VFS perf fixes, icon/stylesheet compat, download filename fix

VFS:
- Open backing fd at mo2_open time for read-only handles so mo2_read can
  splice without re-opening the file on every read call.
- Bump RLIMIT_NOFILE at mount time to fit the resulting fd pressure when
  the game keeps hundreds of BSAs open.
- Dedicated node_cache_mutex so resolveByInode / mo2_lookup stop racing
  unordered_map writes while multiple tree_mutex readers are active.
- max_read=1MB + matching conn->max_read and raised max_readahead/max_write
  so the kernel merges Wine's small sequential reads into bigger FUSE
  requests.
- Per-op wall-clock counters in mo2_init() logs so we can distinguish VFS
  latency from game-side work.

Proton launch:
- Write dxvk.conf to the prefix and set DXVK_CONFIG_FILE to force
  dxvk.enableGraphicsPipelineLibrary=False, avoiding long GPL compile
  stalls on first run.

UI / plugin compat:
- Clamp IconDelegate's per-icon width to [8, 16] so narrow content
  columns don't trigger QIcon::pixmap(0,0) returning null and logging
  "failed to load icon" every repaint.
- Pre-create lowercase symlinks in the stylesheet directory so QSS files
  authored on Windows resolve url(foo.svg) when on-disk files are Foo.svg.
- Flip content icons empty-chessboard.png and facegen.png to 8-bit RGBA
  so Qt's built-in PNG reader loads them uniformly.
- Add mobase.Version.canonicalString shim for legacy Python plugins that
  still call the old VersionInfo method on appVersion()'s return.
- BSPluginList: compare normalized plugin name lists instead of byte
  hashes so the post-run case-fix refresh stops spuriously firing the
  "load order changed" dialog.
- BSPluginList disabled by default.

Download manager:
- Parse CDN URL with QUrl + QUrlQuery and read the filename from the
  response-content-disposition query param (RFC 6266 quoted / unquoted /
  ext-value forms), not QFileInfo on the raw URL.
- When the API or URL gives us a CDN object key (no archive extension),
  prefer the actual Content-Disposition header from the live response in
  metaDataChanged and downloadFinished.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

19 files changed, 1227 insertions, 0 deletions

diff --git a/libs/installer_bsplugins/src/GUI/CopyEventFilter.cpp b/libs/installer_bsplugins/src/GUI/CopyEventFilter.cpp
new file mode 100644
index 0000000..abd23fd
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/CopyEventFilter.cpp
@@ -0,0 +1,53 @@
+#include "CopyEventFilter.h"
+
+#include <QClipboard>
+#include <QGuiApplication>
+#include <QKeyEvent>
+
+namespace GUI
+{
+
+CopyEventFilter::CopyEventFilter(QAbstractItemView* view, int column, int role)
+    : CopyEventFilter(view, [=](const auto& index) {
+        return index.sibling(index.row(), column).data(role).toString();
+      })
+{}
+
+CopyEventFilter::CopyEventFilter(QAbstractItemView* view,
+                                 std::function<QString(const QModelIndex&)> format)
+    : QObject(view), m_View{view}, m_Format{format}
+{}
+
+void CopyEventFilter::copySelection() const
+{
+  if (!m_View->selectionModel()->hasSelection()) {
+    return;
+  }
+
+  // sort to reflect the visual order
+  QModelIndexList selectedRows = m_View->selectionModel()->selectedRows();
+  std::ranges::sort(selectedRows, [this](const auto& lidx, const auto& ridx) {
+    return m_View->visualRect(lidx).top() < m_View->visualRect(ridx).top();
+  });
+
+  QStringList rows;
+  for (const auto& idx : selectedRows) {
+    rows.append(m_Format(idx));
+  }
+
+  QGuiApplication::clipboard()->setText(rows.join("\n"));
+}
+
+bool CopyEventFilter::eventFilter(QObject* sender, QEvent* event)
+{
+  if (sender == m_View && event->type() == QEvent::KeyPress) {
+    QKeyEvent* const keyEvent = static_cast<QKeyEvent*>(event);
+    if (keyEvent->modifiers() == Qt::ControlModifier && keyEvent->key() == Qt::Key_C) {
+      copySelection();
+      return true;
+    }
+  }
+  return QObject::eventFilter(sender, event);
+}
+
+}  // namespace GUI
diff --git a/libs/installer_bsplugins/src/GUI/CopyEventFilter.h b/libs/installer_bsplugins/src/GUI/CopyEventFilter.h
