Async: initial support for native chaining of KJobs

It is now possible use KJob-derived jobs with libasync without having to write
lambda wrappers.

auto job = Async::start<ReturnType, MyKJob, MyKJob::result, Args ...)
           .then<ReturnType, OtherKJob, OtherKJob::result, PrevKJobReturnType>();

job.exec(arg1, arg2, ...);

The reason for this approach (instead of taking KJob* as an argument is that
we usually want the KJob ctor arguments to depend on result of previous job.
At least in case of Async::start() however it makes sense to support passing
KJob* as an argument (not yet implemented).

In future we should also support custom error handlers.

The KJob integration is build-time optional, but enabled by default (pass
-DWITH_KJOB=FALSE to CMake to disable).

Adds KCoreAddons dependency.

4 files changed, 152 insertions, 1 deletions

diff --git a/async/autotests/CMakeLists.txt b/async/autotests/CMakeLists.txt
index a2bedc8..8116f13 100644
--- a/async/autotests/CMakeLists.txt
+++ b/async/autotests/CMakeLists.txt
@@ -2,4 +2,10 @@ include_directories(../src ${CMAKE_CURRENT_BINARY_DIR})
 
 add_executable(asynctest asynctest.cpp)
 qt5_use_modules(asynctest Test)
-target_link_libraries(asynctest akonadi2async Qt5::Core Qt5::Test)
\ No newline at end of file
+target_link_libraries(asynctest akonadi2async Qt5::Core Qt5::Test)
+
+if (WITH_KJOB)
+    add_executable(kjobtest kjobtest.cpp testkjob.cpp)
+    qt5_use_modules(kjobtest Test)
+    target_link_libraries(kjobtest akonadi2async Qt5::Core Qt5::Test KF5::CoreAddons)
+endif ()
\ No newline at end of file
diff --git a/async/autotests/kjobtest.cpp b/async/autotests/kjobtest.cpp
new file mode 100644
index 0000000..be92d68
--- /dev/null
+++ b/async/autotests/kjobtest.cpp
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2015  Daniel Vrátil <dvratil@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License or (at your option) version 3 or any later version
+ * accepted by the membership of KDE e.V. (or its successor approved
+ * by the membership of KDE e.V.), which shall act as a proxy
+ * defined in Section 14 of version 3 of the license.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "../src/async.h"
+#include "testkjob.h"
+
+#include <QtTest/QTest>
+
+class KJobTest : public QObject
+{
+    Q_OBJECT
+
+public:
+    KJobTest()
+    {}
+
+    ~KJobTest()
+    {}
+
+private Q_SLOTS:
+    void testSingleKJob();
+    void testKJobChain();
+
+};
+
+void KJobTest::testSingleKJob()
+{
+    auto job = Async::start<int, TestKJob, &TestKJob::result, int>();
+
+    auto future = job.exec(42);
+    future.waitForFinished();
+
+    QVERIFY(future.isFinished());
+    QCOMPARE(future.value(), 42);
+}
+
+void KJobTest::testKJobChain()
+{
+    auto job = Async::start<int, TestKJob, &TestKJob::result, int>()
+                .then<int, TestKJob, &TestKJob::result, int>();
+
+    auto future = job.exec(42);
+    future.waitForFinished();
+
+    QVERIFY(future.isFinished());
+    QCOMPARE(future.value(), 42);
+}
+
+QTEST_MAIN(KJobTest)
+
+#include "kjobtest.moc"
\ No newline at end of file
diff --git a/async/autotests/testkjob.cpp b/async/autotests/testkjob.cpp
new file mode 100644
index 0000000..b86f913
--- /dev/null
+++ b/async/autotests/testkjob.cpp
@@ -0,0 +1,28 @@
+#include "testkjob.h"
+
+TestKJob::TestKJob(int result)
+    : mResult(result)
+{
+    connect(&mTimer, &QTimer::timeout,
+            this, &TestKJob::onTimeout);
+    mTimer.setSingleShot(true);
+    mTimer.setInterval(200);
+}
+
+TestKJob::~TestKJob()
+{}
+
+void TestKJob::start()
+{
+    mTimer.start();
+}
+
+int TestKJob::result()
+{
+    return mResult;
+}
+
+void TestKJob::onTimeout()
+{
+    emitResult();
+}
\ No newline at end of file
diff --git a/async/autotests/testkjob.h b/async/autotests/testkjob.h
new file mode 100644
index 0000000..eead98e
--- /dev/null
+++ b/async/autotests/testkjob.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2015  Daniel Vrátil <dvratil@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License or (at your option) version 3 or any later version
+ * accepted by the membership of KDE e.V. (or its successor approved
+ * by the membership of KDE e.V.), which shall act as a proxy
+ * defined in Section 14 of version 3 of the license.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef TESTKJOB_H
+#define TESTKJOB_H
+
+#include <KJob>
+#include <QTimer>
+
+class TestKJob : public KJob
+{
+    Q_OBJECT
+
+public:
+    TestKJob(int result);
+    ~TestKJob();
+
+    void start();
+
+    int result();
+
+private Q_SLOTS:
+    void onTimeout();
+
+private:
+    int mResult;
+    QTimer mTimer;
+};
+
+#endif // TESTKJOB_H
\ No newline at end of file