Add an easy way to get a particular component from an entity

Change-Id: I188fab5019d3e05354a4c1582fb12097a569fbb8
Reviewed-by: Mike Krus <mike.krus@kdab.com>

2 files changed, 20 insertions, 0 deletions

diff --git a/src/core/nodes/qentity.cpp b/src/core/nodes/qentity.cpp
index 64ea65087..3c8805a67 100644
--- a/src/core/nodes/qentity.cpp
+++ b/src/core/nodes/qentity.cpp
@@ -77,6 +77,13 @@ namespace Qt3DCore {
     \sa Qt3DCore::QComponent, Qt3DCore::QTransform
  */
 
+/*!
+    \fn template<typename T> QVector<T *> QEntity::componentsOfType() const
+
+    Returns all the components added to this entity that can be cast to
+    type T or an empty vector if there are no such components.
+*/
+
 /*! \internal */
 QEntityPrivate::QEntityPrivate()
     : QNodePrivate()
diff --git a/src/core/nodes/qentity.h b/src/core/nodes/qentity.h
index dc7dc62c1..ef6aedc4d 100644
--- a/src/core/nodes/qentity.h
+++ b/src/core/nodes/qentity.h
@@ -62,6 +62,19 @@ public:
 
     QComponentVector components() const;
 
+    template<class T>
+    QVector<T *> componentsOfType() const
+    {
+        QVector<T*> matchComponents;
+        const QComponentVector components = this->components();
+        for (QComponent *component : components) {
+            T *typedComponent = qobject_cast<T*>(component);
+            if (typedComponent != nullptr)
+                matchComponents.append(typedComponent);
+        }
+        return matchComponents;
+    }
+
     void addComponent(QComponent *comp);
     void removeComponent(QComponent *comp);