Qt UI: Perf improvements, hide date/time in RT Env

Dramatic speed up parsing time zone lists by using const refs.

Closes: #357

2 files changed, 26 insertions, 25 deletions

diff --git a/ui/qt5/datetimepage.cc b/ui/qt5/datetimepage.cc
index 8b01d30..5f38493 100644
--- a/ui/qt5/datetimepage.cc
+++ b/ui/qt5/datetimepage.cc
@@ -27,15 +27,14 @@
 
 TimeZone::TimeZone() : ianaName(), friendlyName(), offset(0) {}
 
-TimeZone::TimeZone(QByteArray iana) {
-    QTimeZone zone(iana);
-    QString offset, longName, comment;
-    this->ianaName = iana;
+TimeZone::TimeZone(const QByteArray &iana) : ianaName(iana) {
+    const QTimeZone zone(iana);
+    QString offset_str, longName, comment;
 
-    offset = zone.displayName(QTimeZone::GenericTime, QTimeZone::OffsetName);
-    this->friendlyName = "(" + offset + ") " + iana;
+    offset_str = zone.displayName(QTimeZone::GenericTime, QTimeZone::OffsetName);
+    this->friendlyName = "(" + offset_str + ") " + iana;
     longName = zone.displayName(QTimeZone::GenericTime, QTimeZone::LongName);
-    if(longName != offset) {
+    if(longName != offset_str) {
         this->friendlyName += " - " + longName;
     }
 
@@ -52,11 +51,11 @@ TimeZoneModel::TimeZoneModel(QWidget *parent) : QAbstractListModel(parent) {
     for(auto &iana : QTimeZone::availableTimeZoneIds()) {
         /* we don't support raw timezones because tzdata doesn't */
         if(iana.startsWith("UTC") && iana.size() > 3) continue;
-        TimeZone tzObj(iana);
+        const TimeZone tzObj(iana);
         zones.push_back(tzObj);
     }
 
-    std::sort(zones.begin(), zones.end(), [](TimeZone tz1, TimeZone tz2) {
+    std::sort(zones.begin(), zones.end(), [](const TimeZone &tz1, const TimeZone &tz2) {
         if(tz1.offset < tz2.offset) return true;
         if(tz2.offset < tz1.offset) return false;
         return tz1.friendlyName < tz2.friendlyName;
@@ -69,14 +68,14 @@ int TimeZoneModel::rowCount(const QModelIndex &) const {
 
 QVariant TimeZoneModel::data(const QModelIndex &index, int role) const {
     if(!index.isValid()) {
-        return QVariant();
+        return {};
     }
 
     if(index.row() > zones.size()) {
-        return QVariant();
+        return {};
     }
 
-    TimeZone zone = zones.at(index.row());
+    const TimeZone &zone = zones.at(index.row());
 
     switch(role)
     {
@@ -85,13 +84,13 @@ QVariant TimeZoneModel::data(const QModelIndex &index, int role) const {
     case Qt::ToolTipRole:
         return QString(zone.ianaName);
     default:
-        return QVariant();
+        return {};
     }
 }
 
 QVariant TimeZoneModel::headerData(int, Qt::Orientation, int role) const {
     if(role != Qt::DisplayRole) {
-        return QVariant();
+        return {};
     }
 
     return QString("Time Zone");
@@ -173,18 +172,18 @@ DateTimePage::DateTimePage(QWidget *parent) : HorizonWizardPage(parent) {
 
     updateTimer = new QTimer(this);
     updateTimer->setInterval(1000);
-    connect(updateTimer, &QTimer::timeout, [=]{
+    connect(updateTimer, &QTimer::timeout, [this]{
         if(!dateEdit->hasFocus()) dateEdit->setDate(QDate::currentDate());
         if(!timeEdit->hasFocus()) timeEdit->setTime(QTime::currentTime());
     });
 
