Added missing render widget to demo application

demo/RenderWidget.cpp

@@ -0,0 +1,114 @@
+//============================================================================
+/// \file   RenderWidget.cpp
+/// \author Uwe Kindler
+/// \date   04.11.2022
+/// \brief  Implementation of CRenderWidget
+//============================================================================
+
+
+//============================================================================
+//                                   INCLUDES
+//============================================================================
+#include "RenderWidget.h"
+
+#include <QPainter>
+#include <math.h>
+
+
+//===========================================================================
+CRenderWidget::CRenderWidget(QWidget* Parent) :
+	QWidget(Parent), m_ScaleFactor(1)
+{
+	//
+	// OpaquePaintEvent indicates that we do not need an auto-filled
+	// background. It is used for widgets filling the whole paint area
+	// with its own opaque colors and need to draw its contents quickly.
+	// This applies for a capture widget.
+	//
+	this->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
+	this->setCursor(Qt::OpenHandCursor);
+}
+
+//===========================================================================
+CRenderWidget::~CRenderWidget()
+{
+
+}
+
+//===========================================================================
+void CRenderWidget::showImage(const QImage& Image)
+{
+	m_Image = QPixmap::fromImage(Image);
+	this->adjustWidgetSize();
+	this->repaint();
+}
+
+//===========================================================================
+void CRenderWidget::paintEvent(QPaintEvent* Event)
+{
+	Q_UNUSED(Event);
+	QPainter Painter(this);
+	Painter.setRenderHint(QPainter::SmoothPixmapTransform, true);
+	Painter.setRenderHint(QPainter::Antialiasing, true);
+	Painter.scale(m_ScaleFactor, m_ScaleFactor);
+	Painter.drawPixmap(QPoint(0, 0), m_Image);
+}
+
+//============================================================================
+void CRenderWidget::zoomIn()
+{
+	scaleImage(1.25);
+}
+
+//============================================================================
+void CRenderWidget::zoomOut()
+{
+	scaleImage(0.8);
+}
+
+//============================================================================
+void CRenderWidget::zoomByValue(double ZoomValue)
+{
+	scaleImage(ZoomValue);
+}
+
+//============================================================================
+void CRenderWidget::normalSize()
+{
+	m_ScaleFactor = 1;
+	this->adjustWidgetSize();
+}
+
+//============================================================================
+void CRenderWidget::scaleImage(double ScaleFactor)
+{
+	m_ScaleFactor *= ScaleFactor;
+	this->adjustWidgetSize();
+}
+
+//============================================================================
+void CRenderWidget::adjustWidgetSize()
+{
+	QSize ScaledImageSize = m_Image.size() * m_ScaleFactor;
+	if (ScaledImageSize != this->size())
+	{
+		this->setFixedSize(ScaledImageSize);
+	}
+}
+
+//============================================================================
+void CRenderWidget::scaleToSize(const QSize& TargetSize)
+{
+	if (m_Image.isNull())
+	{
+		return;
+	}
+	double ScaleFactorH = (double) TargetSize.width() / m_Image.size().width();
+	double ScaleFactorV = (double) TargetSize.height()
+	    / m_Image.size().height();
+	m_ScaleFactor = (ScaleFactorH < ScaleFactorV) ? ScaleFactorH : ScaleFactorV;
+	this->adjustWidgetSize();
+}
+
+//---------------------------------------------------------------------------
+// EOF RenderWidget.cpp