GUI Milestone 8c

CMakeLists.txt

@@ -82,6 +82,7 @@ if(WARPPIPE_BUILD_GUI)
     gui/main.cpp
     gui/WarpGraphModel.cpp
     gui/GraphEditorWidget.cpp
+    gui/PresetManager.cpp
   )
 
   target_link_libraries(warppipe-gui PRIVATE
@@ -96,6 +97,7 @@ if(WARPPIPE_BUILD_GUI)
       tests/gui/warppipe_gui_tests.cpp
       gui/WarpGraphModel.cpp
       gui/GraphEditorWidget.cpp
+      gui/PresetManager.cpp
     )
 
     target_compile_definitions(warppipe-gui-tests PRIVATE WARPPIPE_TESTING)

GUI_PLAN.md

@@ -210,27 +210,27 @@ A Qt6-based node editor GUI for warppipe using the QtNodes (nodeeditor) library.
     - [x] Restore ghosts from layout on load (before live sync)
   - [x] Add middle-click center: `eventFilter` on viewport catches `MiddleButton` → `m_view->centerOn(mapToScene(pos))`
   - [x] Add tests for view state save/load round-trip and ghost persistence
-- [ ] Milestone 8c - Sidebar and Preset System
-  - [ ] Add `QSplitter` between graph view and sidebar panel
-    - [ ] Graph view (stretch factor 1) on left, sidebar (stretch factor 0) on right
-    - [ ] Persist splitter sizes in layout JSON, restore on load
-    - [ ] Default sizes: graph 1200, sidebar 320
-  - [ ] Add `QTabWidget` sidebar with styled tabs (dark theme)
-    - [ ] Tab styling: dark background, selected tab has accent underline
-    - [ ] Initially one tab: "PRESETS" (meters/mixer tabs added in M8d/M8e)
-  - [ ] Implement `PresetManager` class:
-    - [ ] `savePreset(path)` → serialize to JSON:
-      - [ ] Virtual devices: name, description, media_class, channels, rate
-      - [ ] Routing: links by stable_id:port_name pairs
-      - [ ] UI layout: node positions, view state
-    - [ ] `loadPreset(path)` → apply from JSON:
-      - [ ] Create missing virtual devices
-      - [ ] Re-create links from routing entries
-      - [ ] Apply layout positions
-    - [ ] Save on quit via `QCoreApplication::aboutToQuit` signal
-  - [ ] Add "Save Preset..." context menu action → `QFileDialog::getSaveFileName()`
-  - [ ] Add "Load Preset..." context menu action → `QFileDialog::getOpenFileName()`
-  - [ ] Add tests for preset save/load round-trip
+- [x] Milestone 8c - Sidebar and Preset System
+  - [x] Add `QSplitter` between graph view and sidebar panel
+    - [x] Graph view (stretch factor 1) on left, sidebar (stretch factor 0) on right
+    - [x] Persist splitter sizes in layout JSON, restore on load
+    - [x] Default sizes: graph 1200, sidebar 320
+  - [x] Add `QTabWidget` sidebar with styled tabs (dark theme)
+    - [x] Tab styling: dark background, selected tab has accent underline
+    - [x] Initially one tab: "PRESETS" (meters/mixer tabs added in M8d/M8e)
+  - [x] Implement `PresetManager` class:
+    - [x] `savePreset(path)` → serialize to JSON:
+      - [x] Virtual devices: name, description, media_class, channels, rate
+      - [x] Routing: links by stable_id:port_name pairs
+      - [x] UI layout: node positions, view state
+    - [x] `loadPreset(path)` → apply from JSON:
+      - [x] Create missing virtual devices
+      - [x] Re-create links from routing entries
+      - [x] Apply layout positions
+    - [x] Save on quit via `QCoreApplication::aboutToQuit` signal
+  - [x] Add "Save Preset..." context menu action → `QFileDialog::getSaveFileName()`
+  - [x] Add "Load Preset..." context menu action → `QFileDialog::getOpenFileName()`
+  - [x] Add tests for preset save/load round-trip
 - [ ] Milestone 8d - Volume/Mute Controls (requires core API: `SetNodeVolume()`)
   - [ ] Add `NodeVolumeState` struct: `{ float volume; bool mute; }`
   - [ ] Add `ClickSlider : QSlider` — click jumps to position instead of page-stepping

