KPlotWidget Class

KPlotWidget *kpw = new KPlotWidget( parent );
// setting our limits for the plot
kpw->setLimits( 1.0, 5.0, 1.0, 25.0 );

// creating a plot object whose points are connected by red lines ...
KPlotObject *kpo = new KPlotObject( Qt::red, KPlotObject::Lines );
// ... adding some points to it ...
for ( float x = 1.0; x <= 5.0; x += 0.1 )
    kpo->addPoint( x, x*x );

// ... and adding the object to the plot widget
kpw->addPlotObject( kpo );

Member Function Documentation

[explicit] KPlotWidget::KPlotWidget(QWidget *parent = nullptr)

Constructor.

parent the parent widget

void KPlotWidget::addPlotObject(KPlotObject *object)

Add an item to the list of KPlotObjects to be plotted.

The widget takes ownership of the plot object, unless auto-delete was disabled.

object the KPlotObject to be added

void KPlotWidget::addPlotObjects(const QList<KPlotObject *> &objects)

Add more than one KPlotObject at one time.

The widget takes ownership of the plot object, unless auto-delete was disabled.

objects the list of KPlotObjects to be added

bool KPlotWidget::antialiasing() const

Returns whether the antialiasing is active

Antialiasing is not active by default.

See also setAntialiasing().

KPlotAxis *KPlotWidget::axis(KPlotWidget::Axis type)

Returns the axis of the specified type, or 0 if no axis has been set.

See also Axis.

const KPlotAxis *KPlotWidget::axis(KPlotWidget::Axis type) const

Returns the axis of the specified type, or 0 if no axis has been set.

See also Axis.

QColor KPlotWidget::backgroundColor() const

Returns the background color of the plot.

The default color is black.

See also setBackgroundColor().

int KPlotWidget::bottomPadding() const

Returns the number of pixels below the plot area.

Padding values are set to -1 by default; if unchanged, this function will try to guess a good value, based on whether ticklabels and/or axis labels are to be drawn.

See also setBottomPadding().

void KPlotWidget::clearSecondaryLimits()

Unset the secondary limits, so the top and right axes show the same tickmarks as the bottom and left axes (no tickmark labels will be drawn for the top and right axes in this case)

QRectF KPlotWidget::dataRect() const

Returns the rectangle representing the boundaries of the current plot, in natural data units.

See also setLimits().

QColor KPlotWidget::foregroundColor() const

Returns the foreground color, used for axes, tickmarks and associated labels.

The default color is white.

See also setForegroundColor().

QColor KPlotWidget::gridColor() const

Returns the grid color.

The default color is gray.

See also setGridColor().

bool KPlotWidget::isGridShown() const

Returns whether the grid lines are shown

Grid lines are not shown by default.

bool KPlotWidget::isObjectToolTipShown() const

Returns whether the tooltip for the point objects is shown.

Tooltips are enabled by default.

int KPlotWidget::leftPadding() const

Returns the number of pixels to the left of the plot area.

Padding values are set to -1 by default; if unchanged, this function will try to guess a good value, based on whether ticklabels and/or axis labels need to be drawn.

See also setLeftPadding().

QPointF KPlotWidget::mapToWidget(const QPointF &p) const

Map a coordinate p from the data rect to the physical pixel rect.

Used mainly when drawing.

p the point to be converted, in natural data units

Returns the coordinate in the pixel coordinate system

void KPlotWidget::maskAlongLine(const QPointF &p1, const QPointF &p2, float value = 1.0f)

Indicate that object labels should try to avoid the line joining the two given points (in pixel coordinates).

p1 the starting point for the line

p2 the ending point for the line

value Allows you to determine how strongly the line should be avoided. Larger values are avoided more strongly.

void KPlotWidget::maskRect(const QRectF &r, float value = 1.0f)

Indicate that object labels should try to avoid the given rectangle in the plot. The rectangle is in pixel coordinates.

r the rectangle defining the region in the plot that text labels should avoid (in pixel coordinates)

value Allows you to determine how strongly the rectangle should be avoided. Larger values are avoided more strongly.

[override virtual] QSize KPlotWidget::minimumSizeHint() const

Reimplements an access function for property: QWidget::minimumSizeHint.

Returns suggested minimum size for the plot widget

QRect KPlotWidget::pixRect() const

Returns the rectangle representing the boundaries of the current plot, in screen pixel units.

See also setPixRect().

void KPlotWidget::placeLabel(QPainter *painter, KPlotPoint *pp)

Place an object label optimally in the plot. This function will attempt to place the label as close as it can to the point to which the label belongs, while avoiding overlap with regions of the plot that have been masked.

painter Pointer to the painter on which to draw the label

pp pointer to the KPlotPoint whose label is to be drawn.

QList<KPlotObject *> KPlotWidget::plotObjects() const

Returns the current list of plot objects

[protected] QList<KPlotPoint *> KPlotWidget::pointsUnderPoint(const QPoint &p) const

Returns a list of points in the plot which are within 4 pixels of the screen position given as an argument.

p The screen position from which to check for plot points.

void KPlotWidget::removeAllPlotObjects()

Removes all plot objects that were added to the widget.

