ui: the cursors and measurements panels are slide-over pages; the dock is the readouts

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ui.cpp

@@ -2866,20 +2866,6 @@ void on_right_click(GtkGestureClick* gesture, int, double x, double y, gpointer
   open_row_menu(*app, row, x, y, widget);
 }
 
-/// Scrolls the dock to a section. The dock is one scroller (`App::dock_scroller`) holding the cursors and
-/// the measurements top to bottom, so "measure" is the cursors panel's offset in the page. Nothing is
-/// hidden or removed: both stay in the page. An unknown name (the signal list is a slide-over page now,
-/// not a dock section) is a no-op, so a key bound to a section a later version drops cannot blank anything.
-void dock_show_section(App& app, const char* section) {
-  if (app.dock_scroller == nullptr || app.dock_page == nullptr || section == nullptr) return;
-  GtkAdjustment* adj = gtk_scrolled_window_get_vadjustment(GTK_SCROLLED_WINDOW(app.dock_scroller));
-  if (std::strcmp(section, "measure") != 0 || app.cursors_panel == nullptr) return;
-  graphene_point_t zero = GRAPHENE_POINT_INIT(0.f, 0.f);
-  graphene_point_t at;
-  if (!gtk_widget_compute_point(app.cursors_panel, app.dock_page, &zero, &at)) return;
-  gtk_adjustment_set_value(adj, at.y);
-}
-
 /// The dock is on when the user's sidebar button is in -- from the start, with or without signals; the
 /// two panel buttons appear as soon as a CONFIG describes any signal at all.
 void update_side_visibility(App& app) {
@@ -3437,7 +3423,9 @@ gboolean tick(gpointer user) {
     }
   }
   // Captured every frame so the dump has the last live value: see `dbg_measures_pane_w`.
-  if (app->measures_list != nullptr) {
+  // Only while the `measure` page is on screen: a closed page has no allocation, and the dump should
+  // keep the last real size rather than 0.
+  if (app->measures_list != nullptr && gtk_widget_get_width(app->measures_list) > 0) {
     app->dbg_measures_pane_w = gtk_widget_get_width(app->measures_list);
     app->dbg_measures_pane_h = gtk_widget_get_height(app->measures_list);
   }
@@ -3993,7 +3981,7 @@ gboolean tick(gpointer user) {
   // The one thing that has to be decided *per frame* about the dock: whether there is room for it
   // beside the plot. Collapsed, the split view puts it *over* the plot rather than giving it a share of
   // a width that is not there -- so a small window shows fewer pixels of plot, never a panel squeezed
-  // to nothing. `kSidebarRoom` is the sidebar's 320 plus the width below which the plot stops being
+  // to nothing. `kSidebarRoom` is the sidebar's 280 plus the width below which the plot stops being
   // worth looking at.
   if (app->side_view != nullptr && app->window != nullptr) {
     // The split view writes `show-sidebar` itself (at startup and when it collapses), so the wish is
@@ -4656,7 +4644,7 @@ void run_app_action(App& app, AppAction action) {
     case AppAction::CursorsPane:
       toggle(app.cursors_toggle);
       break;
-    case AppAction::ShowMeasure: dock_show_section(app, "measure"); break;
+    case AppAction::ShowMeasure: slideover_toggle(app, "measure"); break;
     case AppAction::ShowSignals: {
       // The `+` badge is insensitive without signals; so is its shortcut.
       bool have_signals = false;
@@ -5038,7 +5026,7 @@ void on_activate(GtkApplication* application, gpointer user) {
 
   // The size the window opens at, stated in code as well as in the `.ui`: `default-width` there is the
   // size it *asks* for, and a window whose content has a larger minimum opens at that minimum instead --
-  // 756 px here, the plot column's own minimum plus the sidebar's 320. The old code set it explicitly;
+  // 756 px here, the plot column's own minimum plus the sidebar's 280. The old code set it explicitly;
   // this is where it went when the window moved into the file, and it is why the window came up small.
   gtk_window_set_default_size(GTK_WINDOW(app->window), 1280, 800);
 
@@ -5140,15 +5128,16 @@ void on_activate(GtkApplication* application, gpointer user) {
     gtk_popover_set_has_arrow(GTK_POPOVER(app->status_popover), TRUE);
   }
 
