source: capability panels as side-stack pages, with a probe for the path

CMakeLists.txt

@@ -263,6 +263,7 @@ add_executable(udpscope
   src/ui_cursors.cpp
   src/ui_math.cpp
   src/ui_layout.cpp
+  src/ui_source.cpp
   src/ui_trigger.cpp
   src/ui_signals.cpp
   src/ui_context_help.cpp

src/source/probe_source.cpp

@@ -128,6 +128,34 @@ class ProbeKind final : public SourceKind {
     f.on_change = [cb](std::function<void()> fn) { *cb = std::move(fn); };
     return f;
   }
+
+  std::vector<SourcePanel> make_panels(DataSource& source) const override {
+    GtkWidget* box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 6);
+    gtk_widget_set_margin_top(box, 12);
+    gtk_widget_set_margin_bottom(box, 12);
+    gtk_widget_set_margin_start(box, 12);
+    gtk_widget_set_margin_end(box, 12);
+    GtkWidget* label = gtk_label_new("Test panel");
+    gtk_widget_set_halign(label, GTK_ALIGN_START);
+    gtk_box_append(GTK_BOX(box), label);
+    // The probe finds the button as the box's last child. It reaches the source only through
+    // `post()`: the command runs inside the next `poll()`, on the producer thread.
+    GtkWidget* poke = gtk_button_new_with_label("Poke");
+    gtk_box_append(GTK_BOX(box), poke);
+    DataSource* src = &source;
+    g_signal_connect_data(
+        poke, "clicked",
+        G_CALLBACK(+[](GtkButton*, gpointer user) {
+          DataSource* s = static_cast<DataSource*>(user);
+          s->post([s] { static_cast<ProbeSource*>(s)->note_applied(); });
+        }),
+        src, nullptr, static_cast<GConnectFlags>(0));
+    SourcePanel p;
+    p.id = "poke";
+    p.title = "Probe";
+    p.widget = box;
+    return {p};
+  }
 };
 
 }  // namespace

src/ui.cpp

@@ -2978,9 +2978,14 @@ std::string icon_report(GtkIconTheme* theme, const char* name, const char* resou
 /// The words the pills do not draw. The pages' `title` is empty on purpose (see the `.ui`), so the
 /// human name of a tab lives here and is put on the pill — its tooltip and its accessible name — by
 /// `name_side_tabs()`. That keeps an icon-only pill a *named* control for a screen reader.
-static const char* side_tab_title(const char* name) {
+static const char* side_tab_title(const App& app, const char* name) {
   if (name != nullptr && std::strcmp(name, "measure") == 0) return "Measure";
   if (name != nullptr && std::strcmp(name, "signals") == 0) return "Signals";
+  if (name != nullptr) {
+    for (const SourcePanelPage& p : app.source_panels) {
+      if (p.name == name) return p.title.c_str();
+    }
+  }
   return "";
 }
 
@@ -3000,7 +3005,7 @@ void name_side_tabs(App& app) {
   for (guint i = 0; pages != nullptr && pill != nullptr && i < g_list_model_get_n_items(pages);
        pill = gtk_widget_get_next_sibling(pill), ++i) {
     AdwViewStackPage* page = ADW_VIEW_STACK_PAGE(g_list_model_get_item(pages, i));
-    const char* title = side_tab_title(adw_view_stack_page_get_name(page));
+    const char* title = side_tab_title(app, adw_view_stack_page_get_name(page));
     g_object_unref(page);
     if (title[0] == '\0') continue;
     gtk_widget_set_tooltip_text(pill, title);
@@ -3457,6 +3462,7 @@ gboolean tick(gpointer user) {
   // no text and no name either.
   name_side_tabs(*app);
   note_panel_controls(*app);
+  sync_source_panels(*app);
   // The tour, re-measured every frame: the target's allocation is 0 on the frame it is first shown
   // (see the allocation bullets in `docs/claude/invariants-trigger-and-pinning.md`) and the widget
   // moves under the spotlight on a window resize, so a one-shot measurement is wrong both ways.
@@ -4551,7 +4557,8 @@ gboolean tick(gpointer user) {
   }
   if (app->capture_button != nullptr) {
     // Insensitive until connected: the capture's path is keyed on the source.
-    gtk_widget_set_sensitive(app->capture_button, snap.connected ? TRUE : FALSE);
+    gtk_widget_set_sensitive(app->capture_button,
+                             snap.connected && app->source_has_datagrams ? TRUE : FALSE);
     if (app->capture_want_ui && !app->acq->capture_want()) {
       // The producer refused the open (a full disk, a read-only directory) and cleared
       // the flag; the button follows the flag rather than lying about the state. Going
@@ -5282,6 +5289,9 @@ void on_activate(GtkApplication* application, gpointer user) {
     g_signal_connect(app->side_stack, "notify::visible-child-name",
                      G_CALLBACK(on_side_tab_changed), app);
   }
+  // The source kind's own tabs (a generator, digital I/O). Before the first tick: that is when
+  // `name_side_tabs()` puts the words on the pills, and it must see these pages too.
+  build_source_panels(*app);
 
