[libcamera-devel] [PATCH 3/3] Documentation: Update the "Start an event loop" section

[Daniel Semkowicz]

Event loop was moved to be a part of CameraManager, so it is no longer
a user responsibility to control the event dispatching.
---
 .../guides/application-developer.rst          | 20 ++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/Documentation/guides/application-developer.rst b/Documentation/guides/application-developer.rst
index 00bafb10..97c032a5 100644
--- a/Documentation/guides/application-developer.rst
+++ b/Documentation/guides/application-developer.rst
@@ -27,10 +27,12 @@ defined names and types without the need of prefixing them.
    #include <iomanip>
    #include <iostream>
    #include <memory>
+   #include <thread>
 
    #include <libcamera/libcamera.h>
 
    using namespace libcamera;
+   using namespace std::chrono_literals;
 
    int main()
    {
@@ -506,7 +508,7 @@ and queue all the previously created requests.
    for (std::unique_ptr<Request> &request : requests)
        camera->queueRequest(request.get());
 
-Start an event loop
+Event loop
 ~~~~~~~~~~~~~~~~~~~
 
 The libcamera library needs an event loop to monitor and dispatch events
@@ -524,17 +526,17 @@ a notifier it is monitoring, it emits the notifier's
 notifiers' signals and emit application visible events, such as the
 ``Camera::bufferReady`` and ``Camera::requestCompleted`` signals.
 
-The code below retrieves a reference to the system-wide event dispatcher and for
-the a fixed duration of 3 seconds, processes all the events detected in the
-system.
+Event loop is handled internally by ``CameraManager`` instance in a separate
+thread. ``CameraManager::start()`` creates a new thread and starts the event
+loop processing.
+
+As the ``CameraManager`` was already started in our example, we need to prevent
+the immediate termination of the application. The code below pauses the main
+thread for 3 seconds, so that the event loop thread can process the requests.
 
 .. code:: cpp
 
-   EventDispatcher *dispatcher = cm->eventDispatcher();
-   Timer timer;
-   timer.start(3000);
-   while (timer.isRunning())
-       dispatcher->processEvents();
+   std::this_thread::sleep_for(3000ms);
 
 Clean up and stop the application
 ---------------------------------
-- 
2.34.1