new file mode 100644
index 0000000..fca7b61
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/CopyEventFilter.h
@@ -0,0 +1,47 @@
+#ifndef GUI_COPY_EVENT_FILTER_H
+#define GUI_COPY_EVENT_FILTER_H
+
+#include <QAbstractItemView>
+#include <QModelIndex>
+#include <QObject>
+
+#include <functional>
+
+namespace GUI
+{
+
+// this small class provides copy on Ctrl+C and also
+// exposes a method to actual copy the selection
+//
+// the way the selection is copied can be customized by
+// passing a functor to format each index, by default
+// it only extracts the display role
+//
+// only works for view that selects whole row since it only
+// considers the first cell in each row
+//
+class CopyEventFilter : public QObject
+{
+  Q_OBJECT
+
+public:
+  explicit CopyEventFilter(QAbstractItemView* view, int column = 0,
+                           int role = Qt::DisplayRole);
+  CopyEventFilter(QAbstractItemView* view,
+                  std::function<QString(const QModelIndex&)> format);
+
+  // copy the selection of the view associated with this
+  // event filter into the clipboard
+  //
+  void copySelection() const;
+
+  bool eventFilter(QObject* sender, QEvent* event) override;
+
+private:
+  QAbstractItemView* m_View;
+  std::function<QString(const QModelIndex&)> m_Format;
+};
+
+}  // namespace GUI
+
+#endif  // GUI_COPY_EVENT_FILTER_H
diff --git a/libs/installer_bsplugins/src/GUI/GenericIconDelegate.cpp b/libs/installer_bsplugins/src/GUI/GenericIconDelegate.cpp
new file mode 100644
index 0000000..9e5f31c
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/GenericIconDelegate.cpp
@@ -0,0 +1,29 @@
+#include "GenericIconDelegate.h"
+
+namespace GUI
+{
+
+GenericIconDelegate::GenericIconDelegate(QTreeView* parent, int role, int logicalIndex,
+                                         int compactSize)
+    : IconDelegate(parent, logicalIndex, compactSize), m_Role{role}
+{}
+
+QList<QString> GenericIconDelegate::getIcons(const QModelIndex& index) const
+{
+  QList<QString> result;
+  if (index.isValid()) {
+    for (const QVariant& var : index.data(m_Role).toList()) {
+      if (!compact() || !var.toString().isEmpty()) {
+        result.append(var.toString());
+      }
+    }
+  }
+  return result;
+}
+
+int GenericIconDelegate::getNumIcons(const QModelIndex& index) const
+{
+  return index.data(m_Role).toList().count();
+}
+
+}  // namespace GUI
diff --git a/libs/installer_bsplugins/src/GUI/GenericIconDelegate.h b/libs/installer_bsplugins/src/GUI/GenericIconDelegate.h
new file mode 100644
index 0000000..c0d517e
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/GenericIconDelegate.h
@@ -0,0 +1,45 @@
+#ifndef GUI_GENERICICONDELEGATE_H
+#define GUI_GENERICICONDELEGATE_H
+
+#include "IconDelegate.h"
+
+namespace GUI
+{
+
+/**
+ * @brief an icon delegate that takes the list of icons from a user-defines data role
+ */
+class GenericIconDelegate : public IconDelegate
+{
+  Q_OBJECT
+public:
+  /**
+   * @brief constructor
+   * @param parent parent object
+   * @param role role of the itemmodel from which the icon list can be queried (as a
+   * QVariantList)
+   * @param logicalIndex logical index within the model. This is part of a "hack".
+   * Normally "empty" icons will be allocated the same space as a regular icon. This way
+   * the model can use empty icons as spacers and thus align same icons horizontally.
+   *                     Now, if you set the logical Index to a valid column and connect
+   * the columnResized slot to the sectionResized signal of the view, the delegate will
+   * turn off this behaviour if the column is smaller than "compactSize"
+   * @param compactSize see explanation of logicalIndex
+   */
+  GenericIconDelegate(QTreeView* parent, int role, int logicalIndex = -1,
+                      int compactSize = 150);
+
+private:
+  [[nodiscard]] QList<QString> getIcons(const QModelIndex& index) const override;
+  [[nodiscard]] int getNumIcons(const QModelIndex& index) const override;
+
+private:
+  int m_Role;
+  int m_LogicalIndex;
+  int m_CompactSize;
+  bool m_Compact;
