Remove support for Qt 5.6, 5.7 and 5.8

We supported these old version as long as they wouldn't break new features,
but that is happening now: Qt < 5.9 does not support including enums of
unrelated C++ classes into the QML scope of another exported C++ class.

At least this will get rid of nearly all the ugly QT_VERSION #ifdefs we had.

Change-Id: I1bc4e9289e685eedb0af7b20e928ed550569196b
Reviewed-by: Dominik Holland <dominik.holland@pelagicore.com>

15 files changed, 21 insertions, 320 deletions

diff --git a/3rdparty/libarchive.pri b/3rdparty/libarchive.pri
index eb352e2b..ad1e0bc6 100644
--- a/3rdparty/libarchive.pri
+++ b/3rdparty/libarchive.pri
@@ -2,23 +2,7 @@
 include(libz.pri)
 
 !config_libarchive|no-system-libarchive {
-    lessThan(QT_MINOR_VERSION, 8) {
-        # this is the "old way" used by Qt <= 5.7
-        load(fix-library-path)
-
-        LIBARCHIVE_PATH = $$PWD/libarchive
-        LIBARCHIVE_BUILD_PATH = $$shadowed($$LIBARCHIVE_PATH)
-
-        INCLUDEPATH += $$LIBARCHIVE_PATH/libarchive
-        LIBS_PRIVATE += $$fixLibraryPath(-L$$LIBARCHIVE_BUILD_PATH) -lqtarchive$$qtPlatformTargetSuffix()
-
-        win32:DEFINES += LIBARCHIVE_STATIC
-
-        CONFIG *= link_prl
-    } else {
-        # the "new way", starting with Qt 5.8
-        QMAKE_USE_PRIVATE += archive
-    }
+    QMAKE_USE_PRIVATE += archive
 } else {
     PKGCONFIG_PRIVATE += "'libarchive >= 3.1.2'"
     CONFIG *= link_pkgconfig
diff --git a/3rdparty/libbacktrace.pri b/3rdparty/libbacktrace.pri
index 58ce43bf..ec9d1da8 100644
--- a/3rdparty/libbacktrace.pri
+++ b/3rdparty/libbacktrace.pri
@@ -1,16 +1,2 @@
 
-lessThan(QT_MINOR_VERSION, 8) {
-    # this is the "old way" used by Qt <= 5.7
-    load(fix-library-path)
-
-    LIBBACKTRACE_PATH = $$PWD/libbacktrace
-    LIBBACKTRACE_BUILD_PATH = $$shadowed($$LIBBACKTRACE_PATH)
-
-    INCLUDEPATH += $$LIBBACKTRACE_PATH
-    LIBS_PRIVATE += $$fixLibraryPath(-L$$LIBBACKTRACE_BUILD_PATH) -lqtbacktrace$$qtPlatformTargetSuffix()
-
-    CONFIG *= link_prl
-} else {
-    # the "new way", starting with Qt 5.8
-    QMAKE_USE_PRIVATE += backtrace
-}
+QMAKE_USE_PRIVATE += backtrace
diff --git a/3rdparty/libyaml.pri b/3rdparty/libyaml.pri
index 02e10ed5..bac439f0 100644
--- a/3rdparty/libyaml.pri
+++ b/3rdparty/libyaml.pri
@@ -1,21 +1,6 @@
 
 !config_libyaml|no-system-libyaml {
-    lessThan(QT_MINOR_VERSION, 8) {
-        # this is the "old way" used by Qt <= 5.7
-        load(fix-library-path)
-
-        LIBYAML_PATH = $$PWD/libyaml
-        LIBYAML_BUILD_PATH = $$shadowed($$LIBYAML_PATH)
-
-        DEFINES *= YAML_DECLARE_STATIC
-        INCLUDEPATH += $$LIBYAML_PATH/include
-        LIBS_PRIVATE += $$fixLibraryPath(-L$$LIBYAML_BUILD_PATH) -lqtyaml$$qtPlatformTargetSuffix()
-
-        CONFIG *= link_prl
-    } else {
-        # the "new way", starting with Qt 5.8
-        QMAKE_USE_PRIVATE += yaml
-    }
+    QMAKE_USE_PRIVATE += yaml
 } else {
     PKGCONFIG_PRIVATE += "'yaml-0.1 >= 0.1.6'"
     CONFIG *= link_pkgconfig
diff --git a/3rdparty/libz.pri b/3rdparty/libz.pri
index 7e4b8136..682bf410 100644
--- a/3rdparty/libz.pri
+++ b/3rdparty/libz.pri
@@ -1,29 +1,8 @@
 # zlib dependency satisfied by bundled 3rd party zlib or system zlib
-lessThan(QT_MINOR_VERSION, 8) {
-    # this is the "old way" used by Qt <= 5.7
+CONFIG *= qt
 