gui/GraphEditorWidget.cpp

@@ -1,4 +1,5 @@
 #include "GraphEditorWidget.h"
+#include "PresetManager.h"
 #include "WarpGraphModel.h"
 
 #include <QtNodes/BasicGraphicsScene>
@@ -11,6 +12,7 @@
 #include <QAction>
 #include <QClipboard>
 #include <QContextMenuEvent>
+#include <QCoreApplication>
 #include <QDateTime>
 #include <QDir>
 #include <QFileDialog>
@@ -21,10 +23,16 @@
 #include <QJsonArray>
 #include <QJsonDocument>
 #include <QMenu>
+#include <QListWidget>
+#include <QMainWindow>
 #include <QMessageBox>
 #include <QMimeData>
 #include <QPixmap>
+#include <QPushButton>
+#include <QSplitter>
 #include <QStandardPaths>
+#include <QStatusBar>
+#include <QTabWidget>
 #include <QTimer>
 #include <QUndoCommand>
 #include <QVBoxLayout>
@@ -142,9 +150,58 @@ GraphEditorWidget::GraphEditorWidget(warppipe::Client *client,
   m_view->viewport()->setFocusPolicy(Qt::StrongFocus);
   m_view->viewport()->installEventFilter(this);
 
+  m_presetDir =
+      QStandardPaths::writableLocation(QStandardPaths::AppConfigLocation) +
+      QStringLiteral("/presets");
+
+  m_sidebar = new QTabWidget();
+  m_sidebar->setTabPosition(QTabWidget::North);
+  m_sidebar->setDocumentMode(true);
+  m_sidebar->setStyleSheet(QStringLiteral(
+      "QTabWidget::pane { border: none; background: #1a1a1e; }"
+      "QTabBar::tab { background: #24242a; color: #a0a8b6; padding: 8px 16px;"
+      "  border: none; border-bottom: 2px solid transparent; }"
+      "QTabBar::tab:selected { color: #ecf0f6;"
+      "  border-bottom: 2px solid #ffa500; }"
+      "QTabBar::tab:hover { background: #2e2e36; }"));
+
+  auto *presetsTab = new QWidget();
+  auto *presetsLayout = new QVBoxLayout(presetsTab);
+  presetsLayout->setContentsMargins(8, 8, 8, 8);
+  presetsLayout->setSpacing(6);
+
+  auto *savePresetBtn = new QPushButton(QStringLiteral("Save Preset..."));
+  savePresetBtn->setStyleSheet(QStringLiteral(
+      "QPushButton { background: #2e2e36; color: #ecf0f6; border: 1px solid #3a3a44;"
+      "  border-radius: 4px; padding: 6px 12px; }"
+      "QPushButton:hover { background: #3a3a44; }"
+      "QPushButton:pressed { background: #44444e; }"));
+  connect(savePresetBtn, &QPushButton::clicked, this,
+          &GraphEditorWidget::savePreset);
+
+  auto *loadPresetBtn = new QPushButton(QStringLiteral("Load Preset..."));
+  loadPresetBtn->setStyleSheet(savePresetBtn->styleSheet());
+  connect(loadPresetBtn, &QPushButton::clicked, this,
+          &GraphEditorWidget::loadPreset);
+
+  presetsLayout->addWidget(savePresetBtn);
+  presetsLayout->addWidget(loadPresetBtn);
+  presetsLayout->addStretch();
+
+  m_sidebar->addTab(presetsTab, QStringLiteral("PRESETS"));
+
+  m_splitter = new QSplitter(Qt::Horizontal);
+  m_splitter->addWidget(m_view);
+  m_splitter->addWidget(m_sidebar);
+  m_splitter->setStretchFactor(0, 1);
+  m_splitter->setStretchFactor(1, 0);
+  m_splitter->setSizes({1200, 320});
+  m_splitter->setStyleSheet(QStringLiteral(
+      "QSplitter::handle { background: #2a2a32; width: 2px; }"));
+
   auto *layout = new QVBoxLayout(this);
   layout->setContentsMargins(0, 0, 0, 0);
-  layout->addWidget(m_view);
+  layout->addWidget(m_splitter);
 