+};
+
+}  // namespace GUI
+
+#endif  // GUI_GENERICICONDELEGATE_H
diff --git a/libs/installer_bsplugins/src/GUI/IGeometrySettings.h b/libs/installer_bsplugins/src/GUI/IGeometrySettings.h
new file mode 100644
index 0000000..681fc11
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/IGeometrySettings.h
@@ -0,0 +1,44 @@
+#ifndef GUI_IGEOMETRYSETTINGS_H
+#define GUI_IGEOMETRYSETTINGS_H
+
+#include <concepts>
+
+namespace GUI
+{
+
+template <class W>
+class IGeometrySettings
+{
+public:
+  virtual void saveGeometry(const W* widget)    = 0;
+  virtual void restoreGeometry(W* widget) const = 0;
+};
+
+template <class W>
+class [[nodiscard]] GeometrySaver final
+{
+public:
+  GeometrySaver(IGeometrySettings<W>& s, W* w) : m_Settings{s}, m_Widget{w}
+  {
+    m_Settings.restoreGeometry(m_Widget);
+  }
+
+  GeometrySaver(const GeometrySaver<W>&) = delete;
+  GeometrySaver(GeometrySaver<W>&&)      = delete;
+
+  ~GeometrySaver() { m_Settings.saveGeometry(m_Widget); }
+
+  GeometrySaver<W>& operator=(const GeometrySaver<W>&) = delete;
+  GeometrySaver<W>& operator=(GeometrySaver<W>&&)      = delete;
+
+private:
+  IGeometrySettings<W>& m_Settings;
+  W* m_Widget;
+};
+
+template <class W, std::derived_from<W> Derived>
+GeometrySaver(IGeometrySettings<W>&, Derived*) -> GeometrySaver<W>;
+
+}  // namespace GUI
+
+#endif  // GUI_IGEOMETRYSETTINGS_H
diff --git a/libs/installer_bsplugins/src/GUI/IStateSettings.h b/libs/installer_bsplugins/src/GUI/IStateSettings.h
new file mode 100644
index 0000000..15425a0
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/IStateSettings.h
@@ -0,0 +1,44 @@
+#ifndef GUI_ISTATESETTINGS_H
+#define GUI_ISTATESETTINGS_H
+
+#include <concepts>
+
+namespace GUI
+{
+
+template <class W>
+class IStateSettings
+{
+public:
+  virtual void saveState(const W* widget)    = 0;
+  virtual void restoreState(W* widget) const = 0;
+};
+
+template <class W>
+class [[nodiscard]] StateSaver final
+{
+public:
+  StateSaver(IStateSettings<W>& s, W* w) : m_Settings{s}, m_Widget{w}
+  {
+    m_Settings.restoreState(m_Widget);
+  }
+
+  StateSaver(const StateSaver<W>&) = delete;
+  StateSaver(StateSaver<W>&&)      = delete;
+
+  ~StateSaver() { m_Settings.saveState(m_Widget); }
+
+  StateSaver<W>& operator=(const StateSaver<W>&) = delete;
+  StateSaver<W>& operator=(StateSaver<W>&&)      = delete;
+
+private:
+  IStateSettings<W>& m_Settings;
+  W* m_Widget;
+};
+
+template <class W, class I = IStateSettings<W>>
+StateSaver(I&, W*) -> StateSaver<W>;
+
+}  // namespace GUI
+
+#endif  // GUI_ISTATESETTINGS_H
diff --git a/libs/installer_bsplugins/src/GUI/IconDelegate.cpp b/libs/installer_bsplugins/src/GUI/IconDelegate.cpp
new file mode 100644
index 0000000..ff99405
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/IconDelegate.cpp
@@ -0,0 +1,89 @@
+#include "IconDelegate.h"
+
+#include <QDebug>
+#include <QHBoxLayout>
+#include <QHeaderView>
+#include <QLabel>
+#include <QPainter>
+#include <QPixmapCache>
+#include <algorithm>
+#include <log.h>
+
+namespace GUI
+{
+
+using namespace MOBase;
+
+constexpr int MAX_WIDTH = 16;
+constexpr int MARGIN_X  = 4;
+
+IconDelegate::IconDelegate(QTreeView* view, int column, int compactSize)
+    : QStyledItemDelegate(view), m_Column{column}, m_CompactSize{compactSize},
+      m_Compact{false}
+{
+  if (view) {
+    connect(view->header(), &QHeaderView::sectionResized,
+            [=](int logicalIndex, [[maybe_unused]] int oldSize, int newSize) {
+              if (logicalIndex == m_Column) {
+                m_Compact = newSize < m_CompactSize;
+              }
+            });
+  }
+}
+
+void IconDelegate::paintIcons(QPainter* painter, const QStyleOptionViewItem& option,
+                              [[maybe_unused]] const QModelIndex& index,
+                              const QList<QString>& icons)
+{
+  int x = MARGIN_X;
+  painter->save();
+
+  int iconWidth =
+      icons.size() > 0 ? ((option.rect.width() / icons.size()) - MARGIN_X) : MAX_WIDTH;
+  // Clamp to at least 8px so narrow columns don't make QIcon::pixmap()
+  // return null and spuriously log "failed to load icon".
