QwtPicker provides selections on a widget. Más...

#include <qwt_picker.h>

Diagrama de herencias de QwtPicker

Clases
class	PickerWidget
class	PrivateData
Tipos públicos
enum	SelectionType { NoSelection = 0, PointSelection = 1, RectSelection = 2, PolygonSelection = 4 }
enum	RectSelectionType { CornerToCorner = 64, CenterToCorner = 128, CenterToRadius = 256 }
	Selection subtype for RectSelection This enum type describes the type of rectangle selections. It can be or'd with QwtPicker::RectSelectionType and QwtPicker::SelectionMode and passed to QwtPicker::setSelectionFlags(). Más...
enum	SelectionMode { ClickSelection = 1024, DragSelection = 2048 }
enum	RubberBand { NoRubberBand = 0, HLineRubberBand, VLineRubberBand, CrossRubberBand, RectRubberBand, EllipseRubberBand, PolygonRubberBand, UserRubberBand = 100 }
enum	DisplayMode { AlwaysOff, AlwaysOn, ActiveOnly }
enum	ResizeMode { Stretch, KeepSize }
Señales
void	selected (const QwtPolygon &pa)
void	appended (const QPoint &pos)
void	moved (const QPoint &pos)
void	changed (const QwtPolygon &pa)
Métodos públicos
	QwtPicker (QWidget *parent)
	QwtPicker (int selectionFlags, RubberBand rubberBand, DisplayMode trackerMode, QWidget *)
virtual	~QwtPicker ()
	Destructor.
virtual void	setSelectionFlags (int)
int	selectionFlags () const
virtual void	setRubberBand (RubberBand)
RubberBand	rubberBand () const
virtual void	setTrackerMode (DisplayMode)
	Set the display mode of the tracker.
DisplayMode	trackerMode () const
virtual void	setResizeMode (ResizeMode)
	Set the resize mode.
ResizeMode	resizeMode () const
virtual void	setRubberBandPen (const QPen &)
QPen	rubberBandPen () const
virtual void	setTrackerPen (const QPen &)
QPen	trackerPen () const
virtual void	setTrackerFont (const QFont &)
QFont	trackerFont () const
bool	isEnabled () const
virtual void	setEnabled (bool)
	En/disable the picker.
bool	isActive () const
virtual bool	eventFilter (QObject , QEvent )
	Event filter.
QWidget *	parentWidget ()
	Return the parent widget, where the selection happens.
const QWidget *	parentWidget () const
	Return the parent widget, where the selection happens.
virtual QRect	pickRect () const
const QwtPolygon &	selection () const
	Return Selected points.
virtual void	drawRubberBand (QPainter *) const
virtual void	drawTracker (QPainter *) const
virtual QwtText	trackerText (const QPoint &pos) const
	Return the label for a position.
QPoint	trackerPosition () const
QRect	trackerRect (const QFont &) const
Métodos protegidos
virtual bool	accept (QwtPolygon &selection) const
	Validate and fixup the selection.
virtual void	transition (const QEvent *)
virtual void	begin ()
virtual void	append (const QPoint &)
virtual void	move (const QPoint &)
virtual bool	end (bool ok=true)
	Close a selection setting the state to inactive.
virtual void	reset ()
virtual void	widgetMousePressEvent (QMouseEvent *)
virtual void	widgetMouseReleaseEvent (QMouseEvent *)
virtual void	widgetMouseDoubleClickEvent (QMouseEvent *)
virtual void	widgetMouseMoveEvent (QMouseEvent *)
virtual void	widgetWheelEvent (QWheelEvent *)
virtual void	widgetKeyPressEvent (QKeyEvent *)
virtual void	widgetKeyReleaseEvent (QKeyEvent *)
virtual void	widgetLeaveEvent (QEvent *)
virtual void	stretchSelection (const QSize &oldSize, const QSize &newSize)
virtual QwtPickerMachine *	stateMachine (int) const
virtual void	updateDisplay ()
const QWidget *	rubberBandWidget () const
const QWidget *	trackerWidget () const
Propiedades
int	selectionFlags
DisplayMode	trackerMode
QFont	trackerFont
RubberBand	rubberBand
ResizeMode	resizeMode
bool	isEnabled
QPen	trackerPen
QPen	rubberBandPen

Descripción detallada

QwtPicker provides selections on a widget.

QwtPicker filters all mouse and keyboard events of a widget and translates them into an array of selected points. Depending on the QwtPicker::SelectionType the selection might be a single point, a rectangle or a polygon. The selection process is supported by optional rubberbands (rubberband selection) and position trackers.

QwtPicker is useful for widgets where the event handlers can't be overloaded, like for components of composite widgets. It offers alternative handlers for mouse and key events.

