Add QGeoJson: a GeoJSON parser

Add a Class to convert a GeoJSON document to a QVariantList ready to be
used as Model in a MapItemView. It comes with autotests, example and
detailed documentation.

[ChangeLog][QtLocation] Added a GeoJSON parser which can be used to
annotate maps with tracks, polygonal boundaries, etc.

Fixes: QTBUG-64111
Change-Id: Ib06d3902a052f69f75ae40be5c9ab56023cad916
Reviewed-by: Paolo Angelelli <paolo.angelelli@qt.io>

1 files changed, 152 insertions, 0 deletions

diff --git a/examples/location/geojson_viewer/GeoJsonDelegate.qml b/examples/location/geojson_viewer/GeoJsonDelegate.qml
new file mode 100644
index 00000000..2f550e8a
--- /dev/null
+++ b/examples/location/geojson_viewer/GeoJsonDelegate.qml
@@ -0,0 +1,152 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.12
+import QtPositioning 5.12
+import QtLocation 5.12
+import Qt.labs.qmlmodels 1.0
+
+DelegateChooser {
+    id: dc
+    role: "type"
+    property color defaultColor: "grey"
+    property real defaultOpacity: 0.4
+
+    DelegateChoice {
+        roleValue: "Point"
+        delegate: MapCircle {
+            property string geojsonType: "Point"
+            property var props: modelData.properties
+            geoShape: modelData.data
+            radius: 100*100
+            border.width: 3
+            opacity: dc.defaultOpacity
+            color: ((props !== undefined && props["color"] !== undefined) ? props["color"] :
+                   ((parent.props !== undefined && parent.props["color"] !== undefined) ? parent.props["color"]: dc.defaultColor))
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "LineString"
+        delegate: MapPolyline {
+            property string geojsonType: "LineString"
+            property var props: modelData.properties
+            geoShape: modelData.data
+            line.width: 1
+            opacity: dc.defaultOpacity
+            line.color: ((props !== undefined && props["color"] !== undefined) ? props["color"] :
+                        ((parent.props !== undefined && parent.props["color"] !== undefined) ? parent.props["color"]: dc.defaultColor))
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "Polygon"
+        delegate: MapPolygon {
+            property string geojsonType: "Polygon"
+            property var props: modelData.properties
+            geoShape: modelData.data
+            opacity: dc.defaultOpacity
+            color: ((props !== undefined && props["color"] !== undefined) ? props["color"] :
+                   ((parent.props !== undefined && parent.props["color"] !== undefined) ? parent.props["color"]: dc.defaultColor))
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "MultiPoint"
+        delegate: MapItemView {
+            property string geojsonType: "MultiPoint"
+            property var props: modelData.properties
+            model: modelData.data
+            delegate: dc
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "MultiLineString"
+        delegate: MapItemView {
+            property string geojsonType: "MultiLineString"
+            property var props: modelData.properties
+            model: modelData.data
+            delegate: dc
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "MultiPolygon"
+        delegate: MapItemView {
+            property string geojsonType: "MultiPolygon"
+            property var props: modelData.properties
+            model: modelData.data
+            delegate: dc
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "GeometryCollection"
+        delegate: MapItemView {
+            property string geojsonType: "GeometryCollection"
+            property var props: modelData.properties
+            model: modelData.data
+            delegate: dc
+        }
+    }
+
+    // Features are explicitly not generated by the parser, but converted straight to their content + the properties.
+
+    DelegateChoice {
+        roleValue: "FeatureCollection"
+        delegate: MapItemView {
+            property string geojsonType: "FeatureCollection"
+            property var props: modelData.properties
+            model: modelData.data
+            delegate: dc
+        }
+    }
+}