   // The left side is the events pane *and* the plot, in one row: the pane is a column of its own
   // (the item's "collapsable pane on the left"), revealed by trigger mode.
@@ -5926,6 +5936,7 @@ int run_ui(int argc, char** argv, const Config& cfg, ScopeModel& model, Acquisit
   } else {
     app.source_title = app.source_host + ":" + std::to_string(app.source_port);
   }
+  if (SourceKind* k = find_kind(cfg.source_kind)) app.source_has_datagrams = k->has_datagrams();
   // The event cache is keyed on the source, like the packet capture. A waveform has no source, so a
   // file-mode run has no cache either -- there are no latches in a file.
   if (!app.source_host.empty() && app.source_port != 0) {
@@ -6098,6 +6109,9 @@ int run_ui(int argc, char** argv, const Config& cfg, ScopeModel& model, Acquisit
   if (const char* env = g_getenv("UDPSCOPE_PROBE_DENSITY_MS")) {
     g_timeout_add(static_cast<guint>(std::atoi(env)), density_probe, &app);
   }
+  if (const char* env = g_getenv("UDPSCOPE_PROBE_SOURCE_KINDS")) {
+    g_timeout_add(static_cast<guint>(std::atoi(env)), source_kinds_probe, &app);
+  }
 
   // Our own options were consumed by parse_args(); GTK would reject them, so only
   // the program name is handed to g_application_run().

src/ui_app.hpp

@@ -109,6 +109,14 @@ struct TourView {
   void* done_user = nullptr;
 };
 
+/// One capability panel a source kind contributed to the side stack. `content` is the kind's own widget
+/// (made insensitive while the source is disconnected); the page wrapping it is named `name`.
+struct SourcePanelPage {
+  std::string name;   ///< stack page name: "source-" + the kind's panel id
+  std::string title;  ///< the pill's tooltip and accessible name; the page's own title stays empty
+  GtkWidget* content = nullptr;
+};
+
 struct App {
   ScopeModel* model = nullptr;
   Acquisition* acq = nullptr;
@@ -843,6 +851,9 @@ struct App {
   std::string source_kind = "udps";
   SourceConfig source_opts;
   std::string source_title;
+  /// The panels the source kind added to `side_stack`, in tab order. Empty for UDPS and in file mode.
+  std::vector<SourcePanelPage> source_panels;
+  bool source_has_datagrams = true;  ///< the kind reports raw datagrams; false leaves the capture button disabled
   guint layout_save_source = 0;
   bool layout_loaded = false;
   unsigned signal_generation = ~0u;
@@ -1558,6 +1569,14 @@ void on_config_save_as(GtkButton*, gpointer user);
 void config_dialog_refresh(ConfigDialog& d);
 void open_configurations(App& app);
 void save_layout_now(App& app);
+
+/// Capability panels (`src/ui_source.cpp`). `build_source_panels` adds the source kind's panels as
+/// pages of `side_stack`, once, before the first tick. `apply_source_panels` sets every panel's
+/// sensitivity from `connected` -- disabled, never hidden: the tab switcher owns visibility.
+/// `sync_source_panels` is the per-tick call: it applies the model's own connection flag.
+void build_source_panels(App& app);
+void apply_source_panels(App& app, bool connected);
+void sync_source_panels(App& app);
 bool save_configuration_as(App& app, const std::string& name, const std::string& comment);
 gboolean layout_save_tick(gpointer user);
 void schedule_layout_save(App& app);
@@ -1855,6 +1874,8 @@ gboolean stats_probe_report(gpointer user);
 gboolean stats_probe(gpointer user);
 gboolean side_tab_probe_report(gpointer user);
 gboolean side_tab_probe(gpointer user);
+gboolean source_kinds_probe_report(gpointer user);
+gboolean source_kinds_probe(gpointer user);
 gboolean pan_probe(gpointer user);
 gboolean arm_probe(gpointer user);
 gboolean trigrenum_probe_step3(gpointer user);