-    contains(QT_CONFIG, system-zlib) {
-        unix|mingw: LIBS_PRIVATE += -lz
-        else:       LIBS += zdll.lib
-    } else {
-        CONFIG *= qt
-        QT *= core
-
-        load(qt_build_paths)
-        git_build: {
-            INCLUDEPATH += $$[QT_INSTALL_HEADERS/get]/QtZlib
-        } else {
-            INCLUDEPATH += $$[QT_INSTALL_HEADERS/src]/QtZlib
-        }
-    }
+qtConfig(system-zlib) {
+    QMAKE_USE_PRIVATE *= zlib
 } else {
-    # the "new way", starting with Qt 5.8
-
-    CONFIG *= qt
-
-    qtConfig(system-zlib) {
-        QMAKE_USE_PRIVATE *= zlib
-    } else {
-        QT_PRIVATE *= core zlib-private
-    }
+    QT_PRIVATE *= core zlib-private
 }
diff --git a/application-manager.pro b/application-manager.pro
index 9d6f85a5..15cbf405 100644
--- a/application-manager.pro
+++ b/application-manager.pro
@@ -26,7 +26,7 @@ if(linux|force-libcrypto) {
     !if(contains(QT_CONFIG,"openssl")|contains(QT_CONFIG,"openssl-linked")|contains(QT_CONFIG,"ssl")):error("Qt was built without OpenSSL support.")
 }
 
-MIN_MINOR=6
+MIN_MINOR=9
 
 !equals(QT_MAJOR_VERSION, 5)|lessThan(QT_MINOR_VERSION, $$MIN_MINOR):error("This application needs to be built against Qt 5.$${MIN_MINOR}+")
 
diff --git a/doc/installation.qdoc b/doc/installation.qdoc
index 5748509e..3a59ed81 100644
--- a/doc/installation.qdoc
+++ b/doc/installation.qdoc
@@ -50,7 +50,7 @@ In order to build the application-manager with all its features, the following
 components are required:
 
 \list
-    \li \b Qt 5.6 or higher.
+    \li \b Qt 5.9.0 or higher.
     \li \b libyaml 1.6 or higher.
     \li \b openssl 1.0.1 or higher \e{- Linux only}. At compile time, only the headers need to be
            available. The needed libraries will be dynamically loaded at runtime.
diff --git a/src/common-lib/dbus-utilities.cpp b/src/common-lib/dbus-utilities.cpp
index 6952c63b..4ad1bebb 100644
--- a/src/common-lib/dbus-utilities.cpp
+++ b/src/common-lib/dbus-utilities.cpp
@@ -68,12 +68,7 @@ QVariant convertFromJSVariant(const QVariant &variant)
     } else if (type == QMetaType::QVariant) {
         // got a matryoshka variant
         return convertFromJSVariant(variant.value<QVariant>());
-    } else if ((type == QMetaType::UnknownType)
-#  if QT_VERSION < QT_VERSION_CHECK(5, 8, 0)
-               || ((type == QMetaType::VoidStar) && (qvariant_cast<void *>(variant) == nullptr))) {
-#  else
-               || (type == QMetaType::Nullptr)) {
-#endif
+    } else if ((type == QMetaType::UnknownType) || (type == QMetaType::Nullptr)) {
         // we cannot send QVariant::Invalid and null values via DBus, so we abuse BYTE(0) for this purpose
         return QVariant::fromValue<uchar>(0);
     } else if (type == QMetaType::QVariantList) {
diff --git a/src/common-lib/global.h b/src/common-lib/global.h
index 11c03231..5ef78a56 100644
--- a/src/common-lib/global.h
+++ b/src/common-lib/global.h
@@ -56,23 +56,3 @@ QT_END_NAMESPACE_AM
 #define qL1C(x) QLatin1Char(x)
 #define qSL(x) QStringLiteral(x)
 