+  iconWidth = std::clamp(iconWidth, 8, MAX_WIDTH);
+
+  const int margin = (option.rect.height() - iconWidth) / 2;
+
+  painter->translate(option.rect.topLeft());
+  for (const QString& iconId : icons) {
+    if (iconId.isEmpty()) {
+      x += iconWidth + MARGIN_X;
+      continue;
+    }
+    QPixmap icon;
+    const QString fullIconId = QString("%1_%2").arg(iconId).arg(iconWidth);
+    if (!QPixmapCache::find(fullIconId, &icon)) {
+      icon = QIcon(iconId).pixmap(iconWidth, iconWidth);
+      if (icon.isNull()) {
+        log::warn("failed to load icon {}", iconId);
+      }
+      QPixmapCache::insert(fullIconId, icon);
+    }
+    painter->drawPixmap(x, margin, iconWidth, iconWidth, icon);
+    x += iconWidth + MARGIN_X;
+  }
+
+  painter->restore();
+}
+
+void IconDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option,
+                         const QModelIndex& index) const
+{
+  if (auto* const w = qobject_cast<QAbstractItemView*>(parent())) {
+    w->itemDelegate()->paint(painter, option, index);
+  } else {
+    QStyledItemDelegate::paint(painter, option, index);
+  }
+
+  paintIcons(painter, option, index, getIcons(index));
+}
+
+QSize IconDelegate::sizeHint(const QStyleOptionViewItem& option,
+                             const QModelIndex& index) const
+{
+  return QSize(getNumIcons(index) * (MAX_WIDTH + MARGIN_X), option.rect.height());
+}
+
+}  // namespace GUI
diff --git a/libs/installer_bsplugins/src/GUI/IconDelegate.h b/libs/installer_bsplugins/src/GUI/IconDelegate.h
new file mode 100644
index 0000000..057cd4e
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/IconDelegate.h
@@ -0,0 +1,44 @@
+#ifndef GUI_ICONDELEGATE_H
+#define GUI_ICONDELEGATE_H
+
+#include <QAbstractItemView>
+#include <QAbstractProxyModel>
+#include <QStyledItemDelegate>
+#include <QTreeView>
+
+namespace GUI
+{
+
+class IconDelegate : public QStyledItemDelegate
+{
+  Q_OBJECT
+
+public:
+  explicit IconDelegate(QTreeView* view, int column = -1, int compactSize = 100);
+
+  void paint(QPainter* painter, const QStyleOptionViewItem& option,
+             const QModelIndex& index) const override;
+
+  QSize sizeHint(const QStyleOptionViewItem& option,
+                 const QModelIndex& index) const override;
+
+protected:
+  // check if icons should be compacted or not
+  //
+  [[nodiscard]] bool compact() const { return m_Compact; }
+
+  static void paintIcons(QPainter* painter, const QStyleOptionViewItem& option,
+                         const QModelIndex& index, const QList<QString>& icons);
+
+  [[nodiscard]] virtual QList<QString> getIcons(const QModelIndex& index) const = 0;
+  [[nodiscard]] virtual int getNumIcons(const QModelIndex& index) const         = 0;
+
+private:
+  int m_Column;
+  int m_CompactSize;
+  bool m_Compact;
+};
+
+}  // namespace GUI
+
+#endif  // GUI_ICONDELEGATE_H
diff --git a/libs/installer_bsplugins/src/GUI/ListDialog.cpp b/libs/installer_bsplugins/src/GUI/ListDialog.cpp
new file mode 100644
index 0000000..784280a
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/ListDialog.cpp
@@ -0,0 +1,66 @@
+#include "ListDialog.h"
+#include "ui_listdialog.h"
+
+namespace GUI
+{
+
+ListDialog::ListDialog(IGeometrySettings<QDialog>& settings, QWidget* parent)
+    : QDialog(parent), ui{new Ui::ListDialog}, m_Settings{settings}
+{
+  ui->setupUi(this);
+  ui->filterEdit->setFocus();
+  connect(ui->choiceList, &QListWidget::itemDoubleClicked, this, &QDialog::accept);
+}
+
+ListDialog::~ListDialog() noexcept
+{
+  delete ui;
+}
+
+int ListDialog::exec()
+{
+  GeometrySaver gs{m_Settings, this};
+  return QDialog::exec();
+}
+
+void ListDialog::setChoices(QStringList choices)
+{
+  m_Choices = choices;
+  ui->choiceList->clear();
+  ui->choiceList->addItems(m_Choices);
+}
+
+QString ListDialog::getChoice() const
+{
+  if (ui->choiceList->selectedItems().length()) {
+    return ui->choiceList->currentItem()->text();
+  } else {
+    return "";
+  }
+}
+
+void ListDialog::on_filterEdit_textChanged(QString filter)
+{
+  QStringList newChoices;
+  for (auto choice : m_Choices) {
+    if (choice.contains(filter, Qt::CaseInsensitive)) {
+      newChoices << choice;
+    }
+  }
+  ui->choiceList->clear();
+  ui->choiceList->addItems(newChoices);
+
+  if (newChoices.length() == 1) {
+    QListWidgetItem* item = ui->choiceList->item(0);
+    item->setSelected(true);
+    ui->choiceList->setCurrentItem(item);
+  }
+
+  if (!filter.isEmpty()) {
+    ui->choiceList->setStyleSheet("QListWidget { border: 2px ridge #f00; }");
+  } else {
+    ui->choiceList->setStyleSheet("");
+  }
+}
+
+}  // namespace GUI
diff --git a/libs/installer_bsplugins/src/GUI/ListDialog.h b/libs/installer_bsplugins/src/GUI/ListDialog.h
new file mode 100644
index 0000000..8cd2373
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/ListDialog.h
@@ -0,0 +1,42 @@
+#ifndef GUI_LISTDIALOG_H
+#define GUI_LISTDIALOG_H
+
+#include "IGeometrySettings.h"
+
+#include <QDialog>
+
+namespace Ui
+{
+class ListDialog;
+}
+