-  // The right-hand side is the dock: one scroller, the cursors then the measurements. Every section is
-  // always there -- "go to Measure" scrolls to it instead of switching a tab, so the measurements are as
-  // live as the cursors above them. The signal list is a slide-over page (reached by the `+` badge).
+  // The right-hand side is the dock: one scroller holding only the compact read-only readouts (the
+  // cursors table and the measurements). The full Cursors and Measurements panels are slide-over pages
+  // (`cursors`, `measure`), live whether or not they are open: the pages hold the same widgets and the
+  // tick writes them either way. The signal list is a page too (reached by the `+` badge).
   // `side` and `dock_page`/`dock_scroller` are resolved above with the rest of the skeleton and checked
   // by the null guard; assign the member here.
   app->side_box = side;
 
-  // Built in the order the panels have always been (cursors, measurements, trigger, signals) and placed in
-  // the dock's: the trigger form goes to the slide-over (reached by the Trigger badge).
+  // Built in the order the panels have always been (cursors, measurements, trigger, signals); each is a
+  // page of the slide-over, reached by its badge, its key or the header's Cursors toggle.
   app->cursors_panel = build_cursors_panel(*app);
   GtkWidget* measures_panel = build_measures_panel(*app);
   app->trigger_panel = build_trigger_panel(*app);
@@ -5160,13 +5149,14 @@ void on_activate(GtkApplication* application, gpointer user) {
   // `build_slideover`, and registered once.
   app->signal_panel = build_signal_panel(*app);
   slideover_add_page(*app, "signals", "Signals", app->signal_panel);
-  gtk_box_append(GTK_BOX(app->dock_page), app->cursors_panel);
-  gtk_box_append(GTK_BOX(app->dock_page), gtk_separator_new(GTK_ORIENTATION_HORIZONTAL));
-  gtk_box_append(GTK_BOX(app->dock_page), measures_panel);
-  // The compact readouts above the full panels (which move to slide-over pages later), with their own
-  // separator: the first child of the dock.
-  gtk_box_prepend(GTK_BOX(app->dock_page), gtk_separator_new(GTK_ORIENTATION_HORIZONTAL));
-  gtk_box_prepend(GTK_BOX(app->dock_page), build_readouts_dock(*app));
+  // `c` / the header toggle drive the cursors themselves; this page is where they are configured and read
+  // in full. `m` toggles the measurements page.
+  gtk_widget_set_valign(app->cursors_panel, GTK_ALIGN_START);
+  gtk_widget_set_valign(measures_panel, GTK_ALIGN_START);
+  slideover_add_page(*app, "cursors", "Cursors", app->cursors_panel);
+  slideover_add_page(*app, "measure", "Measurements", measures_panel);
+  // The dock is the compact readouts alone (step 4 adds the events to it).
+  gtk_box_append(GTK_BOX(app->dock_page), build_readouts_dock(*app));
 
   // The cursors start off, so their readout starts insensitive -- stated here by the one place that
   // knows the default, and the *body* and not the panel, because the panel's heading carries the
@@ -5200,8 +5190,8 @@ void on_activate(GtkApplication* application, gpointer user) {
 
   // Two plots, in a paned so a comparison's divider can move: the primary takes everything while the
   // second is hidden, and the width is the user's once it is not.
-  // Nothing to state about the sidebar's size. It is the split view's: 320 px from the `.ui`, floored
-  // at 240, and never a number derived from the window -- which is what the removed
+  // Nothing to state about the sidebar's size. It is the split view's: 280 px from the `.ui` (min = max),
+  // and never a number derived from the window -- which is what the removed
   // `gtk_paned_set_position(paned, 940)` was, and why a window narrower than 940 px gave the sidebar
   // no width at all.
 

src/ui/main-window.ui

@@ -21,7 +21,7 @@
   What is *not* here is as deliberate as what is. Everything this file nests is fixed — the shape of
   the window does not depend on the stream, the trigger or the layout — while the subtrees that do are
   built by code and put in place: the events pane, into `events_divider`'s start side; the two plot
-  areas, into the split inside `plot_box`; the dock's panels (signals, cursors, measurements), appended to `dock_page`; and the
+  areas, into the split inside `plot_box`; the dock's readouts, appended to `dock_page`; and the
   status popover, attached to `status_info`.
 
