From 37b9bf84ebeeff977a970ace4aafde6d33d21935 Mon Sep 17 00:00:00 2001
From: hjk <qtc-committer@nokia.com>
Date: Wed, 5 Jan 2011 18:35:08 +0100
Subject: [PATCH] extensionsystem: "soft dependencies" infrastructure
Reviewed-by: con
Reviewed-by: ckamm
---
src/libs/extensionsystem/extensionsystem.pro | 2 +
src/libs/extensionsystem/invoker.cpp | 88 ++++++++
src/libs/extensionsystem/invoker.h | 212 +++++++++++++++++++
src/libs/extensionsystem/pluginmanager.cpp | 123 ++++++++++-
src/libs/extensionsystem/pluginmanager.h | 5 +-
5 files changed, 420 insertions(+), 10 deletions(-)
create mode 100644 src/libs/extensionsystem/invoker.cpp
create mode 100644 src/libs/extensionsystem/invoker.h
diff --git a/src/libs/extensionsystem/extensionsystem.pro b/src/libs/extensionsystem/extensionsystem.pro
index 027139c89ee..de1f49f25b2 100644
--- a/src/libs/extensionsystem/extensionsystem.pro
+++ b/src/libs/extensionsystem/extensionsystem.pro
@@ -10,6 +10,7 @@ DEFINES += IDE_TEST_DIR=\\\"$$IDE_SOURCE_TREE\\\"
HEADERS += pluginerrorview.h \
plugindetailsview.h \
+ invoker.h \
iplugin.h \
iplugin_p.h \
extensionsystem_global.h \
@@ -23,6 +24,7 @@ HEADERS += pluginerrorview.h \
plugincollection.h
SOURCES += pluginerrorview.cpp \
plugindetailsview.cpp \
+ invoker.cpp \
iplugin.cpp \
pluginmanager.cpp \
pluginspec.cpp \
diff --git a/src/libs/extensionsystem/invoker.cpp b/src/libs/extensionsystem/invoker.cpp
new file mode 100644
index 00000000000..cbab529c723
--- /dev/null
+++ b/src/libs/extensionsystem/invoker.cpp
@@ -0,0 +1,88 @@
+/**************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** No Commercial Usage
+**
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+**
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**************************************************************************/
+
+#include "invoker.h"
+
+namespace ExtensionSystem {
+
+InvokerBase::InvokerBase()
+{
+ lastArg = 0;
+ useRet = false;
+ nag = true;
+ success = true;
+ target = 0;
+}
+
+InvokerBase::~InvokerBase()
+{
+ if (!success && nag)
+ qWarning("Could not invoke function '%s' in object of type '%s'.",
+ sig.constData(), target->metaObject()->className());
+}
+
+bool InvokerBase::wasSuccessful() const
+{
+ nag = false;
+ return success;
+}
+
+void InvokerBase::invoke(QObject *t, const char *slot)
+{
+ target = t;
+ success = false;
+ sig.append(slot, qstrlen(slot));
+ sig.append('(');
+ for (int paramCount = 0; paramCount < lastArg; ++paramCount) {
+ if (paramCount)
+ sig.append(',');
+ const char *type = arg[paramCount].name();
+ sig.append(type, strlen(type));
+ }
+ sig.append(')');
+ sig.append('\0');
+ int idx = target->metaObject()->indexOfMethod(sig.constData());
+ if (idx < 0)
+ return;
+ QMetaMethod method = target->metaObject()->method(idx);
+ if (useRet)
+ success = method.invoke(target, ret,
+ arg[0], arg[1], arg[2], arg[3], arg[4],
+ arg[5], arg[6], arg[7], arg[8], arg[9]);
+ else
+ success = method.invoke(target,
+ arg[0], arg[1], arg[2], arg[3], arg[4],
+ arg[5], arg[6], arg[7], arg[8], arg[9]);
+}
+
+} // namespace ExtensionSystem
diff --git a/src/libs/extensionsystem/invoker.h b/src/libs/extensionsystem/invoker.h
new file mode 100644
index 00000000000..48815c96ed9
--- /dev/null
+++ b/src/libs/extensionsystem/invoker.h