+namespace GUI
+{
+
+class ListDialog : public QDialog
+{
+  Q_OBJECT
+
+public:
+  ListDialog(IGeometrySettings<QDialog>& settings, QWidget* parent = nullptr);
+  ~ListDialog() noexcept;
+
+  // also saves and restores geometry
+  //
+  int exec() override;
+
+  void setChoices(QStringList choices);
+  [[nodiscard]] QString getChoice() const;
+
+public slots:
+  void on_filterEdit_textChanged(QString filter);
+
+private:
+  Ui::ListDialog* ui;
+  IGeometrySettings<QDialog>& m_Settings;
+  QStringList m_Choices;
+};
+
+}  // namespace GUI
+
+#endif  // GUI_LISTDIALOG_H
diff --git a/libs/installer_bsplugins/src/GUI/MessageDialog.cpp b/libs/installer_bsplugins/src/GUI/MessageDialog.cpp
new file mode 100644
index 0000000..92197c5
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/MessageDialog.cpp
@@ -0,0 +1,98 @@
+#include "MessageDialog.h"
+#include "ui_messagedialog.h"
+
+#include <log.h>
+
+#include <QMainWindow>
+#include <QResizeEvent>
+#include <QTimer>
+
+using namespace MOBase;
+
+namespace GUI
+{
+
+MessageDialog::MessageDialog(const QString& text, QWidget* reference)
+    : QDialog(reference), ui{new Ui::MessageDialog}
+{
+  ui->setupUi(this);
+
+  // very crude way to ensure no single word in the test is wider than the message
+  // window. ellide in the center if necessary
+  QFontMetrics metrics(ui->message->font());
+  QString restrictedText;
+  QStringList lines = text.split("\n");
+  foreach (const QString& line, lines) {
+    QString newLine;
+    QStringList words = line.split(" ");
+    foreach (const QString& word, words) {
+      if (word.length() > 10) {
+        newLine +=
+            "<span style=\"nobreak\">" +
+            metrics.elidedText(word, Qt::ElideMiddle, ui->message->maximumWidth()) +
+            "</span>";
+      } else {
+        newLine += word;
+      }
+      newLine += " ";
+    }
+    restrictedText += newLine + "\n";
+  }
+
+  ui->message->setText(restrictedText);
+  this->setWindowFlags(Qt::Tool | Qt::FramelessWindowHint | Qt::WindowStaysOnTopHint);
+  this->setFocusPolicy(Qt::NoFocus);
+  this->setAttribute(Qt::WA_ShowWithoutActivating);
+  QTimer::singleShot(1000 + (text.length() * 40), this, SLOT(hide()));
+  if (reference != nullptr) {
+    QPoint position =
+        reference->mapToGlobal(QPoint(reference->width() / 2, reference->height()));
+    position.rx() -= this->width() / 2;
+    position.ry() -= this->height() + 5;
+    move(position);
+  }
+}
+
+MessageDialog::~MessageDialog()
+{
+  delete ui;
+}
+
+void MessageDialog::resizeEvent(QResizeEvent* event)
+{
+  QWidget* par = parentWidget();
+  if (par != nullptr) {
+    QPoint position = par->mapToGlobal(QPoint(par->width() / 2, par->height()));
+    position.rx() -= event->size().width() / 2;
+    position.ry() -= event->size().height() + 5;
+    move(position);
+  }
+}
+
+void MessageDialog::showMessage(const QString& text, QWidget* reference,
+                                bool bringToFront)
+{
+  log::debug("{}", text);
+
+  if (!reference) {
+    for (QWidget* w : qApp->topLevelWidgets()) {
+      if (dynamic_cast<QMainWindow*>(w)) {
+        reference = w;
+        break;
+      }
+    }
+  }
+
+  if (!reference) {
+    return;
+  }
+
+  MessageDialog* dialog = new MessageDialog(text, reference);
+  dialog->show();
+
+  if (bringToFront) {
+    reference->activateWindow();
+  }
+}
+
+}  // namespace GUI
diff --git a/libs/installer_bsplugins/src/GUI/MessageDialog.h b/libs/installer_bsplugins/src/GUI/MessageDialog.h
new file mode 100644
index 0000000..4ea63cb
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/MessageDialog.h
@@ -0,0 +1,59 @@
+#ifndef GUI_MESSAGEDIALOG_H
+#define GUI_MESSAGEDIALOG_H
+
+#include <QDialog>
+
+namespace Ui
+{
+class MessageDialog;
+}
+
+namespace GUI
+{
+
+/**
+ * borderless dialog used to display short messages that will automatically
+ * vanish after a moment
+ **/
+class MessageDialog : public QDialog
+{
+  Q_OBJECT
+
+public:
+  /**
+   * @brief constructor
+   *
+   * @param text the message to display
+   * @param reference parent widget. This will also be used to position the message at
+   * the bottom center of the dialog
+   **/
+
+  explicit MessageDialog(const QString& text, QWidget* reference);
+
+  ~MessageDialog();
+
+  /**
+   * factory function for message dialogs. This can be used as a fire-and-forget. The
+   * message will automatically positioned to the reference dialog and get a reasonable
+   * view time
+   *
+   * @param text the text to display. The length of this text is used to determine how
+   * long the dialog is to be shown
+   * @param reference the reference widget on top of which the message should be
+   * displayed
+   * @param true if the message should bring MO to front to ensure this message is
+   * visible
+   **/
+  static void showMessage(const QString& text, QWidget* reference,
+                          bool bringToFront = true);
+
+protected:
+  virtual void resizeEvent(QResizeEvent* event);
+
+private:
