Implement autoranging for analog channels

[pulseview.git] / pv / view / analogsignal.cpp

diff --git a/pv/view/analogsignal.cpp b/pv/view/analogsignal.cpp
index bf1f9017731f679f73d9a836ea706efc47722557..07fb0ef89fa8ab59c2930c5be11972388377f0cd 100644 (file)
--- a/pv/view/analogsignal.cpp
+++ b/pv/view/analogsignal.cpp
@@ -25,6 +25,7 @@
 #include <limits>
 
 #include <QApplication>
+#include <QCheckBox>
 #include <QComboBox>
 #include <QFormLayout>
 #include <QGridLayout>
@@ -78,7 +79,8 @@ AnalogSignal::AnalogSignal(
        div_height_(3 * QFontMetrics(QApplication::font()).height()),
        pos_vdivs_(1),
        neg_vdivs_(1),
-       resolution_(0)
+       resolution_(0),
+       autoranging_(1)
 {
        base_->set_colour(SignalColours[base_->index() % countof(SignalColours)]);
        update_scale();
@@ -94,6 +96,7 @@ void AnalogSignal::save_settings(QSettings &settings) const
        settings.setValue("pos_vdivs", pos_vdivs_);
        settings.setValue("neg_vdivs", neg_vdivs_);
        settings.setValue("scale_index", scale_index_);
+       settings.setValue("autoranging", autoranging_);
 }
 
 void AnalogSignal::restore_settings(QSettings &settings)
@@ -108,6 +111,9 @@ void AnalogSignal::restore_settings(QSettings &settings)
                scale_index_ = settings.value("scale_index").toInt();
                update_scale();
        }
+
+       if (settings.contains("autoranging"))
+               autoranging_ = settings.value("autoranging").toBool();
 }
 
 std::pair<int, int> AnalogSignal::v_extents() const
@@ -348,6 +354,53 @@ void AnalogSignal::update_scale()
        scale_ = div_height_ / resolution_;
 }
 
+void AnalogSignal::perform_autoranging(bool force_update)
+{
+       const deque< shared_ptr<pv::data::AnalogSegment> > &segments =
+               base_->analog_data()->analog_segments();
+
+       if (segments.empty())
+               return;
+
+       static double prev_min = 0, prev_max = 0;
+       double min = 0, max = 0;
+
+       for (shared_ptr<pv::data::AnalogSegment> segment : segments) {
+               std::pair<double, double> mm = segment->get_min_max();
+               min = std::min(min, mm.first);
+               max = std::max(max, mm.second);
+       }
+
+       if ((min == prev_min) && (max == prev_max) && !force_update)
+               return;
+
+       prev_min = min;
+       prev_max = max;
+
+       // Use all divs for the positive range if there are no negative values
+       if ((min == 0) && (neg_vdivs_ > 0)) {
+               pos_vdivs_ += neg_vdivs_;
+               neg_vdivs_ = 0;
+       }
+
+       double min_value_per_div;
+       if ((pos_vdivs_ > 0) && (neg_vdivs_ >  0))
+               min_value_per_div = std::max(max / pos_vdivs_, -min / neg_vdivs_);
+       else if (pos_vdivs_ > 0)
+               min_value_per_div = max / pos_vdivs_;
+       else
+               min_value_per_div = -min / neg_vdivs_;
+
+       // Find first scale value that is bigger than the value we need
+       for (int i = MinScaleIndex; i < MaxScaleIndex; i++)
+               if (get_resolution(i) > min_value_per_div) {
+                       scale_index_ = i;
+                       break;
+               }
+
+       update_scale();
+}
+
 void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
 {
        // Add the standard options
@@ -391,6 +444,15 @@ void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
 
        layout->addRow(tr("Vertical resolution"), vdiv_layout);
 
+       // Add the autoranging checkbox
+       QCheckBox* autoranging_cb = new QCheckBox();
+       autoranging_cb->setCheckState(autoranging_ ? Qt::Checked : Qt::Unchecked);
+
+       connect(autoranging_cb, SIGNAL(stateChanged(int)),
+               this, SLOT(on_autoranging_changed(int)));
+
+       layout->addRow(tr("Autoranging"), autoranging_cb);
+
        form->addRow(layout);
 }
 
@@ -398,6 +460,9 @@ void AnalogSignal::on_pos_vdivs_changed(int vdivs)
 {
        pos_vdivs_ = vdivs;
 
+       if (autoranging_)
+               perform_autoranging(true);
+
        if (owner_) {
                // Call order is important, otherwise the lazy event handler won't work
                owner_->extents_changed(false, true);
@@ -409,6 +474,9 @@ void AnalogSignal::on_neg_vdivs_changed(int vdivs)
 {
        neg_vdivs_ = vdivs;
 
+       if (autoranging_)
+               perform_autoranging(true);
+
        if (owner_) {
                // Call order is important, otherwise the lazy event handler won't work
                owner_->extents_changed(false, true);
@@ -425,6 +493,17 @@ void AnalogSignal::on_resolution_changed(int index)
                owner_->row_item_appearance_changed(false, true);
 }
 
+void AnalogSignal::on_autoranging_changed(int state)
+{
+       autoranging_ = (state == Qt::Checked);
+
+       if (autoranging_)
+               perform_autoranging(true);
+
+       if (owner_)
+               owner_->row_item_appearance_changed(false, true);
+}
+
 } // namespace TraceView
 } // namespace views
 } // namespace pv