]> sigrok.org Git - pulseview.git/blobdiff - pv/views/trace/view.cpp
Trace view: Allow setting cursors via shift-drag
[pulseview.git] / pv / views / trace / view.cpp
index 9cd90be83015bafd4f709dc9d7a376418d11e56c..2a4c4372194749d5c9ce9a6d0bf377d507f1cfd6 100644 (file)
@@ -38,6 +38,7 @@
 #include <QApplication>
 #include <QEvent>
 #include <QFontMetrics>
+#include <QMenu>
 #include <QMouseEvent>
 #include <QScrollBar>
 #include <QVBoxLayout>
@@ -78,6 +79,7 @@ using std::max;
 using std::make_pair;
 using std::make_shared;
 using std::min;
+using std::numeric_limits;
 using std::pair;
 using std::set;
 using std::set_difference;
@@ -124,31 +126,11 @@ bool CustomScrollArea::viewportEvent(QEvent *event)
 
 View::View(Session &session, bool is_main_view, QWidget *parent) :
        ViewBase(session, is_main_view, parent),
+
+       // Note: Place defaults in View::reset_view_state(), not here
        splitter_(new QSplitter()),
-       segment_display_mode_(Trace::ShowLastSegmentOnly),
-       segment_selectable_(false),
-       scale_(1e-3),
-       offset_(0),
-       ruler_offset_(0),
-       updating_scroll_(false),
-       settings_restored_(false),
-       header_was_shrunk_(false),
-       sticky_scrolling_(false), // Default setting is set in MainWindow::setup_ui()
-       always_zoom_to_fit_(false),
-       tick_period_(0),
-       tick_prefix_(pv::util::SIPrefix::yocto),
-       tick_precision_(0),
-       time_unit_(util::TimeUnit::Time),
-       show_cursors_(false),
-       cursors_(new CursorPair(*this)),
-       next_flag_text_('A'),
-       trigger_markers_(),
-       hover_point_(-1, -1),
-       scroll_needs_defaults_(true),
-       saved_v_offset_(0),
-       scale_at_acq_start_(0),
-       offset_at_acq_start_(0),
-       suppress_zoom_to_fit_after_acq_(false)
+       header_was_shrunk_(false),  // The splitter remains unchanged after a reset, so this goes here
+       sticky_scrolling_(false)  // Default setting is set in MainWindow::setup_ui()
 {
        QVBoxLayout *root_layout = new QVBoxLayout(this);
        root_layout->setContentsMargins(0, 0, 0, 0);
@@ -196,7 +178,10 @@ View::View(Session &session, bool is_main_view, QWidget *parent) :
 
        // Set up settings and event handlers
        GlobalSettings settings;
-       coloured_bg_ = settings.value(GlobalSettings::Key_View_ColouredBG).toBool();
+       colored_bg_ = settings.value(GlobalSettings::Key_View_ColoredBG).toBool();
+       snap_distance_ = settings.value(GlobalSettings::Key_View_SnapDistance).toInt();
+
+       GlobalSettings::add_change_handler(this);
 
        connect(scrollarea_->horizontalScrollBar(), SIGNAL(valueChanged(int)),
                this, SLOT(h_scroll_value_changed(int)));
@@ -228,6 +213,46 @@ View::View(Session &session, bool is_main_view, QWidget *parent) :
        ruler_->raise();
        header_->raise();
 
+       reset_view_state();
+}
+
+View::~View()
+{
+       GlobalSettings::remove_change_handler(this);
+}
+
+void View::reset_view_state()
+{
+       ViewBase::reset_view_state();
+
+       segment_display_mode_ = Trace::ShowLastSegmentOnly;
+       segment_selectable_ = false;
+       scale_ = 1e-3;
+       offset_ = 0;
+       ruler_offset_ = 0;
+       updating_scroll_ = false;
+       settings_restored_ = false;
+       always_zoom_to_fit_ = false;
+       tick_period_ = 0;
+       tick_prefix_ = pv::util::SIPrefix::yocto;
+       tick_precision_ = 0;
+       time_unit_ = util::TimeUnit::Time;
+       show_cursors_ = false;
+       cursors_ = make_shared<CursorPair>(*this);
+       next_flag_text_ = 'A';
+       trigger_markers_.clear();
+       hover_widget_ = nullptr;
+       hover_point_ = QPoint(-1, -1);
+       scroll_needs_defaults_ = true;
+       saved_v_offset_ = 0;
+       scale_at_acq_start_ = 0;
+       offset_at_acq_start_ = 0;
+       suppress_zoom_to_fit_after_acq_ = false;
+
+       show_cursors_ = false;
+       cursor_state_changed(show_cursors_);
+       flags_.clear();
+
        // Update the zoom state
        calculate_tick_spacing();
 
