Simplifies and fix bugs in FbTk::Timer

* Calling Timer::setTimeout() from within Timer::start() might lead to ugly
  behavior (as experienced in bugs #3590078, #3600143, etc; see commit
  4d307dcd10af9d817ff5c05fc40ae7487564cb31, fixes the problem partially).

* Stop a timer first, then call the handler (via Timer::fireTimeout()). A
  given handler might call Timer::start() again, which (re)adds the Timer
  to the control list .. the following Timer::stop() would remove it again.

* Use 'm_start' as indicator if timer is running.

* Move the (now quite short) code of ::addTimer / ::removeTimer
  into the Timer::start() and Timer::stop() functions.

1 files changed, 2 insertions, 3 deletions

diff --git a/src/FbTk/Timer.hh b/src/FbTk/Timer.hh
index bdaf3b8..2e82f2a 100644
--- a/src/FbTk/Timer.hh
+++ b/src/FbTk/Timer.hh
@@ -61,7 +61,7 @@ public:
 
     static void updateTimers(int file_descriptor);
 
-    int isTiming() const { return m_timing; }
+    int isTiming() const { return (m_start > 0); }
     int getInterval() const { return m_interval; }
 
     int doOnce() const { return m_once; }
@@ -77,11 +77,10 @@ protected:
 private:
     RefCount<Slot<void> > m_handler; ///< what to do on a timeout
 
-    bool m_timing; ///< clock running?
     bool m_once;  ///< do timeout only once?
     int m_interval; ///< Is an interval-only timer (e.g. clock), in seconds
 
-    uint64_t m_start;   ///< start time in microseconds
+    uint64_t m_start;   ///< start time in microseconds, 0 if not running
     uint64_t m_timeout; ///< time length in microseconds
 };