]> sigrok.org Git - pulseview.git/blobdiff - pv/view/view.cpp
View: Introduce settings_restored_
[pulseview.git] / pv / view / view.cpp
index f46045ad1af482d89d0da7f00d5b853f7ae34ea6..f1486ad9c4cf733dfa8b170c6b1827edcf609621 100644 (file)
 #include <cmath>
 #include <iostream>
 #include <iterator>
-#include <mutex>
 #include <unordered_set>
 
 #include <boost/archive/text_iarchive.hpp>
 #include <boost/archive/text_oarchive.hpp>
 #include <boost/serialization/serialization.hpp>
-#include <boost/thread/locks.hpp>
 
 #include <QApplication>
-#include <QHBoxLayout>
 #include <QEvent>
 #include <QFontMetrics>
 #include <QMouseEvent>
 #include <QScrollBar>
+#include <QVBoxLayout>
 
 #include <libsigrokcxx/libsigrokcxx.hpp>
 
 #include "view.hpp"
 #include "viewport.hpp"
 
-#include "pv/session.hpp"
-#include "pv/globalsettings.hpp"
-#include "pv/devices/device.hpp"
 #include "pv/data/logic.hpp"
 #include "pv/data/logicsegment.hpp"
+#include "pv/devices/device.hpp"
+#include "pv/globalsettings.hpp"
+#include "pv/session.hpp"
 #include "pv/util.hpp"
 
 #ifdef ENABLE_DECODE
 #include "decodetrace.hpp"
 #endif
 
-using boost::shared_lock;
-using boost::shared_mutex;
-
 using pv::data::SignalData;
 using pv::data::Segment;
 using pv::util::TimeUnit;
@@ -77,11 +72,9 @@ using pv::util::Timestamp;
 
 using std::back_inserter;
 using std::copy_if;
-using std::deque;
+using std::count_if;
 using std::dynamic_pointer_cast;
 using std::inserter;
-using std::list;
-using std::lock_guard;
 using std::max;
 using std::make_pair;
 using std::make_shared;
@@ -90,10 +83,10 @@ using std::pair;
 using std::set;
 using std::set_difference;
 using std::shared_ptr;
+using std::stringstream;
 using std::unordered_map;
 using std::unordered_set;
 using std::vector;
-using std::weak_ptr;
 
 namespace pv {
 namespace views {
@@ -103,22 +96,16 @@ const Timestamp View::MaxScale("1e9");
 const Timestamp View::MinScale("1e-12");
 
 const int View::MaxScrollValue = INT_MAX / 2;
-const int View::MaxViewAutoUpdateRate = 25; // No more than 25 Hz with sticky scrolling
 
 const int View::ScaleUnits[3] = {1, 2, 5};
 
 
-CustomAbstractScrollArea::CustomAbstractScrollArea(QWidget *parent) :
+CustomScrollArea::CustomScrollArea(QWidget *parent) :
        QAbstractScrollArea(parent)
 {
 }
 
-void CustomAbstractScrollArea::setViewportMargins(int left, int top, int right, int bottom)
-{
-       QAbstractScrollArea::setViewportMargins(left, top, right, bottom);
-}
-
-bool CustomAbstractScrollArea::viewportEvent(QEvent *event)
+bool CustomScrollArea::viewportEvent(QEvent *event)
 {
        switch (event->type()) {
        case QEvent::Paint:
@@ -138,13 +125,11 @@ bool CustomAbstractScrollArea::viewportEvent(QEvent *event)
 