@@ -298,6 +323,11 @@ void View::remove_decode_signal(shared_ptr<data::DecodeSignal> signal)
 }
 #endif
 
+shared_ptr<Signal> View::get_signal_under_mouse_cursor() const
+{
+       return signal_under_mouse_cursor_;
+}
+
 View* View::view()
 {
        return this;
@@ -318,6 +348,11 @@ const Viewport* View::viewport() const
        return viewport_;
 }
 
+const Ruler* View::ruler() const
+{
+       return ruler_;
+}
+
 void View::save_settings(QSettings &settings) const
 {
        settings.setValue("scale", scale_);
@@ -327,12 +362,6 @@ void View::save_settings(QSettings &settings) const
        settings.setValue("splitter_state", splitter_->saveState());
        settings.setValue("segment_display_mode", segment_display_mode_);
 
-       {
-               stringstream ss;
-               boost::archive::text_oarchive oa(ss);
-               oa << boost::serialization::make_nvp("ruler_shift", ruler_shift_);
-               settings.setValue("ruler_shift", QString::fromStdString(ss.str()));
-       }
        {
                stringstream ss;
                boost::archive::text_oarchive oa(ss);
@@ -340,7 +369,7 @@ void View::save_settings(QSettings &settings) const
                settings.setValue("offset", QString::fromStdString(ss.str()));
        }
 
-       for (shared_ptr<Signal> signal : signals_) {
+       for (const shared_ptr<Signal>& signal : signals_) {
                settings.beginGroup(signal->base()->internal_name());
                signal->save_settings(settings);
                settings.endGroup();
@@ -355,27 +384,19 @@ void View::restore_settings(QSettings &settings)
        if (settings.contains("scale"))
                set_scale(settings.value("scale").toDouble());
 
-       if (settings.contains("ruler_shift")) {
-               util::Timestamp shift;
-               stringstream ss;
-               ss << settings.value("ruler_shift").toString().toStdString();
-
-               boost::archive::text_iarchive ia(ss);
-               ia >> boost::serialization::make_nvp("ruler_shift", shift);
-
-               ruler_shift_ = shift;
-       }
-
        if (settings.contains("offset")) {
                util::Timestamp offset;
                stringstream ss;
                ss << settings.value("offset").toString().toStdString();
 
-               boost::archive::text_iarchive ia(ss);
-               ia >> boost::serialization::make_nvp("offset", offset);
-
-               // This also updates ruler_offset_
-               set_offset(offset);
+               try {
+                       boost::archive::text_iarchive ia(ss);
+                       ia >> boost::serialization::make_nvp("offset", offset);
+                       // This also updates ruler_offset_
+                       set_offset(offset);
+               } catch (boost::archive::archive_exception&) {
+                       qDebug() << "Could not restore the view offset";
+               }
        }
 
        if (settings.contains("splitter_state"))
@@ -409,11 +430,14 @@ vector< shared_ptr<TimeItem> > View::time_items() const
 {
        const vector<shared_ptr<Flag>> f(flags());
        vector<shared_ptr<TimeItem>> items(f.begin(), f.end());
-       items.push_back(cursors_);
-       items.push_back(cursors_->first());
-       items.push_back(cursors_->second());
 
-       for (auto trigger_marker : trigger_markers_)
+       if (cursors_) {
+               items.push_back(cursors_);
+               items.push_back(cursors_->first());
+               items.push_back(cursors_->second());
+       }
+
+       for (auto& trigger_marker : trigger_markers_)
                items.push_back(trigger_marker);
 
        return items;
@@ -432,27 +456,43 @@ void View::set_scale(double scale)
        }
 }
 
