QGraphicsGrid Class Reference

Detailed Description

A 2D cartesian grid as a QGraphicsItem.

A 2D cartesian grid as a QGraphicsItem. The size of the grid cells is constant but can be anisotroph.

Definition at line 15 of file QGraphicsGrid.h.

#include <QGraphicsGrid.h>

Inheritance diagram for QGraphicsGrid:

Collaboration diagram for QGraphicsGrid:

Public Member Functions
	QGraphicsGrid (QRectF rect, int xCells, int yCells, QGraphicsItem *parent=nullptr)
	QGraphicsGrid (int x, int y, int width, int height, int xCells, int yCells, QGraphicsItem *parent=nullptr)
	QGraphicsGrid (QRectF rect, int xCells, int yCells, bool ticks, QPen pen, QGraphicsItem *parent=nullptr)
	QGraphicsGrid (int x, int y, int width, int height, int xCells, int yCells, bool ticks, QPen pen, QGraphicsItem *parent=nullptr)
	~QGraphicsGrid () override
QRectF	boundingRect () const override
	Returns the bounding rectangle of the grid.
void	paint (QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override
	Paints the grid.
void	setNumberOfXCells (int xCells)
	Sets the number of cells in x direction.
void	setNumberOfYCells (int yCells)
	Sets the number of cells in y direction.
void	setRect (QRectF rect)
void	setRect (int x, int y, int width, int height)
	Sets the bounding rectangle of the grid.

Private Member Functions
void	initDefaultPens ()
	Defines the default pens.

Private Attributes
QPen	_inside
QPen	_outside
QRectF	_bounds
int	_numberOfXCells
int	_numberOfYCells
bool	_showTicks

Constructor & Destructor Documentation

QGraphicsGrid() [1/4]

QGraphicsGrid::QGraphicsGrid	(	QRectF	rect,
		int	xCells,
		int	yCells,
		QGraphicsItem *	parent = nullptr )

Creates a grid using a QRectF object and a default pen and no ticks.

Parameters

rect	A rectangle specifying the size of the grid.
xCells	The number of grid cells in x-direction.
yCells	The number of grid cells in y-direction.
parent	The parent QGraphicsItem.

Definition at line 15 of file QGraphicsGrid.cpp.

    : QGraphicsItem(parent)
{
    _numberOfXCells = xCells;
    _numberOfYCells = yCells;
    _bounds = rect;
    _showTicks = false;
 
    initDefaultPens();
}

References _bounds, _numberOfXCells, _numberOfYCells, _showTicks, and initDefaultPens().

QGraphicsGrid() [2/4]

QGraphicsGrid::QGraphicsGrid	(	int	x,
		int	y,
		int	width,
		int	height,
		int	xCells,
		int	yCells,
		QGraphicsItem *	parent = nullptr )

Creates a grid by specifying its bounding rectangle using a default pen and no ticks.

Parameters

x	X-coordinate for the lower left corner of the bounding rectangle for the grid.
y	Y-coordinate for the lower left corner of the bounding rectangle for the grid.
width	Width of the bounding rectangle.
height	Height of the bounding rectangle.
xCells	The number of grid cells in x-direction.
yCells	The number of grid cells in y-direction.
parent	The parent QGraphicsItem.

Definition at line 36 of file QGraphicsGrid.cpp.

    : QGraphicsItem(parent)
{
    _numberOfXCells = xCells;
    _numberOfYCells = yCells;
    _bounds = QRectF(x, y, width, height);
    _showTicks = false;
 
    initDefaultPens();
}

References _bounds, _numberOfXCells, _numberOfYCells, _showTicks, and initDefaultPens().

QGraphicsGrid() [3/4]

QGraphicsGrid::QGraphicsGrid	(	QRectF	rect,
		int	xCells,
		int	yCells,
		bool	ticks,
		QPen	pen,
		QGraphicsItem *	parent = nullptr )

Creates a grid using a QRectF object and a default pen and no ticks.

Parameters

rect	A rectangle specifying the size of the grid.
xCells	The number of grid cells in x-direction.
yCells	The number of grid cells in y-direction.
ticks	Specifies if ticks are displayed for the grid.
pen	The pen for drawing the grid.
parent	The parent QGraphicsItem.

