docs: the readouts strip

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

README.md

@@ -159,7 +159,19 @@ cells are a fixed number of characters wide and ellipsized, so the dock's width
 depend on what a value reads: the **who** cell of a cursor line is 5 characters (the full text is its
 tooltip), a value cell 9 (its tooltip is the full text). The dock and the pages show **one string**:
 `update_cursors_pane()` and `update_measures()` format each value once and hand that variable to the
-page's label and to the dock's, so the two cannot disagree. The **Events** block is a heading with a
+page's label and to the dock's, so the two cannot disagree. **When the dock is not on screen** -- hidden
+with the dock button, or the window narrow enough (< 900 px) for the dock to be a collapsed overlay that is
+not currently open -- the same readouts appear on **one line under the plot**, above the badge bar (the
+*readouts strip*): a **Cursors** button (opens the `cursors` page) and one chip per cursor line (its name and
+its *delta* value), then a **Measures** button (opens the `measure` page) and one chip per measurement (the
+signal's colour chip, the type, the value; a click opens its dialog; "no measurements" when there are none).
+It is a **fixed 26 px** high and its chips are as wide as the dock's cells (name 6 characters, type 10, value
+9, the full text in the tooltip); what does not fit scrolls sideways with no bar taking height. With the
+cursors off the chips are insensitive and read `--`, as the dock's cells do. It is the **third reader of the
+same strings** (the setters that write the dock's labels write the strip's), and it is hidden whenever the
+dock is shown, so the plot never loses its 26 px to both. **Known limit:** a *collapsed* window whose dock
+button is still on has the dock overlaid over the plot (the app re-asserts the button's wish every frame, so
+the overlay cannot be swiped away), and then the strip is hidden; it shows once the dock button is off. The **Events** block is a heading with a
 **Manage** button over a short list of the cached events, newest first -- one compact row each, never a
 picture -- and one click on a row replays that event (see "Captured events"). The full list, with the
 pictures and the comparison actions, is the `events` slide-over page that **Manage** opens. There is no

docs/USER-GUIDE.md

@@ -21,7 +21,8 @@ The window is a plot with three things around it:
   never resizes the plot;
 - the **dock** on the right, which the dock button in the header bar (`s`) shows and hides: read-only
   **Readouts** of the cursors and of the measurements, each with an **Edit** button that opens its
-  page, and an **Events** block.
+  page, and an **Events** block. With the dock hidden, the readouts show in a one-line strip under the
+  plot instead (the cursors' deltas and each measurement's value; **Cursors** and **Measures** open the pages).
 
 ## 1. Connecting
 

docs/claude/architecture.md

@@ -134,6 +134,18 @@ touching the data path.
   kind's panels (those are slide-over pages). The window's measurement editor is a dialog
   (`open_measure_dialog()`), not part of the `measure` page.
 
+  **The readouts strip** (`readouts_strip` in `main-window.ui`, between `plot_overlay` and `badge_bar` in
+  `left_column`; filled by `ui_dock.cpp`) carries the same readouts when the dock is not on screen: a flat
+  **Cursors** button and one chip (`who` + delta) per cursor line, then a **Measures** button and one chip per
+  measurement. `sync_readouts_strip()` shows it exactly when `adw_overlay_split_view_get_show_sidebar()` is
+  false; the tick calls it right after re-asserting `sidebar_wanted` and *before* `set_collapsed()` (so the
+  split view's own collapse-time `show-sidebar` write is never read, and the strip does not flash on a
+  narrowing). Its labels (`strip_cursor_who`, `strip_cursor_deltas`, `strip_measure_labels`) are rebuilt by
+  `dock_rebuild_cursors()` / `dock_rebuild_measures()` and written by `dock_cursor_cell()` /
+  `dock_measure_value()` from the same argument as the dock's, so there is no second formatter;
+  `dock_set_cursors_sensitive()` is the one writer of the cursor readouts' sensitivity (the dock's grid and
+  the strip's chip box).
+
   The **Events** block (`build_events_dock()`, also `ui_dock.cpp`) is a heading with a **Manage** button
   (`open_events_page()`) over a short list (`dock_events_list`, 112 px, scrolled, no thumbnails): one compact
   row per `EventRecord`, newest first, capped at `kDockEventsMax` (24) with a dim "... N more, see Manage"