-#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
-namespace QtPrivate {
-template <typename T> struct QAddConst { typedef const T Type; };
-}
-
-// this adds const to non-const objects (like std::as_const)
-template <typename T>
-Q_DECL_CONSTEXPR typename QtPrivate::QAddConst<T>::Type &qAsConst(T &t) Q_DECL_NOTHROW { return t; }
-// prevent rvalue arguments:
-template <typename T>
-void qAsConst(const T &&) Q_DECL_EQ_DELETE;
-#endif
-
-#if QT_VERSION < QT_VERSION_CHECK(5, 8, 0)
-#  if (defined(Q_CC_GNU) && Q_CC_GNU >= 700) && !defined(Q_CC_INTEL)
-#    define Q_FALLTHROUGH() __attribute__((fallthrough))
-#  else
-#    define Q_FALLTHROUGH() (void)0
-#  endif
-#endif
diff --git a/src/common-lib/logging.cpp b/src/common-lib/logging.cpp
index 42af5482..a3e2237d 100644
--- a/src/common-lib/logging.cpp
+++ b/src/common-lib/logging.cpp
@@ -226,18 +226,7 @@ static void colorLogToStderr(QtMsgType msgType, const QMessageLogContext &contex
             while (spacing < 0)
                 spacing += consoleWidth;
         }
-#if QT_VERSION < QT_VERSION_CHECK(5,7,0)
-        // efficiently appending spaces without allocating is hard in Qt 5.6
-        static const char spacingStr[] = "                                                                               ";
-        Q_STATIC_ASSERT(sizeof(spacingStr) == 80);
-        while (spacing > 0) {
-            int spacingLen = qMin(spacing, int(sizeof(spacingStr)) - 1);
-            out.append(spacingStr, spacingLen);
-            spacing -= spacingLen;
-        }
-#else
         out.append(spacing, ' ');
-#endif
         out.append('[');
 
         color(out, Magenta);
diff --git a/src/common-lib/qml-utilities.cpp b/src/common-lib/qml-utilities.cpp
index 53f3a069..b232bd92 100644
--- a/src/common-lib/qml-utilities.cpp
+++ b/src/common-lib/qml-utilities.cpp
@@ -83,14 +83,7 @@ void fixNullValuesForQml(QVariant &v)
         break;
     }
     case QVariant::Invalid: {
-        QVariant v2 =
-#if QT_VERSION < QT_VERSION_CHECK(5, 8, 0)
-            // QML < 5.8 expects null values in this format
-            QVariant(QMetaType::VoidStar, (void *) 0);
-#else
-            // QML >= 5.8 expects null values in this format
-            QVariant::fromValue(nullptr);
-#endif
+        QVariant v2 = QVariant::fromValue(nullptr);
         qSwap(v.data_ptr(), v2.data_ptr());
         break;
     }
diff --git a/src/manager-lib/fakeapplicationmanagerwindow.cpp b/src/manager-lib/fakeapplicationmanagerwindow.cpp
index ffa65051..7a4ca15a 100644
--- a/src/manager-lib/fakeapplicationmanagerwindow.cpp
+++ b/src/manager-lib/fakeapplicationmanagerwindow.cpp
@@ -266,11 +266,7 @@ QJSValue FakeApplicationManagerWindow::getUndefined() const
 
 void FakeApplicationManagerWindow::referenceError(const char *symbol) const
 {
-#if QT_VERSION < QT_VERSION_CHECK(5, 9, 0)
-        qWarning().noquote() << "ReferenceError:" << symbol << "is not defined";
-#else
-        qmlWarning(this) << "ReferenceError: " << symbol << " is not defined";
-#endif
+    qmlWarning(this) << "ReferenceError: " << symbol << " is not defined";
 }
 
 void FakeApplicationManagerWindow::grabToImage() const          { referenceError("grabToImage"); }
@@ -314,11 +310,7 @@ void FakeApplicationManagerWindow::connectNotify(const QMetaMethod &signal)
 
