viewer: Phase 1a — dockable shell with saved perspectives

Make the layout reconfigurable, the foundation for the redesign:

- The diffraction image becomes the central widget; the right-hand side panel
  is now a dockable "Inspector" (QDockWidget, right area).
- Every dock and toolbar gets a stable objectName so QMainWindow saveState /
  restoreState round-trips. Dataset-info docks are numbered uniquely.
- Persist geometry + dock state to QSettings on close and restore on launch,
  so the user's arrangement resumes.
- New "View" menu with Image / Processing perspectives (show/hide the bottom
  plots + jobs panel) and "Reset layout" (back to the as-built arrangement,
  captured at startup).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

viewer/JFJochViewerMenu.cpp

@@ -65,6 +65,15 @@ JFJochViewerMenu::JFJochViewerMenu(QWidget *parent) : QMenuBar(parent) {
     const QAction *dockCalibration = dockMenu->addAction("New dataset info plot");
     connect(dockCalibration, &QAction::triggered, [this] { emit openDatasetInfo();});
 
+    QMenu *viewMenu = addMenu("View");
+    const QAction *imageLayout = viewMenu->addAction("Image layout");
+    connect(imageLayout, &QAction::triggered, this, &JFJochViewerMenu::imageLayoutSelected);
+    const QAction *processingLayout = viewMenu->addAction("Processing layout");
+    connect(processingLayout, &QAction::triggered, this, &JFJochViewerMenu::processingLayoutSelected);
+    viewMenu->addSeparator();
+    const QAction *resetLayout = viewMenu->addAction("Reset layout");
+    connect(resetLayout, &QAction::triggered, this, &JFJochViewerMenu::resetLayoutSelected);
+
     QMenu *helpMenu = addMenu("Help");
     // Add "About" action
     const QAction *aboutAction = helpMenu->addAction("About");

viewer/JFJochViewerMenu.h

@@ -39,6 +39,10 @@ signals:
     void clearUserMaskSelected();
     void openDatasetInfo();
 
+    void imageLayoutSelected();
+    void processingLayoutSelected();
+    void resetLayoutSelected();
+
 private slots:
     void aboutSelected();
     void licensesSelected();

viewer/JFJochViewerWindow.cpp

@@ -3,12 +3,14 @@
 
 #include "JFJochViewerWindow.h"
 
-#include <QSplitter>
 #include <QThread>
 #include <QDockWidget>
 #include <QKeyEvent>
 #include <QGuiApplication>
 #include <QScreen>
+#include <QScrollArea>
+#include <QSettings>
+#include <QCloseEvent>
 
 #include "JFJochImageReadingWorker.h"
 #include "image_viewer/JFJochDiffractionImage.h"
@@ -43,10 +45,12 @@ JFJochViewerWindow::JFJochViewerWindow(QWidget *parent, bool dbus, const QString
     setFocusPolicy(Qt::StrongFocus);
 
     auto toolBarImage = new JFJochViewerToolbarImage(this);
+    toolBarImage->setObjectName("toolBarImage");   // objectName required for saveState/restoreState
     addToolBar(Qt::TopToolBarArea, toolBarImage);
     addToolBarBreak(Qt::TopToolBarArea);
 
     toolBarDisplay = new JFJochViewerToolbarDisplay(this);
+    toolBarDisplay->setObjectName("toolBarDisplay");
     addToolBar(Qt::TopToolBarArea, toolBarDisplay);
 
     statusbar = new JFJochViewerStatusBar(this);
@@ -77,14 +81,11 @@ JFJochViewerWindow::JFJochViewerWindow(QWidget *parent, bool dbus, const QString
     experiment.ImportIndexingSettings(indexing_settings);
     experiment.DetectIceRings(true);
 
-    // Central area: only the main horizontal splitter (image + side panel)
-    auto h_splitter = new QSplitter(this);
-    h_splitter->setOrientation(Qt::Horizontal);
-    setCentralWidget(h_splitter);
-
+    // Central area: the diffraction image. Everything else (inspector, plots, processing) is a
+    // dock, so the layout can be rearranged, saved, and switched between perspectives.
     auto viewer = new JFJochDiffractionImage(this);
-    viewer->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Expanding);
-    h_splitter->addWidget(viewer);
+    viewer->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+    setCentralWidget(viewer);
 
     auto side_panel = new JFJochViewerSidePanel(this);
     auto side_panel_scroll = new QScrollArea(this);
@@ -94,9 +95,13 @@ JFJochViewerWindow::JFJochViewerWindow(QWidget *parent, bool dbus, const QString
     side_panel_scroll->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
     side_panel_scroll->setMinimumWidth(450);
     side_panel_scroll->setMaximumWidth(600);
-    side_panel_scroll->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);
 
