Item that sticks to QCPGraph data points. More...
Public Types | |
enum | TracerStyle |
Public Functions | |
QCPItemTracer (QCustomPlot *parentPlot) | |
QPen | pen () const |
QPen | selectedPen () const |
QBrush | brush () const |
QBrush | selectedBrush () const |
double | size () const |
TracerStyle | style () const |
QCPGraph * | graph () const |
double | graphKey () const |
bool | interpolating () const |
void | setPen (const QPen &pen) |
void | setSelectedPen (const QPen &pen) |
void | setBrush (const QBrush &brush) |
void | setSelectedBrush (const QBrush &brush) |
void | setSize (double size) |
void | setStyle (TracerStyle style) |
void | setGraph (QCPGraph *graph) |
void | setGraphKey (double key) |
void | setInterpolating (bool enabled) |
virtual double | selectTest (const QPointF &pos) const |
void | updatePosition () |
bool | clipToAxisRect () const |
QCPAxis * | clipKeyAxis () const |
QCPAxis * | clipValueAxis () const |
bool | selectable () const |
bool | selected () const |
void | setClipToAxisRect (bool clip) |
void | setClipAxes (QCPAxis *keyAxis, QCPAxis *valueAxis) |
void | setClipKeyAxis (QCPAxis *axis) |
void | setClipValueAxis (QCPAxis *axis) |
void | setSelectable (bool selectable) |
void | setSelected (bool selected) |
QList< QCPItemPosition * > | positions () const |
QList< QCPItemAnchor * > | anchors () const |
QCPItemPosition * | position (const QString &name) const |
QCPItemAnchor * | anchor (const QString &name) const |
bool | hasAnchor (const QString &name) const |
bool | visible () const |
QCustomPlot * | parentPlot () const |
QCPLayer * | layer () const |
bool | antialiased () const |
void | setVisible (bool on) |
bool | setLayer (QCPLayer *layer) |
bool | setLayer (const QString &layerName) |
void | setAntialiased (bool enabled) |
Public Members | |
QCPItemPosition *const | position |
Signals | |
void | selectionChanged (bool selected) |
Protected Functions | |
virtual void | draw (QCPPainter *painter) |
QPen | mainPen () const |
QBrush | mainBrush () const |
virtual QRect | clipRect () const |
virtual void | applyDefaultAntialiasingHint (QCPPainter *painter) const |
double | distSqrToLine (const QPointF &start, const QPointF &end, const QPointF &point) const |
double | rectSelectTest (const QRectF &rect, const QPointF &pos, bool filledRect) const |
virtual QPointF | anchorPixelPoint (int anchorId) const |
QCPItemPosition * | createPosition (const QString &name) |
QCPItemAnchor * | createAnchor (const QString &name, int anchorId) |
bool | moveToLayer (QCPLayer *layer, bool prepend) |
void | applyAntialiasingHint (QCPPainter *painter, bool localAntialiased, QCP::AntialiasedElement overrideElement) const |
Item that sticks to QCPGraph data points.
The tracer can be connected with a QCPGraph via setGraph. Then it will automatically adopt the coordinate axes of the graph and update its position to be on the graph's data. This means the key stays controllable via setGraphKey, but the value will follow the graph data. If a QCPGraph is connected, note that setting the coordinates directly via position will have no effect, i.e. be overriden in the next redraw (this is when the coodinate update happens).
If the specified key in setGraphKey is outside the key bounds of the graph, the tracer will stay at the respective end of the graph.
With setInterpolating you may specify whether the tracer may only stay exactly on data points or whether it interpolates data points linearly, if given a key that lies between two data points of the graph.
The tracer has different visual styles, see setStyle. It is also possible to make the tracer have no own visual appearance (set the style to tsNone), and just connect other item positions to the tracer position (used as an anchor) via QCPItemPosition::setParentAnchor.
QCPItemTracer::QCPItemTracer | ( | QCustomPlot * | parentPlot | ) |
Creates a tracer item and sets default values.
