Implement dynamic loading of slide resources

Implements loading of textures and images during runtime instead of load
time.
- Images which are not part of any slide are loaded at load time
- Master slide images are always loaded at load time
- Images used in a slide are loaded when the slide is entered
- Images are unloaded when slide is exited and any other slide does not
  use them

Task-number: QT3DS-3208
Change-Id: I7a827a5e828908efd2b104fe25374c66958319d2
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/Viewer/studio3d/q3dspresentation.h b/src/Viewer/studio3d/q3dspresentation.h
index 38625583..34809613 100644
--- a/src/Viewer/studio3d/q3dspresentation.h
+++ b/src/Viewer/studio3d/q3dspresentation.h
@@ -49,6 +49,7 @@ class Q_STUDIO3D_EXPORT Q3DSPresentation : public QObject
     Q_DECLARE_PRIVATE(Q3DSPresentation)
     Q_PROPERTY(QUrl source READ source WRITE setSource NOTIFY sourceChanged)
     Q_PROPERTY(QStringList variantList READ variantList WRITE setVariantList NOTIFY variantListChanged)
+    Q_PROPERTY(bool delayedLoading READ delayedLoading WRITE setDelayedLoading NOTIFY delayedLoadingChanged)
 
 public:
     explicit Q3DSPresentation(QObject *parent = nullptr);
@@ -68,6 +69,12 @@ public:
     Q_INVOKABLE QVariantList getDataInputs() const;
     QVector<Q3DSDataInput *> dataInputs() const;
 
+    bool delayedLoading() const;
+    void setDelayedLoading(bool enable);
+
+    Q_INVOKABLE void preloadSlide(const QString &elementPath);
+    Q_INVOKABLE void unloadSlide(const QString &elementPath);
+
     // Input event handlers
     void mousePressEvent(QMouseEvent *e);
     void mouseReleaseEvent(QMouseEvent *e);
@@ -100,6 +107,7 @@ Q_SIGNALS:
     // and datainputs are available through dataInputs() / getDataInputs().
     void dataInputsReady();
     void customSignalEmitted(const QString &elementPath, const QString &name);
+    void delayedLoadingChanged(bool enable);
 
 private:
     Q_DISABLE_COPY(Q3DSPresentation)