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QCPAbstractLegendItem Class Reference

The abstract base class for all entries in a QCPLegend. More...

Inheritance diagram for QCPAbstractLegendItem:
Inheritance graph

Public Functions

 QCPAbstractLegendItem (QCPLegend *parent)
QCPLegendparentLegend () const
QFont font () const
QColor textColor () const
QFont selectedFont () const
QColor selectedTextColor () const
bool selectable () const
bool selected () const
void setFont (const QFont &font)
void setTextColor (const QColor &color)
void setSelectedFont (const QFont &font)
void setSelectedTextColor (const QColor &color)
void setSelectable (bool selectable)
void setSelected (bool selected)
virtual double selectTest (const QPointF &pos, bool onlySelectable, QVariant *details=0) const
QCPLayoutlayout () const
QRect rect () const
QRect outerRect () const
QMargins margins () const
QMargins minimumMargins () const
QCP::MarginSides autoMargins () const
QSize minimumSize () const
QSize maximumSize () const
QCPMarginGroupmarginGroup (QCP::MarginSide side) const
QHash< QCP::MarginSide,
QCPMarginGroup * > 
marginGroups () const
void setOuterRect (const QRect &rect)
void setMargins (const QMargins &margins)
void setMinimumMargins (const QMargins &margins)
void setAutoMargins (QCP::MarginSides sides)
void setMinimumSize (const QSize &size)
void setMinimumSize (int width, int height)
void setMaximumSize (const QSize &size)
void setMaximumSize (int width, int height)
void setMarginGroup (QCP::MarginSides sides, QCPMarginGroup *group)
virtual void update ()
virtual QSize minimumSizeHint () const
virtual QSize maximumSizeHint () const
virtual QList< QCPLayoutElement * > elements (bool recursive) const
bool visible () const
QCustomPlotparentPlot () const
QCPLayerableparentLayerable () const
QCPLayerlayer () const
bool antialiased () const
void setVisible (bool on)
bool setLayer (QCPLayer *layer)
bool setLayer (const QString &layerName)
void setAntialiased (bool enabled)
bool realVisibility () const

Signals

void selectionChanged (bool selected)

Protected Functions

virtual QCP::Interaction selectionCategory () const
virtual void applyDefaultAntialiasingHint (QCPPainter *painter) const
virtual QRect clipRect () const
virtual void draw (QCPPainter *painter)=0
virtual void selectEvent (QMouseEvent *event, bool additive, const QVariant &details, bool *selectionStateChanged)
virtual void deselectEvent (bool *selectionStateChanged)
virtual int calculateAutoMargin (QCP::MarginSide side)
virtual void mousePressEvent (QMouseEvent *event)
virtual void mouseMoveEvent (QMouseEvent *event)
virtual void mouseReleaseEvent (QMouseEvent *event)
virtual void mouseDoubleClickEvent (QMouseEvent *event)
virtual void wheelEvent (QWheelEvent *event)
virtual void parentPlotInitialized (QCustomPlot *parentPlot)
void initializeParentPlot (QCustomPlot *parentPlot)
void setParentLayerable (QCPLayerable *parentLayerable)
bool moveToLayer (QCPLayer *layer, bool prepend)
void applyAntialiasingHint (QCPPainter *painter, bool localAntialiased, QCP::AntialiasedElement overrideElement) const

Detailed Description

The abstract base class for all entries in a QCPLegend.

It defines a very basic interface for entries in a QCPLegend. For representing plottables in the legend, the subclass QCPPlottableLegendItem is more suitable.

Only derive directly from this class when you need absolute freedom (e.g. a custom legend entry that's not even associated with a plottable).

You must implement the following pure virtual functions:

You inherit the following members you may use:

QCPLegend *mParentLegend A pointer to the parent QCPLegend.
QFont mFont The generic font of the item. You should use this font for all or at least the most prominent text of the item.

Constructor & Destructor Documentation

QCPAbstractLegendItem::QCPAbstractLegendItem ( QCPLegend parent)
explicit

Constructs a QCPAbstractLegendItem and associates it with the QCPLegend parent. This does not cause the item to be added to parent, so QCPLegend::addItem must be called separately.

Member Function Documentation

void QCPAbstractLegendItem::setFont ( const QFont &  font)

Sets the default font of this specific legend item to font.

See Also
setTextColor, QCPLegend::setFont
void QCPAbstractLegendItem::setTextColor ( const QColor &  color)

Sets the default text color of this specific legend item to color.

