Merge lp:~albaguirre/unity-system-compositor/fix-1383279 into lp:unity-system-compositor

[Alberto Aguirre]

Ignore repeated power key up events within 100ms time window.

Ignore repeated power key up events within 100ms time window.

This prevents the queue up of power key events (which make the screen flash on/off for seconds) when the power key is repeatedly pressed specially for krillin devices.

[PS Jenkins bot (ps-jenkins)]

PASSED: Continuous integration, rev:184
http://jenkins.qa.ubuntu.com/job/unity-system-compositor-ci/161/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/unity-system-compositor-utopic-amd64-ci/57
    SUCCESS: http://jenkins.qa.ubuntu.com/job/unity-system-compositor-utopic-armhf-ci/57

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/unity-system-compositor-ci/161/rebuild

review: Approve (continuous-integration)

[Alan Griffiths (alan-griffiths)]

Not quite the way I'd code it. (I'd save the end of the ignore window and compare that with now()).

But seems to do what it intends.

review: Approve

[Alberto Aguirre (albaguirre)]

Will wait to merge https://code.launchpad.net/~andreas-pokorny/unity-system-compositor/expose-powerkey-state-and-screen-toggle-controller-interface/+merge/240834

so that I can write some unit tests for this.

Unmerged revisions

184. By Alberto Aguirre on 2014-10-22

Ignore repeated power key up events within 100ms time window.

=== modified file 'src/powerkey_handler.cpp'
--- src/powerkey_handler.cpp	2014-07-21 21:33:35 +0000
+++ src/powerkey_handler.cpp	2014-10-22 18:30:54 +0000
@@ -67,12 +67,23 @@
 
 void PowerKeyHandler::power_key_up()
 {
+    using namespace std::chrono;
+    static auto prev_tp = steady_clock::now();
+    static std::chrono::milliseconds ignore_repeat_keyups_time_window{100};
+
+    auto time_after_last_key_up = duration_cast<milliseconds>(steady_clock::now() - prev_tp);
+
     std::lock_guard<std::mutex> lock{guard};
-    shutdown_alarm->cancel();
-    long_press_alarm->cancel();
-    if (!long_press_detected)
+    if (time_after_last_key_up > ignore_repeat_keyups_time_window)
     {
-        screen_state_handler->toggle_screen_power_mode(PowerStateChangeReason::power_key);
+        shutdown_alarm->cancel();
+        long_press_alarm->cancel();
+
+        if (!long_press_detected)
+        {
+            screen_state_handler->toggle_screen_power_mode(PowerStateChangeReason::power_key);
+        }
+        prev_tp = steady_clock::now();
     }
 }