The constructed item can be added to the plot with QCustomPlot::addItem.
void QCPItemTracer::setPen | ( | const QPen & | pen | ) |
Sets the pen that will be used to draw the line of the tracer
void QCPItemTracer::setSelectedPen | ( | const QPen & | pen | ) |
Sets the pen that will be used to draw the line of the tracer when selected
void QCPItemTracer::setBrush | ( | const QBrush & | brush | ) |
Sets the brush that will be used to draw any fills of the tracer
void QCPItemTracer::setSelectedBrush | ( | const QBrush & | brush | ) |
Sets the brush that will be used to draw any fills of the tracer, when selected.
void QCPItemTracer::setSize | ( | double | size | ) |
Sets the size of the tracer in pixels, if the style supports setting a size (e.g. tsSquare does, tsCrosshair does not).
void QCPItemTracer::setStyle | ( | QCPItemTracer::TracerStyle | style | ) |
Sets the style/visual appearance of the tracer.
If you only want to use the tracer position as an anchor for other items, set style to tsNone.
void QCPItemTracer::setGraph | ( | QCPGraph * | graph | ) |
Sets the QCPGraph this tracer sticks to. The tracer position will be set to type QCPItemPosition::ptPlotCoords and the axes will be set to the axes of graph.
To free the tracer from any graph, set graph to 0. The tracer position can then be placed freely like any other item position. This is the state the tracer will assume when its graph gets deleted while still attached to it.
void QCPItemTracer::setGraphKey | ( | double | key | ) |
Sets the key of the graph's data point the tracer will be positioned at. This is the only free cordinate of a tracer when attached to a graph.
Depending on setInterpolating, the tracer will be either positioned on the data point closest to key, or will stay exactly at key and interpolate the value linearly.
void QCPItemTracer::setInterpolating | ( | bool | enabled | ) |
Sets whether the value of the graph's data points shall be interpolated, when positioning the tracer.
If enabled is set to false and a key is given with setGraphKey, the tracer is placed on the data point of the graph which is closest to the key, but which is not necessarily exactly there. If enabled is true, the tracer will be positioned exactly at the specified key, and the appropriate value will be interpolated from the graph's data points linearly.
double QCPItemTracer::selectTest | ( | const QPointF & | pos | ) | const [virtual] |
This function is used to decide whether a click hits an item or not.
pos is a point in pixel coordinates on the QCustomPlot surface. This function returns the shortest pixel distance of this point to the item. If the item is either invisible or the distance couldn't be determined, -1.0 is returned. setSelectable has no influence on the return value of this function.
If the item is represented not by single lines but by an area like QCPItemRect or QCPItemText, a click inside the area returns a constant value greater zero (typically 99% of the selectionTolerance of the parent QCustomPlot). If the click lies outside the area, this function returns -1.0.
Providing a constant value for area objects allows selecting line objects even when they are obscured by such area objects, by clicking close to the lines (i.e. closer than 0.99*selectionTolerance).
The actual setting of the selection state is not done by this function. This is handled by the parent QCustomPlot when the mouseReleaseEvent occurs.
Implements QCPAbstractItem.
void QCPItemTracer::updatePosition | ( | ) |
If the tracer is connected with a graph (setGraph), this function updates the tracer's position to reside on the graph data, depending on the configured key (setGraphKey).
It is called automatically on every redraw and normally doesn't need to be called manually. One exception is when you want to read the tracer coordinates via position and are not sure that the graph's data (or the tracer key with setGraphKey) hasn't changed since the last redraw. In that situation, call this function before accessing position, to make sure you don't get out-of-date coordinates.
If there is no graph set on this tracer, this function does nothing.
void QCPItemTracer::draw | ( | QCPPainter * | painter | ) | [protected, virtual] |
Draws this item with the provided painter. Called by QCustomPlot::draw on all its visible items.
The cliprect of the provided painter is set to the rect returned by clipRect before this function is called. For items this depends on the clipping settings defined by setClipToAxisRect, setClipKeyAxis and setClipValueAxis.