See Also
setFont, QCPLegend::setTextColor
void QCPAbstractLegendItem::setSelectedFont ( const QFont &  font)

When this legend item is selected, font is used to draw generic text, instead of the normal font set with setFont.

See Also
setFont, QCPLegend::setSelectedFont
void QCPAbstractLegendItem::setSelectedTextColor ( const QColor &  color)

When this legend item is selected, color is used to draw generic text, instead of the normal color set with setTextColor.

See Also
setTextColor, QCPLegend::setSelectedTextColor
void QCPAbstractLegendItem::setSelectable ( bool  selectable)

Sets whether this specific legend item is selectable.

See Also
setSelectedParts, QCustomPlot::setInteractions
void QCPAbstractLegendItem::setSelected ( bool  selected)

Sets whether this specific legend item is selected.

It is possible to set the selection state of this item by calling this function directly, even if setSelectable is set to false.

See Also
setSelectableParts, QCustomPlot::setInteractions
double QCPAbstractLegendItem::selectTest ( const QPointF &  pos,
bool  onlySelectable,
QVariant *  details = 0 
) const
virtual

Layout elements are sensitive to events inside their outer rect. If pos is within the outer rect, this method returns a value corresponding to 0.99 times the parent plot's selection tolerance. However, layout elements are not selectable by default. So if onlySelectable is true, -1.0 is returned.

See QCPLayerable::selectTest for a general explanation of this virtual method.

QCPLayoutElement subclasses may reimplement this method to provide more specific selection test behaviour.

Reimplemented from QCPLayoutElement.

void QCPAbstractLegendItem::selectionChanged ( bool  selected)
signal

This signal is emitted when the selection state of this legend item has changed, either by user interaction or by a direct call to setSelected.

QCP::Interaction QCPAbstractLegendItem::selectionCategory ( ) const
protectedvirtual

Returns the selection category this layerable shall belong to. The selection category is used in conjunction with QCustomPlot::setInteractions to control which objects are selectable and which aren't.

Subclasses that don't fit any of the normal QCP::Interaction values can use QCP::iSelectOther. This is what the default implementation returns.

See Also
QCustomPlot::setInteractions

Reimplemented from QCPLayerable.

void QCPAbstractLegendItem::applyDefaultAntialiasingHint ( QCPPainter painter) const
protectedvirtual

This function applies the default antialiasing setting to the specified painter, using the function applyAntialiasingHint. It is the antialiasing state the painter is put in, when draw is called on the layerable. If the layerable has multiple entities whose antialiasing setting may be specified individually, this function should set the antialiasing state of the most prominent entity. In this case however, the draw function usually calls the specialized versions of this function before drawing each entity, effectively overriding the setting of the default antialiasing hint.

First example: QCPGraph has multiple entities that have an antialiasing setting: The graph line, fills, scatters and error bars. Those can be configured via QCPGraph::setAntialiased, QCPGraph::setAntialiasedFill, QCPGraph::setAntialiasedScatters etc. Consequently, there isn't only the QCPGraph::applyDefaultAntialiasingHint function (which corresponds to the graph line's antialiasing), but specialized ones like QCPGraph::applyFillAntialiasingHint and QCPGraph::applyScattersAntialiasingHint. So before drawing one of those entities, QCPGraph::draw calls the respective specialized applyAntialiasingHint function.

Second example: QCPItemLine consists only of a line so there is only one antialiasing setting which can be controlled with QCPItemLine::setAntialiased. (This function is inherited by all layerables. The specialized functions, as seen on QCPGraph, must be added explicitly to the respective layerable subclass.) Consequently it only has the normal QCPItemLine::applyDefaultAntialiasingHint. The QCPItemLine::draw function doesn't need to care about setting any antialiasing states, because the default antialiasing hint is already set on the painter when the draw function is called, and that's the state it wants to draw the line with.

Reimplemented from QCPLayoutElement.

QRect QCPAbstractLegendItem::clipRect ( ) const
protectedvirtual

Returns the clipping rectangle of this layerable object. By default, this is the viewport of the parent QCustomPlot. Specific subclasses may reimplement this function to provide different clipping rects.

The returned clipping rect is set on the painter before the draw function of the respective object is called.

Reimplemented from QCPLayerable.

virtual void QCPAbstractLegendItem::draw ( QCPPainter painter)
protectedpure virtual

This function draws the layerable with the specified painter. It is only called by QCustomPlot, if the layerable is visible (setVisible).