-    h_splitter->addWidget(side_panel_scroll);
+    inspectorDock = new QDockWidget("Inspector", this);
+    inspectorDock->setObjectName("inspectorDock");
+    inspectorDock->setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea);
+    inspectorDock->setWidget(side_panel_scroll);
+    addDockWidget(Qt::RightDockWidgetArea, inspectorDock);
+    menuBar->AddDockEntry(inspectorDock, "Inspector");
 
     reading_worker = new JFJochImageReadingWorker(spot_finding_settings, experiment);
     reading_thread = new QThread(this);
@@ -417,7 +422,8 @@ JFJochViewerWindow::JFJochViewerWindow(QWidget *parent, bool dbus, const QString
             });
 
     // Dock the processing panel in the bottom-right corner, next to the dataset-info plots.
-    auto processingDock = new QDockWidget("Processing", this);
+    processingDock = new QDockWidget("Processing", this);
+    processingDock->setObjectName("processingDock");
     processingDock->setAllowedAreas(Qt::BottomDockWidgetArea);
     processingDock->setFeatures(
         QDockWidget::DockWidgetMovable | QDockWidget::DockWidgetFloatable | QDockWidget::DockWidgetClosable);
@@ -432,6 +438,20 @@ JFJochViewerWindow::JFJochViewerWindow(QWidget *parent, bool dbus, const QString
     }
     menuBar->AddDockEntry(processingDock, "Processing");
 
+    connect(menuBar, &JFJochViewerMenu::imageLayoutSelected, this,
+            [this] { ApplyPerspective(Perspective::Image); });
+    connect(menuBar, &JFJochViewerMenu::processingLayoutSelected, this,
+            [this] { ApplyPerspective(Perspective::Processing); });
+    connect(menuBar, &JFJochViewerMenu::resetLayoutSelected, this,
+            [this] { if (!defaultLayoutState.isEmpty()) restoreState(defaultLayoutState); });
+
+    // Remember the freshly-built layout so "Reset layout" can return to it, then restore the
+    // user's last-used arrangement if they have one.
+    defaultLayoutState = saveState();
+    QSettings settings("PSI", "jfjoch_viewer");
+    restoreGeometry(settings.value("geometry").toByteArray());
+    restoreState(settings.value("windowState").toByteArray());
+
     if (!file.isEmpty())
         LoadFile(file, 0, 1, false);
 }
@@ -443,6 +463,24 @@ JFJochViewerWindow::~JFJochViewerWindow() {
     }
 }
 
+void JFJochViewerWindow::ApplyPerspective(Perspective p) {
+    // Image: just the image + inspector. Processing: also the dataset-info plots and jobs panel.
+    const bool processing = (p == Perspective::Processing);
+    if (inspectorDock) inspectorDock->setVisible(true);
+    if (processingDock) processingDock->setVisible(processing);
+    for (auto *d : findChildren<QDockWidget *>())
+        if (d->objectName().startsWith("datasetInfoDock"))
+            d->setVisible(processing);
+}
+
+void JFJochViewerWindow::closeEvent(QCloseEvent *event) {
+    // Persist the dock/toolbar arrangement and window geometry so the next launch resumes it.
+    QSettings settings("PSI", "jfjoch_viewer");
+    settings.setValue("geometry", saveGeometry());
+    settings.setValue("windowState", saveState());
+    QMainWindow::closeEvent(event);
+}
+
 void JFJochViewerWindow::LoadFile(const QString &filename, qint64 image_number, qint64 summation, bool retry) {
     emit LoadFileRequest(filename, image_number, summation, true);
 }
@@ -458,6 +496,7 @@ void JFJochViewerWindow::NewDatasetInfo() {
     info->runsChanged(lastRuns, lastActiveRunId);
 
     auto dock = new QDockWidget(QString("Dataset info"), this);
+    dock->setObjectName(QStringLiteral("datasetInfoDock%1").arg(datasetInfoCounter++));
     dock->setAllowedAreas(Qt::BottomDockWidgetArea);
     dock->setFeatures(
         QDockWidget::DockWidgetMovable | QDockWidget::DockWidgetFloatable | QDockWidget::DockWidgetClosable |

viewer/JFJochViewerWindow.h

@@ -39,11 +39,20 @@ private:
     QProgressDialog *retryDialog = nullptr;
 
     QDockWidget *lastDatasetInfoDock = nullptr;   // most recent dataset-info dock, for docking layout
+    QDockWidget *inspectorDock = nullptr;         // image inspector (former right-hand side panel)
+    QDockWidget *processingDock = nullptr;        // processing jobs panel
+    QByteArray defaultLayoutState;                // captured after construction, for "Reset layout"
+    int datasetInfoCounter = 0;                   // gives each dataset-info dock a unique objectName
 
     QThread *reading_thread;
 
+    // Named layouts. Image = just the image + inspector; Processing = also the plots + jobs panel.
+    enum class Perspective { Image, Processing };
+    void ApplyPerspective(Perspective p);
+
     void keyPressEvent(QKeyEvent *event) override;
     void keyReleaseEvent(QKeyEvent *event) override;
+    void closeEvent(QCloseEvent *event) override;
 public slots:
     void LoadFile(const QString &filename, qint64 image_number, qint64 summation, bool retry);
     void LoadImage(qint64 image_number, qint64 summation);