]> sigrok.org Git - pulseview.git/blobdiff - pv/views/trace/analogsignal.cpp
Session: Fix issue #67 by improving error handling
[pulseview.git] / pv / views / trace / analogsignal.cpp
index f64b94ae4d20b4f0791689fa03cfc34544fd93d9..2a50d5716af2aaf9f88c9468b1e00f50f7b76b63 100644 (file)
@@ -71,18 +71,10 @@ namespace pv {
 namespace views {
 namespace trace {
 
-const QColor AnalogSignal::SignalColors[4] = {
-       QColor(0xC4, 0xA0, 0x00),       // Yellow
-       QColor(0x87, 0x20, 0x7A),       // Magenta
-       QColor(0x20, 0x4A, 0x87),       // Blue
-       QColor(0x4E, 0x9A, 0x06)        // Green
-};
-
 const QPen AnalogSignal::AxisPen(QColor(0, 0, 0, 30 * 256 / 100), 2);
 const QColor AnalogSignal::GridMajorColor = QColor(0, 0, 0, 40 * 256 / 100);
 const QColor AnalogSignal::GridMinorColor = QColor(0, 0, 0, 20 * 256 / 100);
 
-const QColor AnalogSignal::SamplingPointColor(0x77, 0x77, 0x77);
 const QColor AnalogSignal::SamplingPointColorLo = QColor(200, 0, 0, 80 * 256 / 100);
 const QColor AnalogSignal::SamplingPointColorNe = QColor(0,   0, 0, 80 * 256 / 100);
 const QColor AnalogSignal::SamplingPointColorHi = QColor(0, 200, 0, 80 * 256 / 100);
@@ -102,22 +94,20 @@ const int AnalogSignal::MaxScaleIndex = 10;  // 1000 units/div
 const int AnalogSignal::InfoTextMarginRight = 20;
 const int AnalogSignal::InfoTextMarginBottom = 5;
 
-AnalogSignal::AnalogSignal(
-       pv::Session &session,
-       shared_ptr<data::SignalBase> base) :
-       Signal(session, base),
+AnalogSignal::AnalogSignal(pv::Session &session, shared_ptr<data::SignalBase> base) :
+       LogicSignal(session, base),
        value_at_hover_pos_(std::numeric_limits<float>::quiet_NaN()),
        scale_index_(4), // 20 per div
        pos_vdivs_(1),
        neg_vdivs_(1),
        resolution_(0),
-       display_type_(DisplayBoth),
+       display_type_(DisplayAnalog),
        autoranging_(true)
 {
        axis_pen_ = AxisPen;
 
        pv::data::Analog* analog_data =
-               dynamic_cast<pv::data::Analog*>(data().get());
+               dynamic_cast<pv::data::Analog*>(base_->analog_data().get());
 
        connect(analog_data, SIGNAL(min_max_changed(float, float)),
                this, SLOT(on_min_max_changed(float, float)));
@@ -135,24 +125,21 @@ AnalogSignal::AnalogSignal(
                settings.value(GlobalSettings::Key_View_ConversionThresholdDispMode).toInt();
        div_height_ = settings.value(GlobalSettings::Key_View_DefaultDivHeight).toInt();
 
-       base_->set_color(SignalColors[base_->index() % countof(SignalColors)]);
+       update_logic_level_offsets();
        update_scale();
 }
 
-shared_ptr<pv::data::SignalData> AnalogSignal::data() const
-{
-       return base_->analog_data();
-}
-
 std::map<QString, QVariant> AnalogSignal::save_settings() const
 {
+       LogicSignal::save_settings();
+
        std::map<QString, QVariant> result;
 
        result["pos_vdivs"] = pos_vdivs_;
        result["neg_vdivs"] = neg_vdivs_;
        result["scale_index"] = scale_index_;
        result["display_type"] = display_type_;
-       result["autoranging"] = pos_vdivs_;
+       result["autoranging"] = autoranging_;
        result["div_height"] = div_height_;
 
        return result;
@@ -160,6 +147,8 @@ std::map<QString, QVariant> AnalogSignal::save_settings() const
 
 void AnalogSignal::restore_settings(std::map<QString, QVariant> settings)
 {
+       LogicSignal::restore_settings(settings);
+
        auto entry = settings.find("pos_vdivs");
        if (entry != settings.end())
                pos_vdivs_ = settings["pos_vdivs"].toInt();
@@ -187,6 +176,9 @@ void AnalogSignal::restore_settings(std::map<QString, QVariant> settings)
                const int old_height = div_height_;
                div_height_ = settings["div_height"].toInt();
 
