# QwtPlotPicker Class Reference

QwtPlotPicker provides selections on a plot canvas. More...

`#include <qwt_plot_picker.h>`

Inheritance diagram for QwtPlotPicker:
[legend]

List of all members.

## Signals
void | selected (const QwtDoublePoint &pos)
void | selected (const QwtDoubleRect &rect)
void | selected (const QwtArray< QwtDoublePoint > &pa)
void | appended (const QwtDoublePoint &pos)
void | moved (const QwtDoublePoint &pos)
## Public Member Functions
| QwtPlotPicker (QwtPlotCanvas *)
virtual | ~QwtPlotPicker ()
| QwtPlotPicker (int xAxis, int yAxis, QwtPlotCanvas *)
| QwtPlotPicker (int xAxis, int yAxis, int selectionFlags, RubberBand rubberBand, DisplayMode trackerMode, QwtPlotCanvas *)
virtual void | setAxis (int xAxis, int yAxis)
int | xAxis () const
int | yAxis () const
QwtPlot * | plot ()
const QwtPlot * | plot () const
QwtPlotCanvas * | canvas ()
const QwtPlotCanvas * | canvas () const
## Protected Member Functions
QwtDoubleRect | scaleRect () const
QwtDoubleRect | invTransform (const QRect &) const
QRect | transform (const QwtDoubleRect &) const
QwtDoublePoint | invTransform (const QPoint &) const
QPoint | transform (const QwtDoublePoint &) const
virtual QwtText | trackerText (const QPoint &) const
virtual QwtText | trackerText (const QwtDoublePoint &) const
virtual void | move (const QPoint &)
virtual void | append (const QPoint &)
virtual bool | end (bool ok=true)

## Detailed Description

QwtPlotPicker provides selections on a plot canvas.

QwtPlotPicker is a QwtPicker tailored for selections on a plot canvas. It is set to a x-Axis and y-Axis and translates all pixel coordinates into this coodinate system.

## Constructor & Destructor Documentation

QwtPlotPicker::QwtPlotPicker | ( | QwtPlotCanvas * | canvas | ) | `[explicit]`

Create a plot picker.

The picker is set to those x- and y-axis of the plot that are enabled. If both or no x-axis are enabled, the picker is set to QwtPlot::xBottom. If both or no y-axis are enabled, it is set to QwtPlot::yLeft.

Parameters:

  | canvas | Plot canvas to observe, also the parent object

See also:
  QwtPlot::autoReplot(), QwtPlot::replot(), QwtPlotPicker::scaleRect()

QwtPlotPicker::~QwtPlotPicker | ( |  | ) | `[virtual]`

Destructor.

QwtPlotPicker::QwtPlotPicker | ( | int | xAxis,
|  | int | yAxis,
|  | QwtPlotCanvas * | canvas |
| ) |  |  | `[explicit]`

Create a plot picker

Parameters:

  | xAxis | Set the x axis of the picker
  | yAxis | Set the y axis of the picker
  | canvas | Plot canvas to observe, also the parent object

See also:
  QwtPlot::autoReplot(), QwtPlot::replot(), QwtPlotPicker::scaleRect()

QwtPlotPicker::QwtPlotPicker | ( | int | xAxis,
|  | int | yAxis,
|  | int | selectionFlags,
|  | RubberBand | rubberBand,
|  | DisplayMode | trackerMode,
|  | QwtPlotCanvas * | canvas |
| ) |  |  | `[explicit]`

Create a plot picker

Parameters:

  | xAxis | X axis of the picker
  | yAxis | Y axis of the picker
  | selectionFlags | Or'd value of SelectionType, RectSelectionType and SelectionMode
  | rubberBand | Rubberband style
  | trackerMode | Tracker mode
  | canvas | Plot canvas to observe, also the parent object

See also:
  QwtPicker, QwtPicker::setSelectionFlags(), QwtPicker::setRubberBand(), QwtPicker::setTrackerMode
  QwtPlot::autoReplot(), QwtPlot::replot(), QwtPlotPicker::scaleRect()

## Member Function Documentation

void QwtPlotPicker::append | ( | const QPoint & | pos | ) | `[protected, virtual]`

Append a point to the selection and update rubberband and tracker.

Parameters:

  | pos | Additional point

See also:
  isActive, begin(), end(), move(), appended()

Note:
  The appended(const QPoint &), appended(const QDoublePoint &) signals are emitted.

Reimplemented from QwtPicker.

void QwtPlotPicker::appended | ( | const QwtDoublePoint & | pos | ) | `[signal]`

A signal emitted when a point has been appended to the selection

Parameters:

  | pos | Position of the appended point.