         QString name = qSL("on") + QString::fromUtf8(signal.name());
         name[2] = name[2].toUpper();
-#if QT_VERSION < QT_VERSION_CHECK(5, 9, 0)
-        qWarning() << "QML ApplicationManagerWindow: Cannot assign to non-existent property" << name;
-#else
         qmlWarning(this) << "Cannot assign to non-existent property \"" << name << "\"";
-#endif
     }
 }
 
diff --git a/src/window-lib/waylandcompositor.cpp b/src/window-lib/waylandcompositor.cpp
index 4374a668..01ec2c3e 100644
--- a/src/window-lib/waylandcompositor.cpp
+++ b/src/window-lib/waylandcompositor.cpp
@@ -50,39 +50,15 @@
 #include "applicationmanager.h"
 #include "waylandcompositor.h"
 
-#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
-#  include <QWaylandQuickSurface>
-#  include <QWaylandSurfaceItem>
-#  include <QWaylandClient>
-
-#  include "window.h"
-#else
-#  include <QWaylandWlShell>
-#  include <QWaylandQuickOutput>
-#  include <QWaylandTextInputManager>
-#  include <private/qwlextendedsurface_p.h>
-#  if QT_VERSION < QT_VERSION_CHECK(5, 8, 0)
-#    include <QWaylandWindowManagerExtension>
-typedef QWaylandWindowManagerExtension QWaylandQtWindowManager;
-#  else
-#    include <QWaylandQtWindowManager>
-#  endif
-#  include "waylandcompositor_p.h"
-#endif
+#include <QWaylandWlShell>
+#include <QWaylandQuickOutput>
+#include <QWaylandTextInputManager>
+#include <private/qwlextendedsurface_p.h>
+#include <QWaylandQtWindowManager>
+#include "waylandcompositor_p.h"
 
 QT_BEGIN_NAMESPACE_AM
 
-#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
-WindowSurface::WindowSurface(QWaylandSurface *surface)
-    : m_item(nullptr)
-    , m_surface(surface)
-{
-    connect(m_surface, &QObject::destroyed, [this]() { delete this; });
-    connect(m_surface, &QWaylandSurface::pong, this, &WindowSurface::pong);
-    connect(m_surface, &QWaylandSurface::windowPropertyChanged, this, &WindowSurface::windowPropertyChanged);
-}
-#else
-
 WindowSurface::WindowSurface(QWaylandCompositor *comp, QWaylandClient *client, uint id, int version)
     : QWaylandQuickSurface(comp, client, id, version)
     , m_surface(this)
@@ -110,8 +86,6 @@ QWaylandWlShellSurface *WindowSurface::shellSurface() const
     return m_shellSurface;
 }
 
-#endif
-
 
 QWaylandSurface *WindowSurface::surface() const
 {
@@ -130,16 +104,8 @@ qint64 WindowSurface::processId() const
 
 QWindow *WindowSurface::outputWindow() const
 {
-#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
-    if (QWaylandOutput *o = m_surface->mainOutput())
-        return o->window();
-#elif QT_VERSION < QT_VERSION_CHECK(5, 8, 0)
-    if (QWaylandView *v = m_surface->throttlingView())
-        return v->output()->window();
-#else
     if (QWaylandView *v = m_surface->primaryView())
         return v->output()->window();
-#endif
     return nullptr;
 }
 
@@ -150,33 +116,20 @@ void WindowSurface::takeFocus()
 
 void WindowSurface::ping()
 {
-#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
-    m_surface->ping();
-#else
     m_shellSurface->ping();
-#endif
 }
 
 QVariantMap WindowSurface::windowProperties() const
 {
-#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
-    return m_surface->windowProperties();
-#else
     return m_extendedSurface ? m_extendedSurface->windowProperties() : QVariantMap();
-#endif
 }
 
 void WindowSurface::setWindowProperty(const QString &name, const QVariant &value)
 {
-#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
-    m_surface->setWindowProperty(name, value);
-#else
     if (m_extendedSurface)
         m_extendedSurface->setWindowProperty(name, value);
-#endif
 }
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
 
