blame: mainwindow.cpp

#include "mainwindow.h"

#include "imagemodel.h"

#include <QFileSystemModel>

#include <QTreeView>

#include <QListView>

#include <QLabel>

#include <QSplitter>

#include <QDir>

#include <QImageReader>

#include <QHeaderView>

#include <QScrollBar>

#include <QTimer>

#include <QEvent>

#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());

    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);

    // 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->setResizeMode(QListView::Adjust);

    m_listView->setSelectionMode(QAbstractItemView::SingleSelection);

    m_listView->setSpacing(10);

    // 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(m_treeView);

    mainSplitter->addWidget(rightSplitter);

    mainSplitter->setStretchFactor(1, 1);

    setCentralWidget(mainSplitter);

}

void MainWindow::setupConnections()

{

    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)

            {

                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));

            });

    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);

}