   The header bar is not here either: it is the window's own titlebar, built by `build_toolbar()`
@@ -40,22 +40,19 @@
     <child>
       <object class="AdwOverlaySplitView" id="side_view">
         <property name="sidebar-position">end</property>
-        <!-- Its width in pixels, not as a fraction of the window: 320 on a first run, and never less
-             than 240 however small the window gets. -->
+        <!-- Its width in pixels, not as a fraction of the window: 280, the width of the compact readouts. -->
         <!-- Both ends of the range, in pixels: `sidebar-width-fraction` is a 0..1 *fraction* of the
              window (setting a pixel count there is a GObject critical and falls back to 0.25), so the
              width is pinned by min and max instead. -->
         <property name="sidebar-width-unit">px</property>
-        <property name="min-sidebar-width">320</property>
-        <property name="max-sidebar-width">320</property>
+        <property name="min-sidebar-width">280</property>
+        <property name="max-sidebar-width">280</property>
         <property name="sidebar">
-          <!-- The dock: one scroller holding the signal list, then the cursors and the measurements.
-               It replaces the tab switcher (four text tabs did not fit 320 px and a source can add
-               more); it is the temporary home of Measure and Signals until steps 2 and 3 turn them
-               into the badge bar's signals and the compact readouts. -->
+          <!-- The dock: one scroller holding the compact cursor and measurement readouts. The full
+               Cursors and Measurements panels are slide-over pages, and the signal list is a page too. -->
           <object class="GtkBox" id="side_column">
             <property name="orientation">vertical</property>
-            <property name="width-request">300</property>
+            <property name="width-request">260</property>
             <child>
               <object class="GtkScrolledWindow" id="dock_scroller">
                 <property name="vexpand">1</property>

src/ui_app.hpp

@@ -266,9 +266,9 @@ struct App {
   GtkWidget* trigger_panel = nullptr;
   GtkWidget* signal_panel = nullptr;
   GtkWidget* side_box = nullptr;
-  /// The dock: the sidebar's one scroller and the box inside it, which holds the cursors and
-  /// the measurements (`dock_show_section()` scrolls it). A feature's own on/off never
-  /// removes a section (it sets its panel's sensitivity instead).
+  /// The dock: the sidebar's one scroller and the box inside it, which holds only the compact readouts
+  /// (`build_readouts_dock()`). The full cursors and measurements panels are the slide-over's `cursors`
+  /// and `measure` pages. A feature's own on/off never removes a panel (it sets its sensitivity instead).
   GtkWidget* dock_page = nullptr;
   GtkWidget* dock_scroller = nullptr;
   GtkWidget* arm_button = nullptr;
@@ -1609,8 +1609,8 @@ constexpr int kEventThumbH = 46;
 constexpr int kEventThumbMaxH = 104;
 inline int g_stats_phase = 0;
 inline std::vector<std::uint64_t> g_stats_n_before;
-/// The same for the dock-section probe: the accumulator counts recorded while the Measure section was
-/// still scrolled into view, so the report can say whether any of them advanced after it scrolled out.
+/// The same for the dock-section probe: the accumulator counts recorded while the `measure` page was
+/// still open, so the report can say whether any of them advanced after it was closed.
 inline std::vector<std::uint64_t> g_dock_section_n_before;
 inline double g_trigrenum_edge = 0.0;
 inline std::uint64_t g_trigrenum_latches = 0;
@@ -1867,9 +1867,6 @@ void row_menu_fill(RowMenuState& st);
 GtkWidget* open_row_menu(App& app, int row, double x, double y, GtkWidget* parent, bool autohide = true);
 void on_right_click(GtkGestureClick* gesture, int, double x, double y, gpointer user);
 gboolean on_drop_channel(GtkDropTarget*, const GValue* value, double x, double y, gpointer user);
-/// Scrolls the dock to a section: "signals" (the top) or "measure" (the cursors panel, which the
-/// measurements follow). An unknown name is a no-op.
-void dock_show_section(App& app, const char* section);
 /// Reads each pane's own switch back off the header bar's button, and the other way round: the two are
 /// one control in two places, and `panel_switch_sync` keeps the write from looking like a click.
 void sync_panel_switches(App& app);

src/ui_dock.cpp

@@ -22,9 +22,10 @@ namespace ui_impl {
 namespace {
 
 /// The width, in characters, of a value cell and of a `who` / type cell. Fixed, so the dock is as wide
-/// with `--` as with `-123.456 mV`.
+/// with `--` as with `-123.456 mV`; their sum (5 + 3 x 9 characters) is what keeps the readouts inside the
+/// dock's 280 px.
 constexpr int kValueChars = 9;
-constexpr int kNameChars = 8;
+constexpr int kNameChars = 5;
 