Implements QCPAbstractItem.
QPen QCPItemTracer::mainPen | ( | ) | const [protected] |
Returns the pen that should be used for drawing lines. Returns mPen when the item is not selected and mSelectedPen when it is.
QBrush QCPItemTracer::mainBrush | ( | ) | const [protected] |
Returns the brush that should be used for drawing fills of the item. Returns mBrush when the item is not selected and mSelectedBrush when it is.
void QCPAbstractItem::setClipToAxisRect | ( | bool | clip | ) | [inherited] |
Sets whether the item shall be clipped to the axis rect or whether it shall be visible on the entire QCustomPlot. The axis rect is defined by the clip axes which can be set via setClipAxes or individually with setClipKeyAxis and setClipValueAxis.
void QCPAbstractItem::setClipAxes | ( | QCPAxis * | keyAxis, |
QCPAxis * | valueAxis | ||
) | [inherited] |
Sets both clip axes. Together they define the axis rect that will be used to clip the item when setClipToAxisRect is set to true.
void QCPAbstractItem::setClipKeyAxis | ( | QCPAxis * | axis | ) | [inherited] |
Sets the clip key axis. Together with the clip value axis it defines the axis rect that will be used to clip the item when setClipToAxisRect is set to true.
void QCPAbstractItem::setClipValueAxis | ( | QCPAxis * | axis | ) | [inherited] |
Sets the clip value axis. Together with the clip key axis it defines the axis rect that will be used to clip the item when setClipToAxisRect is set to true.
void QCPAbstractItem::setSelectable | ( | bool | selectable | ) | [inherited] |
Sets whether the user can (de-)select this item by clicking on the QCustomPlot surface. (When QCustomPlot::setInteractions contains QCustomPlot::iSelectItems.)
However, even when selectable was set to false, it is possible to set the selection manually, by calling setSelected directly.
void QCPAbstractItem::setSelected | ( | bool | selected | ) | [inherited] |
Sets whether this item is selected or not. When selected, it might use a different visual appearance (e.g. pen and brush), this depends on the specific item, though.
The entire selection mechanism for items is handled automatically when QCustomPlot::setInteractions contains QCustomPlot::iSelectItems. You only need to call this function when you wish to change the selection state manually.
This function can change the selection state even when setSelectable was set to false.
emits the selectionChanged signal when selected is different from the previous selection state.
QList< QCPItemPosition * > QCPAbstractItem::positions | ( | ) | const [inline, inherited] |
QList< QCPItemAnchor * > QCPAbstractItem::anchors | ( | ) | const [inline, inherited] |
Returns all anchors of the item in a list. Note that since a position (QCPItemPosition) is always also an anchor, the list will also contain the positions of this item.
QCPItemPosition * QCPAbstractItem::position | ( | const QString & | name | ) | const [inherited] |
Returns the QCPItemPosition with the specified name. If this item doesn't have a position by that name, returns 0.
This function provides an alternative way to access item positions. Normally, you access positions direcly by their member pointers (which typically have the same variable name as name).
QCPItemAnchor * QCPAbstractItem::anchor | ( | const QString & | name | ) | const [inherited] |
Returns the QCPItemAnchor with the specified name. If this item doesn't have an anchor by that name, returns 0.
This function provides an alternative way to access item anchors. Normally, you access anchors direcly by their member pointers (which typically have the same variable name as name).
bool QCPAbstractItem::hasAnchor | ( | const QString & | name | ) | const [inherited] |
Returns whether this item has an anchor with the specified name.
Note that you can check for positions with this function, too, because every position is also an anchor (QCPItemPosition inherits from QCPItemAnchor).
QRect QCPAbstractItem::clipRect | ( | ) | const [protected, virtual, inherited] |
Returns the rect the visual representation of this item is clipped to. This depends on the current setting of setClipToAxisRect aswell as the clip axes set with setClipAxes.
