Add FUSE external mapping support, BG3/Oblivion Remastered fixes, fomod-plus and NaK integration

FUSE VFS now deploys non-data-dir mod mappings (Paks, OBSE, UE4SS, etc.)
via real symlinks and injects file-level data-dir mappings (plugins.txt,
loadorder.txt) into the VFS tree. Fixes game launches for Oblivion
Remastered (Root Builder path resolution, script extender support) and
BG3 (Wine prefix documents directory, file mapper symlinks on Linux).

Vendors mo2-fomod-plus plugin and NaK crate for FOMOD installer and
game finder/runtime support.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 284 insertions, 0 deletions

diff --git a/libs/installer_fomod_plus/installer/ui/FomodImageViewer.cpp b/libs/installer_fomod_plus/installer/ui/FomodImageViewer.cpp
new file mode 100644
index 0000000..cb99d27
--- /dev/null
+++ b/libs/installer_fomod_plus/installer/ui/FomodImageViewer.cpp
@@ -0,0 +1,284 @@
+#include "FomodImageViewer.h"
+
+#include "ScaleLabel.h"
+#include "UIHelper.h"
+
+#include <QLabel>
+#include <QScrollArea>
+#include <QtConcurrent/QtConcurrent>
+
+constexpr int PREVIEW_IMAGE_WIDTH  = 160;
+constexpr int PREVIEW_IMAGE_HEIGHT = 90;
+
+/*
++----------------------------------------------------------+
+|n/N                                                    X  |
++---+--------------------------------------------------+---+
+|   |                                                  |   |
+|   |                                                  |   |
+|   |                                                  |   |
+|   |                                                  |   |
+|   |                                                  |   |
+|   |                                                  |   |
+| < |               Image                              | > |
+|   |                                                  |   |
+|   |                                                  |   |
+|   |                                                  |   |
+|   |                                                  |   |
+|   |                 label                            |   |
++------+------+------+---------------------------------+---+
+|      |      |      |  ...previews                        |
+|      |      |      |                                     |
++------+------+------+-------------------------------------+
+*/
+constexpr auto BUTTON_STYLE =
+    "font-size: 16px; font-weight: bold; color: white; background-color: black; padding: 5px; border-radius: 1px solid black;";
+
+FomodImageViewer::FomodImageViewer(QWidget* parent,
+    const QString& fomodPath,
+    const std::shared_ptr<StepViewModel>& activeStep,
+    const std::shared_ptr<PluginViewModel>& activePlugin) : QDialog(parent), mFomodPath(fomodPath),
+                                                            mActiveStep(activeStep),
+                                                            mActivePlugin(activePlugin)
+{
+
+    setWindowFlags(Qt::FramelessWindowHint | Qt::Window);
+    setAttribute(Qt::WA_TranslucentBackground);
+    setStyleSheet("background-color: rgba(0, 0, 0, 150);");
+
+    const QScreen* screen         = this->screen();
+    const QRect availableGeometry = screen->availableGeometry();
+    setFixedSize(availableGeometry.width(), availableGeometry.height());
+    move(availableGeometry.x(), availableGeometry.y());
+
+    collectImages();
+    mMainImageWrapper = createSinglePhotoPane(this);
+    mTopBar           = createTopBar(this);
+    mPreviewImages    = createPreviewImages(this);
+    mCenterRow        = createCenterRow(this);
+
+    const auto layout = new QVBoxLayout(this);