   m_view->setContextMenuPolicy(Qt::CustomContextMenu);
   connect(m_view, &QWidget::customContextMenuRequested, this,
@@ -266,6 +323,9 @@ GraphEditorWidget::GraphEditorWidget(warppipe::Client *client,
     Q_EMIT graphReady();
   }
 
+  connect(QCoreApplication::instance(), &QCoreApplication::aboutToQuit, this,
+          &GraphEditorWidget::saveLayoutWithViewState);
+
   m_refreshTimer = new QTimer(this);
   connect(m_refreshTimer, &QTimer::timeout, this,
           &GraphEditorWidget::onRefreshTimer);
@@ -430,6 +490,9 @@ void GraphEditorWidget::showCanvasContextMenu(const QPoint &screenPos,
   menu.addSeparator();
   QAction *saveLayoutAs = menu.addAction(QStringLiteral("Save Layout As..."));
   QAction *resetLayout = menu.addAction(QStringLiteral("Reset Layout"));
+  menu.addSeparator();
+  QAction *savePresetAction = menu.addAction(QStringLiteral("Save Preset..."));
+  QAction *loadPresetAction = menu.addAction(QStringLiteral("Load Preset..."));
 
   QAction *chosen = menu.exec(screenPos);
   if (chosen == createSink) {
@@ -466,6 +529,10 @@ void GraphEditorWidget::showCanvasContextMenu(const QPoint &screenPos,
     m_model->autoArrange();
     m_view->zoomFitAll();
     saveLayoutWithViewState();
+  } else if (chosen == savePresetAction) {
+    savePreset();
+  } else if (chosen == loadPresetAction) {
+    loadPreset();
   }
 }
 
@@ -868,6 +935,9 @@ void GraphEditorWidget::saveLayoutWithViewState() {
   QPointF center = m_view->mapToScene(m_view->viewport()->rect().center());
   vs.centerX = center.x();
   vs.centerY = center.y();
+  QList<int> sizes = m_splitter->sizes();
+  vs.splitterGraph = sizes.value(0, 1200);
+  vs.splitterSidebar = sizes.value(1, 320);
   vs.valid = true;
   m_model->saveLayout(m_layoutPath, vs);
 }
@@ -877,7 +947,50 @@ void GraphEditorWidget::restoreViewState() {
   if (vs.valid) {
     m_view->setupScale(vs.scale);
     m_view->centerOn(QPointF(vs.centerX, vs.centerY));
+    if (vs.splitterGraph > 0 || vs.splitterSidebar > 0) {
+      m_splitter->setSizes({vs.splitterGraph, vs.splitterSidebar});
+    }
   } else {
     m_view->zoomFitAll();
   }
 }
+
+void GraphEditorWidget::savePreset() {
+  QDir dir(m_presetDir);
+  if (!dir.exists())
+    dir.mkpath(".");
+
+  QString path = QFileDialog::getSaveFileName(
+      this, QStringLiteral("Save Preset"), m_presetDir,
+      QStringLiteral("JSON files (*.json)"));
+  if (path.isEmpty())
+    return;
+  if (!path.endsWith(QStringLiteral(".json"), Qt::CaseInsensitive))
+    path += QStringLiteral(".json");
+
+  if (PresetManager::savePreset(path, m_client, m_model)) {
+    if (auto *mw = qobject_cast<QMainWindow *>(window()))
+      mw->statusBar()->showMessage(
+          QStringLiteral("Preset saved: ") + QFileInfo(path).fileName(), 4000);
+  } else {
+    QMessageBox::warning(this, QStringLiteral("Error"),
+                         QStringLiteral("Failed to save preset."));
+  }
+}
+
+void GraphEditorWidget::loadPreset() {
+  QString path = QFileDialog::getOpenFileName(
+      this, QStringLiteral("Load Preset"), m_presetDir,
+      QStringLiteral("JSON files (*.json)"));
+  if (path.isEmpty())
+    return;
+
+  if (PresetManager::loadPreset(path, m_client, m_model)) {
+    if (auto *mw = qobject_cast<QMainWindow *>(window()))
+      mw->statusBar()->showMessage(
+          QStringLiteral("Preset loaded: ") + QFileInfo(path).fileName(), 4000);
+  } else {
+    QMessageBox::warning(this, QStringLiteral("Error"),
+                         QStringLiteral("Failed to load preset."));
+  }
+}

