feat: add Preferences dialog for managing theme, rendering, and unit settings

app/gcompose/CMakeLists.txt

@@ -17,6 +17,8 @@ add_executable(gcompose
     src/PropertyWidgets.cpp
     src/PropertiesPanel.h
     src/PropertiesPanel.cpp
+    src/PreferencesDialog.h
+    src/PreferencesDialog.cpp
 )
 
 set_target_properties(gcompose PROPERTIES

app/gcompose/src/MainPanel.cpp

@@ -18,6 +18,8 @@
 #include <QFileInfo>
 #include "StyleManager.h"
 #include "Math/VoxImage.h"
+#include "PreferencesDialog.h"
+#include "Settings.h"
 
 MainPanel::MainPanel(QWidget* parent) : QWidget(parent), m_context(nullptr), m_mainVtkContext(nullptr) {
     this->setObjectName("MainPanel");
@@ -45,17 +47,12 @@ MainPanel::MainPanel(QWidget* parent) : QWidget(parent), m_context(nullptr), m_m
     fileMenu->addAction("Open", this, &MainPanel::onOpen);
     fileMenu->addAction("Save", this, &MainPanel::onSave);
     fileMenu->addAction("Save As", this, &MainPanel::onSaveAs);
+    fileMenu->addSeparator();
+    fileMenu->addAction("Preferences", this, &MainPanel::onPreferences);
+    fileMenu->addSeparator();
     fileMenu->addAction("Exit", this, &MainPanel::onExit);
     btnFile->setMenu(fileMenu);
 
-    // Theme Menu Button
-    auto* btnTheme = new QPushButton("Theme", menuPanel);
-    btnTheme->setObjectName("MenuButton");
-    auto* themeMenu = new QMenu(btnTheme);
-    themeMenu->addAction("Dark", this, &MainPanel::onDarkTheme);
-    themeMenu->addAction("Bright", this, &MainPanel::onBrightTheme);
-    btnTheme->setMenu(themeMenu);
-
     // New Menu Button
     auto* btnNew = new QPushButton("Add", menuPanel);
     btnNew->setObjectName("MenuButton");
@@ -73,7 +70,6 @@ MainPanel::MainPanel(QWidget* parent) : QWidget(parent), m_context(nullptr), m_m
     menuLayout->addWidget(logo);
     menuLayout->addWidget(btnFile);
     menuLayout->addWidget(btnNew);
-    menuLayout->addWidget(btnTheme);
     menuLayout->addStretch();
 
     mainLayout->addWidget(menuPanel);
@@ -236,12 +232,21 @@ void MainPanel::onExit() {
     qApp->quit();
 }
 
-void MainPanel::onDarkTheme() {
-    StyleManager::applyStyle(qApp, "dark");
-}
+void MainPanel::onPreferences() {
+    uLib::Qt::PreferencesDialog dlg(this);
+    if (dlg.exec() == QDialog::Accepted) {
+        // Apply theme
+        auto theme = uLib::Qt::Settings::Instance().GetTheme();
+        StyleManager::applyStyle(qApp, theme == uLib::Qt::Settings::Dark ? "dark" : "bright");
 
-void MainPanel::onBrightTheme() {
-    StyleManager::applyStyle(qApp, "bright");
+        // Apply rendering preference to all viewports
+        bool throttled = uLib::Qt::Settings::Instance().GetThrottledRendering();
+        auto viewports = this->findChildren<uLib::Vtk::QViewport*>();
+        for (auto* vp : viewports) {
+            vp->SetThrottledRendering(throttled);
+            vp->Render();
+        }
+    }
 }
 
 MainPanel::~MainPanel() {}

app/gcompose/src/MainPanel.h

@@ -30,8 +30,7 @@ private slots:
     void onSaveAs();
     void onExit();
 
-    void onDarkTheme();
-    void onBrightTheme();
+    void onPreferences();
     
     void onCreateObject(const std::string& className);
 