+  Ui::MessageDialog* ui;
+};
+
+}  // namespace GUI
+
+#endif  // GUI_MESSAGEDIALOG_H
diff --git a/libs/installer_bsplugins/src/GUI/SelectionDialog.cpp b/libs/installer_bsplugins/src/GUI/SelectionDialog.cpp
new file mode 100644
index 0000000..3572abe
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/SelectionDialog.cpp
@@ -0,0 +1,102 @@
+#include "SelectionDialog.h"
+#include "ui_selectiondialog.h"
+
+#include <QCommandLinkButton>
+
+namespace GUI
+{
+
+SelectionDialog::SelectionDialog(const QString& description, QWidget* parent,
+                                 const QSize& iconSize)
+    : QDialog(parent), ui{new Ui::SelectionDialog}, m_Choice{nullptr},
+      m_ValidateByData{false}, m_IconSize{iconSize}
+{
+  ui->setupUi(this);
+
+  ui->descriptionLabel->setText(description);
+}
+
+SelectionDialog::~SelectionDialog() noexcept
+{
+  delete ui;
+}
+
+void SelectionDialog::addChoice(const QString& buttonText, const QString& description,
+                                const QVariant& data)
+{
+  QAbstractButton* button =
+      new QCommandLinkButton(buttonText, description, ui->buttonBox);
+  if (m_IconSize.isValid()) {
+    button->setIconSize(m_IconSize);
+  }
+  button->setProperty("data", data);
+  ui->buttonBox->addButton(button, QDialogButtonBox::AcceptRole);
+  if (data.isValid())
+    m_ValidateByData = true;
+}
+
+void SelectionDialog::addChoice(const QIcon& icon, const QString& buttonText,
+                                const QString& description, const QVariant& data)
+{
+  QAbstractButton* button =
+      new QCommandLinkButton(buttonText, description, ui->buttonBox);
+  if (m_IconSize.isValid()) {
+    button->setIconSize(m_IconSize);
+  }
+  button->setIcon(icon);
+  button->setProperty("data", data);
+  ui->buttonBox->addButton(button, QDialogButtonBox::AcceptRole);
+  if (data.isValid())
+    m_ValidateByData = true;
+}
+
+int SelectionDialog::numChoices() const
+{
+  return ui->buttonBox->findChildren<QCommandLinkButton*>(QString()).count();
+}
+
+QVariant SelectionDialog::getChoiceData()
+{
+  return m_Choice->property("data");
+}
+
+QString SelectionDialog::getChoiceString()
+{
+  if ((m_Choice == nullptr) ||
+      (m_ValidateByData && !m_Choice->property("data").isValid())) {
+    return QString();
+  } else {
+    return m_Choice->text();
+  }
+}
+
+QString SelectionDialog::getChoiceDescription()
+{
+  if (m_Choice == nullptr)
+    return QString();
+  else
+    return m_Choice->accessibleDescription();
+}
+
+void SelectionDialog::disableCancel()
+{
+  ui->cancelButton->setEnabled(false);
+  ui->cancelButton->setHidden(true);
+}
+
+void SelectionDialog::on_buttonBox_clicked(QAbstractButton* button)
+{
+  m_Choice = button;
+  if (!m_ValidateByData || m_Choice->property("data").isValid()) {
+    this->accept();
+  } else {
+    this->reject();
+  }
+}
+
+void SelectionDialog::on_cancelButton_clicked()
+{
+  this->reject();
+}
+
+}  // namespace GUI
diff --git a/libs/installer_bsplugins/src/GUI/SelectionDialog.h b/libs/installer_bsplugins/src/GUI/SelectionDialog.h
new file mode 100644
index 0000000..52fdcf9
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/SelectionDialog.h
@@ -0,0 +1,69 @@
+#ifndef GUI_SELECTIONDIALOG_H
+#define GUI_SELECTIONDIALOG_H
+
+#include <QAbstractButton>
+#include <QDialog>
+
+namespace Ui
+{
+class SelectionDialog;
+}
+
+namespace GUI
+{
+
+class SelectionDialog : public QDialog
+{
+  Q_OBJECT
+
+public:
+  explicit SelectionDialog(const QString& description, QWidget* parent = 0,
+                           const QSize& iconSize = QSize());
+
+  SelectionDialog(const SelectionDialog&) = delete;
+  SelectionDialog(SelectionDialog&&)      = delete;
+
+  ~SelectionDialog() noexcept;
+
+  SelectionDialog& operator=(const SelectionDialog&) = delete;
+  SelectionDialog& operator=(SelectionDialog&&)      = delete;
+
+  /**
+   * @brief add a choice to the dialog
+   * @param buttonText the text to be displayed on the button
+   * @param description the description that shows up under in small letters inside the
+   * button
+   * @param data data to be stored with the button. Please note that as soon as one
+   * choice has data associated with it (non-invalid QVariant) all buttons that contain
+   * no data will be treated as "cancel" buttons
+   */
+  void addChoice(const QString& buttonText, const QString& description,
+                 const QVariant& data);
+
+  void addChoice(const QIcon& icon, const QString& buttonText,
+                 const QString& description, const QVariant& data);
+
+  int numChoices() const;
+
+  QVariant getChoiceData();
+  QString getChoiceString();
+  QString getChoiceDescription();
+
+  void disableCancel();
+
+private slots:
+
+  void on_buttonBox_clicked(QAbstractButton* button);
+
+  void on_cancelButton_clicked();
+
+private:
+  Ui::SelectionDialog* ui;
+  QAbstractButton* m_Choice;
+  bool m_ValidateByData;
+  QSize m_IconSize;
+};
+
+}  // namespace GUI
+
+#endif  // GUI_SELECTIONDIALOG_H
