Simplify Models panel and dialog layout

Models panel: replace the manual resizeEvent column-sizing hack with
QHeaderView Stretch/Fixed modes, re-applied via sectionCountChanged so
they survive the model rebuilds that QHeaderView resets them on.

Dialog: only wrap the body in a QScrollArea when scrollable, mirroring
Panel. The scroll area caps its sizeHint at 36x24 cells, which turned
wide fixed-size dialog content into spurious scrollbars.

Add Model dialog: reserve a stable, font-metrics-measured height for the
hover description so longer text never reflows the buttons; regroup the
buttons into LOCAL / CLOUD / TOOLS.

Buttons: move the trailing-separator decision out of makeButtonGroup
into a new addButtonGroups row builder, so the last group in a row
never draws a dangling divider.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/bonsaiviewer/MainWindow.cpp

@@ -232,9 +232,11 @@ QWidget* MainWindow::buildHomeRibbonPage() {
         dialog.exec();
     });
 
-    row->addWidget(components::buttons::makeButtonGroup("PROJECT", {new_project, open_project, open_cloud, open_recent, save_project}, this));
-    row->addWidget(components::buttons::makeButtonGroup("MODELS", {add_model, sync_from_cloud}, this));
-    row->addWidget(components::buttons::makeButtonGroup("SETTINGS", {settings_button}, this));
+    components::buttons::addButtonGroups(row, {
+        components::buttons::makeButtonGroup("PROJECT", {new_project, open_project, open_cloud, open_recent, save_project}, this),
+        components::buttons::makeButtonGroup("MODELS", {add_model, sync_from_cloud}, this),
+        components::buttons::makeButtonGroup("SETTINGS", {settings_button}, this),
+    });
     row->addStretch(1);
     return page;
 }
@@ -296,9 +298,11 @@ QWidget* MainWindow::buildNavigateRibbonPage() {
         modules::viewport::commands::toggleSection(*session_state_, *viewport_widget_->viewport());
     });
 
-    row->addWidget(components::buttons::makeButtonGroup("CAMERA", {set_home, go_home, view_all, view_selected}, this));
-    row->addWidget(components::buttons::makeButtonGroup("ORIENTATION", {plan_view, front_view, side_view, align_object, projection_button}, this));
-    row->addWidget(components::buttons::makeButtonGroup("MODE", {fly_mode, section_mode}, this));
+    components::buttons::addButtonGroups(row, {
+        components::buttons::makeButtonGroup("CAMERA", {set_home, go_home, view_all, view_selected}, this),
+        components::buttons::makeButtonGroup("ORIENTATION", {plan_view, front_view, side_view, align_object, projection_button}, this),
+        components::buttons::makeButtonGroup("MODE", {fly_mode, section_mode}, this),
+    });
     row->addStretch(1);
     return page;
 }
@@ -340,8 +344,10 @@ QWidget* MainWindow::buildInspectRibbonPage() {
         modules::viewport::commands::toggleVolume(*viewport_widget_->viewport());
     });
 
-    row->addWidget(components::buttons::makeButtonGroup("SELECTION", {hide_selected, isolate_selected, show_all, invert_selection}, this));
-    row->addWidget(components::buttons::makeButtonGroup("MEASURE", {distance, area, volume}, this));
+    components::buttons::addButtonGroups(row, {
+        components::buttons::makeButtonGroup("SELECTION", {hide_selected, isolate_selected, show_all, invert_selection}, this),
+        components::buttons::makeButtonGroup("MEASURE", {distance, area, volume}, this),
+    });
     row->addStretch(1);
     return page;
 }
@@ -353,22 +359,24 @@ QWidget* MainWindow::buildPanelsRibbonPage() {
     row->setContentsMargins(2, 4, 2, 4);
     row->setSpacing(0);
 
