From b30fe2fa42a717d6e89710cde82ecf7f419b2fe9 Mon Sep 17 00:00:00 2001
From: Christian Mollekopf <chrigi_1@fastmail.fm>
Date: Fri, 12 Dec 2014 11:48:09 +0100
Subject: ClientAPI: Demonstrate how we can build powerful and flexible API's
 on top of ResultEmitter

---
 client/clientapi.h            | 45 +++++++++++++++++++++++++++++++++++++++++++
 client/test/clientapitest.cpp | 12 +++---------
 2 files changed, 48 insertions(+), 9 deletions(-)

(limited to 'client')

diff --git a/client/clientapi.h b/client/clientapi.h
index 592fa48..662f96c 100644
--- a/client/clientapi.h
+++ b/client/clientapi.h
@@ -6,6 +6,7 @@
 #include <QStandardPaths>
 #include <QTimer>
 #include <QDebug>
+#include <QEventLoop>
 #include <functional>
 
 namespace async {
@@ -64,6 +65,14 @@ namespace async {
     * The future side for the client.
     *
     * It does not directly hold the state.
+    *
+    * The advantage of this is that we can specialize it to:
+    * * do inline transformations to the data
+    * * directly store the state in a suitable datastructure: QList, QSet, std::list, QVector, ...
+    * * build async interfaces with signals
+    * * build sync interfaces that block when accessing the value
+    *
+    * TODO: This should probably be merged with daniels futurebase used in Async
     */
     template<class DomainType>
     class ResultEmitter {
@@ -85,6 +94,42 @@ namespace async {
         std::function<void(void)> completeHandler;
     };
 
+
+    /*
+     * A result set specialization that provides a syncronous list
+     */
+    template<class T>
+    class SyncListResult : public QList<T> {
+    public:
+        SyncListResult(const QSharedPointer<ResultEmitter<T> > &emitter)
+            :QList<T>(),
+            mComplete(false),
+            mEmitter(emitter)
+        {
+            emitter->onAdded([this](const T &value) {
+                this->append(value);
+            });
+            emitter->onComplete([this]() {
+                mComplete = true;
+                auto loop = mWaitLoop.toStrongRef();
+                if (loop) {
+                    loop->quit();
+                }
+            });
+        }
+
+        void exec()
+        {
+            auto loop = QSharedPointer<QEventLoop>::create();
+            mWaitLoop = loop;
+            loop->exec(QEventLoop::ExcludeUserInputEvents);
+        }
+
+    private:
+        bool mComplete;
+        QWeakPointer<QEventLoop> mWaitLoop;
+        QSharedPointer<ResultEmitter<T> > mEmitter;
+    };
 }
 
 namespace Akonadi2 {
diff --git a/client/test/clientapitest.cpp b/client/test/clientapitest.cpp
index bff910b..2d1c238 100644
--- a/client/test/clientapitest.cpp
+++ b/client/test/clientapitest.cpp
@@ -37,15 +37,9 @@ private Q_SLOTS:
         Akonadi2::Query query;
         query.resources << "dummyresource";
 
-        auto result = Akonadi2::Store::load<Akonadi2::Domain::Event>(query);
-
-        QList<Akonadi2::Domain::Event::Ptr> resultSet;
-        result->onAdded([&resultSet](const Akonadi2::Domain::Event::Ptr &event){ resultSet << event; qDebug() << "result added";});
-
-        bool complete;
-        result->onComplete([&complete]{ complete = true; qDebug() << "complete";});
-
-        QTRY_VERIFY(complete);
+        async::SyncListResult<Akonadi2::Domain::Event::Ptr> result(Akonadi2::Store::load<Akonadi2::Domain::Event>(query));
+        result.exec();
+        QCOMPARE(result.size(), 1);
     }
 
 };
-- 
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