[Qt] Do not use non-Qt headers

platform/qt/app/mapwindow.cpp

@@ -1,7 +1,5 @@
 #include "mapwindow.hpp"
 
-#include <mbgl/util/default_styles.hpp>
-
 #include <QApplication>
 #include <QDebug>
 #include <QKeyEvent>
@@ -54,16 +52,12 @@ void MapWindow::changeStyle()
 {
     static uint8_t currentStyleIndex;
 
-    mbgl::util::default_styles::DefaultStyle newStyle =
-        mbgl::util::default_styles::orderedStyles[currentStyleIndex];
+    auto& styles = QMapbox::defaultStyles();
 
-    QString url(newStyle.url);
-    m_map.setStyleURL(url);
+    m_map.setStyleURL(styles[currentStyleIndex].first);
+    setWindowTitle(QString("Mapbox GL: ") + styles[currentStyleIndex].second);
 
-    QString name(newStyle.name);
-    setWindowTitle(QString("Mapbox GL: ") + name);
-
-    if (++currentStyleIndex == mbgl::util::default_styles::numOrderedStyles) {
+    if (++currentStyleIndex == styles.size()) {
         currentStyleIndex = 0;
     }
 }

platform/qt/include/qmapbox.hpp

@@ -39,6 +39,8 @@ struct Q_DECL_EXPORT CameraOptions {
     QVariant pitch;   // double
 };
 
+Q_DECL_EXPORT QList<QPair<QString, QString>>& defaultStyles();
+
 Q_DECL_EXPORT NetworkMode networkMode();
 Q_DECL_EXPORT void setNetworkMode(NetworkMode);
 

platform/qt/src/qmapbox.cpp

@@ -1,4 +1,5 @@
 #include <mbgl/storage/network_status.hpp>
+#include <mbgl/util/default_styles.hpp>
 
 #include <QMapbox>
 
@@ -29,4 +30,18 @@ Q_DECL_EXPORT void setNetworkMode(NetworkMode mode)
     }
 }
 
+Q_DECL_EXPORT QList<QPair<QString, QString>>& defaultStyles()
+{
+    static QList<QPair<QString, QString>> styles;
+
+    if (styles.isEmpty()) {
+        for (auto style : mbgl::util::default_styles::orderedStyles) {
+            styles.append(QPair<QString, QString>(
+                QString::fromStdString(style.url), QString::fromStdString(style.name)));
+        }
+    }
+
+    return styles;
+}
+
 }