src/ui_probe.cpp

@@ -6,6 +6,8 @@
 // automated check, and they are code of their own -- a third of what used to be `ui.cpp` -- so they
 // live in a translation unit of their own.
 
+#include "source/probe_source.hpp"
+#include "source/registry.hpp"
 #include "ui_app.hpp"
 
 #include <sys/stat.h>
@@ -1887,6 +1889,97 @@ gboolean side_tab_probe(gpointer user) {
   return G_SOURCE_REMOVE;
 }
 
+namespace {
+std::uint64_t g_source_kinds_before = 0;
+}
+
+/// Phase two: the command the Poke button posted must have been run by `poll()` on the producer.
+gboolean source_kinds_probe_report(gpointer user) {
+  App* a = static_cast<App*>(user);
+  if (a->window == nullptr) return G_SOURCE_REMOVE;
+  const ProbeSource* src = a->acq != nullptr ? dynamic_cast<const ProbeSource*>(a->acq->source())
+                                             : nullptr;
+  const std::uint64_t after = src != nullptr ? src->commands_applied() : 0;
+  std::fprintf(stderr, "[source-kinds] command: before=%" G_GUINT64_FORMAT " after=%" G_GUINT64_FORMAT
+                       " drained=%d\n",
+               g_source_kinds_before, after, after == g_source_kinds_before + 1 ? 1 : 0);
+  std::fflush(stderr);
+  return G_SOURCE_REMOVE;
+}
+
+/// What the registry offers and what a source kind brings: the kinds, each config form's
+/// round trip, the panel page (insensitive while disconnected, still present), and a posted command.
+gboolean source_kinds_probe(gpointer user) {
+  App* a = static_cast<App*>(user);
+  if (a->window == nullptr) return G_SOURCE_REMOVE;
+
+  std::string ids;
+  for (const SourceKind* k : kinds()) ids += (ids.empty() ? "" : ",") + k->id();
+  std::fprintf(stderr, "[source-kinds] kinds=%s\n", ids.c_str());
+
+  // Each kind's form must hand back what it was given.
+  const auto sample = [](const std::string& id) {
+    SourceConfig c;
+    if (id == "udps") {
+      c.set("server", "10.0.0.5");
+      c.set("port", "9001");
+      c.set("multicast", "239.1.2.3");
+      c.set("interface", "10.0.0.9");
+    } else if (id == "probe") {
+      c.set("rate", "750");
+    }
+    return c;
+  };
+  for (const SourceKind* k : kinds()) {
+    ConfigForm f = k->make_config_form();
+    const SourceConfig in = sample(k->id());
+    f.write(in);
+    const SourceConfig out = f.read();
+    bool same = !in.empty();
+    for (const auto& kv : in.items()) same = same && out.get(kv.first) == kv.second;
+    std::fprintf(stderr, "[source-kinds] form %s: round_trip=%d valid=%d\n", k->id().c_str(),
+                 same ? 1 : 0, f.valid() ? 1 : 0);
+    // The rows were never parented; sink and release them so the form leaves nothing behind.
+    for (GtkWidget* row : f.rows) {
+      g_object_ref_sink(row);
+      g_object_unref(row);
+    }
+  }
+
+  // The panel page: built, insensitive while disconnected, present either way.
+  const SourcePanelPage* page = a->source_panels.empty() ? nullptr : &a->source_panels.front();
+  const auto report = [&](const char* state) {
+    const bool present =
+        page != nullptr && a->side_stack != nullptr &&
+        adw_view_stack_get_child_by_name(ADW_VIEW_STACK(a->side_stack), page->name.c_str()) !=
+            nullptr;
+    std::fprintf(stderr, "[source-kinds] panel %s: panels=%zu present=%d sensitive=%d\n", state,
+                 a->source_panels.size(), present ? 1 : 0,
+                 page != nullptr && gtk_widget_get_sensitive(page->content) ? 1 : 0);
+  };
+  apply_source_panels(*a, false);
+  report("disconnected");
+  apply_source_panels(*a, true);
+  report("connected");
+
+  // The probe kind has no datagrams, so the packet-capture button stays disabled, and is still there.
+  std::fprintf(stderr, "[source-kinds] capture button: present=%d sensitive=%d\n",
+               a->capture_button != nullptr ? 1 : 0,
+               a->capture_button != nullptr && gtk_widget_get_sensitive(a->capture_button) ? 1 : 0);
+
+  // Click the panel's button: it posts a command, and a later `poll()` runs it.
+  ProbeSource* src = a->acq != nullptr ? dynamic_cast<ProbeSource*>(a->acq->source()) : nullptr;
+  g_source_kinds_before = src != nullptr ? src->commands_applied() : 0;
+  if (page != nullptr) {
+    if (GtkWidget* poke = gtk_widget_get_last_child(page->content)) {
+      g_signal_emit_by_name(poke, "clicked");
+    }
+  }
+  std::fflush(stderr);
+  g_timeout_add(500, source_kinds_probe_report, a);
+  return G_SOURCE_REMOVE;
+}
+
 gboolean pan_probe(gpointer user) {
   App* a = static_cast<App*>(user);
   if (a->window == nullptr || a->rows->row_count() <= 0) return G_SOURCE_REMOVE;