@@ -0,0 +1,212 @@
+/**************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** No Commercial Usage
+**
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+**
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**************************************************************************/
+
+#ifndef EXTENSIONSYSTEM_INVOKER_H
+#define EXTENSIONSYSTEM_INVOKER_H
+
+#include "extensionsystem_global.h"
+
+#include <QtCore/QMetaMethod>
+#include <QtCore/QMetaObject>
+#include <QtCore/QMetaType>
+#include <QtCore/QVarLengthArray>
+
+namespace ExtensionSystem {
+
+class InvokerBase
+{
+public:
+ InvokerBase();
+ ~InvokerBase();
+
+ bool wasSuccessful() const;
+
+ template <class T> void addArgument(const T &t)
+ {
+ arg[lastArg++] = QGenericArgument(typeName<T>(), &t);
+ }
+
+ template <class T> void setReturnValue(T &t)
+ {
+ useRet = true;
+ ret = QGenericReturnArgument(typeName<T>(), &t);
+ }
+
+ void invoke(QObject *target, const char *slot);
+
+private:
+ InvokerBase(const InvokerBase &); // Unimplemented.
+ template <class T> const char *typeName()
+ {
+ return QMetaType::typeName(qMetaTypeId<T>());
+ }
+ QObject *target;
+ QGenericArgument arg[10];
+ QGenericReturnArgument ret;
+ QVarLengthArray<char, 512> sig;
+ int lastArg;
+ bool success;
+ bool useRet;
+ mutable bool nag;
+};
+
+template <class Result>
+class Invoker : public InvokerBase
+{
+public:
+ Invoker(QObject *target, const char *slot)
+ {
+ InvokerBase::invoke(target, slot);
+ }
+
+ template <class T0>
+ Invoker(QObject *target, const char *slot, const T0 &t0)
+ {
+ setReturnValue(result);
+ addArgument(t0);
+ InvokerBase::invoke(target, slot);
+ }
+
+ template <class T0, class T1>
+ Invoker(QObject *target, const char *slot, const T0 &t0, const T1 &t1)
+ {
+ setReturnValue(result);
+ addArgument(t0);
+ addArgument(t1);
+ InvokerBase::invoke(target, slot);
+ }
+
+ template <class T0, class T1, class T2>
+ Invoker(QObject *target, const char *slot, const T0 &t0,
+ const T1 &t1, const T2 &t2)
+ {
+ setReturnValue(result);
+ addArgument(t0);
+ addArgument(t1);
+ addArgument(t2);
+ InvokerBase::invoke(target, slot);
+ }
+
+ operator Result() const { return result; }
+
+private:
+ Result result;
+};
+
+template<> class Invoker<void> : public InvokerBase
+{
+public:
+ Invoker(QObject *target, const char *slot)
+ {
+ InvokerBase::invoke(target, slot);
+ }
+
+ template <class T0>
+ Invoker(QObject *target, const char *slot, const T0 &t0)
+ {
+ addArgument(t0);
+ InvokerBase::invoke(target, slot);
+ }
+
+ template <class T0, class T1>
+ Invoker(QObject *target, const char *slot, const T0 &t0, const T1 &t1)
+ {
+ addArgument(t0);
+ addArgument(t1);
+ InvokerBase::invoke(target, slot);
+ }
+
+ template <class T0, class T1, class T2>
+ Invoker(QObject *target, const char *slot, const T0 &t0,
+ const T1 &t1, const T2 &t2)
+ {
+ addArgument(t0);
+ addArgument(t1);
+ addArgument(t2);
+ InvokerBase::invoke(target, slot);
+ }
+};
+
+template <class Result>
+Result invokeHelper(InvokerBase &in, QObject *target, const char *slot)
+{
+ Result result;
+ in.setReturnValue(result);
+ in.invoke(target, slot);
+ return result;
+}
+
+template <>
+inline void invokeHelper<void>(InvokerBase &in, QObject *target, const char *slot)
+{
