cabana: fix sparkline glitch (#30320)

fix glitch

tools/cabana/signalview.cc

@@ -447,7 +447,7 @@ SignalView::SignalView(ChartsWidget *charts, QWidget *parent) : charts(charts),
   QRegularExpression re("\\S+");
   filter_edit->setValidator(new QRegularExpressionValidator(re, this));
   filter_edit->setClearButtonEnabled(true);
-  filter_edit->setPlaceholderText(tr("filter signals"));
+  filter_edit->setPlaceholderText(tr("Filter Signal"));
   hl->addWidget(filter_edit);
   hl->addStretch(1);
 
@@ -502,6 +502,12 @@ SignalView::SignalView(ChartsWidget *charts, QWidget *parent) : charts(charts),
   QObject::connect(tree->verticalScrollBar(), &QScrollBar::valueChanged, [this]() { updateState(); });
   QObject::connect(tree->verticalScrollBar(), &QScrollBar::rangeChanged, [this]() { updateState(); });
   QObject::connect(can, &AbstractStream::msgsReceived, this, &SignalView::updateState);
+  QObject::connect(tree->header(), &QHeaderView::sectionResized, [this](int logicalIndex, int oldSize, int newSize) {
+    if (logicalIndex == 1) {
+      value_column_width = newSize - delegate->button_size.width();
+      updateState();
+    }
+  });
 
   setWhatsThis(tr(R"(
     <b>Signal view</b><br />
@@ -638,11 +644,10 @@ void SignalView::updateState(const QHash<MessageId, CanData> *msgs) {
       last_visible_row = bottom.parent().isValid() ? bottom.parent().row() : bottom.row();
     }
 
-    QSize size(tree->columnWidth(1) - delegate->button_size.width(), delegate->button_size.height());
-    int min_max_width = std::min(size.width() - 10, QFontMetrics(delegate->minmax_font).width("-000.00") + 5);
-    int value_width = std::min<int>(max_value_width, size.width() * 0.35);
-    size -= {value_width + min_max_width, style()->pixelMetric(QStyle::PM_FocusFrameVMargin) * 2};
-
+    const static int min_max_width = QFontMetrics(delegate->minmax_font).width("-000.00") + 5;
+    int value_width = std::min<int>(max_value_width + min_max_width, value_column_width / 2);
+    QSize size(value_column_width - value_width,
+               delegate->button_size.height() - style()->pixelMetric(QStyle::PM_FocusFrameVMargin) * 2);
     QFutureSynchronizer<void> synchronizer;
     for (int i = first_visible_row; i <= last_visible_row; ++i) {
       auto item = model->getItem(model->index(i, 1));

tools/cabana/signalview.h

@@ -136,6 +136,7 @@ private:
     }
   };
   int max_value_width = 0;
+  int value_column_width = 0;
   TreeView *tree;
   QLabel *sparkline_label;
   QSlider *sparkline_range_slider;