 GtkWidget* fixed_label(const char* text, int chars, GtkAlign halign) {
   GtkWidget* l = gtk_label_new(text);

src/ui_probe.cpp

@@ -18,6 +18,7 @@
 #include <cmath>
 #include <cstdio>
 #include <cstring>
+#include <tuple>
 
 namespace udpscope {
 namespace ui_impl {
@@ -183,6 +184,18 @@ gboolean exit_probe_step3b(gpointer user) {
   a->dbg_dock_shown = sidebar_shown;
   a->dbg_dock_sensitive = gtk_widget_get_sensitive(a->side_box) ? 1 : 0;
   a->dbg_dock_w = a->dbg_side_w;
+  {
+    // The dock holds only the readouts box; the full cursors and measurements panels are slide-over pages,
+    // registered whether or not either is open.
+    int children = 0;
+    for (GtkWidget* c = gtk_widget_get_first_child(a->dock_page); c != nullptr;
+         c = gtk_widget_get_next_sibling(c)) {
+      ++children;
+    }
+    std::fprintf(stderr, "[readouts] pages cursors=%d measure=%d dock_children=%d dock_w=%d\n",
+                 slideover_has_page(*a, "cursors") ? 1 : 0, slideover_has_page(*a, "measure") ? 1 : 0,
+                 children, a->dbg_side_w);
+  }
   a->dbg_dock_scrollers = 0;
   for (GtkWidget* c = gtk_widget_get_first_child(a->side_box); c != nullptr;
        c = gtk_widget_get_next_sibling(c)) {
@@ -1792,24 +1805,11 @@ gboolean stats_probe(gpointer user) {
   return G_SOURCE_REMOVE;
 }
 
-/// Which section the dock's scroller is showing at its top: "measure" once it has been scrolled to the
-/// measurements' heading or past it, "cursors" above that (the cursors panel is the dock's first section;
-/// the signal list is a slide-over page). Read from the adjustment, so it is the state the user would see
-/// and not the last call made.
-static const char* dock_section_in_view(App& a) {
-  if (a.dock_scroller == nullptr || a.measures_head == nullptr || a.dock_page == nullptr) return "none";
-  graphene_point_t zero = GRAPHENE_POINT_INIT(0.f, 0.f);
-  graphene_point_t at;
-  if (!gtk_widget_compute_point(a.measures_head, a.dock_page, &zero, &at)) return "none";
-  GtkAdjustment* adj = gtk_scrolled_window_get_vadjustment(GTK_SCROLLED_WINDOW(a.dock_scroller));
-  return gtk_adjustment_get_value(adj) > 0.5 * at.y ? "measure" : "cursors";
-}
-
-/// Phase two of the dock-section probe: the accumulators must have advanced while the Measure section was
-/// scrolled out of view. A statistics readout is *history*, so min/max/avg would gain a gap for exactly as
-/// long as the section was off screen -- which is the one defect the design's "what runs on a hidden
-/// page" rule is there to prevent, and the reason no frame-rate code may be gated on which section is in
-/// view. (It was a tab once; the dock is one scroller, and the rule outlived the tabs.)
+/// Phase two of the dock-section probe: the accumulators must have advanced while the `measure` page was
+/// closed. A statistics readout is *history*, so min/max/avg would gain a gap for exactly as long as the
+/// page was off screen -- which is the one defect the design's "what runs on a hidden page" rule is there
+/// to prevent, and the reason no frame-rate code may be gated on which page is open. (It was a tab once,
+/// then a dock section; the rule outlived both.)
 gboolean dock_section_probe_report(gpointer user) {
   App* a = static_cast<App*>(user);
   if (a->window == nullptr) return G_SOURCE_REMOVE;
@@ -1824,34 +1824,27 @@ gboolean dock_section_probe_report(gpointer user) {
       first = false;
     }
   }
-  if (a->dock_page != nullptr) gtk_widget_set_size_request(a->dock_page, -1, -1);
-  if (a->cursors_panel != nullptr) gtk_widget_set_size_request(a->cursors_panel, -1, -1);
   std::fprintf(stderr,
                "[side-tab-probe] section=%s rows=%zu accums=%zu advanced=%" G_GUINT64_FORMAT
                " min_n=%" G_GUINT64_FORMAT "\n",
-               dock_section_in_view(*a), a->measures.size(), a->measure_stats.size(), advanced, min_n);
+               slideover_page(*a).empty() ? "none" : slideover_page(*a).c_str(), a->measures.size(), a->measure_stats.size(), advanced, min_n);
   std::fflush(stderr);
   return G_SOURCE_REMOVE;
 }
 
