File indexing completed on 2024-04-28 04:32:07

 /*
  * Copyright (C) 2015 by Stephen Allewell
  * steve.allewell@gmail.com
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  */
 
 /** @file
  * This file defines an extension to a QLabel that scales the associated QPixmap
  * to maintain the aspect ratio when scaling to fill the extents of the QLabel
  * area.
  */
 
 // Class include
 #include "ScaledPixmapLabel.h"
 
 // Qt includes
 #include <QMouseEvent>
 #include <QPainter>
 #include <QStyleOptionRubberBand>
 
 ScaledPixmapLabel::ScaledPixmapLabel(QWidget *parent)
     : QLabel(parent)
     , m_cropping(false)
 {
     setMinimumSize(1, 1);
     setAlignment(Qt::AlignCenter);
     setMouseTracking(true);
 }
 
 void ScaledPixmapLabel::setPixmap(const QPixmap &pixmap)
 {
     m_pixmap = pixmap;
     m_crop = QRect();
     QLabel::setPixmap(m_pixmap.scaled(size(), Qt::KeepAspectRatio, Qt::SmoothTransformation));
 }
 
 void ScaledPixmapLabel::setCropping(bool checked)
 {
     m_cropping = checked;
     m_crop = QRect();
     update();
 }
 
 int ScaledPixmapLabel::heightForWidth(int width) const
 {
     return ((qreal)m_pixmap.height() * width) / m_pixmap.width();
 }
 
 QSize ScaledPixmapLabel::sizeHint() const
 {
     int w = width();
     return QSize(w, heightForWidth(w));
 }
 
 QRect ScaledPixmapLabel::pixmapRect() const
 {
     QSize previewSize = size();
     QSize pixmapSize = pixmap()->size();
 
     int dx = (previewSize.width() - pixmapSize.width()) / 2;
     int dy = (previewSize.height() - pixmapSize.height()) / 2;
 
     return QRect(dx, dy, pixmapSize.width(), pixmapSize.height());
 }
 
 void ScaledPixmapLabel::resizeEvent(QResizeEvent *event)
 {
     Q_UNUSED(event);
 
     QLabel::setPixmap(m_pixmap.scaled(this->size(), Qt::KeepAspectRatio, Qt::SmoothTransformation));
 }
 
 void ScaledPixmapLabel::paintEvent(QPaintEvent *event)
 {
     QLabel::paintEvent(event);
 
     QPainter painter(this);
     painter.setRenderHint(QPainter::Qt4CompatiblePainting, true);
 
     if (m_crop.isValid()) {
         QStyleOptionRubberBand opt;
         opt.initFrom(this);
         opt.shape = QRubberBand::Rectangle;
         opt.opaque = false;
         opt.rect = m_crop.adjusted(0, 0, 1, 1);
 
         style()->drawControl(QStyle::CE_RubberBand, &opt, &painter);
     } else {
         if (m_cropping && underMouse() && (children().count() == 0)) {
             // draw guides
             QPoint cursor = mapFromGlobal(QCursor::pos());
             painter.drawLine(cursor.x(), 0, cursor.x(), size().height());
             painter.drawLine(0, cursor.y(), size().width(), cursor.y());
         }
     }
 }
 
 void ScaledPixmapLabel::mousePressEvent(QMouseEvent *event)
 {
     if (m_cropping) {
         m_start = event->pos();
         m_crop = QRect();
         update();
     }
 }
 
 void ScaledPixmapLabel::mouseMoveEvent(QMouseEvent *event)
 {
     if (m_cropping && (event->buttons() & Qt::LeftButton)) {
         m_end = event->pos();
         m_crop = pixmapRect().intersected(QRect(m_start, m_end).normalized());
     }
 
     update();
 }
 
 void ScaledPixmapLabel::mouseReleaseEvent(QMouseEvent *event)
 {
     if (m_cropping) {
         m_end = event->pos();
         m_crop = pixmapRect().intersected(QRect(m_start, m_end).normalized());
         update();
 
         double scale = (double)m_pixmap.size().width() / (double)pixmap()->size().width();
         m_crop.translate(-pixmapRect().topLeft());
         QRectF cropF(scale * m_crop.x(), scale * m_crop.y(), scale * m_crop.width(), scale * m_crop.height());
 
         emit imageCropped(cropF);
 
         m_crop = QRect();
     }
 }
 
 void ScaledPixmapLabel::leaveEvent(QEvent *event)
 {
     update();
     QLabel::leaveEvent(event);
 }
 
 #include "moc_ScaledPixmapLabel.cpp"