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.

1 files changed, 48 insertions, 0 deletions

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