+    layout->setContentsMargins(0, 0, 0, 0); // Remove margins
+    layout->setSpacing(0); // Remove spacing between widgets
+    layout->addWidget(mTopBar);
+    layout->addWidget(mCenterRow, 1);
+    layout->addWidget(mPreviewImages);
+    setLayout(layout);
+
+    select(mCurrentIndex);
+
+    setFocusPolicy(Qt::StrongFocus); // so we can receive key events
+}
+
+void FomodImageViewer::collectImages()
+{
+    mLabelsAndImages.clear();
+    for (const auto& groupViewModel : mActiveStep->getGroups()) {
+        for (const auto& pluginViewModel : groupViewModel->getPlugins()) {
+            if (pluginViewModel->getImagePath().empty()) {
+                continue;
+            }
+            QString imagePath = UIHelper::getFullImagePath(mFomodPath,
+                QString::fromStdString(pluginViewModel->getImagePath()));
+            mLabelsAndImages.emplace_back(QString::fromStdString(pluginViewModel->getName()), imagePath);
+
+            if (pluginViewModel == mActivePlugin) {
+                mCurrentIndex = static_cast<int>(mLabelsAndImages.size()) - 1;
+            }
+        }
+    }
+}
+
+QWidget* FomodImageViewer::createCenterRow(QWidget* parent)
+{
+    const auto centerRow = new QWidget(parent);
+    const auto layout    = new QHBoxLayout(centerRow);
+
+    mBackButton    = createBackButton(centerRow);
+    mForwardButton = createForwardButton(centerRow);
+
+    mBackButton->setFocusPolicy(Qt::NoFocus);
+    mForwardButton->setFocusPolicy(Qt::NoFocus);
+
+    layout->addWidget(mBackButton);
+    layout->addWidget(mMainImageWrapper, 1);
+    layout->addWidget(mForwardButton);
+
+    return centerRow;
+}
+
+// ReSharper disable once CppMemberFunctionMayBeStatic
+QWidget* FomodImageViewer::createSinglePhotoPane(QWidget* parent)
+{
+    const auto singlePhotoPane = new QWidget(parent);
+    const auto layout          = new QVBoxLayout(singlePhotoPane);
+
+    // const auto [labelText, imagePath] = pair;
+
+    mMainImage = new ScaleLabel(singlePhotoPane);
+    mMainImage->setAlignment(Qt::AlignCenter);
+    layout->addWidget(mMainImage, 1);
+
+    mLabel = new QLabel(singlePhotoPane);
+    // mLabel->setText(labelText);
+    mLabel->setAlignment(Qt::AlignCenter);
+    mLabel->setStyleSheet("color: white; font-size: 20px;");
+    layout->addWidget(mLabel);
+
+    return singlePhotoPane;
+}
+
+QScrollArea* FomodImageViewer::createPreviewImages(QWidget* parent)
+{
+    mImagePanes.clear();
+    const auto previewImages = new QScrollArea(parent);
+    const auto widget        = new QWidget(previewImages);
+    const auto layout        = new QHBoxLayout(previewImages);
+
+    layout->setContentsMargins(0, 0, 0, 0);
+    layout->setSpacing(0);
+
+    for (int i = 0; i < mLabelsAndImages.size(); i++) {
+        const auto imageLabel = new ScaleLabel(previewImages);
+        imageLabel->setAlignment(Qt::AlignCenter);
+        imageLabel->setFixedSize(PREVIEW_IMAGE_WIDTH, PREVIEW_IMAGE_HEIGHT);
+        imageLabel->setFocusPolicy(Qt::NoFocus);
+        connect(imageLabel, &ScaleLabel::clicked, this, [this, i] {
+            select(i);
+        });
+        layout->addWidget(imageLabel);
+        mImagePanes.emplace_back(imageLabel);
+
+        // imageLabel->setScalableResource(mLabelsAndImages[i].second);
+        const auto imagePath = mLabelsAndImages[i].second;
+
+        QThreadPool::globalInstance()->start([imageLabel, imagePath]() {
+            QMetaObject::invokeMethod(imageLabel, [imageLabel, imagePath]() {
+                imageLabel->setScalableResource(imagePath);
+            }, Qt::QueuedConnection);
+        });