 WindowSurfaceQuickItem::WindowSurfaceQuickItem(WindowSurface *windowSurface)
     : QWaylandQuickItem()
@@ -202,22 +155,8 @@ void WindowSurfaceQuickItem::geometryChanged(const QRectF &newGeometry, const QR
     QWaylandQuickItem::geometryChanged(newGeometry, oldGeometry);
 }
 
-#endif // QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
-
 
 WaylandCompositor::WaylandCompositor(QQuickWindow *window, const QString &waylandSocketName, WindowManager *manager)
-#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
-    : QWaylandQuickCompositor(qPrintable(waylandSocketName), DefaultExtensions | SubSurfaceExtension)
-    , m_manager(manager)
-{
-    registerOutputWindow(window);
-    window->winId();
-    addDefaultShell();
-    QObject::connect(window, &QQuickWindow::beforeSynchronizing, [this]() { frameStarted(); });
-    QObject::connect(window, &QQuickWindow::afterRendering, [this]() { sendCallbacks(); });
-    setOutputGeometry(window->geometry());
-
-#else // QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
     : QWaylandQuickCompositor()
     , m_shell(new QWaylandWlShell(this))
     , m_surfExt(new QtWayland::SurfaceExtensionGlobal(this))
@@ -227,11 +166,7 @@ WaylandCompositor::WaylandCompositor(QQuickWindow *window, const QString &waylan
     setSocketName(waylandSocketName.toUtf8());
     registerOutputWindow(window);
 
-#  if QT_VERSION < QT_VERSION_CHECK(5, 8, 0)
-    connect(this, &QWaylandCompositor::createSurface, this, &WaylandCompositor::doCreateSurface);
-#  else
     connect(this, &QWaylandCompositor::surfaceRequested, this, &WaylandCompositor::doCreateSurface);
-#  endif
     connect(this, &QWaylandCompositor::surfaceCreated, [this](QWaylandSurface *s) {
         connect(s, &QWaylandSurface::surfaceDestroyed, this, [this, s]() {
             m_manager->waylandSurfaceDestroyed(static_cast<WindowSurface *>(s));
@@ -239,11 +174,7 @@ WaylandCompositor::WaylandCompositor(QQuickWindow *window, const QString &waylan
         m_manager->waylandSurfaceCreated(static_cast<WindowSurface *>(s));
     });
 
-#  if QT_VERSION < QT_VERSION_CHECK(5, 8, 0)
-    connect(m_shell, &QWaylandWlShell::createShellSurface, this, &WaylandCompositor::createShellSurface);
-#  else
     connect(m_shell, &QWaylandWlShell::wlShellSurfaceRequested, this, &WaylandCompositor::createShellSurface);
-#  endif
     connect(m_surfExt, &QtWayland::SurfaceExtensionGlobal::extendedSurfaceReady, this, &WaylandCompositor::extendedSurfaceReady);
 
     auto wmext = new QWaylandQtWindowManager(this);
@@ -253,18 +184,13 @@ WaylandCompositor::WaylandCompositor(QQuickWindow *window, const QString &waylan
     });
 
     create();
-#endif // QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
 }
 
 void WaylandCompositor::registerOutputWindow(QQuickWindow* window)
 {
-#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
-    createOutput(window, QString(), QString());
-#else
     auto output = new QWaylandQuickOutput(this, window);
     output->setSizeFollowsWindow(true);
     m_outputs.append(output);
-#endif
     window->winId();
 }
 