+               update_logic_level_offsets();
+               update_scale();
+
                if ((div_height_ != old_height) && owner_) {
                        // Call order is important, otherwise the lazy event handler won't work
                        owner_->extents_changed(false, true);
@@ -199,6 +191,7 @@ pair<int, int> AnalogSignal::v_extents() const
 {
        const int ph = pos_vdivs_ * div_height_;
        const int nh = neg_vdivs_ * div_height_;
+
        return make_pair(-ph, nh);
 }
 
@@ -265,32 +258,37 @@ void AnalogSignal::paint_mid(QPainter &p, ViewItemPaintParams &pp)
                paint_grid(p, y, pp.left(), pp.right());
 
                shared_ptr<pv::data::AnalogSegment> segment = get_analog_segment_to_paint();
-               if (!segment || (segment->get_sample_count() == 0))
-                       return;
-
-               const double pixels_offset = pp.pixels_offset();
-               const double samplerate = max(1.0, segment->samplerate());
-               const pv::util::Timestamp& start_time = segment->start_time();
-               const int64_t last_sample = (int64_t)segment->get_sample_count() - 1;
-               const double samples_per_pixel = samplerate * pp.scale();
-               const pv::util::Timestamp start = samplerate * (pp.offset() - start_time);
-               const pv::util::Timestamp end = start + samples_per_pixel * pp.width();
-
-               const int64_t start_sample = min(max(floor(start).convert_to<int64_t>(),
-                       (int64_t)0), last_sample);
-               const int64_t end_sample = min(max((ceil(end) + 1).convert_to<int64_t>(),
-                       (int64_t)0), last_sample);
-
-               if (samples_per_pixel < EnvelopeThreshold)
-                       paint_trace(p, segment, y, pp.left(), start_sample, end_sample,
-                               pixels_offset, samples_per_pixel);
-               else
-                       paint_envelope(p, segment, y, pp.left(), start_sample, end_sample,
-                               pixels_offset, samples_per_pixel);
+
+               if (segment && (segment->get_sample_count() > 0)) {
+                       const double pixels_offset = pp.pixels_offset();
+                       const double samplerate = max(1.0, segment->samplerate());
+                       const pv::util::Timestamp& start_time = segment->start_time();
+                       const int64_t last_sample = (int64_t)segment->get_sample_count() - 1;
+                       const double samples_per_pixel = samplerate * pp.scale();
+                       const pv::util::Timestamp start = samplerate * (pp.offset() - start_time);
+                       const pv::util::Timestamp end = start + samples_per_pixel * pp.width();
+
+                       const int64_t start_sample = min(max(floor(start).convert_to<int64_t>(),
+                               (int64_t)0), last_sample);
+                       const int64_t end_sample = min(max((ceil(end) + 1).convert_to<int64_t>(),
+                               (int64_t)0), last_sample);
+
+                       if (samples_per_pixel < EnvelopeThreshold)
+                               paint_trace(p, segment, y, pp.left(), start_sample, end_sample,
+                                       pixels_offset, samples_per_pixel);
+                       else
+                               paint_envelope(p, segment, y, pp.left(), start_sample, end_sample,
+                                       pixels_offset, samples_per_pixel);
+               }
        }
 
        if ((display_type_ == DisplayConverted) || (display_type_ == DisplayBoth))
-               paint_logic_mid(p, pp);
+               if (base_->logic_data())
+                       LogicSignal::paint_mid(p, pp);
+
+       const QString err = base_->get_error_message();
+       if (!err.isEmpty())
+               paint_error(p, pp);
 }
 
 void AnalogSignal::paint_fore(QPainter &p, ViewItemPaintParams &pp)
@@ -328,10 +326,13 @@ void AnalogSignal::paint_fore(QPainter &p, ViewItemPaintParams &pp)
                                v_extents().second - v_extents().first - InfoTextMarginBottom);
 
                p.drawText(bounding_rect, Qt::AlignRight | Qt::AlignBottom, infotext);
+
+               if (show_hover_marker_)
+                       paint_hover_marker(p);
        }
 
