->property(name: "geojsonType");
97 return !geoJsonType.toString().isEmpty();
98 }
99
100 static QVariantMap toVariant(QDeclarativePolygonMapItem *mapPolygon)
101 {
102 QVariantMap ls;
103 ls["type"] = "Polygon";
104 ls["data"] = QVariant::fromValue(value: mapPolygon->geoShape());
105 if (hasProperties(item: mapPolygon))
106 ls["properties"] = mapPolygon->property(name: "props").toMap();
107 return ls;
108 }
109 static QVariantMap toVariant(QDeclarativePolylineMapItem *mapPolyline)
110 {
111 QVariantMap ls;
112 ls["type"] = "LineString";
113 ls["data"] = QVariant::fromValue(value: mapPolyline->geoShape());
114 if (hasProperties(item: mapPolyline))
115 ls["properties"] = mapPolyline->property(name: "props").toMap();
116 return ls;
117 }
118 static QVariantMap toVariant(QDeclarativeCircleMapItem *mapCircle)
119 {
120 QVariantMap pt;
121 pt["type"] = "Point";
122 pt["data"] = QVariant::fromValue(value: mapCircle->geoShape());
123 if (hasProperties(item: mapCircle))
124 pt["properties"] = mapCircle->property(name: "props").toMap();
125 return pt;
126 }
127
128 static QVariantMap toVariant(QDeclarativeGeoMapItemView *mapItemView)
129 {
130 // bool featureCollecton = isFeatureCollection(mapItemView);
131
132 // If not a feature collection, this must be a geometry collection,
133 // or a multilinestring/multipoint/multipolygon.
134 // To disambiguate, one could check for heterogeneity.
135 // For simplicity, in this example, we expect the property "geojsonType" to be injected in the mapItemView
136 // by the delegate, and to be correct.
137
138 QString nodeType = mapItemView->property(name: "geojsonType").toString();
139 QVariantMap root;
140 if (!nodeType.isEmpty()) // Empty nodeType can happen only for the root MIV
141 root["type"] = nodeType;
142 if (hasProperties(item: mapItemView)) // Features are converted to regular types w properties.
143 root["properties"] = mapItemView->property(name: "props").toMap();
144
145 QVariantList features;
146 const QList<QQuickItem *> &quickChildren = mapItemView->childItems();
147 for (auto kid : quickChildren) {
148 QVariant entry;
149 if (QDeclarativeGeoMapItemView *miv = qobject_cast<QDeclarativeGeoMapItemView *>(object: kid)) {
150 // Handle nested miv
151 entry = toVariant(mapItemView: miv);
152 } else if (QDeclarativePolylineMapItem *polyline = qobject_cast<QDeclarativePolylineMapItem *>(object: kid)) {
153 entry = toVariant(mapPolyline: polyline);
154 } else if (QDeclarativePolygonMapItem *polygon = qobject_cast<QDeclarativePolygonMapItem *>(object: kid)) {
155 entry = toVariant(mapPolygon: polygon);
156 } else if (QDeclarativeCircleMapItem *circle = qobject_cast<QDeclarativeCircleMapItem *>(object: kid)) {
157 entry = toVariant(mapCircle: circle); // If GeoJSON Point type is visualized in other ways, handle those types here instead.