@@ -272,17 +198,11 @@ QWaylandSurface *WaylandCompositor::waylandSurfaceFromItem(QQuickItem *surfaceIt
 {
     // QWaylandQuickItem::surface() will return a nullptr to WindowManager::waylandSurfaceDestroyed,
     // if the app crashed. We return our internal copy of that surface pointer instead.
-#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
-    if (QWaylandSurfaceItem *item = qobject_cast<QWaylandSurfaceItem *>(surfaceItem))
-          return item->surface();
-#else
     if (WindowSurfaceQuickItem *item = qobject_cast<WindowSurfaceQuickItem *>(surfaceItem))
         return item->m_windowSurface->surface();
-#endif
     return nullptr;
 }
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
 
 void WaylandCompositor::doCreateSurface(QWaylandClient *client, uint id, int version)
 {
@@ -295,13 +215,8 @@ void WaylandCompositor::createShellSurface(QWaylandSurface *surface, const QWayl
     QWaylandWlShellSurface *ss = new QWaylandWlShellSurface(m_shell, windowSurface, resource);
     windowSurface->setShellSurface(ss);
 
-#if QT_VERSION < QT_VERSION_CHECK(5, 8, 0)
-    connect(windowSurface, &QWaylandSurface::mappedChanged, this, [this, windowSurface]() {
-        if (windowSurface->isMapped())
-#else
     connect(windowSurface, &QWaylandSurface::hasContentChanged, this, [this, windowSurface]() {
         if (windowSurface->hasContent())
-#endif
             m_manager->waylandSurfaceMapped(windowSurface);
         else
             m_manager->waylandSurfaceUnmapped(windowSurface);
@@ -314,66 +229,4 @@ void WaylandCompositor::extendedSurfaceReady(QtWayland::ExtendedSurface *ext, QW
     windowSurface->setExtendedSurface(ext);
 }
 
-#else // if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
-
-void WaylandCompositor::surfaceCreated(QWaylandSurface *surface)
-{
-    WindowSurface *windowSurface = new WindowSurface(surface);
-    m_manager->waylandSurfaceCreated(windowSurface);
-    QObject::connect(surface, &QWaylandSurface::mapped, [windowSurface, surface, this]() {
-        windowSurface->m_item = static_cast<QWaylandSurfaceItem *>(surface->views().at(0));
-        windowSurface->m_item->setResizeSurfaceToItem(true);
-        windowSurface->m_item->setTouchEventsEnabled(true);
-        m_manager->waylandSurfaceMapped(windowSurface);
-    });
-    QObject::connect(surface, &QWaylandSurface::unmapped, [windowSurface, this]() {
-        m_manager->waylandSurfaceUnmapped(windowSurface);
-    });
-    QObject::connect(surface, &QWaylandSurface::surfaceDestroyed, [windowSurface, this]() {
-        m_manager->waylandSurfaceDestroyed(windowSurface);
-    });
-
-}
-
-bool WaylandCompositor::openUrl(QWaylandClient *client, const QUrl &url)
-{
-    if (ApplicationManager::instance()->fromProcessId(client->processId()))
-        return ApplicationManager::instance()->openUrl(url.toString());
-    return false;
-}
-
-void WaylandCompositor::sendCallbacks()
-{
-    QList<QWaylandSurface *> listToSend;
-
-    // TODO: optimize! no need to send this to hidden/minimized/offscreen/etc. surfaces
-    const auto windows = m_manager->windows();
-    for (const Window *win : windows) {
-        if (!win->isClosing() && !win->isInProcess()) {
-            if (QWaylandSurface *surface = waylandSurfaceFromItem(win->windowItem())) {
-                listToSend << surface;
-            }
-        }
-    }
-
-    if (!listToSend.isEmpty())
-        sendFrameCallbacks(listToSend);
-}
-
-const char *WaylandCompositor::socketName() const
-{
-    static QByteArray sn;
-    if (sn.isEmpty()) {
-        sn = QWaylandCompositor::socketName();
-        if (sn.isEmpty()) {
-            sn = qgetenv("WAYLAND_DISPLAY");
-            if (sn.isEmpty())
-                sn = "wayland-0";
-        }
-    }
-    return sn.constData();
-}
-
-#endif // if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
-
 QT_END_NAMESPACE_AM
diff --git a/src/window-lib/waylandcompositor.h b/src/window-lib/waylandcompositor.h
index 79f863e1..c1884d12 100644
--- a/src/window-lib/waylandcompositor.h
+++ b/src/window-lib/waylandcompositor.h
@@ -49,9 +49,8 @@
 #include <QWaylandQuickCompositor>
 #include <QtAppManWindow/windowmanager.h>
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
-#  include <QWaylandQuickSurface>
-#  include <QWaylandQuickItem>
+#include <QWaylandQuickSurface>
+#include <QWaylandQuickItem>
 