src/ui_source.cpp

@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: MIT
+// SPDX-FileCopyrightText: 2026 Martino Ferrari
+
+#include "source/registry.hpp"
+#include "ui_app.hpp"
+
+#include <adwaita.h>
+
+namespace udpscope {
+namespace ui_impl {
+
+void build_source_panels(App& app) {
+  if (app.side_stack == nullptr || app.acq == nullptr || app.acq->source() == nullptr) return;
+  SourceKind* kind = find_kind(app.source_kind);
+  if (kind == nullptr) return;
+  for (const SourcePanel& p : kind->make_panels(*app.acq->source())) {
+    if (p.widget == nullptr || p.id.empty()) continue;
+    // Each page scrolls on its own, like Measure and Signals: panels differ in height.
+    GtkWidget* scroller = gtk_scrolled_window_new();
+    gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scroller), GTK_POLICY_NEVER,
+                                   GTK_POLICY_AUTOMATIC);
+    gtk_scrolled_window_set_child(GTK_SCROLLED_WINDOW(scroller), p.widget);
+    const std::string name = "source-" + p.id;
+    // An empty title on purpose, as for the built-in tabs: the pill is an icon, and
+    // `name_side_tabs()` puts `title` on it as tooltip and accessible name.
+    adw_view_stack_add_titled_with_icon(
+        ADW_VIEW_STACK(app.side_stack), scroller, name.c_str(), "",
+        p.icon.empty() ? "applications-engineering-symbolic" : p.icon.c_str());
+    app.source_panels.push_back({name, p.title, p.widget});
+  }
+  // Disconnected until the first Connected event says otherwise.
+  apply_source_panels(app, false);
+}
+
+void apply_source_panels(App& app, bool connected) {
+  for (const SourcePanelPage& p : app.source_panels) {
+    if (gtk_widget_get_sensitive(p.content) != (connected ? TRUE : FALSE)) {
+      gtk_widget_set_sensitive(p.content, connected);
+    }
+  }
+}
+
+void sync_source_panels(App& app) {
+  if (app.source_panels.empty() || app.model == nullptr) return;
+  apply_source_panels(app, app.model->stats().connected.load(std::memory_order_relaxed));
+}
+
+}  // namespace ui_impl
+}  // namespace udpscope