Before this function is called, the painter's antialiasing state is set via applyDefaultAntialiasingHint, see the documentation there. Further, the clipping rectangle was set to clipRect.

Reimplemented from QCPLayoutElement.

Implemented in QCPPlottableLegendItem.

void QCPAbstractLegendItem::selectEvent ( QMouseEvent *  event,
bool  additive,
const QVariant &  details,
bool *  selectionStateChanged 
)
protectedvirtual

This event is called when the layerable shall be selected, as a consequence of a click by the user. Subclasses should react to it by setting their selection state appropriately. The default implementation does nothing.

event is the mouse event that caused the selection. additive indicates, whether the user was holding the multi-select-modifier while performing the selection (see QCustomPlot::setMultiSelectModifier). if additive is true, the selection state must be toggled (i.e. become selected when unselected and unselected when selected).

Every selectEvent is preceded by a call to selectTest, which has returned positively (i.e. returned a value greater than 0 and less than the selection tolerance of the parent QCustomPlot). The details data you output from selectTest is feeded back via details here. You may use it to transport any kind of information from the selectTest to the possibly subsequent selectEvent. Usually details is used to transfer which part was clicked, if it is a layerable that has multiple individually selectable parts (like QCPAxis). This way selectEvent doesn't need to do the calculation again to find out which part was actually clicked.

selectionStateChanged is an output parameter. If the pointer is non-null, this function must set the value either to true or false, depending on whether the selection state of this layerable was actually changed. For layerables that only are selectable as a whole and not in parts, this is simple: if additive is true, selectionStateChanged must also be set to true, because the selection toggles. If additive is false, selectionStateChanged is only set to true, if the layerable was previously unselected and now is switched to the selected state.

See Also
selectTest, deselectEvent

Reimplemented from QCPLayerable.

void QCPAbstractLegendItem::deselectEvent ( bool *  selectionStateChanged)
protectedvirtual

This event is called when the layerable shall be deselected, either as consequence of a user interaction or a call to QCustomPlot::deselectAll. Subclasses should react to it by unsetting their selection appropriately.

just as in selectEvent, the output parameter selectionStateChanged (if non-null), must return true or false when the selection state of this layerable has changed or not changed, respectively.

See Also
selectTest, selectEvent

Reimplemented from QCPLayerable.

QCPLayout * QCPLayoutElement::layout ( ) const
inlineinherited

Returns the parent layout of this layout element.

QRect QCPLayoutElement::rect ( ) const
inlineinherited

Returns the inner rect of this layout element. The inner rect is the outer rect (setOuterRect) shrinked by the margins (setMargins, setAutoMargins).

In some cases, the area between outer and inner rect is left blank. In other cases the margin area is used to display peripheral graphics while the main content is in the inner rect. This is where automatic margin calculation becomes interesting because it allows the layout element to adapt the margins to the peripheral graphics it wants to draw. For example, QCPAxisRect draws the axis labels and tick labels in the margin area, thus needs to adjust the margins (if setAutoMargins is enabled) according to the space required by the labels of the axes.

void QCPLayoutElement::setOuterRect ( const QRect &  rect)
inherited

Sets the outer rect of this layout element. If the layout element is inside a layout, the layout sets the position and size of this layout element using this function.

Calling this function externally has no effect, since the layout will overwrite any changes to the outer rect upon the next replot.

The layout element will adapt its inner rect by applying the margins inward to the outer rect.

See Also
rect
void QCPLayoutElement::setMargins ( const QMargins &  margins)
inherited

Sets the margins of this layout element. If setAutoMargins is disabled for some or all sides, this function is used to manually set the margin on those sides. Sides that are still set to be handled automatically are ignored and may have any value in margins.

The margin is the distance between the outer rect (controlled by the parent layout via setOuterRect) and the inner rect (which usually contains the main content of this layout element).

See Also
setAutoMargins
void QCPLayoutElement::setMinimumMargins ( const QMargins &  margins)
inherited

If setAutoMargins is enabled on some or all margins, this function is used to provide minimum values for those margins.

The minimum values are not enforced on margin sides that were set to be under manual control via setAutoMargins.

See Also
setAutoMargins
void QCPLayoutElement::setAutoMargins ( QCP::MarginSides  sides)
inherited

Sets on which sides the margin shall be calculated automatically. If a side is calculated automatically, a minimum margin value may be provided with setMinimumMargins. If a side is set to be controlled manually, the value may be specified with setMargins.

Margin sides that are under automatic control may participate in a QCPMarginGroup (see setMarginGroup), to synchronize (align) it with other layout elements in the plot.