 View::View(Session &session, bool is_main_view, QWidget *parent) :
        ViewBase(session, is_main_view, parent),
-       viewport_(new Viewport(*this)),
-       ruler_(new Ruler(*this)),
-       header_(new Header(*this)),
-       scrollarea_(this),
+       splitter_(new QSplitter()),
        scale_(1e-3),
        offset_(0),
        updating_scroll_(false),
+       settings_restored_(false),
        sticky_scrolling_(false), // Default setting is set in MainWindow::setup_ui()
        always_zoom_to_fit_(false),
        tick_period_(0),
@@ -157,15 +142,57 @@ View::View(Session &session, bool is_main_view, QWidget *parent) :
        trigger_markers_(),
        hover_point_(-1, -1),
        scroll_needs_defaults_(false),
-       saved_v_offset_(0),
-       size_finalized_(false)
-{
+       saved_v_offset_(0)
+{
+       QVBoxLayout *root_layout = new QVBoxLayout(this);
+       root_layout->setContentsMargins(0, 0, 0, 0);
+       root_layout->addWidget(splitter_);
+
+       viewport_ = new Viewport(*this);
+       scrollarea_ = new CustomScrollArea(splitter_);
+       scrollarea_->setViewport(viewport_);
+       scrollarea_->setFrameShape(QFrame::NoFrame);
+
+       ruler_ = new Ruler(*this);
+
+       header_ = new Header(*this);
+       header_->setMinimumWidth(10);  // So that the arrow tips show at least
+
+       // We put the header into a simple layout so that we can add the top margin,
+       // allowing us to make it line up with the bottom of the ruler
+       QWidget *header_container = new QWidget();
+       header_container->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+       QVBoxLayout *header_layout = new QVBoxLayout(header_container);
+       header_layout->setContentsMargins(0, ruler_->sizeHint().height(), 0, 0);
+       header_layout->addWidget(header_);
+
+       // To let the ruler and scrollarea be on the same split pane, we need a layout
+       QWidget *trace_container = new QWidget();
+       trace_container->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+       QVBoxLayout *trace_layout = new QVBoxLayout(trace_container);
+       trace_layout->setSpacing(0);  // We don't want space between the ruler and scrollarea
+       trace_layout->setContentsMargins(0, 0, 0, 0);
+       trace_layout->addWidget(ruler_);
+       trace_layout->addWidget(scrollarea_);
+
+       splitter_->addWidget(header_container);
+       splitter_->addWidget(trace_container);
+       splitter_->setHandleWidth(1);  // Don't show a visible rubber band
+       splitter_->setCollapsible(0, false);  // Prevent the header from collapsing
+       splitter_->setCollapsible(1, false);  // Prevent the traces from collapsing
+       splitter_->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+
+       viewport_->installEventFilter(this);
+       ruler_->installEventFilter(this);
+       header_->installEventFilter(this);
+
+       // Set up settings and event handlers
        GlobalSettings settings;
        coloured_bg_ = settings.value(GlobalSettings::Key_View_ColouredBG).toBool();
 
-       connect(scrollarea_.horizontalScrollBar(), SIGNAL(valueChanged(int)),
+       connect(scrollarea_->horizontalScrollBar(), SIGNAL(valueChanged(int)),
                this, SLOT(h_scroll_value_changed(int)));
-       connect(scrollarea_.verticalScrollBar(), SIGNAL(valueChanged(int)),
+       connect(scrollarea_->verticalScrollBar(), SIGNAL(valueChanged(int)),
                this, SLOT(v_scroll_value_changed()));
 
        connect(header_, SIGNAL(selection_changed()),
@@ -178,6 +205,9 @@ View::View(Session &session, bool is_main_view, QWidget *parent) :
        connect(ruler_, SIGNAL(selection_changed()),
                this, SIGNAL(selection_changed()));
 
+       connect(splitter_, SIGNAL(splitterMoved(int, int)),
+               this, SLOT(on_splitter_moved()));
+
        connect(this, SIGNAL(hover_point_changed()),
                this, SLOT(on_hover_point_changed()));
 
@@ -185,23 +215,6 @@ View::View(Session &session, bool is_main_view, QWidget *parent) :
                this, SLOT(process_sticky_events()));
        lazy_event_handler_.setSingleShot(true);
 