gui/GraphEditorWidget.h

@@ -18,6 +18,8 @@ class GraphicsView;
 
 class WarpGraphModel;
 class QLabel;
+class QSplitter;
+class QTabWidget;
 class QTimer;
 class DeleteVirtualNodeCommand;
 
@@ -60,6 +62,8 @@ private:
   void tryResolvePendingLinks();
   void saveLayoutWithViewState();
   void restoreViewState();
+  void savePreset();
+  void loadPreset();
 
   struct PendingPasteLink {
     std::string outNodeName;
@@ -72,9 +76,12 @@ private:
   WarpGraphModel *m_model = nullptr;
   QtNodes::BasicGraphicsScene *m_scene = nullptr;
   QtNodes::GraphicsView *m_view = nullptr;
+  QSplitter *m_splitter = nullptr;
+  QTabWidget *m_sidebar = nullptr;
   QTimer *m_refreshTimer = nullptr;
   QTimer *m_saveTimer = nullptr;
   QString m_layoutPath;
+  QString m_presetDir;
   QString m_debugScreenshotDir;
   bool m_graphReady = false;
   QJsonObject m_clipboardJson;

gui/PresetManager.cpp

@@ -0,0 +1,177 @@
+#include "PresetManager.h"
+#include "WarpGraphModel.h"
+
+#include <QDir>
+#include <QFile>
+#include <QFileInfo>
+#include <QJsonArray>
+#include <QJsonDocument>
+#include <QJsonObject>
+
+bool PresetManager::savePreset(const QString &path, warppipe::Client *client,
+                               const WarpGraphModel *model) {
+  if (!client || !model)
+    return false;
+
+  QJsonArray devicesArray;
+  auto nodesResult = client->ListNodes();
+  if (nodesResult.ok()) {
+    for (const auto &node : nodesResult.value) {
+      if (!node.is_virtual)
+        continue;
+      QJsonObject dev;
+      dev["name"] = QString::fromStdString(node.name);
+      dev["description"] = QString::fromStdString(node.description);
+      dev["media_class"] = QString::fromStdString(node.media_class);
+
+      auto portsResult = client->ListPorts(node.id);
+      int channels = 0;
+      if (portsResult.ok()) {
+        for (const auto &port : portsResult.value) {
+          if (port.is_input)
+            ++channels;
+        }
+        if (channels == 0) {
+          for (const auto &port : portsResult.value) {
+            if (!port.is_input)
+              ++channels;
+          }
+        }
+      }
+      dev["channels"] = channels > 0 ? channels : 2;
+      devicesArray.append(dev);
+    }
+  }
+
+  QJsonArray routingArray;
+  auto linksResult = client->ListLinks();
+  if (linksResult.ok() && nodesResult.ok()) {
+    std::unordered_map<uint32_t, std::pair<std::string, std::string>> portMap;
+    for (const auto &node : nodesResult.value) {
+      auto portsResult = client->ListPorts(node.id);
+      if (!portsResult.ok())
+        continue;
+      for (const auto &port : portsResult.value) {
+        portMap[port.id.value] = {node.name, port.name};
+      }
+    }
+
+    for (const auto &link : linksResult.value) {
+      auto outIt = portMap.find(link.output_port.value);
+      auto inIt = portMap.find(link.input_port.value);
+      if (outIt == portMap.end() || inIt == portMap.end())
+        continue;
+      QJsonObject route;
+      route["out_node"] = QString::fromStdString(outIt->second.first);
+      route["out_port"] = QString::fromStdString(outIt->second.second);
+      route["in_node"] = QString::fromStdString(inIt->second.first);
+      route["in_port"] = QString::fromStdString(inIt->second.second);
+      routingArray.append(route);
+    }
+  }
+