See Also
setMinimumMargins, setMargins
void QCPLayoutElement::setMinimumSize ( const QSize &  size)
inherited

Sets the minimum size for the inner rect of this layout element. A parent layout tries to respect the size here by changing row/column sizes in the layout accordingly.

If the parent layout size is not sufficient to satisfy all minimum size constraints of its child layout elements, the layout may set a size that is actually smaller than size. QCustomPlot propagates the layout's size constraints to the outside by setting its own minimum QWidget size accordingly, so violations of size should be exceptions.

void QCPLayoutElement::setMinimumSize ( int  width,
int  height 
)
inherited

This is an overloaded function.

Sets the minimum size for the inner rect of this layout element.

void QCPLayoutElement::setMaximumSize ( const QSize &  size)
inherited

Sets the maximum size for the inner rect of this layout element. A parent layout tries to respect the size here by changing row/column sizes in the layout accordingly.

void QCPLayoutElement::setMaximumSize ( int  width,
int  height 
)
inherited

This is an overloaded function.

Sets the maximum size for the inner rect of this layout element.

void QCPLayoutElement::setMarginGroup ( QCP::MarginSides  sides,
QCPMarginGroup group 
)
inherited

Sets the margin group of the specified margin sides.

Margin groups allow synchronizing specified margins across layout elements, see the documentation of QCPMarginGroup.

To unset the margin group of sides, set group to 0.

Note that margin groups only work for margin sides that are set to automatic (setAutoMargins).

void QCPLayoutElement::update ( )
virtualinherited

Updates the layout element and sub-elements. This function is automatically called upon replot by the parent layout element.

Layout elements that have child elements should call the update method of their child elements.

The default implementation executes the automatic margin mechanism, so subclasses should make sure to call the base class implementation.

Reimplemented in QCPLayout, and QCPAxisRect.

QSize QCPLayoutElement::minimumSizeHint ( ) const
virtualinherited

Returns the minimum size this layout element (the inner rect) may be compressed to.

if a minimum size (setMinimumSize) was not set manually, parent layouts consult this function to determine the minimum allowed size of this layout element. (A manual minimum size is considered set if it is non-zero.)

Reimplemented in QCPLayoutGrid, QCPPlottableLegendItem, and QCPPlotTitle.

QSize QCPLayoutElement::maximumSizeHint ( ) const
virtualinherited

Returns the maximum size this layout element (the inner rect) may be expanded to.

if a maximum size (setMaximumSize) was not set manually, parent layouts consult this function to determine the maximum allowed size of this layout element. (A manual maximum size is considered set if it is smaller than Qt's QWIDGETSIZE_MAX.)

Reimplemented in QCPLayoutGrid, and QCPPlotTitle.

QList< QCPLayoutElement * > QCPLayoutElement::elements ( bool  recursive) const
virtualinherited

Returns a list of all child elements in this layout element. If recursive is true, all sub-child elements are included in the list, too.

Note that there may be entries with value 0 in the returned list. (For example, QCPLayoutGrid may have empty cells which yield 0 at the respective index.)

Reimplemented in QCPLayoutGrid, QCPLayout, and QCPAxisRect.

int QCPLayoutElement::calculateAutoMargin ( QCP::MarginSide  side)
protectedvirtualinherited

Returns the margin size for this side. It is used if automatic margins is enabled for this side (see setAutoMargins). If a minimum margin was set with setMinimumMargins, the returned value will not be smaller than the specified minimum margin.

The default implementation just returns the respective manual margin (setMargins) or the minimum margin, whichever is larger.

Reimplemented in QCPAxisRect.

void QCPLayoutElement::mousePressEvent ( QMouseEvent *  event)
inlineprotectedvirtualinherited

This event is called, if the mouse was pressed while being inside the outer rect of this layout element.

Reimplemented in QCPAxisRect.

void QCPLayoutElement::mouseMoveEvent ( QMouseEvent *  event)
inlineprotectedvirtualinherited

This event is called, if the mouse is moved inside the outer rect of this layout element.

Reimplemented in QCPAxisRect.

void QCPLayoutElement::mouseReleaseEvent ( QMouseEvent *  event)
inlineprotectedvirtualinherited

This event is called, if the mouse was previously pressed inside the outer rect of this layout element and is now released.

