Q-W1 pt2: core/shell/app relocation + sub-namespaces; one concrete ui::Rect (LTRB fork retired); slot_map split from bank_book; BankIndex→BankModel; 59/59 green

src/core/capture/tail_control.h

@@ -0,0 +1,70 @@
+#pragma once
+// tail_control — the REAPER-free logic behind the docked bank_panel's tail-mode
+// toggle. The panel shell (bank_panel.cpp) owns the SWELL window, LICE drawing, and
+// click hit-testing; what is NOT DAW-bound — the cycle order, the manual-length
+// clamp, and the toggle's label text — lives here so it is unit-tested outside the
+// DAW (CLAUDE.md §load-bearing split). Mirror of bank_grid / mode_switch.
+//
+// PURE MODULE: NO REAPER types, NO SWELL, NO vendor/ includes. Standard library
+// only (plus render_settings for the pure TailMode enum). Builds and unit-tests
+// without REAPER.
+
+#include <optional>
+#include <string>
+
+#include "core/capture/render_settings.h"  // TailMode (pure enum) — the three-state tail contract
+
+namespace reasampler::capture {
+
+// The Manual-mode starting length. 2 s is a musically useful default tail (a bar of
+// reverb throw at a moderate tempo) that is well under the 8 s cap. Also the value a
+// project with no stored tail setting (older / never-adjusted) falls back to on load.
+inline constexpr double kDefaultManualTailMs = 2000.0;
+
+// The fine-adjust step per scroll-wheel notch in Manual mode. 250 ms is coarse enough
+// that a few notches cover the useful range, fine enough to dial a length precisely.
+// Daniel-set. The panel maps one wheel notch to +/- this many ms via adjustManualMs.
+inline constexpr double kManualStepMs = 250.0;
+
+// The panel's current tail setting: the mode plus the length used ONLY when the
+// mode is Manual. Held as in-memory panel/session state (bank_panel.cpp), default
+// None so a capture with no explicit choice stays exact-bounds / byte-identical to
+// today. `manualMs` is a stored default a future fine-adjust UI can tune; it is
+// clamped to the 8 s cap (kMaxTailMs) before it ever reaches a CaptureRequest.
+struct TailSetting {
+    TailMode mode     = TailMode::None;
+    double   manualMs = kDefaultManualTailMs;
+};
+
+// Cycles the tail mode: None -> Auto -> Manual -> None. Pure so the wrap order is
+// pinned by a test and the panel's click handler owns no enum arithmetic of its own.
+// An out-of-range value (unreachable for a valid enum) cycles back to None.
+TailMode cycleTailMode(TailMode current);
+
+// The effective manual length a Manual capture uses: `manualMs` clamped to
+// [0, kMaxTailMs] (the runaway guard the pure tailRenderSettingsFor also applies).
+// Exposed so the panel can show the clamped value and main.cpp hands a pre-clamped
+// tailMs into the CaptureRequest. Meaningful only for TailMode::Manual.
+double clampManualMs(double manualMs);
+
+// Applies `notches` scroll-wheel steps of `stepMs` each to `current`, clamped to
+// [0, kMaxTailMs]. Positive notches lengthen, negative shorten. Pure so the fine-adjust
+// arithmetic (and its clamp at both bounds) is unit-tested; the panel wheel handler
+// owns no arithmetic of its own. Meaningful only for TailMode::Manual.
+double adjustManualMs(double current, int notches, double stepMs);
+
+// The toggle's label for a setting, e.g. "Tail: Off", "Tail: Auto". In Manual mode the
+// clamped length is appended in seconds to one decimal, e.g. "Tail: Manual 2.0s" —
+// Off/Auto carry no length. Pure so the exact strings (and the Manual format) are
+// test-pinned, including the boundary lengths (0.0s, 8.0s).
+std::string tailToggleLabel(const TailSetting& setting);
+
+// JSON round-trip of a TailSetting (mode + manualMs), for persist to store the tail
+// setting per-project alongside the bank and view model. Kept pure/testable here —
+// the natural home, mirroring bank_model's serialize/deserialize. serialize emits a
+// compact object; deserialize returns std::nullopt on malformed input so the caller
+// (persist) falls back to a default setting, exactly as an absent key does.
+std::string serializeTailSetting(const TailSetting& setting);
+std::optional<TailSetting> deserializeTailSetting(const std::string& json);
+
+} // namespace reasampler::capture