-       connect(&delayed_view_updater_, SIGNAL(timeout()),
-               this, SLOT(perform_delayed_view_update()));
-       delayed_view_updater_.setSingleShot(true);
-       delayed_view_updater_.setInterval(1000 / MaxViewAutoUpdateRate);
-
-       /* To let the scroll area fill up the parent QWidget (this), we need a layout */
-       QHBoxLayout *layout = new QHBoxLayout(this);
-       setLayout(layout);
-       layout->setContentsMargins(0, 0, 0, 0);
-       layout->addWidget(&scrollarea_);
-
-       scrollarea_.setViewport(viewport_);
-
-       viewport_->installEventFilter(this);
-       ruler_->installEventFilter(this);
-       header_->installEventFilter(this);
-
        // Trigger the initial event manually. The default device has signals
        // which were created before this object came into being
        signals_changed();
@@ -224,18 +237,20 @@ const Session& View::session() const
        return session_;
 }
 
-std::unordered_set< std::shared_ptr<Signal> > View::signals() const
+unordered_set< shared_ptr<Signal> > View::signals() const
 {
        return signals_;
 }
 
 void View::clear_signals()
 {
+       ViewBase::clear_signalbases();
        signals_.clear();
 }
 
 void View::add_signal(const shared_ptr<Signal> signal)
 {
+       ViewBase::add_signalbase(signal->base());
        signals_.insert(signal);
 }
 
@@ -287,9 +302,11 @@ void View::save_settings(QSettings &settings) const
 {
        settings.setValue("scale", scale_);
        settings.setValue("v_offset",
-               scrollarea_.verticalScrollBar()->sliderPosition());
+               scrollarea_->verticalScrollBar()->sliderPosition());
 
-       std::stringstream ss;
+       settings.setValue("splitter_state", splitter_->saveState());
+
+       stringstream ss;
        boost::archive::text_oarchive oa(ss);
        oa << boost::serialization::make_nvp("offset", offset_);
        settings.setValue("offset", QString::fromStdString(ss.str()));
@@ -311,7 +328,7 @@ void View::restore_settings(QSettings &settings)
 
        if (settings.contains("offset")) {
                util::Timestamp offset;
-               std::stringstream ss;
+               stringstream ss;
                ss << settings.value("offset").toString().toStdString();
 
                boost::archive::text_iarchive ia(ss);
@@ -320,6 +337,9 @@ void View::restore_settings(QSettings &settings)
                set_offset(offset);
        }
 
+       if (settings.contains("splitter_state"))
+               splitter_->restoreState(settings.value("splitter_state").toByteArray());
+
        for (shared_ptr<Signal> signal : signals_) {
                settings.beginGroup(signal->base()->internal_name());
                signal->restore_settings(settings);
@@ -330,8 +350,10 @@ void View::restore_settings(QSettings &settings)
                saved_v_offset_ = settings.value("v_offset").toInt();
                set_v_offset(saved_v_offset_);
                scroll_needs_defaults_ = false;
-               // Note: see resizeEvent() for additional information
+               // Note: see eventFilter() for additional information
        }
+
+       settings_restored_ = true;
 }
 
 vector< shared_ptr<TimeItem> > View::time_items() const
@@ -357,7 +379,7 @@ void View::set_scale(double scale)
 {
        if (scale_ != scale) {
                scale_ = scale;
-               Q_EMIT scale_changed();
+               scale_changed();
        }
 }
 
@@ -370,18 +392,18 @@ void View::set_offset(const pv::util::Timestamp& offset)
 {
        if (offset_ != offset) {
                offset_ = offset;
-               Q_EMIT offset_changed();
+               offset_changed();
        }
 }
 
 int View::owner_visual_v_offset() const
 {
-       return -scrollarea_.verticalScrollBar()->sliderPosition();
+       return -scrollarea_->verticalScrollBar()->sliderPosition();
 }
 
 void View::set_v_offset(int offset)
 {
-       scrollarea_.verticalScrollBar()->setSliderPosition(offset);
+       scrollarea_->verticalScrollBar()->setSliderPosition(offset);
        header_->update();
        viewport_->update();
 }
@@ -400,7 +422,7 @@ void View::set_tick_prefix(pv::util::SIPrefix tick_prefix)
 {
        if (tick_prefix_ != tick_prefix) {
                tick_prefix_ = tick_prefix;
-               Q_EMIT tick_prefix_changed();
+               tick_prefix_changed();
        }
 }
 
