gui, voting: Add a one minute timer to check for current poll expiring and update gui

src/gridcoin/voting/registry.cpp

@@ -603,27 +603,29 @@ const PollRegistry::Sequence PollRegistry::Polls() const
 
 const PollReference* PollRegistry::TryLatestActive() const
 {
-    if (m_latest_poll && !m_latest_poll->Expired(GetAdjustedTime())) {
+    int64_t now = GetAdjustedTime();
+
+    if (m_latest_poll && !m_latest_poll->Expired(now)) {
         return m_latest_poll;
     }
 
     if (m_polls.empty()) {
         return nullptr;
     }
 
-    const PollReference* latest = &m_polls.cbegin()->second;
+    const PollReference* latest_not_expired = nullptr;
+    int64_t latest_not_expired_timestamp = 0;
 
-    for (auto iter = ++m_polls.cbegin(); iter != m_polls.cend(); ++iter) {
-        if (iter->second.m_timestamp > latest->m_timestamp) {
-            latest = &iter->second;
+    // Go through m_polls finding the latest poll that is not expired.
+    for (auto iter = m_polls.cbegin(); iter != m_polls.cend(); ++iter) {
+        // Maybe more than one poll has the same timestamp... therefore use >=.
+        if (!iter->second.Expired(now) && iter->second.m_timestamp >= latest_not_expired_timestamp) {
+            latest_not_expired = &iter->second;
+            latest_not_expired_timestamp = latest_not_expired->m_timestamp;
         }
     }
 
-    if (latest->Expired(GetAdjustedTime())) {
-        return nullptr;
-    }
-
-    return latest;
+    return latest_not_expired;
 }
 
 const PollReference* PollRegistry::TryByTxid(const uint256 txid) const

src/qt/bitcoingui.cpp

@@ -839,6 +839,15 @@ void BitcoinGUI::setVotingModel(VotingModel *votingModel)
     overviewPage->setCurrentPollTitle(votingModel->getCurrentPollTitle());
 
     connect(votingModel, &VotingModel::newPollReceived, this, &BitcoinGUI::handleNewPoll);
+
+    QTimer *expiry_check_timer = new QTimer(this);
+
+    // A call to handle possible expired poll on a timer will update the current polls section of the overview screen
+    // to remove a current poll that has expired.
+    connect(expiry_check_timer, &QTimer::timeout, this, &BitcoinGUI::handleExpiredPoll);
+
+    // Check every minute
+    expiry_check_timer->start(1000 * 60);
 }
 
 void BitcoinGUI::createTrayIcon()
@@ -1860,6 +1869,21 @@ void BitcoinGUI::handleNewPoll()
     overviewPage->setCurrentPollTitle(votingModel->getCurrentPollTitle());
 }
 
+void BitcoinGUI::handleExpiredPoll()
+{
+    // The only difference between this and handleNewPoll() is no call to the event notifier.
+
+    if (!clientModel || !clientModel->getOptionsModel()) {
+        return;
+    }
+
+    if (!votingModel) {
+        return;
+    }
+
+    overviewPage->setCurrentPollTitle(votingModel->getCurrentPollTitle());
+}
+
 // -----------------------------------------------------------------------------
 // Class: ToolbarButtonIconFilter
 // -----------------------------------------------------------------------------

src/qt/bitcoingui.h

@@ -285,6 +285,7 @@ private slots:
     QString GetEstimatedStakingFrequency(unsigned int nEstimateTime);
 
     void handleNewPoll();
+    void handleExpiredPoll();
 };
 
 //!