-void View::set_offset(const pv::util::Timestamp& offset)
+void View::set_offset(const pv::util::Timestamp& offset, bool force_update)
 {
-       if (offset_ != offset) {
+       if ((offset_ != offset) || force_update) {
                offset_ = offset;
-               ruler_offset_ = offset_ + ruler_shift_;
+               ruler_offset_ = offset_ + zero_offset_;
                offset_changed();
        }
 }
 
-// Returns the internal version of the time offset
 const Timestamp& View::offset() const
 {
        return offset_;
 }
 
-// Returns the ruler version of the time offset
 const Timestamp& View::ruler_offset() const
 {
        return ruler_offset_;
 }
 
+void View::set_zero_position(const pv::util::Timestamp& position)
+{
+       zero_offset_ = -position;
+
+       // Force an immediate update of the offsets
+       set_offset(offset_, true);
+       ruler_->update();
+}
+
+void View::reset_zero_position()
+{
+       zero_offset_ = 0;
+
+       // Force an immediate update of the offsets
+       set_offset(offset_, true);
+       ruler_->update();
+}
+
 int View::owner_visual_v_offset() const
 {
        return -scrollarea_->verticalScrollBar()->sliderPosition();
@@ -536,10 +576,25 @@ void View::set_current_segment(uint32_t segment_id)
 {
        current_segment_ = segment_id;
 
-       for (shared_ptr<Signal> signal : signals_)
+       for (const shared_ptr<Signal>& signal : signals_)
                signal->set_current_segment(current_segment_);
-       for (shared_ptr<DecodeTrace> dt : decode_traces_)
+#ifdef ENABLE_DECODE
+       for (shared_ptr<DecodeTrace>& dt : decode_traces_)
                dt->set_current_segment(current_segment_);
+#endif
+
+       vector<util::Timestamp> triggers = session_.get_triggers(current_segment_);
+
+       trigger_markers_.clear();
+       for (util::Timestamp timestamp : triggers)
+               trigger_markers_.push_back(make_shared<TriggerMarker>(*this, timestamp));
+
+       // When enabled, the first trigger for this segment is used as the zero position
+       GlobalSettings settings;
+       bool trigger_is_zero_time = settings.value(GlobalSettings::Key_View_TriggerIsZeroTime).toBool();
+
+       if (trigger_is_zero_time && (triggers.size() > 0))
+               set_zero_position(triggers.front());
 
        viewport_->update();
 
@@ -560,7 +615,7 @@ void View::set_segment_display_mode(Trace::SegmentDisplayMode mode)
 {
        segment_display_mode_ = mode;
 
-       for (shared_ptr<Signal> signal : signals_)
+       for (const shared_ptr<Signal>& signal : signals_)
                signal->set_segment_display_mode(mode);
 
        uint32_t last_segment = session_.get_segment_count() - 1;
@@ -637,23 +692,6 @@ void View::zoom_fit(bool gui_state)
        set_scale_offset(scale.convert_to<double>(), extents.first);
 }
 
-void View::zoom_one_to_one()
-{
-       using pv::data::SignalData;
-
-       // Make a set of all the visible data objects
-       set< shared_ptr<SignalData> > visible_data = get_visible_data();
-       if (visible_data.empty())
-               return;
-
-       assert(viewport_);
-       const int w = viewport_->width();
-       if (w <= 0)
-               return;
-
-       set_zoom(1.0 / session_.get_samplerate(), w / 2);
-}
-
 void View::set_scale_offset(double scale, const Timestamp& offset)
 {
        // Disable sticky scrolling / always zoom to fit when acquisition runs
@@ -686,7 +724,7 @@ set< shared_ptr<SignalData> > View::get_visible_data() const
 {
        // Make a set of all the visible data objects
        set< shared_ptr<SignalData> > visible_data;
-       for (const shared_ptr<Signal> sig : signals_)
+       for (const shared_ptr<Signal>& sig : signals_)
                if (sig->enabled())
                        visible_data.insert(sig->data());
 