+  QJsonArray layoutArray;
+  for (auto qtId : model->allNodeIds()) {
+    const WarpNodeData *data = model->warpNodeData(qtId);
+    if (!data)
+      continue;
+    QPointF pos =
+        model->nodeData(qtId, QtNodes::NodeRole::Position).toPointF();
+    QJsonObject nodeLayout;
+    nodeLayout["name"] = QString::fromStdString(data->info.name);
+    nodeLayout["x"] = pos.x();
+    nodeLayout["y"] = pos.y();
+    layoutArray.append(nodeLayout);
+  }
+
+  QJsonObject root;
+  root["version"] = 1;
+  root["virtual_devices"] = devicesArray;
+  root["routing"] = routingArray;
+  root["layout"] = layoutArray;
+
+  QFileInfo fi(path);
+  QDir dir = fi.absoluteDir();
+  if (!dir.exists())
+    dir.mkpath(".");
+
+  QFile file(path);
+  if (!file.open(QIODevice::WriteOnly | QIODevice::Truncate))
+    return false;
+  file.write(QJsonDocument(root).toJson(QJsonDocument::Indented));
+  return true;
+}
+
+bool PresetManager::loadPreset(const QString &path, warppipe::Client *client,
+                               WarpGraphModel *model) {
+  if (!client || !model)
+    return false;
+
+  QFile file(path);
+  if (!file.open(QIODevice::ReadOnly))
+    return false;
+
+  QJsonDocument doc = QJsonDocument::fromJson(file.readAll());
+  if (!doc.isObject())
+    return false;
+
+  QJsonObject root = doc.object();
+  int version = root["version"].toInt();
+  if (version < 1 || version > 1)
+    return false;
+
+  auto existingNodes = client->ListNodes();
+  std::unordered_set<std::string> existingNames;
+  if (existingNodes.ok()) {
+    for (const auto &node : existingNodes.value) {
+      existingNames.insert(node.name);
+    }
+  }
+
+  QJsonArray devicesArray = root["virtual_devices"].toArray();
+  for (const auto &val : devicesArray) {
+    QJsonObject dev = val.toObject();
+    std::string name = dev["name"].toString().toStdString();
+    std::string mediaClass = dev["media_class"].toString().toStdString();
+    int channels = dev["channels"].toInt(2);
+
+    if (existingNames.count(name))
+      continue;
+
+    warppipe::VirtualNodeOptions opts;
+    opts.format.channels = static_cast<uint32_t>(channels);
+
+    bool isSink = mediaClass == "Audio/Sink" || mediaClass == "Audio/Duplex";
+    if (isSink) {
+      client->CreateVirtualSink(name, opts);
+    } else {
+      client->CreateVirtualSource(name, opts);
+    }
+  }
+
+  QJsonArray layoutArray = root["layout"].toArray();
+  for (const auto &val : layoutArray) {
+    QJsonObject obj = val.toObject();
+    std::string name = obj["name"].toString().toStdString();
+    double x = obj["x"].toDouble();
+    double y = obj["y"].toDouble();
+    model->setPendingPosition(name, QPointF(x, y));
+  }
+
+  model->refreshFromClient();
+
+  QJsonArray routingArray = root["routing"].toArray();
+  for (const auto &val : routingArray) {
+    QJsonObject route = val.toObject();
+    std::string outNode = route["out_node"].toString().toStdString();
+    std::string outPort = route["out_port"].toString().toStdString();
+    std::string inNode = route["in_node"].toString().toStdString();
+    std::string inPort = route["in_port"].toString().toStdString();
+
+    client->CreateLinkByName(outNode, outPort, inNode, inPort,
+                             warppipe::LinkOptions{});
+  }
+
+  model->refreshFromClient();
+  return true;
+}