Definition at line 62 of file QGraphicsGrid.cpp.

    : QGraphicsItem(parent)
{
    _numberOfXCells = xCells;
    _numberOfYCells = yCells;
    _bounds = rect;
    _showTicks = ticks;
 
    _outside = pen;
    _outside.setCosmetic(true);
 
    _inside = pen;
    QColor iColour = pen.color();
    iColour.setAlpha(125);
    _inside.setColor(iColour);
    _inside.setStyle(Qt::DotLine);
    _inside.setCosmetic(true);
}

References _bounds, _inside, _numberOfXCells, _numberOfYCells, _outside, and _showTicks.

QGraphicsGrid() [4/4]

QGraphicsGrid::QGraphicsGrid	(	int	x,
		int	y,
		int	width,
		int	height,
		int	xCells,
		int	yCells,
		bool	ticks,
		QPen	pen,
		QGraphicsItem *	parent = nullptr )

Creates a grid by specifying its bounding rectangle using a default pen and no ticks.

Parameters

x	X-coordinate for the lower left corner of the bounding rectangle for the grid.
y	Y-coordinate for the lower left corner of the bounding rectangle for the grid.
width	Width of the bounding rectangle.
height	Height of the bounding rectangle.
xCells	The number of grid cells in x-direction.
yCells	The number of grid cells in y-direction.
ticks	Specifies if ticks are displayed for the grid.
pen	The pen for drawing the grid.
parent	The parent QGraphicsItem.

Definition at line 97 of file QGraphicsGrid.cpp.

    : QGraphicsItem(parent)
{
    _numberOfXCells = xCells;
    _numberOfYCells = yCells;
    _bounds = QRectF(x, y, width, height);
    _showTicks = ticks;
 
    _outside = pen;
    _outside.setCosmetic(true);
 
    _inside = pen;
    QColor iColour = pen.color();
    iColour.setAlpha(125);
    _inside.setColor(iColour);
    _inside.setStyle(Qt::DotLine);
    _inside.setCosmetic(true);
}

References _bounds, _inside, _numberOfXCells, _numberOfYCells, _outside, and _showTicks.

~QGraphicsGrid()

QGraphicsGrid::~QGraphicsGrid ( )

overridedefault

Member Function Documentation

boundingRect()

QRectF QGraphicsGrid::boundingRect ( ) const

override

Returns the bounding rectangle of the grid.

Definition at line 127 of file QGraphicsGrid.cpp.

{
    return _bounds;
}

References _bounds.

initDefaultPens()

void QGraphicsGrid::initDefaultPens ( )

private

Defines the default pens.

Definition at line 133 of file QGraphicsGrid.cpp.

{
    QPen in(Qt::gray, 1, Qt::DotLine, Qt::SquareCap, Qt::RoundJoin);
    QPen out(Qt::black, 1, Qt::SolidLine, Qt::SquareCap, Qt::RoundJoin);
    _inside = in;
    _outside = out;
    _inside.setCosmetic(true);
    _outside.setCosmetic(true);
}

References _inside, and _outside.

Referenced by QGraphicsGrid(), and QGraphicsGrid().

paint()

void QGraphicsGrid::paint ( QPainter * painter, const QStyleOptionGraphicsItem * option, QWidget * widget )

override

Paints the grid.

Definition at line 144 of file QGraphicsGrid.cpp.

{
    Q_UNUSED(option)
    Q_UNUSED(widget)
 
    if (!_bounds.isValid())
    {
        return;
    }
 
    /* draw outside rectangle */
    QBrush brush(Qt::NoBrush);
    painter->setPen(_outside);
    painter->drawRect(_bounds);
 
    /* draw horizontal lines */
    for (int i = 0; i <= _numberOfXCells; ++i)
    {
        auto x = static_cast<int>(
            _bounds.left() + (i * (_bounds.width() - 1) / _numberOfXCells));
 
        if (i > 0 && i < _numberOfXCells)
        {
            painter->setPen(_inside);
            painter->drawLine(x, static_cast<int>(_bounds.top()), x,
                              static_cast<int>(_bounds.bottom()));
        }
 