@@ -413,7 +435,7 @@ void View::set_tick_precision(unsigned tick_precision)
 {
        if (tick_precision_ != tick_precision) {
                tick_precision_ = tick_precision;
-               Q_EMIT tick_precision_changed();
+               tick_precision_changed();
        }
 }
 
@@ -426,7 +448,7 @@ void View::set_tick_period(const pv::util::Timestamp& tick_period)
 {
        if (tick_period_ != tick_period) {
                tick_period_ = tick_period;
-               Q_EMIT tick_period_changed();
+               tick_period_changed();
        }
 }
 
@@ -439,7 +461,7 @@ void View::set_time_unit(pv::util::TimeUnit time_unit)
 {
        if (time_unit_ != time_unit) {
                time_unit_ = time_unit;
-               Q_EMIT time_unit_changed();
+               time_unit_changed();
        }
 }
 
@@ -450,7 +472,7 @@ void View::zoom(double steps)
 
 void View::zoom(double steps, int offset)
 {
-       set_zoom(scale_ * pow(3.0/2.0, -steps), offset);
+       set_zoom(scale_ * pow(3.0 / 2.0, -steps), offset);
 }
 
 void View::zoom_fit(bool gui_state)
@@ -539,8 +561,7 @@ 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) {
-               const vector< shared_ptr<Segment> > segments =
-                       d->segments();
+               const vector< shared_ptr<Segment> > segments = d->segments();
                for (const shared_ptr<Segment> &s : segments) {
                        double samplerate = s->samplerate();
                        samplerate = (samplerate <= 0.0) ? 1.0 : samplerate;
@@ -562,43 +583,31 @@ pair<Timestamp, Timestamp> View::get_time_extents() const
        return make_pair(*left_time, *right_time);
 }
 
-void View::enable_sticky_scrolling(bool state)
+void View::enable_show_sampling_points(bool state)
 {
-       sticky_scrolling_ = state;
+       (void)state;
+
+       viewport_->update();
 }
 
-void View::toggle_sticky_scrolling(void)
+void View::enable_show_analog_minor_grid(bool state)
 {
-       sticky_scrolling_ = !sticky_scrolling_;
+       (void)state;
+
+       viewport_->update();
 }
 
 void View::enable_coloured_bg(bool state)
 {
-       const vector<shared_ptr<TraceTreeItem>> items(
-               list_by_type<TraceTreeItem>());
-
-       for (shared_ptr<TraceTreeItem> i : items) {
-               // Can't cast to Trace because it's abstract, so we need to
-               // check for any derived classes individually
-
-               shared_ptr<AnalogSignal> a = dynamic_pointer_cast<AnalogSignal>(i);
-               if (a)
-                       a->set_coloured_bg(state);
-
-               shared_ptr<LogicSignal> l = dynamic_pointer_cast<LogicSignal>(i);
-               if (l)
-                       l->set_coloured_bg(state);
-
-#ifdef ENABLE_DECODE
-               shared_ptr<DecodeTrace> d = dynamic_pointer_cast<DecodeTrace>(i);
-               if (d)
-                       d->set_coloured_bg(state);
-#endif
-       }
-
+       coloured_bg_ = state;
        viewport_->update();
 }
 
+bool View::coloured_bg() const
+{
+       return coloured_bg_;
+}
+
 bool View::cursors_shown() const
 {
        return show_cursors_;
@@ -620,7 +629,7 @@ void View::centre_cursors()
        viewport_->update();
 }
 