-    row->addWidget(components::buttons::makeButtonGroup("DATA", {
-        makePanelToggle("Models", models_panel_),
-        makePanelToggle("Spatial", spatial_panel_),
-        makePanelToggle("Layers", layers_panel_),
-        makePanelToggle("Properties", properties_panel_)
-    }, this));
-    row->addWidget(components::buttons::makeButtonGroup("QUERY", {
-        makePanelToggle("Views", stored_views_panel_),
-        makePanelToggle("Search", search_panel_),
-        makePanelToggle("Sheets", spreadsheet_panel_),
-        makePanelToggle("Audit", audit_panel_)
-    }, this));
-    row->addWidget(components::buttons::makeButtonGroup("COLLABORATE", {
-        makePanelToggle("Clash", clash_panel_),
-        makePanelToggle("Issues", issues_panel_)
-    }, this));
+    components::buttons::addButtonGroups(row, {
+        components::buttons::makeButtonGroup("DATA", {
+            makePanelToggle("Models", models_panel_),
+            makePanelToggle("Spatial", spatial_panel_),
+            makePanelToggle("Layers", layers_panel_),
+            makePanelToggle("Properties", properties_panel_)
+        }, this),
+        components::buttons::makeButtonGroup("QUERY", {
+            makePanelToggle("Views", stored_views_panel_),
+            makePanelToggle("Search", search_panel_),
+            makePanelToggle("Sheets", spreadsheet_panel_),
+            makePanelToggle("Audit", audit_panel_)
+        }, this),
+        components::buttons::makeButtonGroup("COLLABORATE", {
+            makePanelToggle("Clash", clash_panel_),
+            makePanelToggle("Issues", issues_panel_)
+        }, this),
+    });
     row->addStretch(1);
     return page;
 }

src/bonsaiviewer/components/Buttons.cpp

@@ -22,6 +22,7 @@
 
 #include "SvgIcon.h"
 
+#include <QBoxLayout>
 #include <QFrame>
 #include <QHBoxLayout>
 #include <QLabel>
@@ -47,11 +48,9 @@ QToolButton* makeButton(const QString& text,
 QWidget* makeButtonGroup(const QString& title,
                          const QList<QToolButton*>& buttons,
                          QWidget* parent,
-                         bool trailing_separator,
                          int vertical_spacing) {
     auto* group = new QFrame(parent);
     group->setObjectName("ribbonGroup");
-    group->setProperty("separator", trailing_separator);
 
     auto* group_layout = new QVBoxLayout(group);
     group_layout->setContentsMargins(8, 6, 8, 4);
@@ -74,4 +73,13 @@ QWidget* makeButtonGroup(const QString& title,
     return group;
 }
 
+void addButtonGroups(QBoxLayout* row, const QList<QWidget*>& groups) {
+    for (int i = 0; i < groups.size(); ++i) {
+        // The divider belongs *between* groups; the last group never draws a
+        // trailing one. The stylesheet keys off this dynamic property.
+        groups[i]->setProperty("separator", i + 1 < groups.size());
+        row->addWidget(groups[i]);
+    }
+}
+
 } // namespace bonsaiviewer::components::buttons

src/bonsaiviewer/components/Buttons.h

@@ -23,6 +23,7 @@
 
 #include <QList>
 
+class QBoxLayout;
 class QToolButton;
 class QWidget;
 
@@ -35,9 +36,13 @@ QToolButton* makeButton(const QString& text,
 QWidget* makeButtonGroup(const QString& title,
                          const QList<QToolButton*>& buttons,
                          QWidget* parent,
-                         bool trailing_separator = true,
                          int vertical_spacing = 4);
 
+// Adds button groups to a ribbon row, drawing a vertical divider between
+// adjacent groups but never after the last one. Centralising the decision
+// here means a row can't end up with a dangling trailing separator.
+void addButtonGroups(QBoxLayout* row, const QList<QWidget*>& groups);
+
 } // namespace bonsaiviewer::components::buttons
 
 #endif

src/bonsaiviewer/components/Dialog.cpp

@@ -49,19 +49,27 @@ Dialog::Dialog(QWidget* parent, bool scrollable)
                                      style::metrics::section_body_padding);
     frame_layout->setSpacing(0);
 
-    auto* scroll = new QScrollArea(frame);
-    scroll->setWidgetResizable(true);
-    scroll->setFrameShape(QFrame::NoFrame);
-
-    auto* scroll_body = new QWidget(scroll);
-    scroll_body->setObjectName("panelScrollBody");
-    body_layout_ = new QVBoxLayout(scroll_body);
+    // A non-scrollable dialog must not be wrapped in a QScrollArea. The scroll
+    // area caps its own sizeHint at 36x24 character cells, and dialogs size
+    // themselves with QLayout::SetFixedSize — so any content wider/taller than
+    // that cap is turned into scrollbars instead of growing the dialog. Only
+    // use a scroll area when scrolling is actually wanted (mirrors Panel).
+    auto* body = new QWidget(frame);
+    body->setObjectName("panelScrollBody");
+    body_layout_ = new QVBoxLayout(body);
     body_layout_->setContentsMargins(0, 0, 0, 0);
     body_layout_->setSpacing(style::metrics::section_body_padding);
     body_layout_->setAlignment(Qt::AlignTop);
 