+    }
+
+    widget->setLayout(layout);
+    previewImages->setFixedHeight(PREVIEW_IMAGE_HEIGHT + 10);
+    previewImages->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    previewImages->setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded);
+    previewImages->setFocusPolicy(Qt::NoFocus);
+
+    previewImages->setWidget(widget);
+    previewImages->setStyleSheet("QScrollArea { border: none; }");
+
+    return previewImages;
+}
+
+QPushButton* FomodImageViewer::createBackButton(QWidget* parent) const
+{
+    const auto backButton = new QPushButton(parent);
+    backButton->setText("<");
+    backButton->setStyleSheet(BUTTON_STYLE);
+    connect(backButton, &QPushButton::clicked, this, &FomodImageViewer::goBack);
+    return backButton;
+}
+
+QPushButton* FomodImageViewer::createForwardButton(QWidget* parent) const
+{
+    const auto forwardButton = new QPushButton(parent);
+    forwardButton->setText(">");
+    forwardButton->
+        setStyleSheet(BUTTON_STYLE);
+    connect(forwardButton, &QPushButton::clicked, this, &FomodImageViewer::goForward);
+    return forwardButton;
+}
+
+QWidget* FomodImageViewer::createTopBar(QWidget* parent)
+{
+    const auto topBar = new QWidget(parent);
+    const auto layout = new QHBoxLayout(topBar);
+
+    // counter, spacer, close button
+    mCounter = new QLabel(topBar);
+    mCounter->setStyleSheet(BUTTON_STYLE);
+    layout->addWidget(mCounter);
+
+    layout->addStretch();
+
+    mCloseButton = createCloseButton(topBar);
+    layout->addWidget(mCloseButton);
+    return topBar;
+}
+
+QPushButton* FomodImageViewer::createCloseButton(QWidget* parent)
+{
+    const auto closeButton = new QPushButton(parent);
+    // const QIcon icon(":/fomod/close");
+    // closeButton->setIcon(icon);
+    closeButton->setText("X");
+    closeButton->setStyleSheet("color: white; background-color: black; padding: 5px; border-radius: 1px solid black;");
+    connect(closeButton, &QPushButton::clicked, this, &FomodImageViewer::close);
+    return closeButton;
+}
+
+void FomodImageViewer::updateCounterText() const
+{
+    mCounter->setText(QString::number(mCurrentIndex + 1) + "/" + QString::number(mLabelsAndImages.size()));
+}
+
+void FomodImageViewer::goBack()
+{
+    if (mCurrentIndex == 0) {
+        return;
+    }
+    select(--mCurrentIndex);
+}
+
+void FomodImageViewer::goForward()
+{
+    if (mCurrentIndex == mLabelsAndImages.size() - 1) {
+        return;
+    }
+    select(++mCurrentIndex);
+}
+
+void FomodImageViewer::select(const int index)
+{
+    if (index < 0 || index >= mLabelsAndImages.size()) {
+        return;
+    }
+
+    // Remove border from previously selected image
+    mCurrentIndex = index; // check for bounds?
+    updateCounterText();
+
+    for (int i = 0; i < mImagePanes.size(); i++) {
+        if (i == mCurrentIndex) {
+            mImagePanes[i]->setStyleSheet("border: 2px solid white;");
+        } else {
+            mImagePanes[i]->setStyleSheet("");
+        }
+    }
+
+    const auto& imagePath = mLabelsAndImages[index].second;
+    const auto& labelText = mLabelsAndImages[index].first;
+    mLabel->setText(labelText);
+    mMainImage->setScalableResource(imagePath);
+}
+
+void FomodImageViewer::keyPressEvent(QKeyEvent* event)
+{
+    switch (event->key()) {
+    case Qt::Key_Left:
+        goBack();
+        break;
+    case Qt::Key_Right:
+        goForward();
+        break;
+    default:
+        QDialog::keyPressEvent(event);
+    }
+}
+
+void FomodImageViewer::showEvent(QShowEvent* event)
+{
+    QDialog::showEvent(event);
+    setFocus();
+}
\ No newline at end of file