@@ -697,9 +735,9 @@ pair<Timestamp, Timestamp> View::get_time_extents() const
 {
        boost::optional<Timestamp> left_time, right_time;
        const set< shared_ptr<SignalData> > visible_data = get_visible_data();
-       for (const shared_ptr<SignalData> d : visible_data) {
+       for (const shared_ptr<SignalData>& d : visible_data) {
                const vector< shared_ptr<Segment> > segments = d->segments();
-               for (const shared_ptr<Segment> &s : segments) {
+               for (const shared_ptr<Segment>s : segments) {
                        double samplerate = s->samplerate();
                        samplerate = (samplerate <= 0.0) ? 1.0 : samplerate;
 
@@ -734,15 +772,15 @@ void View::enable_show_analog_minor_grid(bool state)
        viewport_->update();
 }
 
-void View::enable_coloured_bg(bool state)
+void View::enable_colored_bg(bool state)
 {
-       coloured_bg_ = state;
+       colored_bg_ = state;
        viewport_->update();
 }
 
-bool View::coloured_bg() const
+bool View::colored_bg() const
 {
-       return coloured_bg_;
+       return colored_bg_;
 }
 
 bool View::cursors_shown() const
@@ -752,18 +790,37 @@ bool View::cursors_shown() const
 
 void View::show_cursors(bool show)
 {
-       show_cursors_ = show;
-       ruler_->update();
-       viewport_->update();
+    if (show_cursors_ != show) {
+        show_cursors_ = show;
+        cursor_state_changed(show);
+        ruler_->update();
+        viewport_->update();
+
+    } else {
+        show_cursors_ = show;
+    }
+}
+
+void View::set_cursors(pv::util::Timestamp& first, pv::util::Timestamp& second) {
+    assert(cursors);
+
+    cursors_->first()->set_time(first);
+    cursors_->second()->set_time(second);
+
+    ruler_->update();
+    viewport_->update();
 }
 
 void View::centre_cursors()
 {
-       const double time_width = scale_ * viewport_->width();
-       cursors_->first()->set_time(offset_ + time_width * 0.4);
-       cursors_->second()->set_time(offset_ + time_width * 0.6);
-       ruler_->update();
-       viewport_->update();
+    assert(cursors);
+
+    const double time_width = scale_ * viewport_->width();
+    cursors_->first()->set_time(offset_ + time_width * 0.4);
+    cursors_->second()->set_time(offset_ + time_width * 0.6);
+
+    ruler_->update();
+    viewport_->update();
 }
 
 shared_ptr<CursorPair> View::cursors() const
@@ -804,6 +861,112 @@ const QPoint& View::hover_point() const
        return hover_point_;
 }
 
+const QWidget* View::hover_widget() const
+{
+       return hover_widget_;
+}
+
+int64_t View::get_nearest_level_change(const QPoint &p)
+{
+       // Is snapping disabled?
+       if (snap_distance_ == 0)
+               return -1;
+
+       struct entry_t {
+               entry_t(shared_ptr<Signal> s) :
+                       signal(s), delta(numeric_limits<int64_t>::max()), sample(-1), is_dense(false) {}
+               shared_ptr<Signal> signal;
+               int64_t delta;
+               int64_t sample;
+               bool is_dense;
+       };
+
+       vector<entry_t> list;
+
+       // Create list of signals to consider
+       if (signal_under_mouse_cursor_)
+               list.emplace_back(signal_under_mouse_cursor_);
+       else
+               for (shared_ptr<Signal> s : signals_) {
+                       if (!s->enabled())
+                               continue;
+
+                       list.emplace_back(s);
+               }
+
+       // Get data for listed signals
+       for (entry_t &e : list) {
+               // Calculate sample number from cursor position
+               const double samples_per_pixel = e.signal->base()->get_samplerate() * scale();
+               const int64_t x_offset = offset().convert_to<double>() / scale();
+               const int64_t sample_num = max(((x_offset + p.x()) * samples_per_pixel), 0.0);
+
+               vector<data::LogicSegment::EdgePair> edges =
+                       e.signal->get_nearest_level_changes(sample_num);
+
+               if (edges.empty())
+                       continue;
+
+               // Check first edge
+               const int64_t first_sample_delta = abs(sample_num - edges.front().first);
+               const int64_t first_delta = first_sample_delta / samples_per_pixel;
+               e.delta = first_delta;
+               e.sample = edges.front().first;
+
+               // Check second edge if available
+               if (edges.size() == 2) {
+                       // Note: -1 because this is usually the right edge and sample points are left-aligned
+                       const int64_t second_sample_delta = abs(sample_num - edges.back().first - 1);
+                       const int64_t second_delta = second_sample_delta / samples_per_pixel;
+
+                       // If both edges are too close, we mark this signal as being dense
+                       if ((first_delta + second_delta) <= snap_distance_)
+                               e.is_dense = true;
+
+                       if (second_delta < first_delta) {
+                               e.delta = second_delta;
+                               e.sample = edges.back().first;
+                       }
+               }
+       }
+
+       // Look for the best match: non-dense first, then dense
+       entry_t *match = nullptr;
+
+       for (entry_t &e : list) {
+               if (e.delta > snap_distance_ || e.is_dense)
+                       continue;
+
+               if (match) {
+                       if (e.delta < match->delta)
+                               match = &e;
+               } else
+                       match = &e;
+       }
+
+       if (!match) {
+               for (entry_t &e : list) {
+                       if (!e.is_dense)
+                               continue;
+
+                       if (match) {
+                               if (e.delta < match->delta)
+                                       match = &e;
+                       } else
+                               match = &e;
+               }
+       }
+
+       if (match) {
+               // Somewhat ugly hack to make TimeItem::drag_by() work
+               signal_under_mouse_cursor_ = match->signal;
+
+               return match->sample;
+       }
+
+       return -1;
+}
+
 void View::restack_all_trace_tree_items()
 {
        // Make a list of owners that is sorted from deepest first
@@ -826,16 +989,37 @@ void View::restack_all_trace_tree_items()
                i->animate_to_layout_v_offset();
 }
 