-    QHBoxLayout *dateTimeLayout = new QHBoxLayout;
+    auto dateTimeLayout = new QHBoxLayout;
     dateTimeLayout->addWidget(dateEdit);
     dateTimeLayout->addWidget(timeEdit);
-    QGroupBox *dateTimeGroup = new QGroupBox(tr("Date and Time"));
+    auto dateTimeGroup = new QGroupBox(tr("Date and Time"));
     dateTimeGroup->setLayout(dateTimeLayout);
 
-    QLineEdit *timeZoneSearch = new QLineEdit;
+    auto timeZoneSearch = new QLineEdit;
     timeZoneSearch->addAction(QIcon::fromTheme("edit-find"),
                               QLineEdit::LeadingPosition);
     timeZoneSearch->setPlaceholderText(tr("Search for a time zone"));
@@ -192,7 +191,7 @@ DateTimePage::DateTimePage(QWidget *parent) : HorizonWizardPage(parent) {
     sortModel = new QSortFilterProxyModel(this);
     sortModel->setFilterCaseSensitivity(Qt::CaseInsensitive);
     sortModel->setSourceModel(&zoneModel);
-    connect(timeZoneSearch, &QLineEdit::textChanged, [=](const QString &text) {
+    connect(timeZoneSearch, &QLineEdit::textChanged, [this](const QString &text) {
         sortModel->setFilterFixedString(text);
     });
     timeZoneList = new QListView;
@@ -200,22 +199,24 @@ DateTimePage::DateTimePage(QWidget *parent) : HorizonWizardPage(parent) {
     timeZoneList->setSelectionMode(QAbstractItemView::SingleSelection);
     timeZoneList->setWhatsThis(tr("This list contains all time zones known to the system.  Select the one you wish to use for representing time on this computer."));
     connect(timeZoneList->selectionModel(), &QItemSelectionModel::currentChanged,
-            [=]() {
+            [this]() {
         emit timezoneChanged();
     });
 
     registerField("timezone*", this, "selectedTimeZone", SIGNAL(timezoneChanged()));
 
-    QVBoxLayout *timeZoneLayout = new QVBoxLayout;
+    auto timeZoneLayout = new QVBoxLayout;
     timeZoneLayout->addWidget(timeZoneSearch);
     timeZoneLayout->addWidget(timeZoneList);
-    QGroupBox *timeZoneGroup = new QGroupBox(tr("Time Zone"));
+    auto timeZoneGroup = new QGroupBox(tr("Time Zone"));
     timeZoneGroup->setLayout(timeZoneLayout);
 
-    QVBoxLayout *mainLayout = new QVBoxLayout;
+    auto mainLayout = new QVBoxLayout;
     mainLayout->addStretch();
+#ifdef HAS_INSTALL_ENV
     mainLayout->addWidget(dateTimeGroup);
     mainLayout->addStretch();
+#endif  /* HAS_INSTALL_ENV */
     mainLayout->addWidget(timeZoneGroup);
     mainLayout->addStretch();
     setLayout(mainLayout);
@@ -224,7 +225,7 @@ DateTimePage::DateTimePage(QWidget *parent) : HorizonWizardPage(parent) {
 }
 
 QString DateTimePage::selectedTimeZone() {
-    QModelIndex curr = timeZoneList->selectionModel()->currentIndex();
+    const QModelIndex curr = timeZoneList->selectionModel()->currentIndex();
     return sortModel->data(curr, Qt::ToolTipRole).toString();
 }
 
diff --git a/ui/qt5/datetimepage.hh b/ui/qt5/datetimepage.hh
index a861d90..1a47b64 100644
--- a/ui/qt5/datetimepage.hh
+++ b/ui/qt5/datetimepage.hh
@@ -33,7 +33,7 @@ struct TimeZone {
     int offset;
 
     TimeZone();
-    TimeZone(QByteArray iana);
+    TimeZone(const QByteArray &iana);
 };
 
 class TimeZoneModel : public QAbstractListModel {