        /* draw ticks on x-axis */
        if (_showTicks)
        {
            // double label = bounds.left() + (i * bounds.width() /
            // numberOfXCells);
            painter->setPen(_outside);
            painter->drawLine(x, static_cast<int>(_bounds.bottom()), x,
                              static_cast<int>(_bounds.bottom()) + 5);
            // painter->drawText(x - margin, bounds.bottom() + 5, 2*margin, 20,
            //                   Qt::AlignHCenter | Qt::AlignTop,
            //                   QString::number(label));
        }
    }
 
    /* draw vertical lines */
    for (int j = 0; j <= _numberOfYCells; ++j)
    {
        auto y = static_cast<int>(
            _bounds.bottom() - (j * (_bounds.height() - 1) / _numberOfYCells));
 
        if (j > 0 && j < _numberOfYCells)
        {
            painter->setPen(_inside);
            painter->drawLine(static_cast<int>(_bounds.left()), y,
                              static_cast<int>(_bounds.right()), y);
        }
 
        /* draw ticks on y-axis */
        if (_showTicks)
        {
            // double label = bounds.top() + (j * bounds.height() /
            // numberOfYCells);
            painter->setPen(_outside);
            painter->drawLine(static_cast<int>(_bounds.left()) - 5, y,
                              static_cast<int>(_bounds.left()), y);
            // painter->drawText(bounds.left() - margin, y - 10, margin - 5, 20,
            //                   Qt::AlignRight | Qt::AlignVCenter,
            //                   QString::number(label));
        }
    }
}

References _bounds, _inside, _numberOfXCells, _numberOfYCells, _outside, and _showTicks.

setNumberOfXCells()

void QGraphicsGrid::setNumberOfXCells

(

int

xCells

)

Sets the number of cells in x direction.

Definition at line 217 of file QGraphicsGrid.cpp.

{
    _numberOfXCells = xCells;
}

References _numberOfXCells.

setNumberOfYCells()

void QGraphicsGrid::setNumberOfYCells

(

int

yCells

)

Sets the number of cells in y direction.

Definition at line 223 of file QGraphicsGrid.cpp.

{
    _numberOfYCells = yCells;
}

References _numberOfYCells.

setRect() [1/2]

void QGraphicsGrid::setRect	(	int	x,
		int	y,
		int	width,
		int	height )

Sets the bounding rectangle of the grid.

Definition at line 229 of file QGraphicsGrid.cpp.

{
    _bounds = QRectF(x, y, width, height);
}

References _bounds.

setRect() [2/2]

void QGraphicsGrid::setRect

(

QRectF

rect

)

Member Data Documentation

_bounds

QRectF QGraphicsGrid::_bounds

private

Definition at line 60 of file QGraphicsGrid.h.

Referenced by QGraphicsGrid(), QGraphicsGrid(), QGraphicsGrid(), QGraphicsGrid(), boundingRect(), paint(), and setRect().

_inside

QPen QGraphicsGrid::_inside

private

Definition at line 58 of file QGraphicsGrid.h.

Referenced by QGraphicsGrid(), QGraphicsGrid(), initDefaultPens(), and paint().

_numberOfXCells

int QGraphicsGrid::_numberOfXCells

private

Definition at line 61 of file QGraphicsGrid.h.

Referenced by QGraphicsGrid(), QGraphicsGrid(), QGraphicsGrid(), QGraphicsGrid(), paint(), and setNumberOfXCells().

_numberOfYCells

int QGraphicsGrid::_numberOfYCells

private

Definition at line 62 of file QGraphicsGrid.h.

Referenced by QGraphicsGrid(), QGraphicsGrid(), QGraphicsGrid(), QGraphicsGrid(), paint(), and setNumberOfYCells().

_outside

QPen QGraphicsGrid::_outside

private

Definition at line 59 of file QGraphicsGrid.h.

Referenced by QGraphicsGrid(), QGraphicsGrid(), initDefaultPens(), and paint().

_showTicks

bool QGraphicsGrid::_showTicks

private

Definition at line 63 of file QGraphicsGrid.h.

Referenced by QGraphicsGrid(), QGraphicsGrid(), QGraphicsGrid(), QGraphicsGrid(), and paint().

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

• QGraphicsGrid.h
• QGraphicsGrid.cpp