docs/claude/invariants-plot-and-layout.md

@@ -148,6 +148,18 @@ Part of [CLAUDE.md](../../CLAUDE.md). These are rules that cost a defect to lear
   characters, which made the readouts' minimum width 304 px; that pushed the sidebar to 304 px
   (`dock_w=304`) and defeated the 280 pin. Widening any cell is the same
   trap -- read `[readouts] ... dock_w=` (must be 280) and the `dock cursors:` / `dock measures:` `fits=`, and for the Events block `dock events: ... dock_w=` (268).
+- **The readouts strip is a fixed 26 px, scrolls sideways, and is shown only without the dock.**
+  `readouts_strip` (a `GtkScrolledWindow`, `height-request` 26, horizontal `external`, vertical `never`) sits
+  in `left_column` between `plot_overlay` and `badge_bar`. Its height is a request and not a measurement of
+  its chips (the buttons are trimmed by `button.udpscope-strip-button` in `ui_widgets.cpp`, or Adwaita's
+  34 px flat button would push it past 26), the chips' cells are fixed-width ellipsized labels like the
+  dock's, and an overflow scrolls with no bar taking height: "layout must not depend on content" for the
+  strip, the same as for the badge bar. It is *visible* exactly when `show-sidebar` is false
+  (`sync_readouts_strip()`, from the tick after the wish is re-asserted and before `set_collapsed()` --
+  read after the collapse it would show for a frame each time the window narrowed), and hidden when the dock
+  is on screen, overlaid included, so the plot's 26 px go to one pane of readouts and never both. The plot
+  is 26 px shorter while it shows; that is the dock's state moving the layout, not content. Reading
+  `h=26` with `visible=1` (and `h=0` with `visible=0`) in `strip:` is the assertion.
 - **Trace slots are identified by signal name, not channel index.** Enabling a signal
   or a new CONFIG renumbers the channel list, so an index would silently re-point a
   trace at another signal.

docs/claude/invariants-readouts-and-cursors.md

@@ -57,6 +57,18 @@ Part of [CLAUDE.md](../../CLAUDE.md). These are rules that cost a defect to lear
   pin). `[cursors-probe] ... dock cursors:` and `[measures-probe] ... dock measures:` assert it: `same_text=1`
   compares `gtk_label_get_text()` (the untruncated text) of every dock label with the page's, and
   `fits=1` that the Readouts box is no wider than the dock.
+- **The readouts strip is a third reader of the same string, never a second formatter.** When the dock is
+  not on screen the readouts are shown in the strip under the plot (`readouts_strip`, `src/ui_dock.cpp`): the
+  cursor chips' `who` and *delta* labels and the measurement chips' value labels. They are written **in the
+  same call** as the dock's -- `dock_cursor_cell()` and `dock_measure_value()` set the strip's label from the
+  argument they were handed, and `dock_rebuild_cursors()` / `dock_rebuild_measures()` rebuild its chips
+  beside the dock's lines -- so a value is still formatted once, into one local, and a feature that writes a
+  dock cell without going through those two setters leaves the strip stale. The strip keeps the dock's
+  rules: the same fixed-width ellipsized cells (who 6, type 10, value 9 characters, full text in the
+  tooltip), the delta cell reads `--` on the same branches, and the cursor chips are *insensitive* with the
+  cursors off and never hidden -- through `dock_set_cursors_sensitive()`, which writes the dock's grid and the
+  strip's chip box together; a second `gtk_widget_set_sensitive()` on either is two spellings of one state.
+  `[cursors-probe]` / `[measures-probe]` `strip: ... same_text=1` asserts it.
 - **`format_measure()` is the one formatter for both panes, and its SI prefix does not depend on
   there being a unit.** The cursors pane's values and the measurements pane's `text=` go through
   it, so a change reaches both. The prefix ladder used to be inside `if (!unit.empty())`, which

docs/claude/probe-readings.md

@@ -1842,6 +1842,24 @@ These ride on the `[cursors-probe]` readings (every state line gets a `dock curs
 - **`dock_sensitive=1`** (cursors only): the dock's cursor grid is live whenever the stream has signals; `0` before them ("disable, do not hide"), `0` with signals is the dock never coming back.
 - On a session with no cursors line, or with no measurements, `lines=0 page_lines=0 same_text=1` is correct: the dock then shows `no measurements` for the measurements (one non-value label, not counted in `lines`).
 