See also:
  append(). moved()

const QwtPlotCanvas * QwtPlotPicker::canvas | ( |  | ) | const

Return Observed plot canvas.

QwtPlotCanvas * QwtPlotPicker::canvas | ( |  | ) |

Return observed plot canvas.

bool QwtPlotPicker::end | ( | bool | ok = `true` | ) | `[protected, virtual]`

Close a selection setting the state to inactive.

Parameters:

  | ok | If true, complete the selection and emit selected signals otherwise discard the selection.

Returns:
  true if the selection is accepted, false otherwise

Reimplemented from QwtPicker.

Reimplemented in QwtPlotZoomer.

QwtDoublePoint QwtPlotPicker::invTransform | ( | const QPoint & | pos | ) | const`[protected]`

Translate a point from pixel into plot coordinates

Returns:
  Point in plot coordinates

See also:
  QwtPlotPicker::transform()

QwtDoubleRect QwtPlotPicker::invTransform | ( | const QRect & | rect | ) | const`[protected]`

Translate a rectangle from pixel into plot coordinates

Returns:
  Rectangle in plot coordinates

See also:
  QwtPlotPicker::transform()

void QwtPlotPicker::move | ( | const QPoint & | pos | ) | `[protected, virtual]`

Move the last point of the selection

Parameters:

  | pos | New position

See also:
  isActive, begin(), end(), append()

Note:
  The moved(const QPoint &), moved(const QDoublePoint &) signals are emitted.

Reimplemented from QwtPicker.

void QwtPlotPicker::moved | ( | const QwtDoublePoint & | pos | ) | `[signal]`

A signal emitted whenever the last appended point of the selection has been moved.

Parameters:

  | pos | Position of the moved last point of the selection.

See also:
  move(), appended()

const QwtPlot * QwtPlotPicker::plot | ( |  | ) | const

Return plot widget, containing the observed plot canvas.

QwtPlot * QwtPlotPicker::plot | ( |  | ) |

Return plot widget, containing the observed plot canvas.

QwtDoubleRect QwtPlotPicker::scaleRect | ( |  | ) | const`[protected]`

Return normalized bounding rect of the axes

See also:
  QwtPlot::autoReplot(), QwtPlot::replot().

void QwtPlotPicker::selected | ( | const QwtArray< QwtDoublePoint > & | pa | ) | `[signal]`

A signal emitting the selected points, at the end of a selection.

Parameters:

  | pa | Selected points

void QwtPlotPicker::selected | ( | const QwtDoubleRect & | rect | ) | `[signal]`

A signal emitted in case of selectionFlags() & RectSelection.

Parameters:

  | rect | Selected rectangle

void QwtPlotPicker::selected | ( | const QwtDoublePoint & | pos | ) | `[signal]`

A signal emitted in case of selectionFlags() & PointSelection.

Parameters:

  | pos | Selected point

void QwtPlotPicker::setAxis | ( | int | xAxis,
|  | int | yAxis |
| ) |  |  | `[virtual]`

Set the x and y axes of the picker

Parameters:

  | xAxis | X axis
  | yAxis | Y axis

Reimplemented in QwtPlotZoomer.

QwtText QwtPlotPicker::trackerText | ( | const QwtDoublePoint & | pos | ) | const`[protected, virtual]`

Translate a position into a position string.

In case of HLineRubberBand the label is the value of the y position, in case of VLineRubberBand the value of the x position. Otherwise the label contains x and y position separated by a ',' .

The format for the double to string conversion is "%.4f".

Parameters:

  | pos | Position

Returns:
  Position string

QwtText QwtPlotPicker::trackerText | ( | const QPoint & | pos | ) | const`[protected, virtual]`

Translate a pixel position into a position string

Parameters:

  | pos | Position in pixel coordinates

Returns:
  Position string

Reimplemented from QwtPicker.

QPoint QwtPlotPicker::transform | ( | const QwtDoublePoint & | pos | ) | const`[protected]`

Translate a point from plot into pixel coordinates

Returns:
  Point in pixel coordinates

See also:
  QwtPlotPicker::invTransform()

QRect QwtPlotPicker::transform | ( | const QwtDoubleRect & | rect | ) | const`[protected]`

Translate a rectangle from plot into pixel coordinates

Returns:
  Rectangle in pixel coordinates

See also:
  QwtPlotPicker::invTransform()

int QwtPlotPicker::xAxis | ( |  | ) | const

Return x axis.

int QwtPlotPicker::yAxis | ( |  | ) | const

Return y axis.