-std::shared_ptr<CursorPair> View::cursors() const
+shared_ptr<CursorPair> View::cursors() const
 {
        return cursors_;
 }
@@ -636,15 +645,15 @@ void View::add_flag(const Timestamp& time)
        time_item_appearance_changed(true, true);
 }
 
-void View::remove_flag(std::shared_ptr<Flag> flag)
+void View::remove_flag(shared_ptr<Flag> flag)
 {
        flags_.remove(flag);
        time_item_appearance_changed(true, true);
 }
 
-vector< std::shared_ptr<Flag> > View::flags() const
+vector< shared_ptr<Flag> > View::flags() const
 {
-       vector< std::shared_ptr<Flag> > flags(flags_.begin(), flags_.end());
+       vector< shared_ptr<Flag> > flags(flags_.begin(), flags_.end());
        stable_sort(flags.begin(), flags.end(),
                [](const shared_ptr<Flag> &a, const shared_ptr<Flag> &b) {
                        return a->time() < b->time();
@@ -675,12 +684,6 @@ void View::restack_all_trace_tree_items()
        for (auto &o : sorted_owners)
                o->restack_items();
 
-       // Re-assign background colors
-       bool next_bgcolour_state = 0;
-
-       for (auto &o : sorted_owners)
-               next_bgcolour_state = o->reassign_bgcolour_states(next_bgcolour_state);
-
        // Animate the items to their destination
        for (const auto &i : items)
                i->animate_to_layout_v_offset();
@@ -758,7 +761,7 @@ void View::calculate_tick_spacing()
 
                // Precision is the number of fractional digits required, not
                // taking the prefix into account (and it must never be negative)
-               tick_precision = std::max(ceil(log10(1 / tick_period)).convert_to<int>(), 0);
+               tick_precision = max(ceil(log10(1 / tick_period)).convert_to<int>(), 0);
 
                tick_period_width = (tick_period / scale_).convert_to<double>();
 
@@ -777,11 +780,35 @@ void View::calculate_tick_spacing()
        set_tick_precision(tick_precision);
 }
 
+void View::adjust_top_margin()
+{
+       assert(viewport_);
+
+       const QSize areaSize = viewport_->size();
+
+       const pair<int, int> extents = v_extents();
+       const int top_margin = owner_visual_v_offset() + extents.first;
+       const int trace_bottom = owner_visual_v_offset() + extents.first + extents.second;
+
+       // Do we have empty space at the top while the last trace goes out of screen?
+       if ((top_margin > 0) && (trace_bottom > areaSize.height())) {
+               const int trace_height = extents.second - extents.first;
+
+               // Center everything vertically if there is enough space
+               if (areaSize.height() >= trace_height)
+                       set_v_offset(extents.first -
+                               ((areaSize.height() - trace_height) / 2));
+               else
+                       // Remove the top margin to make as many traces fit on screen as possible
+                       set_v_offset(extents.first);
+       }
+}
+
 void View::update_scroll()
 {
        assert(viewport_);
-       QScrollBar *hscrollbar = scrollarea_.horizontalScrollBar();
-       QScrollBar *vscrollbar = scrollarea_.verticalScrollBar();
+       QScrollBar *hscrollbar = scrollarea_->horizontalScrollBar();
+       QScrollBar *vscrollbar = scrollarea_->verticalScrollBar();
 
        const QSize areaSize = viewport_->size();
 
@@ -826,7 +853,7 @@ void View::update_scroll()
 
 void View::reset_scroll()
 {
-       scrollarea_.verticalScrollBar()->setRange(0, 0);
+       scrollarea_->verticalScrollBar()->setRange(0, 0);
 }
 
 void View::set_scroll_default()
@@ -846,22 +873,41 @@ void View::set_scroll_default()
        else
                // Put the first trace at the top, letting the bottom ones overflow
                set_v_offset(extents.first);
+}
+
+bool View::header_was_shrunk() const
+{
+       const int header_pane_width = splitter_->sizes().front();
+       const int header_width = header_->extended_size_hint().width();
+
+       // 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
+       return (header_pane_width < (header_width - 10));
+}
+
+void View::expand_header_to_fit()
+{
+       int splitter_area_width = 0;
+       for (int w : splitter_->sizes())
+               splitter_area_width += w;
 