app/gcompose/src/PreferencesDialog.cpp

@@ -0,0 +1,99 @@
+#include "PreferencesDialog.h"
+#include <QVBoxLayout>
+#include <QHBoxLayout>
+#include <QFormLayout>
+#include <QPushButton>
+#include <QLabel>
+#include <QGroupBox>
+
+namespace uLib {
+namespace Qt {
+
+PreferencesDialog::PreferencesDialog(QWidget* parent) : QDialog(parent) {
+    setWindowTitle("Preferences");
+    setMinimumWidth(400);
+    
+    auto* mainLayout = new QVBoxLayout(this);
+    mainLayout->setSpacing(20);
+    mainLayout->setContentsMargins(20, 20, 20, 20);
+
+    // ── General / Rendering Settings ────────────────────────────────────────
+    auto* renderingGroup = new QGroupBox("Appearance & Performance", this);
+    auto* renderingLayout = new QVBoxLayout(renderingGroup);
+    
+    auto* themeLayout = new QHBoxLayout();
+    themeLayout->addWidget(new QLabel("Color Theme:"));
+    m_themeCombo = new QComboBox(renderingGroup);
+    m_themeCombo->addItem("Dark");
+    m_themeCombo->addItem("Bright");
+    m_themeCombo->setCurrentIndex(Settings::Instance().GetTheme() == Settings::Dark ? 0 : 1);
+    themeLayout->addWidget(m_themeCombo);
+    themeLayout->addStretch();
+    
+    renderingLayout->addLayout(themeLayout);
+    renderingLayout->addSpacing(10);
+
+    m_throttledRendering = new QCheckBox("Enable throttled rendering (recommended for performance)", renderingGroup);
+    m_throttledRendering->setChecked(Settings::Instance().GetThrottledRendering());
+    m_throttledRendering->setToolTip("Limits framerate to ~60fps to reduce CPU/GPU usage.");
+    
+    renderingLayout->addWidget(m_throttledRendering);
+    mainLayout->addWidget(renderingGroup);
+
+    // ── Units Settings ──────────────────────────────────────────────────────
+    auto* unitsGroup = new QGroupBox("Preferred Units", this);
+    auto* unitsLayout = new QFormLayout(unitsGroup);
+    unitsLayout->setLabelAlignment(::Qt::AlignRight);
+    unitsLayout->setSpacing(10);
+
+    auto addUnitRow = [&](const QString& label, Settings::Dimension dim, const QStringList& units) {
+        auto* combo = new QComboBox(unitsGroup);
+        combo->addItems(units);
+        std::string current = Settings::Instance().GetPreferredUnit(dim);
+        int idx = combo->findText(QString::fromStdString(current));
+        if (idx >= 0) combo->setCurrentIndex(idx);
+        
+        unitsLayout->addRow(label + ":", combo);
+        m_unitCombos[dim] = combo;
+    };
+
+    addUnitRow("Length", Settings::Length, {"m", "cm", "mm", "um", "nm"});
+    addUnitRow("Angle", Settings::Angle, {"deg", "rad"});
+    addUnitRow("Energy", Settings::Energy, {"MeV", "GeV", "eV", "keV", "TeV"});
+    addUnitRow("Time", Settings::Time, {"ns", "s", "ms", "us"});
+
+    mainLayout->addWidget(unitsGroup);
+
+    mainLayout->addStretch();
+
+    // ── Buttons ─────────────────────────────────────────────────────────────
+    auto* buttonLayout = new QHBoxLayout();
+    buttonLayout->addStretch();
+    
+    auto* btnCancel = new QPushButton("Cancel", this);
+    connect(btnCancel, &QPushButton::clicked, this, &QDialog::reject);
+    
+    auto* btnOk = new QPushButton("Apply", this);
+    btnOk->setDefault(true);
+    btnOk->setObjectName("DisplayToggleBtn"); // Reusing high-contrast style
+    btnOk->setMinimumWidth(100);
+    connect(btnOk, &QPushButton::clicked, this, &PreferencesDialog::onAccept);
+    
+    buttonLayout->addWidget(btnCancel);
+    buttonLayout->addWidget(btnOk);
+    mainLayout->addLayout(buttonLayout);
+}
+
+void PreferencesDialog::onAccept() {
+    Settings::Instance().SetThrottledRendering(m_throttledRendering->isChecked());
+    Settings::Instance().SetTheme(m_themeCombo->currentIndex() == 0 ? Settings::Dark : Settings::Bright);
+    
+    for (auto const& pair : m_unitCombos) {
+        Settings::Instance().SetPreferredUnit(pair.first, pair.second->currentText().toStdString());
+    }
+    
+    accept();
+}
+
+} // namespace Qt
+} // namespace uLib

app/gcompose/src/PreferencesDialog.h

@@ -0,0 +1,31 @@
+#ifndef GCOMPOSE_PREFERENCESDIALOG_H
+#define GCOMPOSE_PREFERENCESDIALOG_H
+
+#include <QDialog>
+#include <QCheckBox>
+#include <QComboBox>
+#include <map>
+#include <string>
+#include "Settings.h"
+
+namespace uLib {
+namespace Qt {
+
+class PreferencesDialog : public QDialog {
+    Q_OBJECT
+public:
+    explicit PreferencesDialog(QWidget* parent = nullptr);
+
+private slots:
+    void onAccept();
+
+private:
+    QCheckBox* m_throttledRendering;
+    QComboBox* m_themeCombo;
+    std::map<Settings::Dimension, QComboBox*> m_unitCombos;
+};
+
+} // namespace Qt
+} // namespace uLib
+
+#endif

app/gcompose/src/Settings.h

@@ -23,6 +23,11 @@ public:
         Dimensionless
     };
 