Example

#include <qwt_picker.h>

QwtPicker *picker = new QwtPicker(widget);
picker->setTrackerMode(QwtPicker::ActiveOnly);
connect(picker, SIGNAL(selected(const QwtPolygon &)), ...);

// emit the position of clicks on widget
picker->setSelectionFlags(QwtPicker::PointSelection | QwtPicker::ClickSelection);

    ...
    
// now select rectangles
picker->setSelectionFlags(QwtPicker::RectSelection | QwtPicker::DragSelection);
picker->setRubberBand(QwtPicker::RectRubberBand);

The selection process uses the commands begin(), append(), move() and end(). append() adds a new point to the selection, move() changes the position of the latest point.

The commands are initiated from a small state machine (QwtPickerMachine) that translates mouse and key events. There are a couple of predefined state machines for point, rect and polygon selections. The selectionFlags() control which one should be used. It is possible to use other machines by overloading stateMachine().

The picker is active (isActive()), between begin() and end(). In active state the rubberband is displayed, and the tracker is visible in case of trackerMode is ActiveOnly or AlwaysOn.

The cursor can be moved using the arrow keys. All selections can be aborted using the abort key. (QwtEventPattern::KeyPatternCode)

Atención:: In case of QWidget::NoFocus the focus policy of the observed widget is set to QWidget::WheelFocus and mouse tracking will be manipulated for ClickSelection while the picker is active, or if trackerMode() is AlwayOn.

Documentación de las enumeraciones miembro de la clase

enum QwtPicker::DisplayMode

AlwaysOff
Display never.
AlwaysOn
Display always.
ActiveOnly
Display only when the selection is active.

Ver también:: QwtPicker::setTrackerMode(), QwtPicker::trackerMode(), QwtPicker::isActive()

Valores de enumeraciones:

AlwaysOff
AlwaysOn
ActiveOnly

enum QwtPicker::RectSelectionType

Selection subtype for RectSelection This enum type describes the type of rectangle selections. It can be or'd with QwtPicker::RectSelectionType and QwtPicker::SelectionMode and passed to QwtPicker::setSelectionFlags().

CornerToCorner
The first and the second selected point are the corners of the rectangle.
CenterToCorner
The first point is the center, the second a corner of the rectangle.
CenterToRadius
The first point is the center of a quadrat, calculated by the maximum of the x- and y-distance.

The default value is CornerToCorner.

Ver también:: QwtPicker::setSelectionFlags(), QwtPicker::selectionFlags()

Valores de enumeraciones:

CornerToCorner
CenterToCorner
CenterToRadius

enum QwtPicker::ResizeMode

Controls what to do with the selected points of an active selection when the observed widget is resized.

Stretch
All points are scaled according to the new size,
KeepSize
All points remain unchanged.

The default value is Stretch.

Ver también:: QwtPicker::setResizeMode(), QwtPicker::resize()

Valores de enumeraciones:

Stretch
KeepSize

enum QwtPicker::RubberBand

Rubberband style

NoRubberBand
No rubberband.
HLineRubberBand & PointSelection
A horizontal line.
VLineRubberBand & PointSelection
A vertical line.
CrossRubberBand & PointSelection
A horizontal and a vertical line.
RectRubberBand & RectSelection
A rectangle.
EllipseRubberBand & RectSelection
An ellipse.
PolygonRubberBand &PolygonSelection
A polygon.
UserRubberBand
Values >= UserRubberBand can be used to define additional rubber bands.

The default value is NoRubberBand.

Ver también:: QwtPicker::setRubberBand(), QwtPicker::rubberBand()

Valores de enumeraciones:

NoRubberBand
HLineRubberBand
VLineRubberBand
CrossRubberBand
RectRubberBand
EllipseRubberBand
PolygonRubberBand
UserRubberBand

enum QwtPicker::SelectionMode

Values of this enum type or'd together with a SelectionType value identifies which state machine should be used for the selection.

The default value is ClickSelection.

Ver también:: stateMachine()

Valores de enumeraciones:

ClickSelection
DragSelection

enum QwtPicker::SelectionType

This enum type describes the type of a selection. It can be or'd with QwtPicker::RectSelectionType and QwtPicker::SelectionMode and passed to QwtPicker::setSelectionFlags()

NoSelection
Selection is disabled. Note this is different to the disabled state, as you might have a tracker.
PointSelection
Select a single point.
RectSelection
Select a rectangle.
PolygonSelection
Select a polygon.

The default value is NoSelection.

Ver también:: QwtPicker::setSelectionFlags(), QwtPicker::selectionFlags()

Valores de enumeraciones:

NoSelection
PointSelection
RectSelection
PolygonSelection

Documentación del constructor y destructor

QwtPicker::QwtPicker ( QWidget * parent ) [explicit]

Constructor

Creates an picker that is enabled, but where selection flag is set to NoSelection, rubberband and tracker are disabled.