gui/PresetManager.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <warppipe/warppipe.hpp>
+
+#include <QString>
+
+class WarpGraphModel;
+
+class PresetManager {
+public:
+  static bool savePreset(const QString &path, warppipe::Client *client,
+                         const WarpGraphModel *model);
+  static bool loadPreset(const QString &path, warppipe::Client *client,
+                         WarpGraphModel *model);
+};

gui/WarpGraphModel.cpp

@@ -810,6 +810,10 @@ void WarpGraphModel::saveLayout(const QString &path,
     viewObj["scale"] = viewState.scale;
     viewObj["center_x"] = viewState.centerX;
     viewObj["center_y"] = viewState.centerY;
+    if (viewState.splitterGraph > 0 || viewState.splitterSidebar > 0) {
+      viewObj["splitter_graph"] = viewState.splitterGraph;
+      viewObj["splitter_sidebar"] = viewState.splitterSidebar;
+    }
     root["view"] = viewObj;
   }
 
@@ -867,6 +871,8 @@ bool WarpGraphModel::loadLayout(const QString &path) {
     m_savedViewState.scale = viewObj["scale"].toDouble(1.0);
     m_savedViewState.centerX = viewObj["center_x"].toDouble();
     m_savedViewState.centerY = viewObj["center_y"].toDouble();
+    m_savedViewState.splitterGraph = viewObj["splitter_graph"].toInt(0);
+    m_savedViewState.splitterSidebar = viewObj["splitter_sidebar"].toInt(0);
     m_savedViewState.valid = true;
   }
 

gui/WarpGraphModel.h

@@ -73,6 +73,8 @@ public:
     double scale;
     double centerX;
     double centerY;
+    int splitterGraph;
+    int splitterSidebar;
     bool valid;
   };
 

tests/gui/warppipe_gui_tests.cpp

@@ -1,11 +1,15 @@
 #include <warppipe/warppipe.hpp>
 
 #include "../../gui/GraphEditorWidget.h"
+#include "../../gui/PresetManager.h"
 #include "../../gui/WarpGraphModel.h"
 
 #include <QAction>
 #include <QApplication>
 #include <QFile>
+#include <QJsonArray>
+#include <QJsonDocument>
+#include <QJsonObject>
 #include <QStandardPaths>
 
 #include <catch2/catch_test_macros.hpp>
@@ -849,3 +853,113 @@ TEST_CASE("clearSavedPositions resets model positions") {
 