+    enum Theme {
+        Dark,
+        Bright
+    };
+
     void SetPreferredUnit(Dimension dim, const std::string& unit) {
         m_PreferredUnits[dim] = unit;
     }
@@ -64,9 +69,17 @@ public:
         return Dimensionless;
     }
 
+    bool GetThrottledRendering() const { return m_ThrottledRendering; }
+    void SetThrottledRendering(bool enabled) { m_ThrottledRendering = enabled; }
+
+    Theme GetTheme() const { return m_Theme; }
+    void SetTheme(Theme theme) { m_Theme = theme; }
+
 private:
-    Settings() {}
+    Settings() : m_ThrottledRendering(true), m_Theme(Dark) {}
     std::map<Dimension, std::string> m_PreferredUnits;
+    bool m_ThrottledRendering;
+    Theme m_Theme;
 };
 
 } // namespace Qt

src/Vtk/vtkQViewport.cpp

@@ -20,17 +20,25 @@ QViewport::QViewport(QWidget* parent)
     , m_VtkWidget(nullptr)
     , m_GridButton(nullptr)
     , m_ProjButton(nullptr)
+    , m_renderTimer(nullptr)
+    , m_renderPending(false)
 {
     // Build the layout – zero margins so VTK fills the entire widget
     auto* layout = new QVBoxLayout(this);
     layout->setContentsMargins(0, 0, 0, 0);
     layout->setSpacing(0);
-
+ 
     m_VtkWidget = new QVTKOpenGLNativeWidget(this);
     layout->addWidget(m_VtkWidget);
-
+ 
+    // Initialize render timer
+    m_renderTimer = new QTimer(this);
+    m_renderTimer->setSingleShot(true);
+    connect(m_renderTimer, &QTimer::timeout, this, &QViewport::doRender);
+ 
     // Grid Toggle Button
     m_GridButton = new QPushButton(m_VtkWidget);
+
     m_GridButton->setText("#");
     m_GridButton->setFixedSize(40, 40);
     m_GridButton->setToolTip("Toggle Grid");
@@ -112,9 +120,21 @@ void QViewport::SetupPipeline()
 
 void QViewport::Render()
 {
-    if (m_VtkWidget && m_VtkWidget->renderWindow())
-        m_VtkWidget->renderWindow()->Render();
+    if (!m_throttledRendering) {
+        doRender();
+        return;
+    }
+    if (m_renderPending) return;
+    m_renderPending = true;
+    m_renderTimer->start(16);
 }
+ 
+ void QViewport::doRender()
+ {
+     m_renderPending = false;
+     if (m_VtkWidget && m_VtkWidget->renderWindow())
+         m_VtkWidget->renderWindow()->Render();
+ }
 
 vtkRenderWindow* QViewport::GetRenderWindow()
 {

src/Vtk/vtkQViewport.h

@@ -4,6 +4,7 @@
 #include <QWidget>
 #include <QVTKOpenGLNativeWidget.h>
 #include <QPushButton>
+#include <QTimer>
 
 #include <vtkCornerAnnotation.h>
 #include <vtkOrientationMarkerWidget.h>
@@ -39,27 +40,35 @@ public:
     // Render scene
     virtual void Render() override;
 
+    void SetThrottledRendering(bool enabled) { m_throttledRendering = enabled; }
+    bool GetThrottledRendering() const { return m_throttledRendering; }
+
     // Direct access to VTK internals
     virtual vtkRenderWindow*            GetRenderWindow() override;
     virtual vtkRenderWindowInteractor*  GetInteractor() override;
     QVTKOpenGLNativeWidget*     GetWidget()      { return m_VtkWidget; }
 
     virtual void OnSelectionChanged(Prop3D* p) override;
+ 
+ protected:
+     virtual void resizeEvent(QResizeEvent* event) override;
+ 
+ private slots:
+     void onGridButtonClicked();
+     void onProjButtonClicked();
+     void doRender();
+ 
+ private:
+     void SetupPipeline();
+ 
+     QVTKOpenGLNativeWidget*             m_VtkWidget;
+     QPushButton*                        m_GridButton;
+     QPushButton*                        m_ProjButton;
+     QTimer*                             m_renderTimer;
+     bool                                m_renderPending = false;
+     bool                                m_throttledRendering = true;
+ };
 
-protected:
-    virtual void resizeEvent(QResizeEvent* event) override;
-
-private slots:
-    void onGridButtonClicked();
-    void onProjButtonClicked();
-
-private:
-    void SetupPipeline();
-
-    QVTKOpenGLNativeWidget*             m_VtkWidget;
-    QPushButton*                        m_GridButton;
-    QPushButton*                        m_ProjButton;
-};
 
 } // namespace Vtk
 } // namespace uLib