+ in.invoke(target, slot);
+}
+
+template<class Result>
+Result invoke(QObject *target, const char *slot)
+{
+ InvokerBase in;
+ return invokeHelper<Result>(in, target, slot);
+}
+
+template<class Result, class T0>
+Result invoke(QObject *target, const char *slot, const T0 &t0)
+{
+ InvokerBase in;
+ in.addArgument(t0);
+ return invokeHelper<Result>(in, target, slot);
+}
+
+template<class Result, class T0, class T1>
+Result invoke(QObject *target, const char *slot, const T0 &t0, const T1 &t1)
+{
+ InvokerBase in;
+ in.addArgument(t0);
+ in.addArgument(t1);
+ return invokeHelper<Result>(in, target, slot);
+}
+
+template<class Result, class T0, class T1, class T2>
+Result invoke(QObject *target, const char *slot,
+ const T0 &t0, const T1 &t1, const T2 &t2)
+{
+ InvokerBase in;
+ in.addArgument(t0);
+ in.addArgument(t1);
+ in.addArgument(t2);
+ return invokeHelper<Result>(in, target, slot);
+}
+
+} // namespace ExtensionSystem
+
+#endif // EXTENSIONSYSTEM_INVOKER_H
diff --git a/src/libs/extensionsystem/pluginmanager.cpp b/src/libs/extensionsystem/pluginmanager.cpp
index 7373e57bf3f..a8be0a37e49 100644
--- a/src/libs/extensionsystem/pluginmanager.cpp
+++ b/src/libs/extensionsystem/pluginmanager.cpp
@@ -39,14 +39,15 @@
#include "iplugin.h"
#include "plugincollection.h"
-#include <QtCore/QMetaProperty>
+#include <QtCore/QDateTime>
#include <QtCore/QDir>
+#include <QtCore/QMetaProperty>
+#include <QtCore/QSettings>
#include <QtCore/QTextStream>
-#include <QtCore/QWriteLocker>
#include <QtCore/QTime>
-#include <QtCore/QDateTime>
-#include <QtCore/QSettings>
-#include <QtDebug>
+#include <QtCore/QWriteLocker>
+#include <QtCore/QtDebug>
+
#ifdef WITH_TESTS
#include <QTest>
#endif
@@ -60,9 +61,10 @@ enum { debugLeaks = 0 };
/*!
\namespace ExtensionSystem
- \brief The ExtensionSystem namespace provides classes that belong to the core plugin system.
+ \brief The ExtensionSystem namespace provides classes that belong to the
+ core plugin system.
- The basic extension system contains of the plugin manager and its supporting classes,
+ The basic extension system contains the plugin manager and its supporting classes,
and the IPlugin interface that must be implemented by plugin providers.
*/
@@ -114,15 +116,83 @@ enum { debugLeaks = 0 };
be implemented and added to the object pool. The plugin that provides the
extension point looks for implementations of the class / interface in the object pool.
\code
- // plugin A provides a "MimeTypeHandler" extension point
+ // Plugin A provides a "MimeTypeHandler" extension point
// in plugin B:
MyMimeTypeHandler *handler = new MyMimeTypeHandler();
ExtensionSystem::PluginManager::instance()->addObject(handler);
- // in plugin A:
+ // In plugin A:
QList<MimeTypeHandler *> mimeHandlers =
ExtensionSystem::PluginManager::instance()->getObjects<MimeTypeHandler>();
\endcode
+
+ The \c{ExtensionSystem::Invoker} class template provides "syntactic sugar"
+ for using "soft" extension points that may or may not be provided by an
+ object in the pool. This approach does neither require the "user" plugin being
+ linked against the "provider" plugin nor a common shared
+ header file. The exposed interface is implicitly given by the
+ invokable methods of the "provider" object in the object pool.