-       // If we're not sure whether setting the defaults worked as
-       // the window wasn't set up entirely yet, we want to be called
-       // again later to make sure
-       scroll_needs_defaults_ = !size_finalized_;
+       // Workaround for when the header needs resizing but the view
+       // isn't visible yet and thus splitter_->sizes() returns (0, 0)
+       if (splitter_area_width == 0) {
+               QTimer::singleShot(50, this, SLOT(on_repeat_splitter_expansion()));
+               return;
+       }
+
+       // Make sure the header has enough horizontal space to show all labels fully
+       QList<int> pane_sizes;
+       pane_sizes.push_back(header_->extended_size_hint().width());
+       pane_sizes.push_back(splitter_area_width - header_->extended_size_hint().width());
+       splitter_->setSizes(pane_sizes);
 }
 
 void View::update_layout()
 {
-       scrollarea_.setViewportMargins(
-               header_->sizeHint().width() - Header::BaselineOffset,
-               ruler_->sizeHint().height(), 0, 0);
-       ruler_->setGeometry(viewport_->x(), 0,
-               viewport_->width(), ruler_->extended_size_hint().height());
-       header_->setGeometry(0, viewport_->y(),
-               header_->extended_size_hint().width(), viewport_->height());
        update_scroll();
 }
 
@@ -890,7 +936,7 @@ TraceTreeItemOwner* View::find_prevalent_trace_group(
        size_t max_prevalence = 0;
        TraceTreeItemOwner *prevalent_owner = nullptr;
        for (TraceTreeItemOwner *owner : owners) {
-               const size_t prevalence = std::count_if(
+               const size_t prevalence = count_if(
                        owner_list.begin(), owner_list.end(),
                        [&](TraceTreeItemOwner *o) { return o == owner; });
                if (prevalence > max_prevalence) {
@@ -966,35 +1012,38 @@ bool View::eventFilter(QObject *object, QEvent *event)
        } else if (type == QEvent::Leave) {
                hover_point_ = QPoint(-1, -1);
                hover_point_changed();
+       } else if (type == QEvent::Show) {
+
+               // This is somewhat of a hack, unfortunately. We cannot use
+               // set_v_offset() from within restore_settings() as the view
+               // at that point is neither visible nor properly sized.
+               // This is the least intrusive workaround I could come up
+               // with: set the vertical offset (or scroll defaults) when
+               // the view is shown, which happens after all widgets were
+               // resized to their final sizes.
+               update_layout();
+
+               if (scroll_needs_defaults_) {
+                       set_scroll_default();
+                       scroll_needs_defaults_ = false;
+               }
+
+               if (saved_v_offset_) {
+                       set_v_offset(saved_v_offset_);
+                       saved_v_offset_ = 0;
+               }
        }
 
        return QObject::eventFilter(object, event);
 }
 
-void View::resizeEvent(QResizeEvent*)
+void View::resizeEvent(QResizeEvent* event)
 {
-       update_layout();
-
-       // This is somewhat of a hack, unfortunately. We cannot use
-       // set_v_offset() from within restore_settings() as the view
-       // at that point is neither visible nor properly sized.
-       // This is the least intrusive workaround I could come up
-       // with: set the vertical offset (or scroll defaults) when
-       // the view is visible and resized to its final size.
-       // Resize events that are sent when the view is not visible
-       // must be ignored as they have wrong sizes, potentially
-       // preventing the v offset from being set successfully.
-
-       if (isVisible())
-               size_finalized_ = true;
-
-       if (size_finalized_ && saved_v_offset_) {
-               set_v_offset(saved_v_offset_);
-               saved_v_offset_ = 0;
-       }
+       // Only adjust the top margin if we shrunk vertically
+       if (event->size().height() < event->oldSize().height())
+               adjust_top_margin();
 