-       if (show_hover_marker_)
-               paint_hover_marker(p);
+       if ((display_type_ == DisplayConverted) || (display_type_ == DisplayBoth))
+               LogicSignal::paint_fore(p, pp);
 }
 
 void AnalogSignal::paint_grid(QPainter &p, int y, int left, int right)
@@ -531,186 +532,6 @@ void AnalogSignal::paint_envelope(QPainter &p,
        delete[] e.samples;
 }
 
-void AnalogSignal::paint_logic_mid(QPainter &p, ViewItemPaintParams &pp)
-{
-       QLineF *line;
-
-       vector< pair<int64_t, bool> > edges;
-
-       assert(base_);
-
-       const int y = get_visual_y();
-
-       if (!base_->enabled() || !base_->logic_data())
-               return;
-
-       const int signal_margin =
-               QFontMetrics(QApplication::font()).height() / 2;
-
-       const int ph = min(pos_vdivs_, 1) * div_height_;
-       const int nh = min(neg_vdivs_, 1) * div_height_;
-       const float high_offset = y - ph + signal_margin + 0.5f;
-       const float low_offset = y + nh - signal_margin - 0.5f;
-       const float signal_height = low_offset - high_offset;
-
-       shared_ptr<pv::data::LogicSegment> segment = get_logic_segment_to_paint();
-       if (!segment || (segment->get_sample_count() == 0))
-               return;
-
-       double samplerate = segment->samplerate();
-
-       // Show sample rate as 1Hz when it is unknown
-       if (samplerate == 0.0)
-               samplerate = 1.0;
-
-       const double pixels_offset = pp.pixels_offset();
-       const pv::util::Timestamp& start_time = segment->start_time();
-       const int64_t last_sample = (int64_t)segment->get_sample_count() - 1;
-       const double samples_per_pixel = samplerate * pp.scale();
-       const double pixels_per_sample = 1 / samples_per_pixel;
-       const pv::util::Timestamp start = samplerate * (pp.offset() - start_time);
-       const pv::util::Timestamp end = start + samples_per_pixel * pp.width();
-
-       const int64_t start_sample = min(max(floor(start).convert_to<int64_t>(),
-               (int64_t)0), last_sample);
-       const uint64_t end_sample = min(max(ceil(end).convert_to<int64_t>(),
-               (int64_t)0), last_sample);
-
-       segment->get_subsampled_edges(edges, start_sample, end_sample,
-               samples_per_pixel / LogicSignal::Oversampling, 0);
-       assert(edges.size() >= 2);
-
-       const float first_sample_x =
-               pp.left() + (edges.front().first / samples_per_pixel - pixels_offset);
-       const float last_sample_x =
-               pp.left() + (edges.back().first / samples_per_pixel - pixels_offset);
-
-       // Check whether we need to paint the sampling points
-       const bool show_sampling_points = show_sampling_points_ && (samples_per_pixel < 0.25);
-       vector<QRectF> sampling_points;
-       float sampling_point_x = first_sample_x;
-       int64_t sampling_point_sample = start_sample;
-       const int w = 2;
-
-       if (show_sampling_points)
-               sampling_points.reserve(end_sample - start_sample + 1);
-
-       vector<QRectF> high_rects;
-       float rising_edge_x;
-       bool rising_edge_seen = false;
-
-       // Paint the edges
-       const unsigned int edge_count = edges.size() - 2;
-       QLineF *const edge_lines = new QLineF[edge_count];
-       line = edge_lines;
-
-       if (edges.front().second) {
-               // Beginning of trace is high
-               rising_edge_x = first_sample_x;
-               rising_edge_seen = true;
-       }
-
-       for (auto i = edges.cbegin() + 1; i != edges.cend() - 1; i++) {
-               // Note: multiple edges occupying a single pixel are represented by an edge
-               // with undefined logic level. This means that only the first falling edge
-               // after a rising edge corresponds to said rising edge - and vice versa. If
-               // more edges with the same logic level follow, they denote multiple edges.
-
-               const float x = pp.left() + ((*i).first / samples_per_pixel - pixels_offset);
-               *line++ = QLineF(x, high_offset, x, low_offset);
-
-               if (fill_high_areas_) {
-                       // Any edge terminates a high area
-                       if (rising_edge_seen) {
