Fixed triggering mode change when acquiring

src/plot_host.cpp

@@ -143,7 +143,7 @@ int RowSet::channel_of(int row_index, int slot) const {
   return row(row_index).channel[static_cast<std::size_t>(slot)];
 }
 
-void RowSet::bind(ScopeModel& model) {
+void RowSet::bind(ScopeModel& model, DisplayMode mode) {
   const std::vector<SignalInfo>& signals = model.signals();
   const std::vector<ChannelInfo>& channels = model.channels();
   for (int i = 0; i < kMaxRows; ++i) {
@@ -181,20 +181,26 @@ void RowSet::bind(ScopeModel& model) {
         r.slots[si].bind(nullptr);
         continue;
       }
-      // In trigger mode the trace shows the captured event and nothing else: the
-      // last one latched, or nothing at all before the first. Never the live ring,
-      // not even while the post window is filling -- a frozen picture that only
-      // changes on an event is the whole point of trigger mode, and binding the
-      // live ring mid-capture made the plot scroll for most of every event cycle.
+      // The source is the frame's one `DisplayMode`, decided by the caller: `Held` is
+      // the frozen snapshot, `Waiting` is blank (armed, nothing captured yet), and both
+      // `Live` and `Capturing` are the live ring -- what differs between those two is
+      // the *clock*, which the display epoch carries, not the binding.
       const std::size_t ci = static_cast<std::size_t>(channel);
-      if (model.trigger_enabled()) {
-        if (auto snap = model.event()) {
-          r.slots[si].bind_event(std::move(snap), ci);
-        } else {
-          r.slots[si].bind(nullptr);  // armed, waiting for the first event: blank
-        }
-      } else {
-        r.slots[si].bind(model.live().shared_channel(ci));
+      switch (mode) {
+        case DisplayMode::Held:
+          if (auto snap = model.event()) {
+            r.slots[si].bind_event(std::move(snap), ci);
+          } else {
+            r.slots[si].bind(nullptr);
+          }
+          break;
+        case DisplayMode::Waiting:
+          r.slots[si].bind(nullptr);
+          break;
+        case DisplayMode::Live:
+        case DisplayMode::Capturing:
+          r.slots[si].bind(model.live().shared_channel(ci));
+          break;
       }
     }
   }