Enable compiling non-QML API against Qt 5.15

Built with QtQuick disabled.

- C++17 required
- minor issues with QList vs QVector
- QMutexLocker templated vs not
- moc forward declaration handling

Change-Id: I5540625e74e2c009e528f56203e4b88be8d54599
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

11 files changed, 27 insertions, 8 deletions

diff --git a/src/animation/backend/animationclip.cpp b/src/animation/backend/animationclip.cpp
index 699d4dc50..93a70eadd 100644
--- a/src/animation/backend/animationclip.cpp
+++ b/src/animation/backend/animationclip.cpp
@@ -354,7 +354,7 @@ void AnimationClip::clearData()
 float AnimationClip::findDuration()
 {
     // Iterate over the contained fcurves and find the longest one
-    double tMax = 0.0;
+    float tMax = 0.f;
     for (const Channel &channel : qAsConst(m_channels)) {
         for (const ChannelComponent &channelComponent : qAsConst(channel.channelComponents)) {
             const float t = channelComponent.fcurve.endTime();
diff --git a/src/core/qscene.cpp b/src/core/qscene.cpp
index 475f63214..3381dfbe7 100644
--- a/src/core/qscene.cpp
+++ b/src/core/qscene.cpp
@@ -123,7 +123,12 @@ QList<QNode *> QScene::lookupNodes(const QList<QNodeId> &ids) const
 {
     Q_D(const QScene);
     QReadLocker lock(&d->m_lock);
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
     QList<QNode *> nodes(ids.size());
+#else
+    QList<QNode *> nodes;
+    nodes.reserve(ids.size());
+#endif
     int index = 0;
     for (QNodeId id : ids)
         nodes[index++] = d->m_nodeLookupTable.value(id);
diff --git a/src/core/resources/qresourcemanager_p.h b/src/core/resources/qresourcemanager_p.h
index 954f7b5e4..32d8d081c 100644
--- a/src/core/resources/qresourcemanager_p.h
+++ b/src/core/resources/qresourcemanager_p.h
@@ -165,7 +165,11 @@ public :
         }
 
     private:
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
         QMutexLocker<QMutex> m_locker;
+#else
+        QMutexLocker m_locker;
+#endif
     };
 
 private:
diff --git a/src/input/backend/actioninput.cpp b/src/input/backend/actioninput.cpp
index 805fde1cf..ed8708949 100644
--- a/src/input/backend/actioninput.cpp
+++ b/src/input/backend/actioninput.cpp
@@ -53,7 +53,6 @@ namespace Input {
 
 ActionInput::ActionInput()
     : AbstractActionInput()
-    , m_buttons(0)
 {
 }
 
diff --git a/src/input/backend/axissetting.cpp b/src/input/backend/axissetting.cpp
index 53e645c4d..c640cd35a 100644
--- a/src/input/backend/axissetting.cpp
+++ b/src/input/backend/axissetting.cpp
@@ -51,7 +51,6 @@ namespace Input {
 AxisSetting::AxisSetting()
     : BackendNode()
     , m_deadZoneRadius(0.0f)
-    , m_axes(0)
     , m_smooth(false)
 {
 }
diff --git a/src/input/frontend/qkeyboardhandler.h b/src/input/frontend/qkeyboardhandler.h
index 6dac60c37..ba6119bc0 100644
--- a/src/input/frontend/qkeyboardhandler.h
+++ b/src/input/frontend/qkeyboardhandler.h
@@ -56,7 +56,9 @@ class Q_3DINPUTSHARED_EXPORT QKeyboardHandler : public Qt3DCore::QComponent
     Q_OBJECT
     Q_PROPERTY(Qt3DInput::QKeyboardDevice *sourceDevice READ sourceDevice WRITE setSourceDevice NOTIFY sourceDeviceChanged)
     Q_PROPERTY(bool focus READ focus WRITE setFocus NOTIFY focusChanged)
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
     Q_MOC_INCLUDE("Qt3DInput/qkeyboarddevice.h")
+#endif
 public:
     explicit QKeyboardHandler(QNode *parent = nullptr);
     ~QKeyboardHandler();
diff --git a/src/plugins/renderers/opengl/opengl.pri b/src/plugins/renderers/opengl/opengl.pri
index 37da69a1f..4308992e5 100644
--- a/src/plugins/renderers/opengl/opengl.pri
+++ b/src/plugins/renderers/opengl/opengl.pri
@@ -1,5 +1,7 @@
 QT += core-private gui-private 3dcore 3dcore-private 3drender 3drender-private opengl-private
 
