DecodeTrace: Let the view know when we need more space

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

diff --git a/pv/view/decodetrace.cpp b/pv/view/decodetrace.cpp
index 19decfd4928420f484cf213c8329f0899dd068cd..c2369e866fbe3b7286c602adc41735ed1c6a579b 100644 (file)
--- a/pv/view/decodetrace.cpp
+++ b/pv/view/decodetrace.cpp
@@ -141,6 +141,10 @@ DecodeTrace::DecodeTrace(pv::Session &session,
 {
        assert(decoder_stack_);
 
+       // Determine shortest string we want to see displayed in full
+       QFontMetrics m(QApplication::font());
+       min_useful_label_width_ = m.width("XX"); // e.g. two hex characters
+
        set_colour(DecodeColours[index % countof(DecodeColours)]);
 
        connect(decoder_stack_.get(), SIGNAL(new_decode_data()),
@@ -165,7 +169,10 @@ pair<int, int> DecodeTrace::v_extents() const
 {
        const int row_height = (ViewItemPaintParams::text_height() * 6) / 4;
 
-       return make_pair(-row_height, row_height * max_visible_rows_);
+       // Make an empty decode trace appear symmetrical
+       const int row_count = max(1, max_visible_rows_);
+
+       return make_pair(-row_height, row_height * row_count);
 }
 
 void DecodeTrace::paint_back(QPainter &p, const ViewItemPaintParams &pp)
@@ -191,6 +198,9 @@ void DecodeTrace::paint_mid(QPainter &p, const ViewItemPaintParams &pp)
                return;
        }
 
+       // Set default pen to allow for text width calculation
+       p.setPen(Qt::black);
+
        // Iterate through the rows
        int y = get_visual_y();
        pair<uint64_t, uint64_t> sample_range = get_sample_range(
@@ -235,6 +245,9 @@ void DecodeTrace::paint_mid(QPainter &p, const ViewItemPaintParams &pp)
        // Draw the hatching
        draw_unresolved_period(p, annotation_height, pp.left(), pp.right());
 
+       if ((int)visible_rows_.size() > max_visible_rows_)
+               owner_->extents_changed(false, true);
+
        // Update the maximum row count if needed
        max_visible_rows_ = std::max(max_visible_rows_, (int)visible_rows_.size());
 }
@@ -373,7 +386,7 @@ void DecodeTrace::draw_annotations(vector<pv::data::decode::Annotation> annotati
                bool a_is_separate = false;
 
                // Annotation wider than the threshold for a useful label width?
-               if (a_width > 20) {
+               if (a_width >= min_useful_label_width_) {
                        for (const QString &ann_text : a.annotations()) {
                                const int w = p.boundingRect(QRectF(), 0, ann_text).width();
                                // Annotation wide enough to fit a label? Don't put it in a block then