[Qt] Allow setting the style via QML

platform/qt/include/qquickmapboxgl.hpp

@@ -13,6 +13,7 @@ class Q_DECL_EXPORT QQuickMapboxGL : public QQuickFramebufferObject
 {
     Q_OBJECT
 
+    // Map QML Type interface implementation.
     Q_ENUMS(QGeoServiceProvider::Error)
     Q_PROPERTY(QDeclarativeGeoServiceProvider *plugin READ plugin WRITE setPlugin NOTIFY pluginChanged)
     Q_PROPERTY(qreal minimumZoomLevel READ minimumZoomLevel WRITE setMinimumZoomLevel NOTIFY minimumZoomLevelChanged)
@@ -25,6 +26,9 @@ class Q_DECL_EXPORT QQuickMapboxGL : public QQuickFramebufferObject
     Q_PROPERTY(bool copyrightsVisible READ copyrightsVisible WRITE setCopyrightsVisible NOTIFY copyrightsVisibleChanged)
     Q_PROPERTY(QColor color READ color WRITE setColor NOTIFY colorChanged)
 
+    // MapboxGL QML Type interface.
+    Q_PROPERTY(QString style READ style WRITE setStyle NOTIFY styleChanged)
+
 public:
     QQuickMapboxGL(QQuickItem *parent = 0);
     virtual ~QQuickMapboxGL();
@@ -59,10 +63,14 @@ public:
     void setColor(const QColor &color);
     QColor color() const;
 
+    void setStyle(const QString &style);
+    QString style() const;
+
     enum SyncState {
         NothingNeedsSync = 0x00,
         ZoomNeedsSync    = 0x01,
         CenterNeedsSync  = 0x02,
+        StyleNeedsSync   = 0x04,
     };
 
     int swapSyncState();
@@ -80,6 +88,8 @@ signals:
     void copyrightsVisibleChanged(bool visible);
     void colorChanged(const QColor &color);
 
+    void styleChanged();
+
 private:
     qreal m_minimumZoomLevel = 0;
     qreal m_maximumZoomLevel = 20;
@@ -88,6 +98,8 @@ private:
     QGeoCoordinate m_center;
     QGeoShape m_visibleRegion;
 
+    QString m_style;
+
     int m_syncState = NothingNeedsSync;
 };
 

platform/qt/qmlapp/main.qml

@@ -21,6 +21,8 @@ ApplicationWindow {
             id: map
             anchors.fill: parent
 
+            style: "mapbox://styles/mapbox/streets-v8"
+
             center: QtPositioning.coordinate(60.170448, 24.942046)
             zoomLevel: 14
             minimumZoomLevel: 8

platform/qt/src/qquickmapboxgl.cpp

@@ -3,6 +3,7 @@
 #include <QQuickMapboxGL>
 
 #include <QQuickItem>
+#include <QString>
 #include <QtGlobal>
 
 QQuickMapboxGL::QQuickMapboxGL(QQuickItem *parent_)
@@ -156,6 +157,25 @@ QColor QQuickMapboxGL::color() const
     return QColor();
 }
 
+void QQuickMapboxGL::setStyle(const QString &styleUrl)
+{
+    if (m_style == styleUrl) {
+        return;
+    }
+
+    m_style = styleUrl;
+
+    m_syncState |= StyleNeedsSync;
+    update();
+
+    emit styleChanged();
+}
+
+QString QQuickMapboxGL::style() const
+{
+    return m_style;
+}
+
 int QQuickMapboxGL::swapSyncState()
 {
     int oldState = m_syncState;

platform/qt/src/qquickmapboxglrenderer.cpp

@@ -42,7 +42,6 @@ void QQuickMapboxGLRenderer::render()
 void QQuickMapboxGLRenderer::synchronize(QQuickFramebufferObject *item)
 {
     if (!m_initialized) {
-        m_map->setStyleURL(QMapbox::defaultStyles()[0].first);
         QObject::connect(m_map.data(), SIGNAL(needsRendering()), item, SLOT(update()));
         m_initialized = true;
     }
@@ -58,4 +57,8 @@ void QQuickMapboxGLRenderer::synchronize(QQuickFramebufferObject *item)
         const auto& center = quickMap->center();
         m_map->setCoordinate(QMapbox::Coordinate(center.latitude(), center.longitude()));
     }
+
+    if (syncStatus & QQuickMapboxGL::StyleNeedsSync) {
+        m_map->setStyleURL(quickMap->style());
+    }
 }