-                               const int width = x - rising_edge_x;
-                               if (width > 0)
-                                       high_rects.emplace_back(rising_edge_x, high_offset,
-                                               width, signal_height);
-                               rising_edge_seen = false;
-                       }
-
-                       // Only rising edges start high areas
-                       if ((*i).second) {
-                               rising_edge_x = x;
-                               rising_edge_seen = true;
-                       }
-               }
-
-               if (show_sampling_points)
-                       while (sampling_point_sample < (*i).first) {
-                               const float y = (*i).second ? low_offset : high_offset;
-                               sampling_points.emplace_back(
-                                       QRectF(sampling_point_x - (w / 2), y - (w / 2), w, w));
-                               sampling_point_sample++;
-                               sampling_point_x += pixels_per_sample;
-                       };
-       }
-
-       // Calculate the sample points from the last edge to the end of the trace
-       if (show_sampling_points)
-               while ((uint64_t)sampling_point_sample <= end_sample) {
-                       // Signal changed after the last edge, so the level is inverted
-                       const float y = (edges.cend() - 1)->second ? high_offset : low_offset;
-                       sampling_points.emplace_back(
-                               QRectF(sampling_point_x - (w / 2), y - (w / 2), w, w));
-                       sampling_point_sample++;
-                       sampling_point_x += pixels_per_sample;
-               };
-
-       if (fill_high_areas_) {
-               // Add last high rectangle if the signal is still high at the end of the trace
-               if (rising_edge_seen && (edges.cend() - 1)->second)
-                       high_rects.emplace_back(rising_edge_x, high_offset,
-                               last_sample_x - rising_edge_x, signal_height);
-
-               p.setPen(high_fill_color_);
-               p.setBrush(high_fill_color_);
-               p.drawRects((const QRectF*)(high_rects.data()), high_rects.size());
-       }
-
-       p.setPen(LogicSignal::EdgeColor);
-       p.drawLines(edge_lines, edge_count);
-       delete[] edge_lines;
-
-       // Paint the caps
-       const unsigned int max_cap_line_count = edges.size();
-       QLineF *const cap_lines = new QLineF[max_cap_line_count];
-
-       p.setPen(LogicSignal::HighColor);
-       paint_logic_caps(p, cap_lines, edges, true, samples_per_pixel,
-               pixels_offset, pp.left(), high_offset);
-       p.setPen(LogicSignal::LowColor);
-       paint_logic_caps(p, cap_lines, edges, false, samples_per_pixel,
-               pixels_offset, pp.left(), low_offset);
-
-       delete[] cap_lines;
-
-       // Paint the sampling points
-       if (show_sampling_points) {
-               p.setPen(SamplingPointColor);
-               p.drawRects(sampling_points.data(), sampling_points.size());
-       }
-}
-
-void AnalogSignal::paint_logic_caps(QPainter &p, QLineF *const lines,
-       vector< pair<int64_t, bool> > &edges, bool level,
-       double samples_per_pixel, double pixels_offset, float x_offset,
-       float y_offset)
-{
-       QLineF *line = lines;
-
-       for (auto i = edges.begin(); i != (edges.end() - 1); i++)
-               if ((*i).second == level) {
-                       *line++ = QLineF(
-                               ((*i).first / samples_per_pixel -
-                                       pixels_offset) + x_offset, y_offset,
-                               ((*(i+1)).first / samples_per_pixel -
-                                       pixels_offset) + x_offset, y_offset);
-               }
-
-       p.drawLines(lines, line - lines);
-}
-
 shared_ptr<pv::data::AnalogSegment> AnalogSignal::get_analog_segment_to_paint() const
 {
        shared_ptr<pv::data::AnalogSegment> segment;
@@ -723,7 +544,7 @@ shared_ptr<pv::data::AnalogSegment> AnalogSignal::get_analog_segment_to_paint()
                        segment = segments.back();
 