+## `strip:` (the readouts strip)
+
+```
+[cursors-probe]  <what> strip: visible=0 dock_shown=1 cursors=4 measures=0  same_text=1 h=0  sens_same=1 collapsed=1 window=756
+[measures-probe] <what> strip: visible=0 dock_shown=1 cursors=0 measures=12 same_text=1 h=0  sens_same=1 collapsed=1 window=756
+[cursors-probe]  dock hidden strip: visible=1 dock_shown=0 cursors=4 measures=0 same_text=1 h=26 sens_same=1 ...
+[cursors-probe]  dock restored strip: visible=0 dock_shown=1 ...
+```
+
+One `strip:` line follows every `dock cursors:` / `dock measures:` line, and each probe ends with a drive that puts the dock away through the wish (`sidebar_wanted = false`), reads the strip 600 ms later (`dock hidden`), restores the wish and reads again (`dock restored`).
+
+- **`visible` is the opposite of `dock_shown`** (`dock_shown` is `show-sidebar`) on every settled line. `visible=0 dock_shown=0` or `visible=1 dock_shown=1` is `sync_readouts_strip()` not run (or run before the reconciliation); a single such line right after the probe's own `update_side_visibility()` is the sub-frame before the next tick and not a defect.
+- **`h` is 26 with `visible=1`, 0 with `visible=0`.** Any other visible height is the chips setting the strip's height (the button trim in `ui_widgets.cpp` or the `height-request` lost).
+- **`same_text=1` is the assertion**: every strip label (the cursors' `who` and delta, the measurements' values) has the dock's text, and the counts of chips match the dock's lines. `0` is a value written to one view only -- a dock cell set without `dock_cursor_cell()` / `dock_measure_value()`, or a rebuild that did not mirror.
+- **`cursors` / `measures`** are the chip counts and equal the dock's `lines`.
+- **`sens_same=1`**: the strip's cursor chips and the dock's cursor grid have the same sensitivity (`dock_set_cursors_sensitive()`).
+- **`collapsed=1 window=756`** on every line under `xvfb-run`: the window is below the 900 px `kSidebarRoom`, so these lines are all the *collapsed* case (a wished dock stays overlaid, `visible=0`; a hidden one shows the strip). The non-collapsed case is not reachable from a probe, because a window with no manager cannot be resized by `gtk_window_set_default_size()`. The very first line can read `collapsed=0` (the tick has not set it yet).
+
 ## `[sidebar-probe]`
 
 ```

docs/claude/verification.md

@@ -437,8 +437,10 @@ precedent, not an exception.
   no scroll and no padding.)
 - `UDPSCOPE_PROBE_CURSORS_MS` and `UDPSCOPE_PROBE_MEASURES_MS` also print the dock's copy of what they read:
   a `dock cursors:` line after every `[cursors-probe]` report and a `dock measures:` line at the
-  measures probe's added / settled / final stops. **`same_text=1` on every one** is the assertion that the
+  measures probe's added / settled / final stops, each with a `strip:` line beside it (the readouts strip,
-  dock and the page show one string; `fits=1` that the Readouts box is no wider than the dock. Entries in
+  shown only without the dock); each probe ends by hiding the dock for 0.6 s and reading the strip (`dock hidden`:
+  `visible=1 h=26 same_text=1`; `dock restored`: `visible=0`). **`same_text=1` on every one** is the assertion that the
+  dock, the strip and the page show one string; `fits=1` that the Readouts box is no wider than the dock. Entries in
   `probe-readings.md`. The exit chain also prints one `[readouts]` line (pages registered, the dock page's three
   children, the dock's width, the pages' sensitivity, whether the stream has signals) on every exit-dump run.
 - `UDPSCOPE_PROBE_DOCK_SESSION_MS=2500` with `UDPSCOPE_EXIT_AFTER_MS=8000` -- the session file's `dock` key,

help/C/org.udpscope.app/overview.page

@@ -116,7 +116,8 @@
         shows and hides. Its <gui>Readouts</gui> are a read-only copy of the cursors and of
         every measurement; <gui>Edit</gui> beside each heading opens that instrument's full
         page. Under them, <gui>Events</gui> lists the captured events, newest first; a click
-        replays one and <gui>Manage</gui> opens the full list.</p>
+        replays one and <gui>Manage</gui> opens the full list. While the dock is hidden, the
+        readouts show in a strip under the plot instead.</p>
       </item>
       <item>
         <title>The status bar</title>