-void View::trigger_event(util::Timestamp location)
+int View::header_width() const
+{
+        return header_->extended_size_hint().width();
+}
+
+void View::on_setting_changed(const QString &key, const QVariant &value)
 {
-       // Set up ruler_shift if the Key_View_TriggerIsZeroTime option is set.
+       if (key == GlobalSettings::Key_View_TriggerIsZeroTime)
+               on_settingViewTriggerIsZeroTime_changed(value);
+
+       if (key == GlobalSettings::Key_View_SnapDistance) {
+               GlobalSettings settings;
+               snap_distance_ = settings.value(GlobalSettings::Key_View_SnapDistance).toInt();
+       }
+}
+
+void View::trigger_event(int segment_id, util::Timestamp location)
+{
+       // TODO This doesn't work if we're showing multiple segments at once
+       if ((uint32_t)segment_id != current_segment_)
+               return;
+
+       // Set zero location if the Key_View_TriggerIsZeroTime setting is set and
+       // if this is the first trigger for this segment.
        GlobalSettings settings;
        bool trigger_is_zero_time = settings.value(GlobalSettings::Key_View_TriggerIsZeroTime).toBool();
 
-       ruler_shift_ = (trigger_is_zero_time) ? (-location) : (0);
-       // Force an immediate update of both offsets
-       offset_ -= 0.001;
-       set_offset(offset_ + 0.001);
+       size_t trigger_count = session_.get_triggers(current_segment_).size();
+
+       if (trigger_is_zero_time && trigger_count == 1)
+               set_zero_position(location);
 
        trigger_markers_.push_back(make_shared<TriggerMarker>(*this, location));
 }
@@ -901,7 +1085,7 @@ void View::calculate_tick_spacing()
                                (ScaleUnits[unit++] + tp_margin);
                } while (tp_with_margin < min_period && unit < countof(ScaleUnits));
 
-               minor_tick_count_ = (unit == 2) ? (4) : (5);
+               minor_tick_count_ = (unit == 2) ? 4 : 5;
                tick_period = order_decimal * ScaleUnits[unit - 1];
                tick_prefix = static_cast<pv::util::SIPrefix>(
                        (order - pv::util::exponent(pv::util::SIPrefix::yocto)) / 3);
@@ -994,8 +1178,10 @@ void View::update_scroll()
                vscrollbar->setRange(extents.first - areaSize.height(),
                        extents.second);
 
-       if (scroll_needs_defaults_)
+       if (scroll_needs_defaults_) {
                set_scroll_default();
+               scroll_needs_defaults_ = false;
+       }
 }
 
 void View::reset_scroll()
@@ -1024,13 +1210,13 @@ void View::set_scroll_default()
 
 void View::determine_if_header_was_shrunk()
 {
-       const int header_pane_width = splitter_->sizes().front();
-       const int header_width = header_->extended_size_hint().width();
+       const int header_pane_width =
+               splitter_->sizes().front();  // clazy:exclude=detaching-temporary
 