+
+ The \c{ExtensionSystem::invoke} function template encapsulates
+ {ExtensionSystem::Invoker} construction for the common case where
+ the success of the call is not checked.
+
+ \code
+ // In the "provide" plugin A:
+ namespace PluginA {
+ class SomeProvider : public QObject
+ {
+ Q_OBJECT
+
+ public:
+ Q_INVOKABLE QString doit(const QString &msg, int n) {
+ {
+ qDebug() << "I AM DOING IT " << msg;
+ return QString::number(n);
+ }
+ };
+ } // namespace PluginA
+
+
+ // In the "user" plugin B:
+ int someFuntionUsingPluginA()
+ {
+ using namespace ExtensionSystem;
+
+ QObject *target = PluginManager::instance()
+ ->getObjectByClassName("PluginA::SomeProvider");
+
+ if (target) {
+ // Some random argument.
+ QString msg = "REALLY.";
+
+ // Plain function call, no return value.
+ invoke<void>(target, "doit", msg, 2);
+
+ // Plain function with no return value.
+ qDebug() << "Result: " << invoke<QString>(target, "doit", msg, 21);
+
+ // Record success of function call with return value.
+ Invoker<QString> in1(target, "doit", msg, 21);
+ qDebug() << "Success: (expected)" << in1.wasSuccessful();
+
+ // Try to invoke a non-existing function.
+ Invoker<QString> in2(target, "doitWrong", msg, 22);
+ qDebug() << "Success (not expected):" << in2.wasSuccessful();
+
+ } else {
+
+ // We have to cope with plugin A's absence.
+ }
+ };
+ \endcode
+
+ \bold Note: The type of the parameters passed to the \c{invoke()} calls
+ is deduced from the parameters themselves and must match the type of
+ the arguments of the called functions \e{exactly}. No conversion or even
+ integer promotions are applicable, so to invoke a function with a \c{long}
+ parameter explicitly use \c{long(43)} or such.
+
\bold Note: The object pool manipulating functions are thread-safe.
*/
@@ -1095,3 +1165,38 @@ void PluginManagerPrivate::profilingReport(const char *what, const PluginSpec *s
}
}
}
+
+/*!
+ \fn void PluginManager::getObjectByName()
+ Retrieves one object with a given name from the object pool.
+ \sa addObject()
+*/
+
+QObject *PluginManager::getObjectByName(const QString &name) const
+{
+ QReadLocker lock(&m_lock);
+ QList<QObject *> all = allObjects();
+ foreach (QObject *obj, all) {
+ if (obj->objectName() == name)
+ return obj;
+ }
+ return 0;
+}
+
+/*!
+ \fn void PluginManager::getObjectByClassName()
+ Retrieves one object inheriting a class with a given name from the object pool.
+ \sa addObject()
+*/
+
+QObject *PluginManager::getObjectByClassName(const QString &className) const
+{
+ const QByteArray ba = className.toUtf8();
+ QReadLocker lock(&m_lock);
+ QList<QObject *> all = allObjects();
+ foreach (QObject *obj, all) {
+ if (obj->inherits(ba.constData()))
+ return obj;
+ }
+ return 0;
+}
diff --git a/src/libs/extensionsystem/pluginmanager.h b/src/libs/extensionsystem/pluginmanager.h
index ee70ecb9bdd..8d62ee8b09c 100644
--- a/src/libs/extensionsystem/pluginmanager.h
+++ b/src/libs/extensionsystem/pluginmanager.h
@@ -38,8 +38,8 @@
#include <aggregation/aggregate.h>
#include <QtCore/QObject>
-#include <QtCore/QStringList>
#include <QtCore/QReadWriteLock>
+#include <QtCore/QStringList>
QT_BEGIN_NAMESPACE
class QTextStream;
@@ -95,6 +95,9 @@ public:
return result;
}
+ QObject *getObjectByName(const QString &name) const;
+ QObject *getObjectByClassName(const QString &className) const;
+
// Plugin operations
QList<PluginSpec *> loadQueue();
void loadPlugins();
--
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