docs: the readouts strip follows the collapsed state

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

docs/USER-GUIDE.md

@@ -21,8 +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. 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).
+  page, and an **Events** block. With the dock hidden, or in a narrow window where the dock slides over the plot, 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

@@ -135,12 +135,14 @@ touching the data path.
   (`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
+  `left_column`; filled by `ui_dock.cpp`) carries the same readouts when the dock is not beside the plot: 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
+  measurement. `sync_readouts_strip()` shows it exactly when `!adw_overlay_split_view_get_show_sidebar() ||
+  adw_overlay_split_view_get_collapsed()` -- the Dock button put the dock away, or the window is collapsed and
+  the dock is an overlay on the plot (the strip stays on screen even while that overlay is open). 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); that means the `collapsed` it reads is the previous
+  frame's, and the strip follows a collapse or a widening one tick late, never through a wrong state. 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

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

@@ -148,18 +148,20 @@ 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.**
+- **The readouts strip is a fixed 26 px, scrolls sideways, and is shown whenever the dock is not beside the plot.**
   `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.
+  strip, the same as for the badge bar. It is *visible* exactly when `show-sidebar` is false **or** the split view is `collapsed`
+  (`sync_readouts_strip()`, from the tick after the wish is re-asserted and before `set_collapsed()` -- so
+  `show-sidebar` is the wish and not the split view's collapse-time write, and `collapsed` is the previous
+  frame's value). Hidden only with a wide window and the dock beside the plot, so the plot's 26 px go to one
+  pane of readouts and never both; in a collapsed window the dock is an overlay on the plot and the strip
+  stays, overlay open or not. The plot is 26 px shorter while it shows; that is the dock's and the window's
+  state moving the layout, not content. Reading `h=26` with `visible=1` (and `h=0` with `visible=0`) in
+  `strip:` is the assertion, and `visible_ok=1` that `visible` equals `expected`.
 - **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

@@ -58,7 +58,7 @@ Part of [CLAUDE.md](../../CLAUDE.md). These are rules that cost a defect to lear
   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
+  not beside the plot (hidden, or the window collapsed so the dock is an overlay) 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

docs/claude/probe-readings.md

@@ -1845,20 +1845,21 @@ These ride on the `[cursors-probe]` readings (every state line gets a `dock curs
 ## `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 ...
+[cursors-probe]  <what> strip: visible=1 expected=1 visible_ok=1 dock_shown=1 cursors=4 measures=0 same_text=1 h=26 sens_same=1 collapsed=1 window=756
+[measures-probe] <what> strip: visible=1 expected=1 visible_ok=1 dock_shown=1 cursors=0 measures=12 same_text=1 h=26 sens_same=1 collapsed=1 window=756
+[cursors-probe]  dock hidden strip: visible=1 expected=1 visible_ok=1 dock_shown=0 cursors=4 measures=0 same_text=1 h=26 sens_same=1 ...
+[cursors-probe]  dock restored strip: visible=1 expected=1 visible_ok=1 dock_shown=1 ... collapsed=1 window=756
 ```
 
 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.
+- **`visible` equals `expected`, and `expected = !dock_shown || collapsed`** (`dock_shown` is `show-sidebar`, `collapsed` the split view's, both read in the same frame as `visible`). `visible_ok=1` is that equality; `visible_ok=0` is `sync_readouts_strip()` not run, or run before the reconciliation. A single such line right after the probe's own `update_side_visibility()` or on the very first line (the tick has not set `collapsed` yet) is the sub-frame before the next tick and not a defect.
+- **`visible=1 expected=1` on every line under `xvfb-run`**, the `dock restored` line and the lines with `dock_shown=1` included: the window is 756 px, below the 900 px `kSidebarRoom`, so the split view is collapsed, the dock is an overlay on the plot, and the strip stays. `visible=0` there is the old rule (hidden whenever the dock is shown) or `collapsed` not being read. The wide case (`collapsed=0`, `dock_shown=1`, `visible=0 expected=0`) is **not reachable from a probe**, because a window with no manager cannot be resized by `gtk_window_set_default_size()`.
 - **`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).
+- **`collapsed=1 window=756`** on every line under `xvfb-run`; the very first line can read `collapsed=0` (the tick has not set it yet), and then `expected` follows it.
 
 ## `[sidebar-probe]`
 

docs/claude/verification.md

@@ -438,8 +438,9 @@ precedent, not an exception.
 - `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, each with a `strip:` line beside it (the readouts strip,
-  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
+  shown when `!dock_shown || collapsed`; `expected=` is that, `visible_ok=1` that the strip agrees); each probe
+  ends by hiding the dock for 0.6 s and reading the strip (`dock hidden`, `dock restored`: under xvfb the
+  window is collapsed, so `visible=1 expected=1 h=26 same_text=1` on both). **`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.