        // Allow for a slight margin of error so that we also accept
        // slight differences when e.g. a label name change increased
        // the overall width
-       header_was_shrunk_ = (header_pane_width < (header_width - 10));
+       header_was_shrunk_ = (header_pane_width < (header_width() - 10));
 }
 
 void View::resize_header_to_fit()
@@ -1044,7 +1230,7 @@ void View::resize_header_to_fit()
        // splitter to the maximum allowed position.
 
        int splitter_area_width = 0;
-       for (int w : splitter_->sizes())
+       for (int w : splitter_->sizes())  // clazy:exclude=range-loop
                splitter_area_width += w;
 
        // Make sure the header has enough horizontal space to show all labels fully
@@ -1070,8 +1256,8 @@ TraceTreeItemOwner* View::find_prevalent_trace_group(
        vector<TraceTreeItemOwner*> owner_list;
 
        // Make a set and a list of all the owners
-       for (const auto &channel : group->channels()) {
-               for (auto entry : signal_map) {
+       for (const autochannel : group->channels()) {
+               for (auto& entry : signal_map) {
                        if (entry.first->channel() == channel) {
                                TraceTreeItemOwner *const o = (entry.second)->owner();
                                owner_list.push_back(o);
@@ -1104,8 +1290,8 @@ vector< shared_ptr<Trace> > View::extract_new_traces_for_channels(
 {
        vector< shared_ptr<Trace> > filtered_traces;
 
-       for (const auto &channel : channels) {
-               for (auto entry : signal_map) {
+       for (const autochannel : channels) {
+               for (auto& entry : signal_map) {
                        if (entry.first->channel() == channel) {
                                shared_ptr<Trace> trace = entry.second;
                                const auto list_iter = add_list.find(trace);
@@ -1126,7 +1312,7 @@ void View::determine_time_unit()
        // Check whether we know the sample rate and hence can use time as the unit
        if (time_unit_ == util::TimeUnit::Samples) {
                // Check all signals but...
-               for (const shared_ptr<Signal> signal : signals_) {
+               for (const shared_ptr<Signal>& signal : signals_) {
                        const shared_ptr<SignalData> data = signal->data();
 
                        // ...only check first segment of each
@@ -1145,11 +1331,14 @@ bool View::eventFilter(QObject *object, QEvent *event)
        const QEvent::Type type = event->type();
        if (type == QEvent::MouseMove) {
 
+               if (object)
+                       hover_widget_ = qobject_cast<QWidget*>(object);
+
                const QMouseEvent *const mouse_event = (QMouseEvent*)event;
                if (object == viewport_)
                        hover_point_ = mouse_event->pos();
                else if (object == ruler_)
-                       hover_point_ = QPoint(mouse_event->x(), 0);
+                       hover_point_ = mouse_event->pos();
                else if (object == header_)
                        hover_point_ = QPoint(0, mouse_event->y());
                else
@@ -1190,6 +1379,19 @@ bool View::eventFilter(QObject *object, QEvent *event)
        return QObject::eventFilter(object, event);
 }
 
+void View::contextMenuEvent(QContextMenuEvent *event)
+{
+       QPoint pos = event->pos() - QPoint(0, ruler_->sizeHint().height());
+
+       const shared_ptr<ViewItem> r = viewport_->get_mouse_over_item(pos);
+       if (!r)
+               return;
+
+       QMenu *menu = r->create_view_context_menu(this, pos);
+       if (menu)
+               menu->popup(event->globalPos());
+}
+
 void View::resizeEvent(QResizeEvent* event)
 {
        // Only adjust the top margin if we shrunk vertically
@@ -1201,12 +1403,27 @@ void View::resizeEvent(QResizeEvent* event)
 