Parámetros:

parent Parent widget, that will be observed

QwtPicker::QwtPicker	(	int	selectionFlags,
		RubberBand	rubberBand,
		DisplayMode	trackerMode,
		QWidget *	parent
	)		`[explicit]`

Constructor

Parámetros:

selectionFlags	Or'd value of SelectionType, RectSelectionType and SelectionMode
rubberBand	Rubberband style
trackerMode	Tracker mode
parent	Parent widget, that will be observed

QwtPicker::~QwtPicker ( ) [virtual]

Destructor.

Documentación de las funciones miembro

bool QwtPicker::accept ( QwtPolygon & selection ) const [protected, virtual]

Validate and fixup the selection.

Accepts all selections unmodified

Parámetros:

selection Selection to validate and fixup

Devuelve:: true, when accepted, false otherwise

Reimplementado en QwtPlotZoomer.

void QwtPicker::append ( const QPoint & pos ) [protected, virtual]

Append a point to the selection and update rubberband and tracker. The appended() signal is emitted.

Parámetros:

pos	Additional point

Ver también:: isActive, begin(), end(), move(), appended()

Reimplementado en QwtPlotPicker.

void QwtPicker::appended ( const QPoint & pos ) [signal]

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

Parámetros:

pos	Position of the appended point.

Ver también:: append(). moved()

void QwtPicker::begin ( ) [protected, virtual]

Open a selection setting the state to active

Ver también:: isActive, end(), append(), move()

Reimplementado en QwtPlotZoomer.

void QwtPicker::changed ( const QwtPolygon & pa ) [signal]

A signal emitted when the active selection has been changed. This might happen when the observed widget is resized.

Parámetros:

pa	Changed selection

Ver también:: stretchSelection()

void QwtPicker::drawRubberBand ( QPainter * painter ) const [virtual]

Draw a rubberband , depending on rubberBand() and selectionFlags()

Parámetros:

painter Painter, initialized with clip rect

Ver también:: rubberBand(), RubberBand, selectionFlags()

void QwtPicker::drawTracker ( QPainter * painter ) const [virtual]

Draw the tracker

Parámetros:

painter Painter

Ver también:: trackerRect(), trackerText()

bool QwtPicker::end ( bool ok = true ) [protected, virtual]

Close a selection setting the state to inactive.

The selection is validated and maybe fixed by QwtPicker::accept().

Parámetros:

ok	If true, complete the selection and emit a selected signal otherwise discard the selection.

Devuelve:: true if the selection is accepted, false otherwise

Ver también:: isActive, begin(), append(), move(), selected(), accept()

Reimplementado en QwtPlotPicker y QwtPlotZoomer.

bool QwtPicker::eventFilter	(	QObject *	o,
		QEvent *	e
	)		`[virtual]`

Event filter.

When isEnabled() == true all events of the observed widget are filtered. Mouse and keyboard events are translated into widgetMouse- and widgetKey- and widgetWheel-events. Paint and Resize events are handled to keep rubberband and tracker up to date.

Ver también:: event(), widgetMousePressEvent(), widgetMouseReleaseEvent(), widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(), widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()

Reimplementado de QObject.

bool QwtPicker::isActive ( ) const

A picker is active between begin() and end().

Devuelve:: true if the selection is active.

bool QwtPicker::isEnabled ( ) const

void QwtPicker::move ( const QPoint & pos ) [protected, virtual]

Move the last point of the selection The moved() signal is emitted.

Parámetros:

pos	New position

Ver también:: isActive, begin(), end(), append()

Reimplementado en QwtPlotPicker.

void QwtPicker::moved ( const QPoint & pos ) [signal]

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

Parámetros:

pos	Position of the moved last point of the selection.

Ver también:: move(), appended()

QWidget * QwtPicker::parentWidget ( )

Return the parent widget, where the selection happens.

const QWidget * QwtPicker::parentWidget ( ) const

Return the parent widget, where the selection happens.

QRect QwtPicker::pickRect ( ) const [virtual]

Find the area of the observed widget, where selection might happen.

Devuelve:: QFrame::contentsRect() if it is a QFrame, QWidget::rect() otherwise.

void QwtPicker::reset ( void ) [protected, virtual]

Reset the state machine and terminate (end(false)) the selection

ResizeMode QwtPicker::resizeMode ( ) const

RubberBand QwtPicker::rubberBand ( ) const

QPen QwtPicker::rubberBandPen ( ) const

const QWidget * QwtPicker::rubberBandWidget ( ) const [protected]

void QwtPicker::selected ( const QwtPolygon & pa ) [signal]

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

Parámetros:

pa	Selected points

const QwtPolygon & QwtPicker::selection ( ) const

Return Selected points.

int QwtPicker::selectionFlags ( ) const

void QwtPicker::setEnabled ( bool enabled ) [virtual]

En/disable the picker.