-/// Phase one: four measurements on the first channel, statistics on, then scroll the dock *away* from the
-/// Measure section and come back in two seconds to read what ran while it was not in view. (The probe
-/// keeps its old environment variable, `UDPSCOPE_PROBE_SIDE_TAB_MS`, and its `[side-tab-probe]` tag.)
+/// Phase one: four measurements on the first channel, statistics on, then the `measure` page opened for a
+/// forced pass and *closed* again; it comes back in two seconds to read what ran while the page was not on
+/// screen. (The probe keeps its old environment variable, `UDPSCOPE_PROBE_SIDE_TAB_MS`, and its
+/// `[side-tab-probe]` tag.) Run it against a config that has seen the first-run tour, which would close the page.
 gboolean dock_section_probe(gpointer user) {
   App* a = static_cast<App*>(user);
   if (a->window == nullptr) return G_SOURCE_REMOVE;
-  // A dock whose content fits has nothing to scroll away from, and a tall window does that. The first
-  // pass makes the page taller than any window (a probe-only minimum height, undone in the report) and
-  // comes back once it has been laid out, so "scrolled out of view" is a state this run really reaches.
-  static bool padded = false;
-  if (!padded && a->dock_page != nullptr) {
-    padded = true;
-    gtk_widget_set_size_request(a->dock_page, -1, 3000);
-    // ... and the cursors panel (the dock's first section, above the measurements) taller than any window
-    // too, which is what pushes the measurements below the viewport at offset 0 (padding the page's end only
-    // makes it scrollable, and on a window taller than the section's y the section would stay in view).
-    // Undone in the report.
-    if (a->cursors_panel != nullptr) gtk_widget_set_size_request(a->cursors_panel, -1, 3000);
+  // The first pass only waits 400 ms: the enable-all probe switches signals on and off around this time,
+  // and a buffer rebuild between the baseline and the report would drop the accumulators and read as a
+  // gated pass. (It also gives the layout the pass this probe's own row assignment needs.)
+  static bool waited = false;
+  if (!waited) {
+    waited = true;
     g_timeout_add(400, dock_section_probe, a);
     return G_SOURCE_REMOVE;
   }
@@ -1892,32 +1885,21 @@ gboolean dock_section_probe(gpointer user) {
   if (a->measures_stats_check != nullptr) {
     gtk_check_button_set_active(GTK_CHECK_BUTTON(a->measures_stats_check), TRUE);
   }
-  GtkAdjustment* dock_adj = gtk_scrolled_window_get_vadjustment(GTK_SCROLLED_WINDOW(a->dock_scroller));
-  // From the top, is the measure section (the measurements' heading) below the viewport? Only then is scrolling to it a move *into* view and back out a move *away*; a
-  // section already in view at offset 0 would make the whole probe a reading of nothing.
-  gtk_adjustment_set_value(dock_adj, 0.0);
-  graphene_point_t zero = GRAPHENE_POINT_INIT(0.f, 0.f);
-  graphene_point_t measure_at = GRAPHENE_POINT_INIT(-1.f, -1.f);
-  const bool located =
-      a->measures_head != nullptr && gtk_widget_compute_point(a->measures_head, a->dock_page, &zero, &measure_at);
-  const bool outside_at_top = located && static_cast<double>(measure_at.y) >= gtk_adjustment_get_page_size(dock_adj);