 void View::update_hover_point()
 {
+       // Determine signal that the mouse cursor is hovering over
+       signal_under_mouse_cursor_.reset();
+       if (hover_widget_ == this) {
+               for (const shared_ptr<Signal>& s : signals_) {
+                       const pair<int, int> extents = s->v_extents();
+                       const int top = s->get_visual_y() + extents.first;
+                       const int btm = s->get_visual_y() + extents.second;
+                       if ((hover_point_.y() >= top) && (hover_point_.y() <= btm)
+                               && s->base()->enabled())
+                               signal_under_mouse_cursor_ = s;
+               }
+       }
+
+       // Update all trace tree items
        const vector<shared_ptr<TraceTreeItem>> trace_tree_items(
                list_by_type<TraceTreeItem>());
-       for (shared_ptr<TraceTreeItem> r : trace_tree_items)
+       for (const shared_ptr<TraceTreeItem>& r : trace_tree_items)
                r->hover_point_changed(hover_point_);
 
-       hover_point_changed(hover_point_);
+       // Notify any other listeners
+       hover_point_changed(hover_widget_, hover_point_);
 }
 
 void View::row_item_appearance_changed(bool label, bool content)
@@ -1236,6 +1453,7 @@ void View::extents_changed(bool horz, bool vert)
                (horz ? TraceTreeItemHExtentsChanged : 0) |
                (vert ? TraceTreeItemVExtentsChanged : 0);
 
+       lazy_event_handler_.stop();
        lazy_event_handler_.start();
 }
 
@@ -1336,12 +1554,12 @@ void View::signals_changed()
        // Make a look-up table of sigrok Channels to pulseview Signals
        unordered_map<shared_ptr<data::SignalBase>, shared_ptr<Signal> >
                signal_map;
-       for (const shared_ptr<Signal> &sig : signals_)
+       for (const shared_ptr<Signal>sig : signals_)
                signal_map[sig->base()] = sig;
 
        // Populate channel groups
        if (sr_dev)
-               for (auto entry : sr_dev->channel_groups()) {
+               for (auto& entry : sr_dev->channel_groups()) {
                        const shared_ptr<sigrok::ChannelGroup> &group = entry.second;
 
                        if (group->channels().size() <= 1)
@@ -1367,7 +1585,7 @@ void View::signals_changed()
                        // Add the traces to the group
                        const pair<int, int> prev_v_extents = owner->v_extents();
                        int offset = prev_v_extents.second - prev_v_extents.first;
-                       for (shared_ptr<Trace> trace : new_traces_in_group) {
+                       for (const shared_ptr<Trace>& trace : new_traces_in_group) {
                                assert(trace);
                                owner->add_child_item(trace);
 
@@ -1402,7 +1620,7 @@ void View::signals_changed()
        if (non_grouped_logic_signals.size() > 0) {
                const shared_ptr<TraceGroup> non_grouped_trace_group(
                        make_shared<TraceGroup>());
-               for (shared_ptr<Trace> trace : non_grouped_logic_signals)
+               for (const shared_ptr<Trace>& trace : non_grouped_logic_signals)
                        non_grouped_trace_group->add_child_item(trace);
 
                non_grouped_trace_group->restack_items();
@@ -1420,7 +1638,7 @@ void View::signals_changed()
                add_traces.begin(), add_traces.end());
 
        // Remove any removed traces
-       for (shared_ptr<Trace> trace : remove_traces) {
+       for (const shared_ptr<Trace>& trace : remove_traces) {
                TraceTreeItemOwner *const owner = trace->owner();
                assert(owner);
                owner->remove_child_item(trace);
@@ -1473,6 +1691,7 @@ void View::capture_state_updated(int state)
                set_time_unit(util::TimeUnit::Samples);
 
                trigger_markers_.clear();
+               set_zero_position(0);
 
                scale_at_acq_start_ = scale_;
                offset_at_acq_start_ = offset_;
@@ -1553,6 +1772,17 @@ void View::on_segment_changed(int segment)
        }
 }
 
+void View::on_settingViewTriggerIsZeroTime_changed(const QVariant new_value)
+{
+       if (new_value.toBool()) {
+               // The first trigger for this segment is used as the zero position
+               vector<util::Timestamp> triggers = session_.get_triggers(current_segment_);
+               if (triggers.size() > 0)
+                       set_zero_position(triggers.front());
+       } else
+               reset_zero_position();
+}
+
 void View::perform_delayed_view_update()
 {
        if (always_zoom_to_fit_) {