Continues migration with DDS, Common

Lts/Common/LtsWidgets/LtsImageCropper/lts_image_cropper.cpp

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+
+
+
+#include "lts_image_cropper.h"
+#include <QGraphicsItem>
+#include <QMouseEvent>
+#include <QApplication>
+
+namespace LtsWidgets
+{
+
+LtsImageCropper::LtsImageCropper(QWidget *parent, const QSize &size, const QPixmap &pixmap)
+  : QGraphicsView(parent)
+  , m_scene(new QGraphicsScene(this))
+  , m_maxScale(2.0f)
+  , m_multiplier(1.0f)
+{
+  if(!size.isNull())
+    setFixedSize(size);
+
+  setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+  setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+  setFrameStyle(QFrame::NoFrame);
+  setDragMode(QGraphicsView::ScrollHandDrag);
+  setTransformationAnchor(QGraphicsView::AnchorViewCenter);
+
+  m_scene->setBackgroundBrush(Qt::Dense6Pattern);
+  setScene(m_scene);
+
+  setPixmap(pixmap);
+}
+
+LtsImageCropper::~LtsImageCropper()
+{
+  delete m_pixmapItem;
+}
+
+void LtsImageCropper::setPixmap(const QPixmap &pixmap)
+{
+  if(pixmap.isNull())
+    return;
+
+  delete m_pixmapItem; 
+
+  m_pixmapItem = new QGraphicsPixmapItem(pixmap);
+  m_scene->addItem(m_pixmapItem);
+
+  setTransform(QTransform()); 
+  m_currentZoom = 1.0; 
+
+  
+  double sx = static_cast<double>(size().height()) / pixmap.height();
+  double sy = static_cast<double>(size().width()) / pixmap.width();
+  if(sx > 1 )
+    scale(sx,sx);
+  if(sy > 1)
+    scale(sy,sy);
+
+  
+  double ratioWidth  = 1.0 * size().width()  / pixmap.width();
+  double ratioHeight = 1.0 * size().height() / pixmap.height();
+  m_minScale = qMax(ratioHeight,ratioWidth);
+
+  calculateScaleStep();
+
+  
+  m_scene->setSceneRect(pixmap.rect());
+  centerOn(m_scene->sceneRect().center());
+}
+
+void LtsImageCropper::setImage(const QImage &image)
+{
+  setPixmap(QPixmap::fromImage(image));
+}
+
+void LtsImageCropper::setMultiplier(double multiplier)
+{
+  m_multiplier = multiplier;
+  calculateScaleStep();
+}
+
+void LtsImageCropper::calculateScaleStep()
+{
+  m_stepScale = (m_maxScale - m_minScale) / 100.0;
+}
+
+QImage LtsImageCropper::image()
+{
+  return grab().toImage();
+}
+
+void LtsImageCropper::wheelEvent(QWheelEvent *event)
+{
+  if(!m_pixmapItem)
+    return;
+
+  auto value = event->pixelDelta();
+  if(value.isNull())
+    value = event->angleDelta() / 15.0;
+
+  
+  double scrollZoom = m_stepScale * value.y() * m_multiplier / 8.0;
+
+  m_currentZoom += scrollZoom;
+
+  if(m_currentZoom > m_maxScale)
+    m_currentZoom = m_maxScale;
+  else if (m_currentZoom < m_minScale)
+    m_currentZoom = m_minScale;
+
+  
+  setTransform(QTransform(m_currentZoom, transform().m12(), transform().m13(),
+                          transform().m21(), m_currentZoom, transform().m23(),
+                          transform().m31(), transform().m32(), 1));
+}
+
+void LtsImageCropper::mousePressEvent(QMouseEvent *event)
+{
+  QApplication::setOverrideCursor(Qt::DragMoveCursor);
+  update();
+  QGraphicsView::mousePressEvent(event);
+}
+
+void LtsImageCropper::mouseReleaseEvent(QMouseEvent *event)
+{
+  QApplication::restoreOverrideCursor();
+  update();
+  QGraphicsView::mouseReleaseEvent(event);
+}
+
+}