Kwave::ImageView Class Reference

#include <ImageView.h>

Inheritance diagram for Kwave::ImageView:

Collaboration diagram for Kwave::ImageView:

Public Slots
void	setImage (QImage image)
void	setHorizOffset (int offset)
void	setVertOffset (int offset)

Signals
void	viewInfo (int, int, int)
void	sigCursorPos (const QPoint pos)

Public Member Functions
	ImageView (QWidget *parent=Q_NULLPTR, bool fit_width=true, bool fit_height=true)
virtual	~ImageView () Q_DECL_OVERRIDE
QRect	imageRect ()

Protected Member Functions
virtual void	mouseMoveEvent (QMouseEvent *e) Q_DECL_OVERRIDE
virtual void	mousePressEvent (QMouseEvent *e) Q_DECL_OVERRIDE
virtual void	paintEvent (QPaintEvent *) Q_DECL_OVERRIDE

Private Attributes
QPoint	m_offset
QRect	m_last_rect
QImage	m_image
bool	m_fit_width
bool	m_fit_height
double	m_scale_x
double	m_scale_y

Detailed Description

Simple widget class for displaying a QImage.

Definition at line 33 of file ImageView.h.

Constructor & Destructor Documentation

ImageView()

Kwave::ImageView::ImageView ( QWidget *  parent = Q_NULLPTR, bool  fit_width = true, bool  fit_height = true  )

explicit

Constructor.

Parameters

parent	pointer to the parent widget, can be 0
fit_width	if set to true, the image will be scaled to fit horizontally into the widget; if false the image will be cut off at the edge and should be scrolled
fit_height	if set to true, the image will be scaled to fit vertically into the widget; if false the image will be cut off at the edge and should be scrolled

Definition at line 28 of file ImageView.cpp.

    :QWidget(parent), m_offset(0,0), m_last_rect(0,0,0,0),
     m_image(), m_fit_width(fit_width), m_fit_height(fit_height),
     m_scale_x(1.0), m_scale_y(1.0)
{
    setCursor(Qt::CrossCursor);
    setMouseTracking(true);
}

~ImageView()

Kwave::ImageView::~ImageView ( )

virtual

Destructor

Definition at line 38 of file ImageView.cpp.

{
}

Member Function Documentation

imageRect()

QRect Kwave::ImageView::imageRect

(

)

Returns the position and size of the current image, packed into a QRect object.

Returns

rectangle with the image coordinates and size

Definition at line 82 of file ImageView.cpp.

References m_image, and m_offset.

Referenced by paintEvent().

{
    return QRect(m_offset.x(), m_offset.y(),
                 m_image.width(), m_image.height());
}

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mouseMoveEvent()

void Kwave::ImageView::mouseMoveEvent ( QMouseEvent *  e )

protectedvirtual

Reimplemented in Kwave::OverViewWidget.

Definition at line 43 of file ImageView.cpp.

References m_image, m_offset, m_scale_x, m_scale_y, sigCursorPos(), and Kwave::toInt().

Referenced by mousePressEvent().

{
    Q_ASSERT(e);
    if (!e) return;

    if (!m_image.width() || !m_image.height())
        return; // image not yet loaded

    int x = e->pos().x();
    int y = e->pos().y();

    if ((x > width()) || (x < 0)) return;
    if ((y > height()) || (y < 0)) return;

    /*
     * re-transform the coordinates from the screen (pixmap) coordinates to
     * the original image coordinates and emit a cursor position signal
     */
    x = m_offset.x() + Kwave::toInt((!qFuzzyIsNull(m_scale_x)) ?
        (static_cast<double>(x) / m_scale_x) : 0);
    y = m_offset.y() + Kwave::toInt((!qFuzzyIsNull(m_scale_y)) ?
        (static_cast<double>(y) / m_scale_y) : 0);
    emit sigCursorPos(QPoint(x, y));
}

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mousePressEvent()

void Kwave::ImageView::mousePressEvent ( QMouseEvent *  e )

protectedvirtual

Reimplemented in Kwave::OverViewWidget.

Definition at line 69 of file ImageView.cpp.

References mouseMoveEvent().

{
    mouseMoveEvent(e);
}

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paintEvent()

void Kwave::ImageView::paintEvent ( QPaintEvent *  )

protectedvirtual

Definition at line 107 of file ImageView.cpp.