diff --git a/libs/installer_bsplugins/src/GUI/ViewMarkingScrollBar.cpp b/libs/installer_bsplugins/src/GUI/ViewMarkingScrollBar.cpp
new file mode 100644
index 0000000..94da308
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/ViewMarkingScrollBar.cpp
@@ -0,0 +1,80 @@
+#include "ViewMarkingScrollBar.h"
+
+#include <QPainter>
+#include <QStyle>
+#include <QStyleOptionSlider>
+
+namespace GUI
+{
+
+static QModelIndexList visibleIndexImpl(QTreeView* view, int column,
+                                        const QModelIndex& parent)
+{
+  if (parent.isValid() && !view->isExpanded(parent)) {
+    return {};
+  }
+
+  const auto* const model = view->model();
+  QModelIndexList index;
+  for (int i = 0; i < model->rowCount(parent); ++i) {
+    index.append(model->index(i, column, parent));
+    index.append(visibleIndexImpl(view, column, index.back()));
+  }
+  return index;
+}
+
+static QModelIndexList visibleIndex(QTreeView* view, int column)
+{
+  return visibleIndexImpl(view, column, QModelIndex());
+}
+
+ViewMarkingScrollBar::ViewMarkingScrollBar(QTreeView* view, int role)
+    : QScrollBar(view), m_View{view}, m_Role{role}
+{
+  // not implemented for horizontal sliders
+  Q_ASSERT(this->orientation() == Qt::Vertical);
+}
+
+QColor ViewMarkingScrollBar::color(const QModelIndex& index) const
+{
+  const auto data = index.data(m_Role);
+  if (data.canConvert<QColor>()) {
+    return data.value<QColor>();
+  }
+  return QColor();
+}
+
+void ViewMarkingScrollBar::paintEvent(QPaintEvent* event)
+{
+  if (m_View->model() == nullptr) {
+    return;
+  }
+  QScrollBar::paintEvent(event);
+
+  QStyleOptionSlider styleOption;
+  initStyleOption(&styleOption);
+
+  QPainter painter(this);
+
+  QRect handleRect = style()->subControlRect(QStyle::CC_ScrollBar, &styleOption,
+                                             QStyle::SC_ScrollBarSlider, this);
+  QRect innerRect  = style()->subControlRect(QStyle::CC_ScrollBar, &styleOption,
+                                             QStyle::SC_ScrollBarGroove, this);
+
+  auto indices = visibleIndex(m_View, 0);
+
+  painter.translate(innerRect.topLeft() + QPoint(0, 3));
+  const qreal scale =
+      static_cast<qreal>(innerRect.height() - 3) / static_cast<qreal>(indices.size());
+
+  for (int i = 0; i < indices.size(); ++i) {
+    const QColor color = this->color(indices[i]);
+    if (color.isValid()) {
+      painter.setPen(color);
+      painter.setBrush(color);
+      painter.drawRect(QRect(2, i * scale - 2, handleRect.width() - 5, 3));
+    }
+  }
+}
+
+}  // namespace GUI
diff --git a/libs/installer_bsplugins/src/GUI/ViewMarkingScrollBar.h b/libs/installer_bsplugins/src/GUI/ViewMarkingScrollBar.h
new file mode 100644
index 0000000..750c743
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/ViewMarkingScrollBar.h
@@ -0,0 +1,34 @@
+#ifndef GUI_VIEWMARKINGSCROLLBAR_H
+#define GUI_VIEWMARKINGSCROLLBAR_H
+
+#include <QColor>
+#include <QModelIndex>
+#include <QPaintEvent>
+#include <QScrollBar>
+#include <QTreeView>
+
+namespace GUI
+{
+
+class ViewMarkingScrollBar : public QScrollBar
+{
+public:
+  ViewMarkingScrollBar(QTreeView* view, int role);
+
+protected:
+  void paintEvent(QPaintEvent* event) override;
+
+  // retrieve the color of the marker for the given index
+  //
+  [[nodiscard]] virtual QColor color(const QModelIndex& index) const;
+
+protected:
+  QTreeView* m_View;
+
+private:
+  int m_Role;
+};
+
+}  // namespace GUI
+
+#endif  // GUI_VIEWMARKINGSCROLLBAR_H
diff --git a/libs/installer_bsplugins/src/GUI/listdialog.ui b/libs/installer_bsplugins/src/GUI/listdialog.ui
new file mode 100644
index 0000000..7aa3eba
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/listdialog.ui
@@ -0,0 +1,103 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>ListDialog</class>
+ <widget class="QDialog" name="ListDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>260</width>
+    <height>380</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Select an item...</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QListWidget" name="choiceList">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+     <property name="minimumSize">
+      <size>
+       <width>240</width>
+       <height>280</height>
+      </size>
+     </property>
+     <property name="verticalScrollMode">
+      <enum>QAbstractItemView::ScrollPerPixel</enum>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="MOBase::LineEditClear" name="filterEdit">
+     <property name="text">
+      <string/>
+     </property>
+     <property name="placeholderText">
+      <string>Filter</string>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="layoutDirection">
+      <enum>Qt::LeftToRight</enum>
+     </property>
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>MOBase::LineEditClear</class>
+   <extends>QLineEdit</extends>
+   <header>lineeditclear.h</header>
+  </customwidget>
+ </customwidgets>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
