Qt 5.8 | Qt Charts | C++ Classes | QLegend

Qt 5.8.0 Reference Documentation

# QLegend Class

The QLegend class displays the legend of a chart. More...

Header: | #include <QLegend>
Instantiated By: | Legend

- List of all members, including inherited members

## Properties

- alignment : Qt::Alignment
- backgroundVisible : bool
- borderColor : QColor
- color : QColor

- font : QFont
- labelColor : QColor
- reverseMarkers : bool
- showToolTips : bool

## Public Functions

| ~QLegend()
Qt::Alignment | alignment() const
void | attachToChart()
QColor | borderColor()
QBrush | brush() const
QColor | color()
void | detachFromChart()
QFont | font() const
bool | isAttachedToChart()
bool | isBackgroundVisible() const
QBrush | labelBrush() const
QColor | labelColor() const
QList<QLegendMarker *> | markers(QAbstractSeries *series = Q_NULLPTR) const
QPen | pen() const
bool | reverseMarkers()
void | setAlignment(Qt::Alignment alignment)
void | setBackgroundVisible(bool visible = true)
void | setBorderColor(QColor color)
void | setBrush(const QBrush &brush)
void | setColor(QColor color)
void | setFont(const QFont &font)
void | setLabelBrush(const QBrush &brush)
void | setLabelColor(QColor color)
void | setPen(const QPen &pen)
void | setReverseMarkers(bool reverseMarkers = true)
void | setShowToolTips(bool show)
bool | showToolTips() const

## Signals

void | backgroundVisibleChanged(bool visible)
void | borderColorChanged(QColor color)
void | colorChanged(QColor color)
void | fontChanged(QFont font)
void | labelColorChanged(QColor color)
void | reverseMarkersChanged(bool reverseMarkers)
void | showToolTipsChanged(bool showToolTips)

## Detailed Description

The QLegend class displays the legend of a chart.

A legend is a graphical object that displays the legend of a chart. The legend state is updated by QChart when series change. By default, the legend is attached to the chart, but it can be detached to make it independent of chart layout. Legend objects cannot be created or deleted, but they can be referenced via the QChart class.

See also QChart.

## Property Documentation

### alignment : Qt::Alignment

This property holds how the legend is aligned with the chart.

Can be Qt::AlignTop, Qt::AlignBottom, Qt::AlignLeft, Qt::AlignRight. If you set more than one flag, the result is undefined.

Access functions:

Qt::Alignment | alignment() const
void | setAlignment(Qt::Alignment alignment)

### backgroundVisible : bool

This property holds whether the legend background is visible.

Access functions:

bool | isBackgroundVisible() const
void | setBackgroundVisible(bool visible = true)

Notifier signal:

void | backgroundVisibleChanged(bool visible)

### borderColor : QColor

This property holds the line color of the legend.

Access functions:

QColor | borderColor()
void | setBorderColor(QColor color)

Notifier signal:

void | borderColorChanged(QColor color)

### color : QColor

This property holds the background (brush) color of the legend.

If you change the color of the legend, the style of the legend brush is set to Qt::SolidPattern.

Access functions:

QColor | color()
void | setColor(QColor color)

Notifier signal:

void | colorChanged(QColor color)

### font : QFont

This property holds the font of the markers used by the legend.

Access functions:

QFont | font() const
void | setFont(const QFont &font)

Notifier signal:

void | fontChanged(QFont font)

### labelColor : QColor

This property holds the color of the brush used to draw labels.

Access functions:

QColor | labelColor() const
void | setLabelColor(QColor color)

Notifier signal:

void | labelColorChanged(QColor color)

### reverseMarkers : bool

This property holds whether reverse order is used for the markers in the legend.

This property is `false` by default.

Access functions:

bool | reverseMarkers()
void | setReverseMarkers(bool reverseMarkers = true)

Notifier signal:

void | reverseMarkersChanged(bool reverseMarkers)

### showToolTips : bool

This property holds whether tooltips are shown when the text is truncated.

This property is `false` by default.

Access functions:

bool | showToolTips() const
void | setShowToolTips(bool show)

Notifier signal:

void | showToolTipsChanged(bool showToolTips)

## Member Function Documentation

### QLegend::~QLegend()

Destroys the legend object. The legend is always owned by a QChart, so an application should never call this function.

### void QLegend::attachToChart()

Attaches the legend to a chart. The chart may adjust the layout of the legend.

### `[signal]` void QLegend::backgroundVisibleChanged(bool visible)

This signal is emitted when the visibility of the legend background changes to visible.

Note: Notifier signal for property backgroundVisible.

### `[signal]` void QLegend::borderColorChanged(QColor color)

This signal is emitted when the border color of the legend background changes to color.

Note: Notifier signal for property borderColor.

### QBrush QLegend::brush() const

Returns the brush used by the legend.

See also setBrush().

### `[signal]` void QLegend::colorChanged(QColor color)

This signal is emitted when the color of the legend background changes to color.

Note: Notifier signal for property color.

### void QLegend::detachFromChart()

Detaches the legend from the chart. The chart will no longer adjust the layout of the legend.

### `[signal]` void QLegend::fontChanged(QFont font)

This signal is emitted when the font of the markers of the legend changes to font.

Note: Notifier signal for property font.

### bool QLegend::isAttachedToChart()

Returns `true`, if the legend is attached to a chart.

### bool QLegend::isBackgroundVisible() const

Returns the visibility of the legend background.

Note: Getter function for property backgroundVisible.

### QBrush QLegend::labelBrush() const

Returns the brush used to draw labels.

See also setLabelBrush().

### `[signal]` void QLegend::labelColorChanged(QColor color)

This signal is emitted when the color of the brush used to draw the legend labels changes to color.

Note: Notifier signal for property labelColor.

### QList<QLegendMarker *> QLegend::markers(QAbstractSeries *series = Q_NULLPTR) const

Returns the list of markers in the legend. The list can be filtered by specifying the series for which the markers are returned.

### QPen QLegend::pen() const

Returns the pen used by the legend.

See also setPen().

### `[signal]` void QLegend::reverseMarkersChanged(bool reverseMarkers)

This signal is emitted when the use of reverse order for the markers in the legend is changed to reverseMarkers.

Note: Notifier signal for property reverseMarkers.

### void QLegend::setBackgroundVisible(bool visible = true)

Sets the visibility of the legend background to visible.

Note: Setter function for property backgroundVisible.

See also isBackgroundVisible().

### void QLegend::setBrush(const QBrush &brush)

Sets the brush that is used to draw the background of the legend.

See also brush().

### void QLegend::setLabelBrush(const QBrush &brush)

Sets the brush used to draw the legend labels to brush.

See also labelBrush().

### void QLegend::setPen(const QPen &pen)

Sets the pen that is used to draw the legend borders.

See also pen().

### void QLegend::setShowToolTips(bool show)

When show is `true`, the legend labels will show a tooltip when the mouse hovers over them if the label itself is shown elided. This is `false` by default.

Note: Setter function for property showToolTips.

See also showToolTips().

### bool QLegend::showToolTips() const

Returns whether the tooltips are shown for the legend labels when they are elided.

Note: Getter function for property showToolTips.

See also setShowToolTips().

### `[signal]` void QLegend::showToolTipsChanged(bool showToolTips)

This signal is emitted when the visibility of tooltips is changed to showToolTips.

Note: Notifier signal for property showToolTips.