References imageRect(), m_fit_height, m_fit_width, m_image, m_last_rect, m_offset, m_scale_x, m_scale_y, and Kwave::toInt().

{
    if (m_image.isNull() || !m_image.width() || !m_image.height()) return;

    QPainter p(this);
    QMatrix matrix;
    QPixmap newmap = QPixmap::fromImage(m_image,
        Qt::ColorOnly | Qt::ThresholdDither | Qt::AvoidDither);

    m_scale_x = m_fit_width  ? static_cast<double>(width())  /
                               static_cast<double>(m_image.width()) : 1.0;
    m_scale_y = m_fit_height ? static_cast<double>(height()) /
                               static_cast<double>(m_image.height()) : 1.0;

    if (m_offset.x() + m_scale_x * m_image.width() > width())
        m_offset.setX(Kwave::toInt(m_scale_x * m_image.width() - width()));
    if (m_offset.y() + m_scale_y * m_image.height() > height())
        m_offset.setY(Kwave::toInt(
            m_scale_y * m_image.height() - height()));

    matrix.scale(m_scale_x, m_scale_y);
    QPixmap pixmap = newmap.transformed(matrix);

    p.drawPixmap(0, 0, pixmap, m_offset.x(), m_offset.y(),
        width(), height()
    );

    m_last_rect = imageRect();
}

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setHorizOffset

void Kwave::ImageView::setHorizOffset ( int  offset )

slot

sets a new horizontal offset, useful for scrolling

Definition at line 89 of file ImageView.cpp.

References m_offset.

{
    if (m_offset.x() != offset) {
        m_offset.setX(offset);
        repaint();
    }
}

setImage

void Kwave::ImageView::setImage ( QImage  image )

slot

Sets a new QImage for displaying.

Parameters

image

a pointer to the image

Definition at line 75 of file ImageView.cpp.

References m_image.

Referenced by Kwave::OverViewWidget::OverViewWidget(), Kwave::SonagramWindow::refresh_view(), and Kwave::SonagramWindow::setOverView().

{
    m_image = image;
    update();
}

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setVertOffset

void Kwave::ImageView::setVertOffset ( int  offset )

slot

sets a new vertical offset, useful for scrolling

Definition at line 98 of file ImageView.cpp.

References m_offset.

{
    if (m_offset.y() != offset) {
        m_offset.setY(offset);
        repaint();
    }
}

sigCursorPos

void Kwave::ImageView::sigCursorPos ( const QPoint  pos )

signal

Referenced by mouseMoveEvent().

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viewInfo

void Kwave::ImageView::viewInfo ( int  , int  , int    )

signal

Member Data Documentation

m_fit_height

bool Kwave::ImageView::m_fit_height

private

if true, scale to fit vertically

Definition at line 111 of file ImageView.h.

Referenced by paintEvent().

m_fit_width

bool Kwave::ImageView::m_fit_width

private

if true, scale to fit horizontally

Definition at line 108 of file ImageView.h.

Referenced by paintEvent().

m_image

QImage Kwave::ImageView::m_image

private

pointer to the QImage to be displayed

Definition at line 105 of file ImageView.h.

Referenced by imageRect(), mouseMoveEvent(), paintEvent(), and setImage().

m_last_rect

QRect Kwave::ImageView::m_last_rect

private

last displayed image rectangle. Note that the left and top coordinates are unscaled, but the width and height might be scaled to screen coordinates!

Definition at line 102 of file ImageView.h.

Referenced by paintEvent().

m_offset

QPoint Kwave::ImageView::m_offset

private

offset of the image, in original unscaled coordinates of the internal QImage

Definition at line 95 of file ImageView.h.

Referenced by imageRect(), mouseMoveEvent(), paintEvent(), setHorizOffset(), and setVertOffset().

m_scale_x

double Kwave::ImageView::m_scale_x

private

scale factor in horizontal direction, will be (width of the image / width of the widget) if m_fit_width is true, or 1.0 else

Definition at line 118 of file ImageView.h.

Referenced by mouseMoveEvent(), and paintEvent().

m_scale_y

double Kwave::ImageView::m_scale_y

private

scale factor in vertical direction, will be (height of the image / height of the widget) if m_fit_height is true, or 1.0 else

Definition at line 125 of file ImageView.h.

Referenced by mouseMoveEvent(), and paintEvent().

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The documentation for this class was generated from the following files:

• libgui/ImageView.h
• libgui/ImageView.cpp