+   <receiver>ListDialog</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>248</x>
+     <y>254</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>157</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>ListDialog</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>316</x>
+     <y>260</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>286</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>
diff --git a/libs/installer_bsplugins/src/GUI/messagedialog.ui b/libs/installer_bsplugins/src/GUI/messagedialog.ui
new file mode 100644
index 0000000..ed785ff
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/messagedialog.ui
@@ -0,0 +1,94 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MessageDialog</class>
+ <widget class="QDialog" name="MessageDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>106</width>
+    <height>35</height>
+   </rect>
+  </property>
+  <property name="sizePolicy">
+   <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
+    <horstretch>0</horstretch>
+    <verstretch>0</verstretch>
+   </sizepolicy>
+  </property>
+  <property name="maximumSize">
+   <size>
+    <width>16777215</width>
+    <height>16777215</height>
+   </size>
+  </property>
+  <property name="sizeIncrement">
+   <size>
+    <width>0</width>
+    <height>0</height>
+   </size>
+  </property>
+  <property name="windowTitle">
+   <string>Placeholder</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <property name="leftMargin">
+    <number>0</number>
+   </property>
+   <property name="topMargin">
+    <number>0</number>
+   </property>
+   <property name="rightMargin">
+    <number>0</number>
+   </property>
+   <property name="bottomMargin">
+    <number>0</number>
+   </property>
+   <item>
+    <widget class="QLabel" name="message">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="MinimumExpanding" vsizetype="MinimumExpanding">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+     <property name="maximumSize">
+      <size>
+       <width>300</width>
+       <height>16777215</height>
+      </size>
+     </property>
+     <property name="sizeIncrement">
+      <size>
+       <width>0</width>
+       <height>0</height>
+      </size>
+     </property>
+     <property name="frameShape">
+      <enum>QFrame::Box</enum>
+     </property>
+     <property name="text">
+      <string>Placeholder</string>
+     </property>
+     <property name="textFormat">
+      <enum>Qt::RichText</enum>
+     </property>
+     <property name="alignment">
+      <set>Qt::AlignCenter</set>
+     </property>
+     <property name="wordWrap">
+      <bool>true</bool>
+     </property>
+     <property name="margin">
+      <number>2</number>
+     </property>
+     <property name="textInteractionFlags">
+      <set>Qt::NoTextInteraction</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/libs/installer_bsplugins/src/GUI/selectiondialog.ui b/libs/installer_bsplugins/src/GUI/selectiondialog.ui
new file mode 100644
index 0000000..9b7f7e3
--- /dev/null
+++ b/libs/installer_bsplugins/src/GUI/selectiondialog.ui
@@ -0,0 +1,85 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>SelectionDialog</class>
+ <widget class="QDialog" name="SelectionDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>527</width>
+    <height>327</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Select</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <property name="spacing">
+    <number>20</number>
+   </property>
+   <item>
+    <widget class="QLabel" name="descriptionLabel">
+     <property name="text">
+      <string>Placeholder</string>
+     </property>
+     <property name="wordWrap">
+      <bool>true</bool>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QScrollArea" name="scrollArea">
+     <property name="horizontalScrollBarPolicy">
+      <enum>Qt::ScrollBarAlwaysOff</enum>
+     </property>
+     <property name="widgetResizable">
+      <bool>true</bool>
+     </property>
+     <widget class="QWidget" name="scrollAreaWidgetContents">
+      <property name="geometry">
+       <rect>
+        <x>0</x>
+        <y>0</y>
+        <width>503</width>
+        <height>219</height>
+       </rect>
+      </property>
+      <layout class="QVBoxLayout" name="verticalLayout_2">
+       <property name="margin">
+        <number>0</number>
+       </property>
+       <item>
+        <widget class="QDialogButtonBox" name="buttonBox">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="orientation">
+          <enum>Qt::Vertical</enum>
+         </property>
+         <property name="standardButtons">
+          <set>QDialogButtonBox::NoButton</set>
+         </property>
+         <property name="centerButtons">
+          <bool>false</bool>
+         </property>
+        </widget>
+       </item>
+      </layout>
+     </widget>
+    </widget>
+   </item>
+   <item>
+    <widget class="QPushButton" name="cancelButton">
+     <property name="text">
+      <string>Cancel</string>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>