-    scroll->setWidget(scroll_body);
-    frame_layout->addWidget(scroll, scrollable ? 1 : 0);
+    if (scrollable) {
+        auto* scroll = new QScrollArea(frame);
+        scroll->setWidgetResizable(true);
+        scroll->setFrameShape(QFrame::NoFrame);
+        scroll->setWidget(body);
+        frame_layout->addWidget(scroll, 1);
+    } else {
+        frame_layout->addWidget(body);
+    }
 
     auto* footer = new QWidget(frame);
     footer_layout_ = new QVBoxLayout(footer);

src/bonsaiviewer/modules/connectors/PickerDialog.cpp

@@ -69,7 +69,9 @@ ConnectorPickerDialog::ConnectorPickerDialog(const std::vector<ConnectorManifest
         });
         buttons.push_back(button);
     }
-    row->addWidget(components::buttons::makeButtonGroup("CONNECTORS", buttons, choices, true, 8));
+    components::buttons::addButtonGroups(row, {
+        components::buttons::makeButtonGroup("CONNECTORS", buttons, choices, 8),
+    });
     choices_section->addBodyWidget(choices);
 
     addBodyWidget(description_section);

src/bonsaiviewer/modules/models/AddModelDialog.cpp

@@ -74,13 +74,12 @@ void AddModelDialog::setupUi() {
     }
 
     const QString default_description = "Choose what to add to the project";
+
     auto* description_section = new components::Section("", components::SectionHeaderMode::Hidden, this);
     auto* description = new QLabel(default_description, description_section);
     description->setProperty("textRole", "secondary");
     description->setWordWrap(true);
     description->setAlignment(Qt::AlignCenter);
-    description->setMinimumWidth((90 * 4) + (components::style::metrics::padding * 3));
-    description->setMinimumHeight(description->fontMetrics().lineSpacing() * 2 + 4);
     description_section->addBodyWidget(description);
 
     auto* choices_section = new components::Section("", components::SectionHeaderMode::Hidden, this);
@@ -89,70 +88,73 @@ void AddModelDialog::setupUi() {
     row->setContentsMargins(0, 0, 0, 0);
     row->setSpacing(components::style::metrics::padding);
 
-    auto* add_ifc = components::buttons::makeButton("Add IFC File", ":/icons/cube.svg", choices);
-    connect(add_ifc, &QToolButton::clicked, this, [this]() {
-        selected_mode_ = SourceMode::IfcFile;
-        accept();
-    });
-    add_ifc->installEventFilter(new HoverDescriptionFilter(
-        description,
-        "Add IFC files and load both geometry and data.",
-        default_description));
+    struct Choice {
+        SourceMode mode;
+        QString text;
+        QString icon;
+        QString hover;
+    };
+    const QList<Choice> local_choices = {
+        {SourceMode::IfcFile, "Add IFC File", ":/icons/cube.svg",
+         "Add IFC files and load both geometry and data."},
+        {SourceMode::IfcDatabase, "Add IFC\nDatabase", ":/icons/database.svg",
+         "Add IFC RDB databases for optimised performance"},
+        {SourceMode::GeometryOnly, "Add Geometry", ":/icons/cube-bandage.svg",
+         "Add pure geometry for fast visualisation"},
+    };
+    const QList<Choice> cloud_choices = {
+        {SourceMode::CloudModel, "Add From\nCloud", ":/icons/cloud-square.svg",
+         "Browse a cloud connector and add one or more models from there."},
+    };
+    const QList<Choice> tool_choices = {
+        {SourceMode::ConvertToDatabase, "Convert IFC File\nto Database", ":/icons/database-restore.svg",
+         "Convert IFC files to databases for smaller filesizes, reduced memory, "
+         "and faster access. No data is lost."},
+        {SourceMode::ExportGeometryDatabase, "Export Geometry\nDatabase", ":/icons/database-restore.svg",
+         "Convert IFC files to a read-only geometry database for smaller filesizes, "
+         "reduced memory, and faster access. Ideal for cloud read-only coordination "
+         "workflows. Only parametric geometry editing capabilities are lost."},
+    };
 
