blame: src/mainwindow.cpp

#include "mainwindow.h"

#include "imagemodel.h"

#include "imageviewwidget.h"

#include <QFileSystemModel>

#include <QTreeView>

#include <QListView>

#include <QLabel>

#include <QSplitter>

#include <QStackedWidget>

#include <QDir>

#include <QComboBox>

#include <QVBoxLayout>

#include <QStandardPaths>

#include <QImageReader>

#include <QHeaderView>

#include <QScrollBar>

#include <QTimer>

#include <QEvent>

#include <QKeyEvent>

#include <QCloseEvent>

#include <QItemSelectionModel>

#include <iostream>

MainWindow::MainWindow(QWidget *parent)

    : QMainWindow(parent)

{

    setupUi();

    setupConnections();

}

void MainWindow::setupUi()

{

    // Folder model (left pane)

    m_dirModel = new QFileSystemModel(this);

    m_dirModel->setFilter(QDir::AllDirs | QDir::NoDotAndDotDot);

    m_dirModel->setRootPath(QDir::homePath());

    // Root chooser combo box

    m_rootCombo = new QComboBox;

    m_rootCombo->addItem("Home",     QDir::homePath());

    m_rootCombo->addItem("Pictures", QStandardPaths::writableLocation(QStandardPaths::PicturesLocation));

    m_rootCombo->addItem("File System", QDir::rootPath());

    m_treeView = new QTreeView;

    m_treeView->setModel(m_dirModel);

    m_treeView->setRootIndex(m_dirModel->index(QDir::homePath()));

    m_treeView->header()->hide();

    m_treeView->setColumnHidden(1, true);

    m_treeView->setColumnHidden(2, true);

    m_treeView->setColumnHidden(3, true);

    // Left pane: combo + tree inside a container widget

    QWidget *leftPane = new QWidget;

    QVBoxLayout *leftLayout = new QVBoxLayout(leftPane);

    leftLayout->setContentsMargins(0, 0, 0, 0);

    leftLayout->addWidget(m_rootCombo);

    leftLayout->addWidget(m_treeView);

    // Thumbnail model (center pane)

    m_imageModel = new ImageModel(this);

    m_listView = new QListView;

    m_listView->setModel(m_imageModel);

    m_listView->setViewMode(QListView::IconMode);

    m_listView->setIconSize(QSize(128, 128));

    m_listView->setGridSize(QSize(148, 168));

    m_listView->setResizeMode(QListView::Adjust);

    m_listView->setSelectionMode(QAbstractItemView::SingleSelection);

    m_listView->setSpacing(4);

    m_listView->setWordWrap(true);

    m_listView->setTextElideMode(Qt::ElideRight);

    // Preview pane (right)

    m_previewLabel = new QLabel;

    m_previewLabel->setAlignment(Qt::AlignCenter);

    m_previewLabel->setMinimumWidth(300);

    // Layout

    QSplitter *rightSplitter = new QSplitter(Qt::Horizontal);

    rightSplitter->addWidget(m_listView);

    rightSplitter->addWidget(m_previewLabel);

    rightSplitter->setStretchFactor(0, 3);

    rightSplitter->setStretchFactor(1, 2);

    QSplitter *mainSplitter = new QSplitter(Qt::Horizontal);

    mainSplitter->addWidget(leftPane);

    mainSplitter->addWidget(rightSplitter);

    mainSplitter->setStretchFactor(1, 1);

    m_browserPage = mainSplitter;

    // Single image view

    m_imageView = new ImageViewWidget;

    // Stack to switch between browser and single image

    m_stack = new QStackedWidget;

    m_stack->addWidget(m_browserPage);

    m_stack->addWidget(m_imageView);

    setCentralWidget(m_stack);

}

void MainWindow::setupConnections()

{

    connect(m_rootCombo, QOverload<int>::of(&QComboBox::currentIndexChanged), this,

            [this](int index) {

                QString rootPath = m_rootCombo->itemData(index).toString();

                m_dirModel->setRootPath(rootPath);

                m_treeView->setRootIndex(m_dirModel->index(rootPath));

            });

    connect(m_treeView, &QTreeView::clicked, this,

            [this](const QModelIndex &index)

            {

                QString path = m_dirModel->filePath(index);

                m_imageModel->setDirectory(path);

                // Defer thumbnail load so the view has time to lay out items

                QTimer::singleShot(0, this, &MainWindow::loadVisibleThumbnails);

            });

    connect(m_listView, &QListView::clicked, this,

            [this](const QModelIndex &index) { showPreview(index); });

    connect(m_listView->selectionModel(), &QItemSelectionModel::currentChanged,

            this, [this](const QModelIndex &current) { showPreview(current); });

    connect(m_listView, &QListView::doubleClicked, this,

            [this](const QModelIndex &index) {

                if (m_imageModel->isFolder(index)) {

                    QString path = m_imageModel->filePath(index);

                    m_imageModel->setDirectory(path);

                    // Update tree view selection to match

                    QModelIndex dirIdx = m_dirModel->index(path);

                    if (dirIdx.isValid())

                        m_treeView->setCurrentIndex(dirIdx);

