PluginManager: Introduce a getObjects() function taking a predicate

Change-Id: I8a822d76a3dc358de48e96801e4e531f3bbb8669
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/libs/extensionsystem/pluginmanager.cpp

@@ -220,7 +220,21 @@ enum { debugLeaks = 0 };
 
     This function uses \c qobject_cast to determine the type of an object.
     If there are more than one object of the given type in
-    the object pool, this function will choose an arbitrary one of them.
+    the object pool, this function will arbitrarily choose one of them.
+
+    \sa addObject()
+*/
+
+/*!
+    \fn T *PluginManager::getObject(Predicate predicate)
+
+    Retrieves the object of a given type from the object pool that matches
+    the \a predicate.
+
+    This function uses \c qobject_cast to determine the type of an object.
+    The predicate must be a function taking T * and returning a bool.
+    If there is more than one object matching the type and predicate,
+    this function will arbitrarily choose one of them.
 
     \sa addObject()
 */
@@ -235,6 +249,20 @@ enum { debugLeaks = 0 };
     \sa addObject()
 */
 
+/*!
+    \fn QList<T *> PluginManager::getObjects(Predicate predicate)
+
+    Retrieves all objects of a given type from the object pool that
+    match the \a predicate.
+
+    This function uses \c qobject_cast to determine the type of an object.
+    The predicate should be a unary function taking a T* parameter and
+    returning a bool.
+
+    \sa addObject()
+*/
+
+
 using namespace ExtensionSystem;
 using namespace ExtensionSystem::Internal;
 

src/libs/extensionsystem/pluginmanager.h

@@ -75,6 +75,19 @@ public:
         }
         return results;
     }
+    template <typename T, typename Predicate>
+    static QList<T *> getObjects(Predicate predicate)
+    {
+        QReadLocker lock(listLock());
+        QList<T *> results;
+        QList<QObject *> all = allObjects();
+        foreach (QObject *obj, all) {
+            T *result = qobject_cast<T *>(obj);
+            if (result && predicate(result))
+                results += result;
+        }
+        return results;
+    }
     template <typename T> static T *getObject()
     {
         QReadLocker lock(listLock());
@@ -85,6 +98,17 @@ public:
         }
         return 0;
     }
+    template <typename T, typename Predicate> static T *getObject(Predicate predicate)
+    {
+        QReadLocker lock(listLock());
+        QList<QObject *> all = allObjects();
+        foreach (QObject *obj, all) {
+            if (T *result = qobject_cast<T *>(obj))
+                if (predicate(result))
+                    return result;
+        }
+        return 0;
+    }
 
     static QObject *getObjectByName(const QString &name);
     static QObject *getObjectByClassName(const QString &className);

tests/auto/extensionsystem/pluginmanager/tst_pluginmanager.cpp

@@ -138,6 +138,9 @@ void tst_PluginManager::getObject()
 {
     MyClass2 *object2 = new MyClass2;
     MyClass11 *object11 = new MyClass11;
+    MyClass2 *object2b = new MyClass2;
+    const QString objectName = QLatin1String("OBJECTNAME");
+    object2b->setObjectName(objectName);
     m_pm->addObject(object2);
     QCOMPARE(m_pm->getObject<MyClass11>(), (MyClass11*)0);
     QCOMPARE(m_pm->getObject<MyClass1>(), (MyClass1*)0);
@@ -146,10 +149,17 @@ void tst_PluginManager::getObject()
     QCOMPARE(m_pm->getObject<MyClass11>(), object11);
     QCOMPARE(m_pm->getObject<MyClass1>(), qobject_cast<MyClass1*>(object11));
     QCOMPARE(m_pm->getObject<MyClass2>(), object2);
+    QCOMPARE(m_pm->getObjectByName(objectName), (QObject*)0);
+    m_pm->addObject(object2b);
+    QCOMPARE(m_pm->getObjectByName(objectName), object2b);
+    QCOMPARE(m_pm->getObject<MyClass2>(
+                    [&objectName](MyClass2 *obj) { return obj->objectName() == objectName;}), object2b);
     m_pm->removeObject(object2);
     m_pm->removeObject(object11);
+    m_pm->removeObject(object2b);
     delete object2;
     delete object11;
+    delete object2b;
 }
 
 void tst_PluginManager::getObjects()
@@ -172,6 +182,12 @@ void tst_PluginManager::getObjects()
     QCOMPARE(m_pm->getObjects<MyClass1>(), QList<MyClass1*>() << object11 << object1);
     QCOMPARE(m_pm->getObjects<MyClass2>(), QList<MyClass2*>() << object2);
     QCOMPARE(m_pm->allObjects(), QList<QObject*>() << object2 << object11 << object1);
+
+    QCOMPARE(m_pm->getObjects<MyClass1>(
+                 [](MyClass1 *o){
+                    return !qobject_cast<MyClass11 *>(o);} ),
+             QList<MyClass1 *>() << object1);
+
     m_pm->removeObject(object2);
     m_pm->removeObject(object11);
     m_pm->removeObject(object1);