                if ((segment_display_mode_ == ShowSingleSegmentOnly) ||
-                               (segment_display_mode_ == ShowLastCompleteSegmentOnly)) {
+                       (segment_display_mode_ == ShowLastCompleteSegmentOnly)) {
                        try {
                                segment = segments.at(current_segment_);
                        } catch (out_of_range&) {
@@ -735,30 +556,6 @@ shared_ptr<pv::data::AnalogSegment> AnalogSignal::get_analog_segment_to_paint()
        return segment;
 }
 
-shared_ptr<pv::data::LogicSegment> AnalogSignal::get_logic_segment_to_paint() const
-{
-       shared_ptr<pv::data::LogicSegment> segment;
-
-       const deque< shared_ptr<pv::data::LogicSegment> > &segments =
-               base_->logic_data()->logic_segments();
-
-       if (!segments.empty()) {
-               if (segment_display_mode_ == ShowLastSegmentOnly)
-                       segment = segments.back();
-
-               if ((segment_display_mode_ == ShowSingleSegmentOnly) ||
-                               (segment_display_mode_ == ShowLastCompleteSegmentOnly)) {
-                       try {
-                               segment = segments.at(current_segment_);
-                       } catch (out_of_range&) {
-                               qDebug() << "Current logic segment out of range for signal" << base_->name() << ":" << current_segment_;
-                       }
-               }
-       }
-
-       return segment;
-}
-
 float AnalogSignal::get_resolution(int scale_index)
 {
        const float seq[] = {1.0f, 2.0f, 5.0f};
@@ -776,6 +573,17 @@ void AnalogSignal::update_scale()
        scale_ = div_height_ / resolution_;
 }
 
+void AnalogSignal::update_logic_level_offsets()
+{
+       const int signal_margin = QFontMetrics(QApplication::font()).height() / 2;
+
+       const int ph = min(pos_vdivs_, 1) * div_height_;
+       const int nh = min(neg_vdivs_, 1) * div_height_;
+
+       high_level_offset_ = -ph + signal_margin + 0.5f;
+       low_level_offset_  =  nh - signal_margin - 0.5f;
+}
+
 void AnalogSignal::update_conversion_widgets()
 {
        SignalBase::ConversionType conv_type = base_->get_conversion_type();
@@ -888,16 +696,18 @@ void AnalogSignal::perform_autoranging(bool keep_divs, bool force_update)
                }
        }
 
+       const bool showing_logic = (display_type_ == DisplayConverted) || (display_type_ == DisplayBoth);
+
        // If there is still no positive div when we need it, add one
        // (this can happen when pos_vdivs==neg_vdivs==0)
-       if ((max > 0) && (pos_vdivs_ == 0)) {
+       if (((max > 0) && (pos_vdivs_ == 0)) || showing_logic) {
                pos_vdivs_ = 1;
                owner_->extents_changed(false, true);
        }
 
        // If there is still no negative div when we need it, add one
        // (this can happen when pos_vdivs was 0 or 1 when trying to split)
-       if ((min < 0) && (neg_vdivs_ == 0)) {
+       if (((min < 0) && (neg_vdivs_ == 0)) || showing_logic) {
                neg_vdivs_ = 1;
                owner_->extents_changed(false, true);
        }
@@ -987,6 +797,7 @@ void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
        pvdiv_sb_ = new QSpinBox(parent);
        pvdiv_sb_->setRange(0, MaximumVDivs);
        pvdiv_sb_->setValue(pos_vdivs_);
+       pvdiv_sb_->setEnabled(!autoranging_);
        connect(pvdiv_sb_, SIGNAL(valueChanged(int)),
                this, SLOT(on_pos_vdivs_changed(int)));
        form->addRow(tr("Number of pos vertical divs"), pvdiv_sb_);
@@ -994,6 +805,7 @@ void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
        nvdiv_sb_ = new QSpinBox(parent);
        nvdiv_sb_->setRange(0, MaximumVDivs);
        nvdiv_sb_->setValue(neg_vdivs_);
+       nvdiv_sb_->setEnabled(!autoranging_);
        connect(nvdiv_sb_, SIGNAL(valueChanged(int)),
                this, SLOT(on_neg_vdivs_changed(int)));
        form->addRow(tr("Number of neg vertical divs"), nvdiv_sb_);
@@ -1009,6 +821,7 @@ void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
 
        // Add the vertical resolution
        resolution_cb_ = new QComboBox(parent);
+       resolution_cb_->setEnabled(!autoranging_);
 
        for (int i = MinScaleIndex; i < MaxScaleIndex; i++) {
                const QString label = QString("%1").arg(get_resolution(i));
@@ -1160,6 +973,8 @@ void AnalogSignal::on_pos_vdivs_changed(int vdivs)
                }
        }
 
+       update_logic_level_offsets();
+
        if (owner_) {
                // Call order is important, otherwise the lazy event handler won't work
                owner_->extents_changed(false, true);
@@ -1191,6 +1006,8 @@ void AnalogSignal::on_neg_vdivs_changed(int vdivs)
                }
        }
 