If auto-delete was not disabled, the plot objects are deleted.

void KPlotWidget::replacePlotObject(int i, KPlotObject *o)

Replace an item in the KPlotObject list.

i the index of the item to be replaced

o pointer to the replacement KPlotObject

Since 5.12, if auto-deletion is enabled, the previous plot object is deleted. Call setAutoDeletePlotObjects(false) if you want to swap between available plot objects and therefore you want to handle deletion externally.

void KPlotWidget::resetPlot()

Clear the object list, reset the data limits, and remove axis labels

If auto-delete was not disabled, the plot objects are deleted.

void KPlotWidget::resetPlotMask()

Reset the mask used for non-overlapping labels so that all regions of the plot area are considered empty.

int KPlotWidget::rightPadding() const

Returns the number of pixels to the right of the plot area.

Padding values are set to -1 by default; if unchanged, this function will try to guess a good value, based on whether ticklabels and/or axis labels are to be drawn.

See also setRightPadding().

QRectF KPlotWidget::secondaryDataRect() const

Returns the rectangle representing the boundaries of the secondary data limits, if they have been set. Otherwise, this function behaves the same as dataRect().

See also setSecondaryLimits().

void KPlotWidget::setAntialiasing(bool b)

Toggle antialiased drawing.

b if true, the plot graphics will be antialiased.

See also antialiasing().

[since 5.12] void KPlotWidget::setAutoDeletePlotObjects(bool autoDelete)

Enables auto-deletion of plot objects if autoDelete is true; otherwise auto-deletion is disabled.

Auto-deletion is enabled by default.

This function was introduced in 5.12.

void KPlotWidget::setBackgroundColor(const QColor &bg)

Set the background color

bg the new background color

See also backgroundColor().

void KPlotWidget::setBottomPadding(int padding)

Set the number of pixels below the plot area.

Set this to -1 to revert to automatic determination of padding values.

See also bottomPadding().

void KPlotWidget::setDefaultPaddings()

Revert all four padding values to -1, so that they will be automatically determined.

void KPlotWidget::setForegroundColor(const QColor &fg)

Set the foreground color

fg the new foreground color

See also foregroundColor().

void KPlotWidget::setGridColor(const QColor &gc)

Set the grid color

gc the new grid color

See also gridColor().

void KPlotWidget::setLeftPadding(int padding)

Set the number of pixels to the left of the plot area.

Set this to -1 to revert to automatic determination of padding values.

See also leftPadding().

void KPlotWidget::setLimits(double x1, double x2, double y1, double y2)

Set new data limits for the plot.

x1 the minimum X value in data units

x2 the maximum X value in data units

y1 the minimum Y value in data units

y2 the maximum Y value in data units

[slot] void KPlotWidget::setObjectToolTipShown(bool show)

Toggle the display of a tooltip for point objects.

show whether show the tooltip.

See also isObjectToolTipShown().

[protected] void KPlotWidget::setPixRect()

Synchronize the PixRect with the current widget size and padding settings.

See also pixRect().

void KPlotWidget::setRightPadding(int padding)

Set the number of pixels to the right of the plot area.

Set this to -1 to revert to automatic determination of padding values.

See also rightPadding().

void KPlotWidget::setSecondaryLimits(double x1, double x2, double y1, double y2)

Reset the secondary data limits, which control the values displayed along the top and right axes.

All data points are *plotted* using the coordinates defined by setLimits(), so this function is only useful for showing alternate tickmark labels along the top and right edges. For example, if you were plotting temperature on the X-axis, you could use Centigrade units for the primary (bottom) axis, using setLimits( 0.0, 100.0, 0.0, 1.0 ). If you also wanted to show Fahrenheit units along the secondary (top) axis, you would additionally use setSecondaryLimits( 32.0, 212.0, 0.0, 1.0 ). The data added to the plot would have x-coordinates in Centigrade degrees.

x1 the minimum X value in secondary data units

x2 the maximum X value in secondary data units

y1 the minimum Y value in secondary data units

y2 the maximum Y value in secondary data units

See also setLimits().

[slot] void KPlotWidget::setShowGrid(bool show)

Toggle whether grid lines are drawn at major tickmarks.

show if true, grid lines will be drawn.

See also isGridShown().

void KPlotWidget::setTopPadding(int padding)

Set the number of pixels above the plot area.

Set this to -1 to revert to automatic determination of padding values.

See also topPadding().

[override virtual] QSize KPlotWidget::sizeHint() const

Reimplements: QFrame::sizeHint() const.

Returns suggested size for the plot widget

int KPlotWidget::topPadding() const

Returns the number of pixels above the plot area.

Padding values are set to -1 by default; if unchanged, this function will try to guess a good value, based on whether ticklabels and/or axis labels are to be drawn.

See also setTopPadding().