1 files changed, 163 insertions, 0 deletions
diff --git a/src/clock-live.cpp b/src/clock-live.cpp
new file mode 100644
index 0000000..69ebda7
--- /dev/null
+++ b/src/clock-live.cpp
@@ -0,0 +1,163 @@
+/*
+ * Copyright 2013 Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ */
+
+#include <datetime/clock.h>
+#include <datetime/timezones.h>
+
+namespace unity {
+namespace indicator {
+namespace datetime {
+
+/***
+****
+***/
+
+namespace
+{
+
+void clearTimer(guint& tag)
+{
+    if (tag)
+    {
+        g_source_remove(tag);
+        tag = 0;
+    }
+}
+
+guint calculate_milliseconds_until_next_minute(const DateTime& now)
+{
+    auto next = g_date_time_add_minutes(now.get(), 1);
+    auto start_of_next = g_date_time_add_seconds (next, -g_date_time_get_seconds(next));
+    const auto interval_usec = g_date_time_difference(start_of_next, now.get());
+    const guint interval_msec = (interval_usec + 999) / 1000;
+    g_date_time_unref(start_of_next);
+    g_date_time_unref(next);
+    g_assert (interval_msec <= 60000);
+    return interval_msec;
+}
+
+} // unnamed namespace
+
+
+class LiveClock::Impl
+{
+public:
+
+    Impl(LiveClock& owner, const std::shared_ptr<Timezones>& tzd):
+        m_owner(owner),
+        m_timezones(tzd)
+    {
+        if (m_timezones)
+        {
+            m_timezones->timezone.changed().connect([this](const std::string& z) {setTimezone(z);});
+            setTimezone(m_timezones->timezone.get());
+        }
+
+        restart_minute_timer();
+    }
+
+    ~Impl()
+    {
+        clearTimer(m_timer);
+
+        g_clear_pointer(&m_timezone, g_time_zone_unref);
+    }
+
+    DateTime localtime() const
+    {
+        g_assert(m_timezone != nullptr);
+
+        auto gdt = g_date_time_new_now(m_timezone);
+        DateTime ret(gdt);
+        g_date_time_unref(gdt);
+        return ret;
+    }
+
+private:
+
+    void setTimezone(const std::string& str)
+    {
+        g_clear_pointer(&m_timezone, g_time_zone_unref);
+        m_timezone = g_time_zone_new(str.c_str());
+        m_owner.minuteChanged();
+    }
+
+    /***
+    ****
+    ***/
+
+    void restart_minute_timer()
+    {
+        clearTimer(m_timer);
+
+        // maybe emit change signals
+        const auto now = localtime();
+        if (!DateTime::is_same_minute(m_prev_datetime, now))
+            m_owner.minuteChanged();
+        if (!DateTime::is_same_day(m_prev_datetime, now))
+            m_owner.dateChanged();
+
+        // queue up a timer to fire at the next minute
+        m_prev_datetime = now;
+        auto interval_msec = calculate_milliseconds_until_next_minute(now);
+        interval_msec += 50; // add a small margin to ensure the callback
+                             // fires /after/ next is reached
+        m_timer = g_timeout_add_full(G_PRIORITY_HIGH,
+                                     interval_msec,
+                                     on_minute_timer_reached,
+                                     this,
+                                     nullptr);
+    }
+
+    static gboolean on_minute_timer_reached(gpointer gself)
+    {
+        static_cast<LiveClock::Impl*>(gself)->restart_minute_timer();
+        return G_SOURCE_REMOVE;
+    }
+
+protected:
+
+    LiveClock& m_owner;
+    GTimeZone* m_timezone = nullptr;
+    std::shared_ptr<Timezones> m_timezones;
+
+    DateTime m_prev_datetime;
+    unsigned int m_timer = 0;
+};
+
+LiveClock::LiveClock(const std::shared_ptr<Timezones>& tzd):
+    p(new Impl(*this, tzd))
+{
+}
+
+LiveClock::~LiveClock() =default;
+
+DateTime LiveClock::localtime() const
+{
+    return p->localtime();
+}
+
+/***
+****
+***/
+
+} // namespace datetime
+} // namespace indicator
+} // namespace unity
+