+       update_logic_level_offsets();
+
        if (owner_) {
                // Call order is important, otherwise the lazy event handler won't work
                owner_->extents_changed(false, true);
@@ -1201,6 +1018,7 @@ void AnalogSignal::on_neg_vdivs_changed(int vdivs)
 void AnalogSignal::on_div_height_changed(int height)
 {
        div_height_ = height;
+       update_logic_level_offsets();
        update_scale();
 
        if (owner_) {
@@ -1223,6 +1041,13 @@ void AnalogSignal::on_autoranging_changed(int state)
 {
        autoranging_ = (state == Qt::Checked);
 
+       if (pvdiv_sb_)
+               pvdiv_sb_->setEnabled(!autoranging_);
+       if (nvdiv_sb_)
+               nvdiv_sb_->setEnabled(!autoranging_);
+       if (resolution_cb_)
+               resolution_cb_->setEnabled(!autoranging_);
+
        if (autoranging_)
                perform_autoranging(false, true);
 
@@ -1244,6 +1069,11 @@ void AnalogSignal::on_conversion_changed(int index)
                base_->set_conversion_type(conv_type);
                update_conversion_widgets();
 
+               if (conv_type == SignalBase::ConversionType::NoConversion)
+                       on_display_type_changed(DisplayType::DisplayAnalog);
+               else
+                       on_display_type_changed(DisplayType::DisplayBoth);
+
                if (owner_)
                        owner_->row_item_appearance_changed(false, true);
        }
@@ -1271,13 +1101,20 @@ void AnalogSignal::on_conv_threshold_changed(int index)
                // https://txt2re.com/index-c++.php3?s=0.1V&1&-13
                QString re1 = "([+-]?\\d*[\\.,]?\\d*)"; // Float value
                QString re2 = "([a-zA-Z]*)"; // SI unit
-               QRegExp regex(re1 + re2);
-
                const QString text = conv_threshold_cb_->currentText();
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+               QRegularExpression regex(re1 + re2);
+               if (!regex.match(text).hasMatch())
+                       return;  // String doesn't match the regex
+
+               QStringList tokens = regex.match(text).capturedTexts();
+#else
+               QRegExp regex(re1 + re2);
                if (!regex.exactMatch(text))
                        return;  // String doesn't match the regex
 
                QStringList tokens = regex.capturedTexts();
+#endif
 
                // For now, we simply assume that the unit is volt without modifiers
                const double thr = tokens.at(1).toDouble();
@@ -1298,13 +1135,22 @@ void AnalogSignal::on_conv_threshold_changed(int index)
                QString re3 = "\\/"; // Forward slash, not captured
                QString re4 = "([+-]?\\d*[\\.,]?\\d*)"; // Float value
                QString re5 = "([a-zA-Z]*)"; // SI unit
+               const QString text = conv_threshold_cb_->currentText();
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+               QRegularExpression regex(re1 + re2 + re3 + re4 + re5);
+
+               if (!regex.match(text).hasMatch())
+                       return;  // String doesn't match the regex
+
+               QStringList tokens = regex.match(text).capturedTexts();
+#else
                QRegExp regex(re1 + re2 + re3 + re4 + re5);
 
-               const QString text = conv_threshold_cb_->currentText();
                if (!regex.exactMatch(text))
                        return;  // String doesn't match the regex
 
                QStringList tokens = regex.capturedTexts();
+#endif
 
                // For now, we simply assume that the unit is volt without modifiers
                const double low_thr = tokens.at(1).toDouble();
@@ -1334,8 +1180,21 @@ void AnalogSignal::on_delayed_conversion_starter()
 
 void AnalogSignal::on_display_type_changed(int index)
 {
+       const bool prev_showing_logic = (display_type_ == DisplayConverted) || (display_type_ == DisplayBoth);
+
        display_type_ = (DisplayType)(display_type_cb_->itemData(index).toInt());
 
+       const bool showing_logic = (display_type_ == DisplayConverted) || (display_type_ == DisplayBoth);
+
+       // If we show a logic trace, make sure we have at least one div for each
+       // polarity as that's where we paint it
+       if (showing_logic && !prev_showing_logic) {
+               if (pos_vdivs_ == 0)
+                       on_pos_vdivs_changed(1);
+               if (neg_vdivs_ == 0)
+                       on_neg_vdivs_changed(1);
+       }
+
        if (owner_)
                owner_->row_item_appearance_changed(false, true);
 }