-       if (size_finalized_ && scroll_needs_defaults_)
-               set_scroll_default();
+       update_layout();
 }
 
 void View::row_item_appearance_changed(bool label, bool content)
@@ -1007,8 +1056,13 @@ void View::row_item_appearance_changed(bool label, bool content)
 
 void View::time_item_appearance_changed(bool label, bool content)
 {
-       if (label)
+       if (label) {
                ruler_->update();
+
+               // Make sure the header pane width is updated, too
+               update_layout();
+       }
+
        if (content)
                viewport_->update();
 }
@@ -1018,9 +1072,30 @@ void View::extents_changed(bool horz, bool vert)
        sticky_events_ |=
                (horz ? TraceTreeItemHExtentsChanged : 0) |
                (vert ? TraceTreeItemVExtentsChanged : 0);
+
        lazy_event_handler_.start();
 }
 
+void View::on_splitter_moved()
+{
+       // Setting the maximum width of the header widget doesn't work as
+       // expected because the splitter would allow the user to make the
+       // pane wider than that, creating empty space as a result.
+       // To make this work, we stricly enforce the maximum width by
+       // expanding the header unless the user shrunk it on purpose.
+       // As we're then setting the width of the header pane, we set the
+       // splitter to the maximum allowed position.
+       if (!header_was_shrunk())
+               expand_header_to_fit();
+}
+
+void View::on_repeat_splitter_expansion()
+{
+       // Don't mess with the header if settings were restored in the meanwhile
+       if (!settings_restored_)
+               expand_header_to_fit();
+}
+
 void View::h_scroll_value_changed(int value)
 {
        if (updating_scroll_)
@@ -1033,7 +1108,7 @@ void View::h_scroll_value_changed(int value)
                sticky_scrolling_changed(false);
        }
 
-       const int range = scrollarea_.horizontalScrollBar()->maximum();
+       const int range = scrollarea_->horizontalScrollBar()->maximum();
        if (range < MaxScrollValue)
                set_offset(scale_ * value);
        else {
@@ -1063,8 +1138,8 @@ void View::signals_changed()
        // Do we need to set the vertical scrollbar to its default position later?
        // We do if there are no traces, i.e. the scroll bar has no range set
        bool reset_scrollbar =
-               (scrollarea_.verticalScrollBar()->minimum() ==
-                       scrollarea_.verticalScrollBar()->maximum());
+               (scrollarea_->verticalScrollBar()->minimum() ==
+                       scrollarea_->verticalScrollBar()->maximum());
 
        if (!session_.device()) {
                reset_scroll();
@@ -1216,6 +1291,12 @@ void View::signals_changed()
                        offset += extents.second;
        }
 
+
+       if (!new_top_level_items.empty())
+               // Expand the header pane because the header should become fully
+               // visible when new signals are added
+               expand_header_to_fit();
+
        update_layout();
 
        header_->update();
@@ -1241,6 +1322,9 @@ void View::capture_state_updated(int state)
                        always_zoom_to_fit_ = true;
                        always_zoom_to_fit_changed(always_zoom_to_fit_);
                }
+
+               // Enable sticky scrolling if the setting is enabled
+               sticky_scrolling_ = settings.value(GlobalSettings::Key_View_StickyScrolling).toBool();
        }
 
        if (state == Session::Stopped) {
@@ -1258,19 +1342,6 @@ void View::capture_state_updated(int state)
        }
 }
 
-void View::data_updated()
-{
-       if (always_zoom_to_fit_ || sticky_scrolling_) {
-               if (!delayed_view_updater_.isActive())
-                       delayed_view_updater_.start();
-       } else {
-               determine_time_unit();
-               update_scroll();
-               ruler_->update();
-               viewport_->update();
-       }
-}
-
 void View::perform_delayed_view_update()
 {
        if (always_zoom_to_fit_) {