-    auto* add_database = components::buttons::makeButton("Add IFC\nDatabase", ":/icons/database.svg", choices);
-    connect(add_database, &QToolButton::clicked, this, [this]() {
-        selected_mode_ = SourceMode::IfcDatabase;
-        accept();
-    });
-    add_database->installEventFilter(new HoverDescriptionFilter(
-        description,
-        "Add IFC RDB databases for optimised performance",
-        default_description));
+    QStringList descriptions = {default_description};
+    auto build_group = [&](const QString& title, const QList<Choice>& group_choices) {
+        QList<QToolButton*> buttons;
+        for (const Choice& choice : group_choices) {
+            auto* button = components::buttons::makeButton(choice.text, choice.icon, choices);
+            const SourceMode mode = choice.mode;
+            connect(button, &QToolButton::clicked, this, [this, mode]() {
+                selected_mode_ = mode;
+                accept();
+            });
+            button->installEventFilter(
+                new HoverDescriptionFilter(description, choice.hover, default_description));
+            descriptions << choice.hover;
+            buttons << button;
+        }
+        return components::buttons::makeButtonGroup(title, buttons, choices, 8);
+    };
 
-    auto* add_geometry = components::buttons::makeButton("Add Geometry", ":/icons/cube-bandage.svg", choices);
-    connect(add_geometry, &QToolButton::clicked, this, [this]() {
-        selected_mode_ = SourceMode::GeometryOnly;
-        accept();
+    components::buttons::addButtonGroups(row, {
+        build_group("LOCAL", local_choices),
+        build_group("CLOUD", cloud_choices),
+        build_group("TOOLS", tool_choices),
     });
-    add_geometry->installEventFilter(new HoverDescriptionFilter(
-        description,
-        "Add pure geometry for fast visualisation",
-        default_description));
-
-    auto* add_cloud = components::buttons::makeButton("Add From\nCloud", ":/icons/cloud-square.svg", choices);
-    connect(add_cloud, &QToolButton::clicked, this, [this]() {
-        selected_mode_ = SourceMode::CloudModel;
-        accept();
-    });
-    add_cloud->installEventFilter(new HoverDescriptionFilter(
-        description,
-        "Browse a cloud connector and add one or more models from there.",
-        default_description));
-
-    auto* convert_database = components::buttons::makeButton("Convert IFC File\nto Database", ":/icons/database-restore.svg", choices);
-    connect(convert_database, &QToolButton::clicked, this, [this]() {
-        selected_mode_ = SourceMode::ConvertToDatabase;
-        accept();
-    });
-    convert_database->installEventFilter(new HoverDescriptionFilter(
-        description,
-        "Convert IFC files to databases for smaller filesizes, reduced memory, and faster access. No data is lost.",
-        default_description));
-
-    auto* export_geometry_database = components::buttons::makeButton("Export Geometry\nDatabase", ":/icons/database-restore.svg", choices);
-    connect(export_geometry_database, &QToolButton::clicked, this, [this]() {
-        selected_mode_ = SourceMode::ExportGeometryDatabase;
-        accept();
-    });
-    export_geometry_database->installEventFilter(new HoverDescriptionFilter(
-        description,
-        "Convert IFC files to a read-only geometry database for smaller filesizes, reduced memory, and faster access. Ideal for cloud read-only coordination workflows. Only parametric geometry editing capabilities are lost.",
-        default_description));
-
-    row->addWidget(components::buttons::makeButtonGroup("ADD", {add_ifc, add_database, add_geometry, add_cloud}, choices, true, 8));
-    row->addWidget(components::buttons::makeButtonGroup("TOOLS", {convert_database, export_geometry_database}, choices, false, 8));
     choices_section->addBodyWidget(choices);
 
