libcamera: timer: Remove the interval() method

The libcamera timers are single-shot timers. They are started with a
duration, but fire once only, not based on an interval. Remove the
interval concept by removing the interval() method, and rename other
occurences of interval to duration.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

3 files changed, 13 insertions, 17 deletions

diff --git a/include/libcamera/timer.h b/include/libcamera/timer.h
index 476ae45f..09f426a5 100644
--- a/include/libcamera/timer.h
+++ b/include/libcamera/timer.h
@@ -24,11 +24,10 @@ public:
 	~Timer();
 
 	void start(unsigned int msec) { start(std::chrono::milliseconds(msec)); }
-	void start(std::chrono::milliseconds interval);
+	void start(std::chrono::milliseconds duration);
 	void stop();
 	bool isRunning() const;
 
-	std::chrono::milliseconds interval() const { return interval_; }
 	std::chrono::steady_clock::time_point deadline() const { return deadline_; }
 
 	Signal<Timer *> timeout;
@@ -40,7 +39,6 @@ private:
 	void registerTimer();
 	void unregisterTimer();
 
-	std::chrono::milliseconds interval_;
 	std::chrono::steady_clock::time_point deadline_;
 };
 
diff --git a/src/libcamera/timer.cpp b/src/libcamera/timer.cpp
index b3cea3da..34410bab 100644
--- a/src/libcamera/timer.cpp
+++ b/src/libcamera/timer.cpp
@@ -61,19 +61,18 @@ Timer::~Timer()
  */
 
 /**
- * \brief Start or restart the timer with a timeout of \a interval
- * \param[in] interval The timer duration in milliseconds
+ * \brief Start or restart the timer with a timeout of \a duration
+ * \param[in] duration The timer duration in milliseconds
  *
  * If the timer is already running it will be stopped and restarted.
  */
-void Timer::start(std::chrono::milliseconds interval)
+void Timer::start(std::chrono::milliseconds duration)
 {
-	interval_ = interval;
-	deadline_ = utils::clock::now() + interval;
+	deadline_ = utils::clock::now() + duration;
 
 	LOG(Timer, Debug)
-		<< "Starting timer " << this << " with interval "
-		<< interval.count() << ": deadline "
+		<< "Starting timer " << this << " with duration "
+		<< duration.count() << ": deadline "
 		<< utils::time_point_to_string(deadline_);
 
 	registerTimer();
@@ -114,12 +113,6 @@ bool Timer::isRunning() const
 }
 
 /**
- * \fn Timer::interval()
- * \brief Retrieve the timer interval
- * \return The timer interval in milliseconds
- */
-
-/**
  * \fn Timer::deadline()
  * \brief Retrieve the timer deadline
  * \return The timer deadline
diff --git a/src/qcam/qt_event_dispatcher.cpp b/src/qcam/qt_event_dispatcher.cpp
index 994af3ea..9e989bef 100644
--- a/src/qcam/qt_event_dispatcher.cpp
+++ b/src/qcam/qt_event_dispatcher.cpp
@@ -5,6 +5,7 @@
  * qt_event_dispatcher.cpp - qcam - Qt-based event dispatcher
  */
 
+#include <chrono>
 #include <iostream>
 
 #include <QAbstractEventDispatcher>
@@ -112,7 +113,11 @@ void QtEventDispatcher::exceptionNotifierActivated(int socket)
 
 void QtEventDispatcher::registerTimer(Timer *timer)
 {
-	int timerId = startTimer(timer->interval());
+	std::chrono::steady_clock::time_point now = std::chrono::steady_clock::now();
+	std::chrono::steady_clock::duration duration = timer->deadline() - now;
+	std::chrono::milliseconds msec =
+		std::chrono::duration_cast<std::chrono::milliseconds>(duration);
+	int timerId = startTimer(msec);
 	timers_[timerId] = timer;
 	timerIds_[timer] = timerId;
 }