#include "previewfiledialog.h"
#include <QGridLayout>

PreviewFileDialog::PreviewFileDialog(QWidget *parent, const QString &caption, const QString &directory,
                                     const QString &filter, int previewWidth) :
    QFileDialog(parent, caption, directory, filter)
{
    QGridLayout *layout = (QGridLayout *)this->layout();
    if (!layout) {
        // this QFileDialog is a native one (Windows/KDE/...) and doesn't need to be extended with preview
        return;
    }
    setObjectName("PreviewFileDialog");
    QVBoxLayout *box = new QVBoxLayout();

    mpPreview = new QLabel(tr("Preview"), this);
    mpPreview->setAlignment(Qt::AlignCenter);
    mpPreview->setObjectName("labelPreview");
    mpPreview->setMinimumWidth(previewWidth);
    mpPreview->setMinimumHeight(height());
    setMinimumWidth(width() + previewWidth);
    box->addWidget(mpPreview);

    box->addStretch();

    // add to QFileDialog layout
    layout->addLayout(box, 1, 3, 3, 1);
    connect(this, SIGNAL(currentChanged(const QString &)), this, SLOT(onCurrentChanged(const QString &)));
}

void PreviewFileDialog::onCurrentChanged(const QString &path)
{
    QPixmap pixmap = QPixmap(path);
    if (pixmap.isNull()) {
        mpPreview->setText(tr("Not an image"));
    } else {
        mpPreview->setPixmap(
            pixmap.scaled(mpPreview->width(), height(), Qt::KeepAspectRatio, Qt::SmoothTransformation));
    }
}