+    // Hovering a button swaps in a longer description; with a free-growing
+    // label that reflow shoves the buttons below it downward. Lock the label
+    // to the tallest string it will ever show. The label is laid out at the
+    // choices' width (both sit in Section bodies with identical margins), so
+    // measure every string at that width and keep the largest result.
+    const int label_width = choices->sizeHint().width();
+    int reserved_height = 0;
+    for (const QString& text : descriptions) {
+        description->setText(text);
+        reserved_height = qMax(reserved_height, description->heightForWidth(label_width));
+    }
+    description->setText(default_description);
+    description->setFixedHeight(reserved_height);
+
     addBodyWidget(description_section);
     addBodyWidget(choices_section);
 }

src/bonsaiviewer/modules/models/Panel.cpp

@@ -89,15 +89,6 @@ public:
         : QTreeView(parent), session_state_(session_state) {}
 
 protected:
-    void resizeEvent(QResizeEvent* event) override {
-        QTreeView::resizeEvent(event);
-        if (model() && model()->columnCount() >= 2) {
-            const int vw = viewport()->width();
-            setColumnWidth(0, std::max(40, vw - kVisibilityColumnWidth));
-            setColumnWidth(1, kVisibilityColumnWidth);
-        }
-    }
-
     void startDrag(Qt::DropActions actions) override {
         const QModelIndexList selection = selectionModel()->selectedRows(0);
         if (selection.isEmpty()) return;
@@ -382,14 +373,25 @@ ModelsPanel::ModelsPanel(bonsaiviewer::SessionState* session_state,
 void ModelsPanel::setModel(FederationItemModel* model) {
     model_ = model;
     tree_->setModel(model);
-    // Columns are sized by ModelsTreeView::resizeEvent — header is hidden so
-    // there's no user-facing resize affordance, and Stretch mode on
-    // non-last sections proved unreliable here. Manual sizing is simpler.
-    tree_->header()->setMinimumSectionSize(16);
-    tree_->header()->setStretchLastSection(false);
-    tree_->setColumnWidth(0, std::max(40, tree_->viewport()->width() - kVisibilityColumnWidth));
-    tree_->setColumnWidth(1, kVisibilityColumnWidth);
+    // QHeaderView resets per-section resize modes to Interactive whenever the
+    // column set is rebuilt — which FederationItemModel::rebuildAll() does on
+    // project open / theme change (clear() + setColumnCount()). Re-apply the
+    // layout every time the columns reappear.
+    connect(tree_->header(), &QHeaderView::sectionCountChanged,
+            this, [this]() { applyColumnLayout(); });
+    applyColumnLayout();
     tree_->expandAll();
 }
 
+void ModelsPanel::applyColumnLayout() {
+    // Column 0 (name) stretches to fill; column 1 (visibility icon) is fixed.
+    QHeaderView* header = tree_->header();
+    if (header->count() < 2) return;
+    header->setStretchLastSection(false);
+    header->setMinimumSectionSize(kVisibilityColumnWidth);
+    header->setSectionResizeMode(0, QHeaderView::Stretch);
+    header->setSectionResizeMode(1, QHeaderView::Fixed);
+    header->resizeSection(1, kVisibilityColumnWidth);
+}
+
 } // namespace bonsaiviewer::modules::models

src/bonsaiviewer/modules/models/Panel.h

@@ -49,6 +49,8 @@ public:
     void setModel(FederationItemModel* model);
 
 private:
+    void applyColumnLayout();
+
     bonsaiviewer::SessionState* session_state_ = nullptr;
     ViewportWindow* viewport_ = nullptr;
     QTreeView* tree_ = nullptr;

src/bonsaiviewer/modules/project/SaveProjectDialog.cpp

@@ -135,10 +135,10 @@ void SaveProjectDialog::setupUi(bool has_manifest) {
         "Pick a connector and push this project to a fresh cloud location.",
         default_description));
 
-    row->addWidget(components::buttons::makeButtonGroup(
-        "LOCAL", {save_local, save_as_local}, choices, true, 8));
-    row->addWidget(components::buttons::makeButtonGroup(
-        "CLOUD", {save_cloud, save_as_cloud}, choices, false, 8));
+    components::buttons::addButtonGroups(row, {
+        components::buttons::makeButtonGroup("LOCAL", {save_local, save_as_local}, choices, 8),
+        components::buttons::makeButtonGroup("CLOUD", {save_cloud, save_as_cloud}, choices, 8),
+    });
     choices_section->addBodyWidget(choices);
 
     addBodyWidget(description_section);