 QT_FORWARD_DECLARE_CLASS(QWaylandResource)
 QT_FORWARD_DECLARE_CLASS(QWaylandWlShell)
@@ -64,13 +63,6 @@ class SurfaceExtensionGlobal;
 }
 QT_END_NAMESPACE
 
-#else // QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
-#  include <QtAppManWindow/windowmanager.h>
-
-QT_FORWARD_DECLARE_CLASS(QWaylandSurfaceItem)
-
-#endif // QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
-
 QT_BEGIN_NAMESPACE_AM
 
 class WindowSurfaceQuickItem;
@@ -79,17 +71,6 @@ class WindowSurfaceQuickItem;
 // Not every WindowSurface maybe an application's Window though - those that are, are available
 // through the WindowManager model.
 
-#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
-class WindowSurface : public QObject
-{
-    Q_OBJECT
-public:
-    WindowSurface(QWaylandSurface *surface);
-
-private:
-    QWaylandSurfaceItem *m_item;
-
-#else
 class WindowSurface : public QWaylandQuickSurface
 {
     Q_OBJECT
@@ -105,7 +86,6 @@ private:
     WindowSurfaceQuickItem *m_item = nullptr;
     QWaylandWlShellSurface *m_shellSurface = nullptr;
     QtWayland::ExtendedSurface *m_extendedSurface = nullptr;
-#endif
 
 public:
     QWaylandSurface *surface() const;
@@ -137,7 +117,6 @@ public:
     QWaylandSurface *waylandSurfaceFromItem(QQuickItem *surfaceItem) const;
 
 protected:
-#if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
     void doCreateSurface(QWaylandClient *client, uint id, int version);
     void createShellSurface(QWaylandSurface *surface, const QWaylandResource &resource);
     void extendedSurfaceReady(QtWayland::ExtendedSurface *ext, QWaylandSurface *surface);
@@ -146,13 +125,6 @@ protected:
     QVector<QWaylandOutput *> m_outputs;
     QtWayland::SurfaceExtensionGlobal *m_surfExt;
     QWaylandTextInputManager *m_textInputManager;
-#else
-    void surfaceCreated(QWaylandSurface *surface) override;
-    bool openUrl(QWaylandClient *client, const QUrl &url) override;
-    void sendCallbacks();
-public:
-    const char *socketName() const; // we need to shadow the base class' version, since it is broken
-#endif // QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
 
 private:
     WindowManager *m_manager;
diff --git a/src/window-lib/waylandcompositor_p.h b/src/window-lib/waylandcompositor_p.h
index 6f645138..322b229a 100644
--- a/src/window-lib/waylandcompositor_p.h
+++ b/src/window-lib/waylandcompositor_p.h
@@ -43,9 +43,7 @@
 #pragma once
 
 #include <QtAppManCommon/global.h>
-
-#if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
-#  include <QWaylandQuickItem>
+#include <QWaylandQuickItem>
 
 QT_BEGIN_NAMESPACE_AM
 
@@ -63,5 +61,4 @@ public:
 
 QT_END_NAMESPACE_AM
 
-#endif
 // We mean it. Dummy comment since syncqt needs this also for completely private Qt modules.
diff --git a/src/window-lib/windowmanager.cpp b/src/window-lib/windowmanager.cpp
index 2502c158..41968aca 100644
--- a/src/window-lib/windowmanager.cpp
+++ b/src/window-lib/windowmanager.cpp
@@ -518,11 +518,7 @@ QVariant WindowManager::data(const QModelIndex &index, int role) const
 #if defined(AM_MULTI_PROCESS)
             auto ww = qobject_cast<const WaylandWindow*>(win);
             if (ww && ww->surface() && ww->surface()->surface())
-#  if QT_VERSION < QT_VERSION_CHECK(5, 8, 0)
-                return ww->surface()->surface()->isMapped();
-#  else
                 return ww->surface()->surface()->hasContent();
-#  endif
 #endif
             return false;
         }