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/shell/view/view.h

@@ -0,0 +1,96 @@
+#include "core/namespaces.h"
+#pragma once
+// view — the REAPER-facing shell of the Design View feature (Phase D2). It is the
+// mirror of the capture shell: the ViewModeModel (pure, D1) holds the mode/
+// membership/snapshot state and emits the toggle plan; this shell reads the live
+// project's folder tree, snapshots the tracks it is about to park, runs the model's
+// planner, and applies the resulting flag + per-FX-offline writes to REAPER.
+//
+// It includes view_mode_model (pure) but NO REAPER headers — the .cpp is the one
+// REAPER-facing translation unit (CLAUDE.md §contract: only main.cpp defines the
+// API pointers; every other .cpp gets them extern). Callers (persist, actions)
+// depend on this seam without dragging the SDK into their include sites.
+//
+// Hard invariants this shell enforces (CONTEXT.md §Design View, precision
+// invariants) — verified in self-review, never crossed:
+//   * Never touches the master track's visibility (SDK forbids B_SHOWINTCP/
+//     B_SHOWINMIXER on master); the master is never a node in the tree.
+//   * Never reads or writes B_MUTE / I_SOLO on any track.
+//   * Manages ALL leaves via the mode system: an untagged leaf is an Arrange member,
+//     so it is fully parked in non-Arrange modes and restored in Arrange, identically
+//     to a tagged leaf. show-both is the always-visible escape; parents are
+//     visibility-only (derived); the master is never touched.
+//   * Snapshots every to-be-parked track's prior flags BEFORE parking, storing
+//     them into the model so restore is faithful and survives a save-while-parked.
+
+#include <string>
+
+#include "core/view/view_mode_model.h"
+
+// REAPER's opaque project handle. Forward-declared to keep this header SDK-free;
+// the .cpp includes reaper_plugin_functions.h and sees the real class.
+class ReaProject;
+
+namespace reasampler {
+
+// Applies `targetModeId` to the live project `proj`:
+//   1. Reads the arrange-ordered track list, builds the FolderTree from
+//      I_FOLDERDEPTH (via the pure buildFolderTree helper).
+//   2. Runs model.planToggle(tree, targetModeId).
+//   3. For each track about to be PARKED: snapshots its current B_SHOWINTCP /
+//      B_SHOWINMIXER / B_MAINSEND / I_FXEN and per-FX offline state, stores the
+//      snapshot into the model, THEN applies the park writes (expanding the
+//      per-FX offline loop from TrackFX_GetCount, which the pure plan leaves empty).
+//   4. For each track to RESTORE: applies the plan's snapshot-sourced flag + per-FX
+//      offline writes verbatim.
+//   5. For each PARENT (folder) node: drives B_SHOWINTCP / B_SHOWINMIXER to 1 if the
+//      parent is in model.visibleTracks(tree, targetModeId), else 0 — derived from
+//      membership, never parked/snapshotted. Only the two visibility flags.
+//   6. Sets the model's active mode to `targetModeId`.
+// All track mutations are wrapped in Undo_BeginBlock2 / Undo_EndBlock2.
+//
+// Returns false (no mutation, active mode unchanged) if `targetModeId` is not a
+// registered mode. `proj` may be nullptr to mean REAPER's current project.
+bool applyMode(ViewModeModel& model, const std::string& targetModeId, ReaProject* proj);
+
+// Mints managed fixed lanes for any track in `proj` that is VISIBLE IN MORE THAN ONE
+// MODE while carrying its own media, and assigns each item to its mode's managed lane
+// (Phase D2 Wave 3; visibility trigger added by the folder-media fix).
+//   1. Enumerates every track + its items; resolves each item's mode from the model's
+//      membership (untagged ⇒ Arrange) and reads whether it currently sits on a MANUAL
+//      lane (exempt). Builds the FolderTree (I_FOLDERDEPTH) so derived visibility counts.
+//   2. Runs the pure planLaneMinting decision (model + tree aware). A track visible in
+//      exactly one mode is left whole-track-parked (D1) — NOT lane-split. A track visible
+//      in >1 mode while carrying own media splits: its own items span modes, OR it is a
+//      content-bearing folder derived-visible across modes. show-both tracks never split.
+//   3. For each track that must split: enables fixed-lane mode (I_FREEMODE=2), ensures
+//      enough fixed lanes (I_NUMFIXEDLANES), stamps each managed lane's durable name
+//      (P_LANENAME:n), records the lane MANAGED-for-its-mode in the model's ownership
+//      index, and assigns each managed-eligible item to its mode's lane (I_FIXEDLANE).
+//      Manual lanes and the items on them are NEVER minted-over or reassigned.
+//   4. Reapplies the active mode's lane visibility so the just-minted lanes take their
+//      correct play/show state immediately (the active mode's lane plays; others hide).
+// The whole structural mutation is wrapped in ONE Undo_BeginBlock2/EndBlock2 — but only
+// when the plan is non-empty (no undo point for a tick that mints nothing).
+//
+// Returns true if any lane was minted this call (⇒ the caller may want a repaint).
+// `proj` may be nullptr to mean REAPER's current project. READ of the membership index
+// only; the sole model mutation is recording new managed-lane ownership.
+bool mintManagedLanes(ViewModeModel& model, ReaProject* proj);
+
+// Reconciles the model's lane-ownership index against the live project's lanes on
+// project open (Phase D2 Wave 3). REAPER's durable P_LANENAME is the source of truth for
+// lane identity across sessions (design point #2): a lane whose name carries the managed
+// prefix is tool-managed and owned by the mode encoded in that name. This walks every
+// track's lanes and records each managed-named lane MANAGED-for-its-mode in the index —
+// self-healing a saved project's classification WITHOUT re-minting (it never creates a
+// lane, changes I_FREEMODE/I_NUMFIXEDLANES, or reassigns an item) and WITHOUT mass-
+// tagging (it never touches membership). A lane without the managed prefix is left
+// untouched (manual by default). Reload's active-mode lane visibility is then reapplied
+// by the caller's applyMode, mirroring D1's reapply-on-open.
+//
+// `proj` may be nullptr to mean REAPER's current project. The only model mutation is
+// recording managed ownership recovered from durable lane names.
+void reconcileManagedLanes(ViewModeModel& model, ReaProject* proj);
+
+} // namespace reasampler