-  dock_show_section(*a, "measure");  // lands on the cursors panel, the dock's top: a no-op scroll
-  if (located) gtk_adjustment_set_value(dock_adj, measure_at.y);  // ... so go to the measurements themselves
-  // Where the dock went: `scrolled` is its offset and `reach` the most it can scroll. A reach of 0 would
-  // mean the content fits and "away from the section" is not a state this run can reach.
-  const double scrolled = gtk_adjustment_get_value(dock_adj);
-  const double reach = gtk_adjustment_get_upper(dock_adj) - gtk_adjustment_get_page_size(dock_adj);
+  // On the page: the section is where the user reads the measurements in full.
+  slideover_open(*a, "measure");
+  const bool was_open = slideover_page(*a) == "measure";
   update_measures(*a, /*force=*/true, /*accumulate=*/true);
   g_dock_section_n_before.clear();
   for (const MeasureStatsAccum& s : a->measure_stats) g_dock_section_n_before.push_back(s.n);
-  // Away from the section the measurements are in: they are scrolled out of the viewport (the widgets
-  // stay mapped, only clipped), and the tick keeps calling `update_measures()` regardless.
-  gtk_adjustment_set_value(dock_adj, 0.0);
+  // Away from the page: it is closed (its widgets stay in the tree, unmapped), and the tick keeps calling
+  // `update_measures()` regardless.
+  slideover_close(*a);
+  const bool hidden = slideover_page(*a).empty();
   std::fprintf(stderr,
-               "[side-tab-probe] section=%s accums=%zu baseline recorded (measure at scroll %.0f of %.0f, "
-               "outside_at_top=%d)\n",
-               dock_section_in_view(*a), g_dock_section_n_before.size(), scrolled, reach,
-               outside_at_top ? 1 : 0);
+               "[side-tab-probe] section=%s accums=%zu baseline recorded (measure page was_open=%d, "
+               "now closed=%d)\n",
+               slideover_page(*a).empty() ? "none" : slideover_page(*a).c_str(),
+               g_dock_section_n_before.size(), was_open ? 1 : 0, hidden ? 1 : 0);
   std::fflush(stderr);
   // Long enough for several throttled recomputes (one per 100 ms while the window moves).
   g_timeout_add(2000, dock_section_probe_report, a);
@@ -4687,7 +4669,7 @@ gboolean measures_probe_step(gpointer user) {
         m.options.show_on_plot = measure_can_show_on_plot(m.type);
         a->measures.push_back(std::move(m));
       }
-      dock_show_section(*a, "measure");
+      slideover_open(*a, "measure");  // the page the probe reads and edits
       rebuild_measures_pane(*a);
       std::fprintf(stderr, "[measures-probe] added %zu measurements on '%s'\n", a->measures.size(),
                    signal.c_str());
@@ -4849,7 +4831,7 @@ gboolean bandavg_probe_step(gpointer user) {
         m.options.show_on_plot = measure_can_show_on_plot(m.type);
         a->measures.push_back(std::move(m));
       }
-      dock_show_section(*a, "measure");
+      slideover_open(*a, "measure");  // the page the probe reads and edits
       rebuild_measures_pane(*a);
       g_timeout_add(250, measure_trace, a);
       bandavg_probe_next(*a, 1, 1500);
@@ -6414,16 +6396,6 @@ gboolean defaults_probe(gpointer user) {
 