If the item is not clipped to an axis rect, the QCustomPlot::viewport rect is returned.
Reimplemented from QCPLayerable.
void QCPAbstractItem::applyDefaultAntialiasingHint | ( | QCPPainter * | painter | ) | const [protected, virtual, inherited] |
A convenience function to easily set the QPainter::Antialiased hint on the provided painter before drawing item lines.
This is the antialiasing state the painter passed to the draw method is in by default.
This function takes into account the local setting of the antialiasing flag as well as the overrides set e.g. with QCustomPlot::setNotAntialiasedElements.
Implements QCPLayerable.
double QCPAbstractItem::distSqrToLine | ( | const QPointF & | start, |
const QPointF & | end, | ||
const QPointF & | point | ||
) | const [protected, inherited] |
Finds the shortest squared distance of point to the line segment defined by start and end.
This function may be used to help with the implementation of the selectTest function for specific items.
double QCPAbstractItem::rectSelectTest | ( | const QRectF & | rect, |
const QPointF & | pos, | ||
bool | filledRect | ||
) | const [protected, inherited] |
A convenience function which returns the selectTest value for a specified rect and a specified click position pos. filledRect defines whether a click inside the rect should also be considered a hit or whether only the rect border is sensitive to hits.
This function may be used to help with the implementation of the selectTest function for specific items.
For example, if your item consists of four rects, call this function four times, once for each rect, in your selectTest reimplementation. Finally, return the minimum of all four returned values which were greater or equal to zero. (Because this function may return -1.0 when pos doesn't hit rect at all). If all calls returned -1.0, return -1.0, too, because your item wasn't hit.
QPointF QCPAbstractItem::anchorPixelPoint | ( | int | anchorId | ) | const [protected, virtual, inherited] |
Returns the pixel position of the anchor with Id anchorId. This function must be reimplemented in item subclasses if they want to provide anchors (QCPItemAnchor).
For example, if the item has two anchors with id 0 and 1, this function takes one of these anchor ids and returns the respective pixel points of the specified anchor.
Reimplemented in QCPItemBracket, QCPItemText, QCPItemPixmap, QCPItemRect, and QCPItemEllipse.
QCPItemPosition * QCPAbstractItem::createPosition | ( | const QString & | name | ) | [protected, inherited] |
Creates a QCPItemPosition, registers it with this item and returns a pointer to it. The specified name must be a unique string that is usually identical to the variable name of the position member (This is needed to provide the name based position access to positions).
Don't delete positions created by this function manually, as the item will take care of it.
Use this function in the constructor (initialization list) of the specific item subclass to create each position member. Don't create QCPItemPositions with new yourself, because they won't be registered with the item properly.
QCPItemAnchor * QCPAbstractItem::createAnchor | ( | const QString & | name, |
int | anchorId | ||
) | [protected, inherited] |
Creates a QCPItemAnchor, registers it with this item and returns a pointer to it. The specified name must be a unique string that is usually identical to the variable name of the anchor member (This is needed to provide the name based anchor access to anchors).
The anchorId must be a number identifying the created anchor. It is recommended to create an enum (e.g. "AnchorIndex") for this on each item that uses anchors. This id is used by the anchor to identify itself when it calls QCPAbstractItem::anchorPixelPoint. That function then returns the correct pixel coordinates for the passed anchor id.
Don't delete anchors created by this function manually, as the item will take care of it.
Use this function in the constructor (initialization list) of the specific item subclass to create each anchor member. Don't create QCPItemAnchors with new yourself, because then they won't be registered with the item properly.
void QCPAbstractItem::selectionChanged | ( | bool | selected | ) | [signal, inherited] |
This signal is emitted when the selection state of this item has changed, either by user interaction or by a direct call to setSelected.
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/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::moveToLayer | ( | QCPLayer * | layer, |
bool | prepend | ||
) | [protected, inherited] |
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 [protected, inherited] |
Sets the QPainter::Antialiasing render hint 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.