                    QTimer::singleShot(0, this, &MainWindow::loadVisibleThumbnails);

                } else {

                    enterSingleImageMode(index);

                }

            });

    connect(m_imageView, &ImageViewWidget::closeRequested,

            this, &MainWindow::leaveSingleImageMode);

    connect(m_imageView, &ImageViewWidget::nextRequested, this, [this]() {

        QModelIndex cur = m_listView->currentIndex();

        int next = cur.isValid() ? cur.row() + 1 : 0;

        while (next < m_imageModel->rowCount() && m_imageModel->isFolder(m_imageModel->index(next)))

            ++next;

        if (next < m_imageModel->rowCount())

        {

            QModelIndex idx = m_imageModel->index(next);

            m_listView->setCurrentIndex(idx);

            enterSingleImageMode(idx);

        }

    });

    connect(m_imageView, &ImageViewWidget::previousRequested, this, [this]() {

        QModelIndex cur = m_listView->currentIndex();

        int prev = cur.isValid() ? cur.row() - 1 : 0;

        while (prev >= 0 && m_imageModel->isFolder(m_imageModel->index(prev)))

            --prev;

        if (prev >= 0)

        {

            QModelIndex idx = m_imageModel->index(prev);

            m_listView->setCurrentIndex(idx);

            enterSingleImageMode(idx);

        }

    });

    connect(m_listView->verticalScrollBar(), &QScrollBar::valueChanged,

            this, [this]()

            { loadVisibleThumbnails(); });

    // Also catch resize — visible range changes when the viewport is resized

    m_listView->viewport()->installEventFilter(this);

}

bool MainWindow::eventFilter(QObject *obj, QEvent *event)

{

    if (obj == m_listView->viewport() && event->type() == QEvent::Resize)

        QTimer::singleShot(0, this, &MainWindow::loadVisibleThumbnails);

    return QMainWindow::eventFilter(obj, event);

}

void MainWindow::loadVisibleThumbnails()

{

    QModelIndex topLeft = m_listView->indexAt(QPoint(0, 0));

    QModelIndex bottomRight = m_listView->indexAt(

        QPoint(m_listView->viewport()->width() - 1,

               m_listView->viewport()->height() - 1));

    int first = topLeft.isValid() ? topLeft.row() : 0;

    int last = bottomRight.isValid() ? bottomRight.row()

                                     : m_imageModel->rowCount() - 1;

    if (last < 0)

        return;

    std::cout << "loadVisibleThumbnails: " << first << " - " << last << "\n";

    m_imageModel->requestThumbnails(first, last);

}

void MainWindow::showPreview(const QModelIndex &index)

{

    if (!index.isValid())

        return;

    QString path = m_imageModel->filePath(index);

    QImageReader reader(path);

    reader.setAutoTransform(true);

    QImage image = reader.read();

    m_previewLabel->setPixmap(

        QPixmap::fromImage(image).scaled(

            m_previewLabel->size(),

            Qt::KeepAspectRatio,

            Qt::SmoothTransformation));

}

void MainWindow::enterSingleImageMode(const QModelIndex &index)

{

    if (!index.isValid())

        return;

    m_wasFullScreen = isFullScreen();

    m_wasMaximized = isMaximized();

    QString path = m_imageModel->filePath(index);

    m_imageView->setImage(path);

    m_stack->setCurrentWidget(m_imageView);

    m_imageView->setFocus();

}

void MainWindow::leaveSingleImageMode()

{

    if (isFullScreen()) {

        if (m_wasFullScreen) {

            showFullScreen();

        }

        else if (m_wasMaximized) {

            showMaximized();

        }

        else {

            showNormal();

        }

    }

    m_stack->setCurrentWidget(m_browserPage);

    m_listView->setFocus();

}

void MainWindow::keyPressEvent(QKeyEvent *event)

{

    if (event->key() == Qt::Key_F11 && m_stack->currentWidget() == m_imageView)

    {

        if (isFullScreen())

        {

            if (m_wasMaximized) {

                showMaximized();

            }

            else {

                showNormal();

            }

        }

        else {

            showFullScreen();

        }

        event->accept();

        return;

    }

    if (event->key() == Qt::Key_Return && m_stack->currentWidget() == m_browserPage)

    {

        QModelIndex current = m_listView->currentIndex();

        if (current.isValid())

        {

            if (m_imageModel->isFolder(current)) {

                QString path = m_imageModel->filePath(current);

                m_imageModel->setDirectory(path);

                QModelIndex dirIdx = m_dirModel->index(path);

                if (dirIdx.isValid())

                    m_treeView->setCurrentIndex(dirIdx);

                QTimer::singleShot(0, this, &MainWindow::loadVisibleThumbnails);

            } else {

                enterSingleImageMode(current);

            }

            event->accept();

            return;

        }

    }

    QMainWindow::keyPressEvent(event);

}

void MainWindow::closeEvent(QCloseEvent *event)

{

    if (m_stack->currentWidget() == m_imageView)

    {

        leaveSingleImageMode();

        event->ignore();

        return;

    }

    QMainWindow::closeEvent(event);

}