 gboolean keys_probe(gpointer user) {
   App* a = static_cast<App*>(user);
-  // `m` scrolls the dock, and a dock whose content fits has nothing to scroll: a run on a tall window
-  // would read 0->0 and prove nothing. So the first pass only makes the page taller than any window
-  // (a probe-only minimum height, undone below) and comes back once it has been laid out.
-  static bool padded = false;
-  if (!padded && a->dock_page != nullptr) {
-    padded = true;
-    gtk_widget_set_size_request(a->dock_page, -1, 3000);
-    g_timeout_add(400, keys_probe, a);
-    return G_SOURCE_REMOVE;
-  }
   std::string line = "[keys]";
 
   const auto before_after = [&](const char* name, GtkWidget* button, AppAction action) {
@@ -6459,39 +6431,23 @@ gboolean keys_probe(gpointer user) {
 
   before_after("t: trigger panel", a->trigger_toggle, AppAction::TriggerPanel);
   before_after("c: cursors", a->cursors_toggle, AppAction::CursorsPane);
-  // `m` and `g` scroll the dock: the reading is the scroller's offset before and after, and `m` must land
-  // on the cursors panel's own y (clamped to what the page can scroll, which is why the reachable maximum
-  // is printed beside it), `g` back on 0.
+  // `m` and `g` open a slide-over page: `m` the measurements, `g` the signal list, and a second press of
+  // either closes it again. The dock does not move (it holds only the readouts).
   const auto dock_adjustment = [a]() {
     return gtk_scrolled_window_get_vadjustment(GTK_SCROLLED_WINDOW(a->dock_scroller));
   };
   const auto dock_value = [&]() { return gtk_adjustment_get_value(dock_adjustment()); };
-  {
+  for (const auto& [key, action, page] :
+       {std::tuple<const char*, AppAction, const char*>{"m", AppAction::ShowMeasure, "measure"},
+        {"g", AppAction::ShowSignals, "signals"}}) {
     const double before = dock_value();
-    run_app_action(*a, AppAction::ShowMeasure);
+    run_app_action(*a, action);
+    const bool opened = slideover_page(*a) == page;
     const double after = dock_value();
-    graphene_point_t zero = GRAPHENE_POINT_INIT(0.f, 0.f);
-    graphene_point_t at = GRAPHENE_POINT_INIT(-1.f, -1.f);
-    if (!gtk_widget_compute_point(a->cursors_panel, a->dock_page, &zero, &at)) at.y = -1.f;
-    GtkAdjustment* adj = dock_adjustment();
-    const double reach = gtk_adjustment_get_upper(adj) - gtk_adjustment_get_page_size(adj);
-    char buf[160];
-    std::snprintf(buf, sizeof(buf), " m: dock %.0f->%.0f (cursors_y=%.0f reach=%.0f at_cursors=%d) |", before,
-                  after, static_cast<double>(at.y), reach,
-                  std::fabs(after - std::min(static_cast<double>(at.y), reach)) < 1.0 ? 1 : 0);
-    line += buf;
-  }
-  {
-    // `g` is the signal list's slide-over page now: it opens it, the dock does not move, and a second `g`
-    // closes it again.
-    const double before = dock_value();
-    run_app_action(*a, AppAction::ShowSignals);
-    const bool opened = slideover_page(*a) == "signals";
-    const double after = dock_value();
-    run_app_action(*a, AppAction::ShowSignals);
+    run_app_action(*a, action);
     const bool closed = slideover_page(*a).empty();
     char buf[96];
-    std::snprintf(buf, sizeof(buf), " g: page=%d dock_still=%d closed=%d |", opened ? 1 : 0,
+    std::snprintf(buf, sizeof(buf), " %s: page=%d dock_still=%d closed=%d |", key, opened ? 1 : 0,
                   std::fabs(after - before) < 1.0 ? 1 : 0, closed ? 1 : 0);
     line += buf;
   }
@@ -6512,21 +6468,17 @@ gboolean keys_probe(gpointer user) {
   }
 
   // An accel must be refused while text is being typed. Focus the window entry, send 'm'
-  // through the real handler, and require the dock not to scroll.
+  // through the real handler, and require no page to open.
   int refused = -1;
   if (a->window_entry != nullptr) {
     gtk_menu_button_popup(GTK_MENU_BUTTON(a->window_button));
     gtk_widget_grab_focus(a->window_entry);
-    // The dock has to be somewhere other than where `m` would take it, or "did not scroll" proves nothing.
-    gtk_adjustment_set_value(dock_adjustment(), 0.0);
-    const double before_dock = dock_value();
+    const std::string page_before = slideover_page(*a);
     const gboolean handled = on_app_key_pressed(nullptr, GDK_KEY_m, 0,
                                                 static_cast<GdkModifierType>(0), a);
-    const double after_dock = dock_value();
-    refused = (handled == FALSE && before_dock == after_dock) ? 1 : 0;
+    refused = (handled == FALSE && slideover_page(*a) == page_before) ? 1 : 0;
     gtk_menu_button_popdown(GTK_MENU_BUTTON(a->window_button));
   }
-  if (a->dock_page != nullptr) gtk_widget_set_size_request(a->dock_page, -1, -1);
   char tail[64];
   std::snprintf(tail, sizeof(tail), " editable focused: 'm' refused=%d\n", refused);
   line += tail;