Reimplemented in QCPAxisRect.

void QCPLayoutElement::mouseDoubleClickEvent ( QMouseEvent *  event)
inlineprotectedvirtualinherited

This event is called, if the mouse is double-clicked inside the outer rect of this layout element.

void QCPLayoutElement::wheelEvent ( QWheelEvent *  event)
inlineprotectedvirtualinherited

This event is called, if the mouse wheel is scrolled while the cursor is inside the rect of this layout element.

Reimplemented in QCPAxisRect.

void QCPLayoutElement::parentPlotInitialized ( QCustomPlot parentPlot)
protectedvirtualinherited

propagates the parent plot initialization to all child elements, by calling QCPLayerable::initializeParentPlot on them.

Reimplemented from QCPLayerable.

Reimplemented in QCPLegend.

QCPLayerable * QCPLayerable::parentLayerable ( ) const
inlineinherited

Returns the parent layerable of this layerable. The parent layerable is used to provide visibility hierarchies in conjunction with the method realVisibility. This way, layerables only get drawn if their parent layerables are visible, too.

Note that a parent layerable is not necessarily also the QObject parent for memory management. Further, a layerable doesn't always have a parent layerable, so this function may return 0.

A parent layerable is set implicitly with when placed inside layout elements and doesn't need to be set manually by the user.

void QCPLayerable::setVisible ( bool  on)
inherited

Sets the visibility of this layerable object. If an object is not visible, it will not be drawn on the QCustomPlot surface, and user interaction with it (e.g. click and selection) is not possible.

bool QCPLayerable::setLayer ( QCPLayer layer)
inherited

Sets the layer of this layerable object. The object will be placed on top of the other objects already on layer.

Returns true on success, i.e. if layer is a valid layer.

bool QCPLayerable::setLayer ( const QString &  layerName)
inherited

This is an overloaded function.

Sets the layer of this layerable object by name

Returns true on success, i.e. if layerName is a valid layer name.

void QCPLayerable::setAntialiased ( bool  enabled)
inherited

Sets whether this object will be drawn antialiased or not.

Note that antialiasing settings may be overridden by QCustomPlot::setAntialiasedElements and QCustomPlot::setNotAntialiasedElements.

bool QCPLayerable::realVisibility ( ) const
inherited

Returns whether this layerable is visible, taking possible direct layerable parent visibility into account. This is the method that is consulted to decide whether a layerable shall be drawn or not.

If this layerable has a direct layerable parent (usually set via hierarchies implemented in subclasses, like in the case of QCPLayoutElement), this function returns true only if this layerable has its visibility set to true and the parent layerable's realVisibility returns true.

If this layerable doesn't have a direct layerable parent, returns the state of this layerable's visibility.

void QCPLayerable::initializeParentPlot ( QCustomPlot parentPlot)
protectedinherited

Sets the parent plot of this layerable. Use this function once to set the parent plot if you have passed 0 in the constructor. It can not be used to move a layerable from one QCustomPlot to another one.

Note that, unlike when passing a non-null parent plot in the constructor, this function does not make parentPlot the QObject-parent of this layerable. If you want this, call QObject::setParent(parentPlot) in addition to this function.

Further, you will probably want to set a layer (setLayer) after calling this function, to make the layerable appear on the QCustomPlot.

The parent plot change will be propagated to subclasses via a call to parentPlotInitialized so they can react accordingly (e.g. also initialize the parent plot of child layerables, like QCPLayout does).

void QCPLayerable::setParentLayerable ( QCPLayerable parentLayerable)
protectedinherited

Sets the parent layerable of this layerable to parentLayerable. Note that parentLayerable does not become the QObject-parent (for memory management) of this layerable.

The parent layerable has influence on the return value of the realVisibility method. Only layerables with a fully visible parent tree will return true for realVisibility, and thus be drawn.

See Also
realVisibility
bool QCPLayerable::moveToLayer ( QCPLayer layer,
bool  prepend 
)
protectedinherited

Moves this layerable object to layer. If prepend is true, this object will be prepended to the new layer's list, i.e. it will be drawn below the objects already on the layer. If it is false, the object will be appended.

Returns true on success, i.e. if layer is a valid layer.

void QCPLayerable::applyAntialiasingHint ( QCPPainter painter,
bool  localAntialiased,
QCP::AntialiasedElement  overrideElement 
) const
protectedinherited

Sets the QCPainter::setAntialiasing state on the provided painter, depending on the localAntialiased value as well as the overrides QCustomPlot::setAntialiasedElements and QCustomPlot::setNotAntialiasedElements. Which override enum this function takes into account is controlled via overrideElement.


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