Support Qt 5.11 and fix image provider.

matrix/imageprovider.h

@@ -3,26 +3,47 @@
 
 #include <QtQuick/QQuickImageProvider>
 #include <QtCore/QReadWriteLock>
+#include <QObject>
 
-namespace QMatrixClient {
-    class Connection;
-}
+#include "libqmatrixclient/connection.h"
+
+class ImageProviderConnection: public QObject
+{
+    Q_OBJECT
+
+    Q_PROPERTY(QMatrixClient::Connection* connection READ getConnection WRITE setConnection NOTIFY connectionChanged)
+
+    public:
+        explicit ImageProviderConnection(QObject* parent = nullptr);
+        ~ImageProviderConnection();
+
+        QMatrixClient::Connection* getConnection() { return m_connection; }
+        Q_INVOKABLE void setConnection(QMatrixClient::Connection* connection) {
+            qDebug() << "Connection changed.";
+            emit connectionChanged();
+            m_connection = connection;
+        }
+    private:
+        QMatrixClient::Connection* m_connection;
+    signals:
+        void connectionChanged();
+};
 
 class ImageProvider: public QQuickImageProvider
 {
     public:
-        explicit ImageProvider(QObject *parent = nullptr);
+        explicit ImageProvider(QObject* parent = nullptr);
 
         QImage requestImage(const QString& id, QSize* pSize,
                               const QSize& requestedSize) override;
 
-        void setConnection(QMatrixClient::Connection* connection);
-
         void initializeEngine(QQmlEngine *engine, const char *uri);
 
+        ImageProviderConnection* getConnection() { return m_connection; }
+
     private:
-        QMatrixClient::Connection* m_connection;
         QReadWriteLock m_lock;
+        ImageProviderConnection* m_connection;
 };
 
 #endif // IMAGEPROVIDER_H