158 }
159 features.append(t: entry);
160 }
161 if (nodeType.isEmpty()) // Dirty hack to handle (=skip) the first MIV used to process the fictitious list with 1 element
162 return features.first().toMap();
163 root["data"] = features;
164 return root;
165 }
166};
167
168class GeoJsoner: public QObject
169{
170 Q_OBJECT
171 Q_PROPERTY(QVariant model MEMBER m_importedGeoJson NOTIFY modelChanged)
172
173public:
174 GeoJsoner(QObject *parent = nullptr) : QObject(parent)
175 {
176
177 }
178
179public slots:
180
181 Q_INVOKABLE bool load(QUrl url)
182 {
183 // Reading GeoJSON file
184 QFile loadFile(url.toLocalFile());
185 if (!loadFile.open(flags: QIODevice::ReadOnly)) {
186 qWarning() << "Error while opening the file: " << url;
187 qWarning() << loadFile.error() << loadFile.errorString();
188 return false;
189 }
190
191 // Load the GeoJSON file using Qt's API
192 QJsonParseError err;
193 QJsonDocument loadDoc(QJsonDocument::fromJson(json: loadFile.readAll(), error: &err));
194 if (err.error) {
195 qWarning() << "Parsing while importing the JSON document:\n" << err.errorString();
196 return false;
197 }
198
199 // Import geographic data to a QVariantList
200 QVariantList modelList = QGeoJson::importGeoJson(doc: loadDoc);
201 m_importedGeoJson = modelList;
202 emit modelChanged();
203 return true;
204 }
205
206 // Used by the MapItemView Extractor to identify a Feature
207 Q_INVOKABLE QVariantList toGeoJson(QDeclarativeGeoMapItemView *mapItemView)
208 {
209 QVariantList res;
210 QDeclarativeGeoMapItemView *root = mapItemView;
211 QVariantMap miv = extractor::toVariant(mapItemView: root);
212 if (!miv.isEmpty())
213 res.append(t: miv);
214 return res;
215 }
216
217 Q_INVOKABLE void dumpGeoJSON(QVariantList geoJson, QUrl url)
218 {
219 QJsonDocument json = QGeoJson::exportGeoJson(list: geoJson);
220 QFile jsonFile(url.toLocalFile());
221 jsonFile.open(flags: QIODevice::WriteOnly);
222 jsonFile.write(data: json.toJson());
223 jsonFile.close();
224 }
225
226 Q_INVOKABLE void writeDebug(QVariantList geoJson, QUrl url)
227 {
228 QString prettyPrint = QGeoJson::toString(importedGeoJson: geoJson);
229 QFile debugFile(url.toLocalFile());
230 debugFile.open(flags: QIODevice::WriteOnly);
231 debugFile.write(data: prettyPrint.toUtf8());
232 debugFile.close();
233 }
234
235 Q_INVOKABLE void print(QDeclarativeGeoMapItemView *view)
236 {
237 QVariantList list;
238 list.append(t: extractor::toVariant(mapItemView: view));
239 QString prettyPrint =
240 QGeoJson::toString(importedGeoJson: list);
241 qDebug().noquote() << prettyPrint;
242 }
243
244signals:
245 void modelChanged();
246
247public:
248 QVariant m_importedGeoJson;
249};
250
251#include "main.moc"
252
253#ifdef Q_OS_ANDROID
254// Request permissions because we're using QStandardPaths::writableLocation()
255bool requestStoragePermissions() {
256 using namespace QtAndroid;
257
258 QString permission = QStringLiteral("android.permission.WRITE_EXTERNAL_STORAGE");
259 const QHash<QString, PermissionResult> results = requestPermissionsSync(QStringList({permission}));
260 if (!results.contains(permission) || results[permission] == PermissionResult::Denied) {
261 qWarning() << "Couldn't get permission: " << permission;
262 return false;
263 }
264
265 return true;
266}
267#endif
268
269int main(int argc, char *argv[])
270{
271 QCoreApplication::setAttribute(attribute: Qt::AA_EnableHighDpiScaling);
272 QApplication app(argc, argv);
273#ifdef Q_OS_ANDROID
274 if (!requestStoragePermissions())
275 return -1;
276#endif
277
278 QQmlApplicationEngine engine;
279 QUrl absoluteFilePath = argc > 1 ?
280 QUrl(QStringLiteral("file://") + QFileInfo(argv[1]).absoluteFilePath()) :
281 QUrl();
282 engine.rootContext()->setContextProperty("dataPath", QUrl(QStringLiteral("file://")
283 + qPrintable(QT_STRINGIFY(SRC_PATH))
284 + QStringLiteral("/data")));
285 qmlRegisterType<GeoJsoner>("Qt.GeoJson", 1, 0, "GeoJsoner");
286 engine.load(url: QUrl(QStringLiteral("qrc:/main.qml")));
287
288 if (engine.rootObjects().isEmpty())
289 return -1;
290 if (!absoluteFilePath.isEmpty()) {
291 GeoJsoner *geoJsoner = engine.rootObjects().first()->findChild<GeoJsoner*>();
292 QMetaObject::invokeMethod(geoJsoner, "load", Qt::QueuedConnection, Q_ARG(QUrl, absoluteFilePath));
293 }
294
295 return app.exec();
296}
297

source code of qtlocation/examples/location/geojson_viewer/main.cpp