+CONFIG += c++17
+
 # Qt3D is free of Q_FOREACH - make sure it stays that way:
 DEFINES += QT_NO_FOREACH
 DEFINES += BUILD_QT3D_MODULE
diff --git a/src/plugins/renderers/opengl/renderer/frameprofiler_p.h b/src/plugins/renderers/opengl/renderer/frameprofiler_p.h
index e94de299f..6a8f884d0 100644
--- a/src/plugins/renderers/opengl/renderer/frameprofiler_p.h
+++ b/src/plugins/renderers/opengl/renderer/frameprofiler_p.h
@@ -141,8 +141,8 @@ public:
     {
 #ifdef QT3D_SUPPORTS_GL_MONITOR
         if (m_monitor.isResultAvailable()) {
-            const QList<GLuint64> samples = m_monitor.waitForSamples();
-            Q_ASSERT(samples.count() >= 2 * m_recordings.count());
+            const auto &samples = m_monitor.waitForSamples();
+            Q_ASSERT(samples.size() >= 2 * m_recordings.size());
 
             Qt3DCore::QSystemInformationServicePrivate *dservice = Qt3DCore::QSystemInformationServicePrivate::get(m_service);
 
diff --git a/src/render/framegraph/qframegraphnode.cpp b/src/render/framegraph/qframegraphnode.cpp
index 53b362f01..2a2bda3f2 100644
--- a/src/render/framegraph/qframegraphnode.cpp
+++ b/src/render/framegraph/qframegraphnode.cpp
@@ -379,15 +379,20 @@ QList<QFrameGraphNode *> QFrameGraphNodePrivate::childFrameGraphNodes() const
     Q_Q(const QFrameGraphNode);
     QList<QFrameGraphNode *> result;
     QQueue<QNode *> queue;
-    queue.append(q->childNodes().toList());
+    const auto childNodes = q->childNodes();
+    for (auto c: childNodes)
+        queue.append(c);
     result.reserve(queue.size());
     while (!queue.isEmpty()) {
         auto *child = queue.dequeue();
         auto *childFGNode = qobject_cast<QFrameGraphNode *>(child);
         if (childFGNode != nullptr)
             result.push_back(childFGNode);
-        else
-            queue.append(child->childNodes().toList());
+        else {
+            const auto childNodes = child->childNodes();
+            for (auto c: childNodes)
+                queue.append(c);
+        }
     }
     return result;
 }
diff --git a/src/render/materialsystem/qparameter.cpp b/src/render/materialsystem/qparameter.cpp
index d4a457115..2ce0d172c 100644
--- a/src/render/materialsystem/qparameter.cpp
+++ b/src/render/materialsystem/qparameter.cpp
@@ -41,8 +41,10 @@
 #include "qparameter_p.h"
 #include <Qt3DRender/private/renderlogging_p.h>
 #include <Qt3DRender/qtexture.h>
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 #include <QtCore/qiterable.h>
 #include <QtCore/qsequentialiterable.h>
+#endif
 
 /*!
     \qmltype Parameter
diff --git a/src/render/render.pro b/src/render/render.pro
index c497ff551..353f95778 100644
--- a/src/render/render.pro
+++ b/src/render/render.pro
@@ -4,6 +4,7 @@ MODULE   = 3drender
 QT = core-private 3dcore-private opengl
 QT_FOR_PRIVATE = concurrent
 DEFINES += BUILD_QT3D_MODULE
+CONFIG += c++17
 
 include (backend/render-backend.pri)
 include (geometry/geometry.pri)