Merge Phase D3: persist ViewModeModel in project ext state

src/persist.cpp

@@ -163,10 +163,46 @@ void ReaSamplerSession::saveToActiveProject() {
     const std::string json = bank_.serialize();
     SetProjExtState(static_cast<ReaProject*>(proj), kProjExtNamespace,
                     kProjExtIndexKey, json.c_str());
+
+    // Additive: the Design-View model rides alongside the bank in its own key.
+    // Independent write — does not disturb the bank_index above.
+    const std::string viewJson = view_.serialize();
+    SetProjExtState(static_cast<ReaProject*>(proj), kProjExtNamespace,
+                    kProjExtViewKey, viewJson.c_str());
+
     MarkProjectDirty(static_cast<ReaProject*>(proj));
 }
 
+namespace {
+
+// Load the Design-View model from a project's view_state key, or return a fresh
+// default. An absent/empty key (older project with no view state) yields a
+// default-constructed model (Arrange + Design seeded, active = Arrange) — graceful,
+// never a crash. Malformed JSON is warned and also falls back to default, mirroring
+// the bank's malformed-index handling. The whole model round-trips: modes,
+// membership, show-both, snapshots, and active mode all ride inside the one blob.
+ViewModeModel loadViewModel(ReaProject* proj) {
+    if (!proj) return ViewModeModel{};
+    const std::string viewJson =
+        getProjExtStateString(proj, kProjExtNamespace, kProjExtViewKey);
+    if (viewJson.empty()) return ViewModeModel{};  // no stored view state -> default
+    std::optional<ViewModeModel> loaded = ViewModeModel::deserialize(viewJson);
+    if (!loaded) {
+        ShowConsoleMsg("ReaSampler: stored view state is malformed — ignoring.\n");
+        return ViewModeModel{};
+    }
+    return std::move(*loaded);
+}
+
+}  // namespace
+
 void ReaSamplerSession::loadFromProject(void* proj, const std::string& projectDir) {
+    // The view model is restored on EVERY load path (peer-symmetry with the bank
+    // reset below): switching to a project with no view state must clear stale
+    // in-memory state, not inherit the previous project's. D3 restores MODEL STATE
+    // only — no visibility/processing is applied here (that is D4).
+    view_ = loadViewModel(static_cast<ReaProject*>(proj));
+
     if (!proj) {
         bank_ = BankIndex{};
         return;

src/persist.h

@@ -20,6 +20,7 @@
 #include <string>
 
 #include "bank_model.h"
+#include "view_mode_model.h"
 
 namespace reasampler {
 
@@ -31,6 +32,12 @@ inline constexpr const char* kProjExtNamespace = "reasampler";
 // serialized BankIndex). FOREVER-STABLE for the same reason.
 inline constexpr const char* kProjExtIndexKey = "bank_index";
 
+// The ext-state key the Design-View ViewModeModel JSON is stored under (one key
+// holds the whole serialized model: modes + membership + show-both + snapshots +
+// active mode). Distinct from kProjExtIndexKey — one namespace, two keys.
+// FOREVER-STABLE: changing it orphans every already-saved project's view state.
+inline constexpr const char* kProjExtViewKey = "view_state";
+
 // The ext-state key holding a GUID we mint per project to establish CONTENT-BASED
 // project identity (REAPER exposes no stable per-project GUID). poll() uses it to
 // tell a genuine Save-As (same GUID, new .rpp path) apart from a project switch
@@ -62,6 +69,13 @@ public:
     BankIndex& bank() { return bank_; }
     const BankIndex& bank() const { return bank_; }
 
+    // The in-memory Design-View model. The view/action layer mutates it (tag,
+    // toggle, snapshot); persist serializes it on save and replaces it on project
+    // load — exactly as it treats the bank. D3 persists MODEL STATE only; applying
+    // visibility/processing (reapply-on-open) is D4's job, not this member's.
+    ViewModeModel& view() { return view_; }
+    const ViewModeModel& view() const { return view_; }
+
     // Serialize the current bank to the active project's ext state (namespace
     // "reasampler"). Non-destructive beyond writing our own ext-state key. Safe
     // to call when there is no active/saved project (it no-ops).
@@ -75,6 +89,11 @@ public:
 private:
     BankIndex bank_;
 
+    // The Design-View model. Default-constructed = Arrange + Design seeded, active
+    // = Arrange; loadFromProject leaves this default when a project has no stored
+    // view_state (older project), so an absent key is graceful, not a crash.
+    ViewModeModel view_;
+
     // The project identity last observed by poll(), used to detect load/Save-As.
     // Identity is the GUID we mint per project (kProjExtGuidKey), NOT the raw
     // ReaProject* pointer — see the class comment for why. The .rpp path is