   REQUIRE(posAfter != QPointF(0, 0));
 }
+
+TEST_CASE("preset save/load round-trip preserves virtual devices and layout") {
+  auto tc = TestClient::Create();
+  if (!tc.available()) { SUCCEED("PipeWire unavailable"); return; }
+  ensureApp();
+
+  REQUIRE(tc.client->Test_InsertNode(
+      MakeNode(100500, "preset-vsink", "Audio/Sink", {}, {}, true)).ok());
+  REQUIRE(tc.client->Test_InsertPort(
+      MakePort(100501, 100500, "FL", true)).ok());
+  REQUIRE(tc.client->Test_InsertPort(
+      MakePort(100502, 100500, "FR", true)).ok());
+
+  REQUIRE(tc.client->Test_InsertNode(
+      MakeNode(100503, "preset-src", "Audio/Source")).ok());
+  REQUIRE(tc.client->Test_InsertPort(
+      MakePort(100504, 100503, "out_FL", false)).ok());
+
+  REQUIRE(tc.client->Test_InsertLink(
+      MakeLink(100505, 100504, 100501)).ok());
+
+  WarpGraphModel model(tc.client.get());
+  model.refreshFromClient();
+  model.setNodeData(model.qtNodeIdForPw(100500),
+                    QtNodes::NodeRole::Position, QPointF(300, 400));
+
+  QString path = QStandardPaths::writableLocation(
+                     QStandardPaths::TempLocation) +
+                 "/warppipe_test_preset.json";
+  REQUIRE(PresetManager::savePreset(path, tc.client.get(), &model));
+
+  QFile file(path);
+  REQUIRE(file.open(QIODevice::ReadOnly));
+  QJsonDocument doc = QJsonDocument::fromJson(file.readAll());
+  file.close();
+  REQUIRE(doc.isObject());
+
+  QJsonObject root = doc.object();
+  REQUIRE(root["version"].toInt() == 1);
+  REQUIRE(root["virtual_devices"].toArray().size() >= 1);
+  REQUIRE(root["routing"].toArray().size() >= 1);
+  REQUIRE(root["layout"].toArray().size() >= 2);
+
+  bool foundVsink = false;
+  for (const auto &val : root["virtual_devices"].toArray()) {
+    if (val.toObject()["name"].toString() == "preset-vsink") {
+      foundVsink = true;
+      REQUIRE(val.toObject()["channels"].toInt() == 2);
+    }
+  }
+  REQUIRE(foundVsink);
+
+  bool foundRoute = false;
+  for (const auto &val : root["routing"].toArray()) {
+    QJsonObject route = val.toObject();
+    if (route["out_node"].toString() == "preset-src" &&
+        route["in_node"].toString() == "preset-vsink") {
+      foundRoute = true;
+    }
+  }
+  REQUIRE(foundRoute);
+
+  bool foundLayout = false;
+  for (const auto &val : root["layout"].toArray()) {
+    QJsonObject obj = val.toObject();
+    if (obj["name"].toString() == "preset-vsink") {
+      foundLayout = true;
+      REQUIRE(obj["x"].toDouble() == Catch::Approx(300.0));
+      REQUIRE(obj["y"].toDouble() == Catch::Approx(400.0));
+    }
+  }
+  REQUIRE(foundLayout);
+
+  QFile::remove(path);
+}
+
+TEST_CASE("splitter sizes persist in layout JSON") {
+  auto tc = TestClient::Create();
+  if (!tc.available()) { SUCCEED("PipeWire unavailable"); return; }
+  ensureApp();
+
+  REQUIRE(tc.client->Test_InsertNode(
+      MakeNode(100510, "splitter-node", "Audio/Sink")).ok());
+
+  WarpGraphModel model(tc.client.get());
+  model.refreshFromClient();
+
+  WarpGraphModel::ViewState vs;
+  vs.scale = 1.0;
+  vs.centerX = 0.0;
+  vs.centerY = 0.0;
+  vs.splitterGraph = 900;
+  vs.splitterSidebar = 400;
+  vs.valid = true;
+
+  QString path = QStandardPaths::writableLocation(
+                     QStandardPaths::TempLocation) +
+                 "/warppipe_test_splitter.json";
+  model.saveLayout(path, vs);
+
+  WarpGraphModel model2(tc.client.get());
+  model2.loadLayout(path);
+
+  auto restored = model2.savedViewState();
+  REQUIRE(restored.valid);
+  REQUIRE(restored.splitterGraph == 900);
+  REQUIRE(restored.splitterSidebar == 400);
+
+  QFile::remove(path);
+}