When enabled is true an event filter is installed for the observed widget, otherwise the event filter is removed.

Parámetros:

enabled true or false

Ver también:: isEnabled(), eventFilter()

void QwtPicker::setResizeMode ( ResizeMode mode ) [virtual]

Set the resize mode.

The resize mode controls what to do with the selected points of an active selection when the observed widget is resized.

Stretch means the points are scaled according to the new size, KeepSize means the points remain unchanged.

The default mode is Stretch.

Parámetros:

mode	Resize mode

Ver también:: resizeMode(), ResizeMode

void QwtPicker::setRubberBand ( RubberBand rubberBand ) [virtual]

Set the rubberband style

Parámetros:

rubberBand Rubberband style The default value is NoRubberBand.

Ver también:: rubberBand(), RubberBand, setRubberBandPen()

void QwtPicker::setRubberBandPen ( const QPen & pen ) [virtual]

Set the pen for the rubberband

Parámetros:

pen	Rubberband pen

Ver también:: rubberBandPen(), setRubberBand()

void QwtPicker::setSelectionFlags ( int flags ) [virtual]

Set the selection flags

Parámetros:

flags Or'd value of SelectionType, RectSelectionType and SelectionMode. The default value is NoSelection.

Ver también:: selectionFlags(), SelectionType, RectSelectionType, SelectionMode

Reimplementado en QwtPlotZoomer.

void QwtPicker::setTrackerFont ( const QFont & font ) [virtual]

Set the font for the tracker

Parámetros:

font	Tracker font

Ver también:: trackerFont(), setTrackerMode(), setTrackerPen()

void QwtPicker::setTrackerMode ( DisplayMode mode ) [virtual]

Set the display mode of the tracker.

A tracker displays information about current position of the cursor as a string. The display mode controls if the tracker has to be displayed whenever the observed widget has focus and cursor (AlwaysOn), never (AlwaysOff), or only when the selection is active (ActiveOnly).

Parámetros:

mode	Tracker display mode

Atención:: In case of AlwaysOn, mouseTracking will be enabled for the observed widget.

Ver también:: trackerMode(), DisplayMode

void QwtPicker::setTrackerPen ( const QPen & pen ) [virtual]

Set the pen for the tracker

Parámetros:

pen	Tracker pen

Ver también:: trackerPen(), setTrackerMode(), setTrackerFont()

QwtPickerMachine * QwtPicker::stateMachine ( int flags ) const [protected, virtual]

Create a state machine depending on the selection flags.

PointSelection | ClickSelection
QwtPickerClickPointMachine()
PointSelection | DragSelection
QwtPickerDragPointMachine()
RectSelection | ClickSelection
QwtPickerClickRectMachine()
RectSelection | DragSelection
QwtPickerDragRectMachine()
PolygonSelection
QwtPickerPolygonMachine()

Ver también:: setSelectionFlags()

void QwtPicker::stretchSelection	(	const QSize &	oldSize,
		const QSize &	newSize
	)		`[protected, virtual]`

Scale the selection by the ratios of oldSize and newSize The changed() signal is emitted.

Parámetros:

oldSize	Previous size
newSize	Current size

Ver también:: ResizeMode, setResizeMode(), resizeMode()

QFont QwtPicker::trackerFont ( ) const

DisplayMode QwtPicker::trackerMode ( ) const

QPen QwtPicker::trackerPen ( ) const

QPoint QwtPicker::trackerPosition ( ) const

QRect QwtPicker::trackerRect ( const QFont & font ) const

QwtText QwtPicker::trackerText ( const QPoint & pos ) const [virtual]

Return the label for a position.

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 string conversion is "%d".

Parámetros:

pos Position

Devuelve:: Converted position as string

Reimplementado en QwtPlotPicker.

const QWidget * QwtPicker::trackerWidget ( ) const [protected]

void QwtPicker::transition ( const QEvent * e ) [protected, virtual]

Passes an event to the state machine and executes the resulting commands. Append and Move commands use the current position of the cursor (QCursor::pos()).

Parámetros:

e Event

void QwtPicker::updateDisplay ( ) [protected, virtual]

void QwtPicker::widgetKeyPressEvent ( QKeyEvent * ke ) [protected, virtual]

Handle a key press event for the observed widget.

Selections can be completely done by the keyboard. The arrow keys move the cursor, the abort key aborts a selection. All other keys are handled by the current state machine.