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, 7 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