QwtPanner provides panning of a widget. More...

#include <qwt_panner.h>

Inheritance diagram for QwtPanner:

Signals
void	panned (int dx, int dy)

void	moved (int dx, int dy)

Public Member Functions
	QwtPanner (QWidget *parent)

virtual	~QwtPanner ()
	Destructor.

void	setEnabled (bool)
	En/disable the panner. More...

bool	isEnabled () const

void	setMouseButton (Qt::MouseButton, Qt::KeyboardModifiers=Qt::NoModifier)

void	getMouseButton (Qt::MouseButton &button, Qt::KeyboardModifiers &) const
	Get mouse button and modifiers used for panning.

void	setAbortKey (int key, Qt::KeyboardModifiers=Qt::NoModifier)

void	getAbortKey (int &key, Qt::KeyboardModifiers &) const
	Get the abort key and modifiers.

void	setCursor (const QCursor &)

const QCursor	cursor () const

void	setOrientations (Qt::Orientations)

Qt::Orientations	orientations () const
	Return the orientation, where paning is enabled.

bool	isOrientationEnabled (Qt::Orientation) const

virtual bool	eventFilter (QObject , QEvent )
	Event filter. More...

Protected Member Functions
virtual void	widgetMousePressEvent (QMouseEvent *)

virtual void	widgetMouseReleaseEvent (QMouseEvent *)

virtual void	widgetMouseMoveEvent (QMouseEvent *)

virtual void	widgetKeyPressEvent (QKeyEvent *)

virtual void	widgetKeyReleaseEvent (QKeyEvent *)

virtual void	paintEvent (QPaintEvent *)
	Paint event. More...

virtual QBitmap	contentsMask () const
	Calculate a mask for the contents of the panned widget. More...

virtual QPixmap	grab () const

Detailed Description

QwtPanner provides panning of a widget.

QwtPanner grabs the contents of a widget, that can be dragged in all directions. The offset between the start and the end position is emitted by the panned signal.

QwtPanner grabs the content of the widget into a pixmap and moves the pixmap around, without initiating any repaint events for the widget. Areas, that are not part of content are not painted while panning. This makes panning fast enough for widgets, where repaints are too slow for mouse movements.

For widgets, where repaints are very fast it might be better to implement panning manually by mapping mouse events into paint events.

Constructor & Destructor Documentation

◆ QwtPanner()

QwtPanner::QwtPanner ( QWidget * parent )

Creates an panner that is enabled for the left mouse button.

Parameters

parent Parent widget to be panned

Member Function Documentation

◆ contentsMask()

QBitmap QwtPanner::contentsMask ( ) const

protectedvirtual

Calculate a mask for the contents of the panned widget.

Sometimes only parts of the contents of a widget should be panned. F.e. for a widget with a styled background with rounded borders only the area inside of the border should be panned.

Returns: An empty bitmap, indicating no mask

Reimplemented in QwtPlotPanner.

◆ cursor()

const QCursor QwtPanner::cursor ( ) const

Returns: Cursor that is active while panning

See also: setCursor()

◆ eventFilter()

bool QwtPanner::eventFilter	(	QObject *	object,
		QEvent *	event
	)

virtual

Event filter.

When isEnabled() is true mouse events of the observed widget are filtered.

Parameters

object	Object to be filtered
event	Event

Returns: Always false, beside for paint events for the parent widget.

See also: widgetMousePressEvent(), widgetMouseReleaseEvent(), widgetMouseMoveEvent()

◆ grab()

QPixmap QwtPanner::grab ( ) const

protectedvirtual

Grab the widget into a pixmap.

Returns: Grabbed pixmap

Reimplemented in QwtPlotPanner.

◆ isEnabled()

bool QwtPanner::isEnabled ( ) const

Returns: true when enabled, false otherwise

See also: setEnabled, eventFilter()

◆ isOrientationEnabled()

bool QwtPanner::isOrientationEnabled ( Qt::Orientation o ) const

Returns: True if an orientation is enabled

See also: orientations(), setOrientations()

◆ moved

void QwtPanner::moved	(	int	dx,
		int	dy
	)

signal

Signal emitted, while the widget moved, but panning is not finished.

Parameters

dx	Offset in horizontal direction
dy	Offset in vertical direction

◆ paintEvent()

void QwtPanner::paintEvent ( QPaintEvent * event )

protectedvirtual

Paint event.

Repaint the grabbed pixmap on its current position and fill the empty spaces by the background of the parent widget.

Parameters

event Paint event

◆ panned

void QwtPanner::panned	(	int	dx,
		int	dy
	)

signal

Signal emitted, when panning is done

Parameters

dx	Offset in horizontal direction
dy	Offset in vertical direction

◆ setAbortKey()

void QwtPanner::setAbortKey	(	int	key,
		Qt::KeyboardModifiers	modifiers = `Qt::NoModifier`
	)

Change the abort key The defaults are Qt::Key_Escape and Qt::NoModifiers

Parameters

key	Key ( See Qt::Keycode )
modifiers	Keyboard modifiers

◆ setCursor()

void QwtPanner::setCursor ( const QCursor & cursor )

Change the cursor, that is active while panning The default is the cursor of the parent widget.

Parameters

cursor New cursor

See also: setCursor()

◆ setEnabled()

void QwtPanner::setEnabled ( bool on )

En/disable the panner.

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

Parameters

on	true or false

See also: isEnabled(), eventFilter()

◆ setMouseButton()

void QwtPanner::setMouseButton	(	Qt::MouseButton	button,
		Qt::KeyboardModifiers	modifiers = `Qt::NoModifier`
	)

Change the mouse button and modifiers used for panning The defaults are Qt::LeftButton and Qt::NoModifier

◆ setOrientations()

void QwtPanner::setOrientations ( Qt::Orientations o )

Set the orientations, where panning is enabled The default value is in both directions: Qt::Horizontal | Qt::Vertical

/param o Orientation

◆ widgetKeyPressEvent()

void QwtPanner::widgetKeyPressEvent ( QKeyEvent * keyEvent )

protectedvirtual

Handle a key press event for the observed widget.

Parameters

keyEvent Key event

See also: eventFilter(), widgetKeyReleaseEvent()

◆ widgetKeyReleaseEvent()

void QwtPanner::widgetKeyReleaseEvent ( QKeyEvent * keyEvent )

protectedvirtual

Handle a key release event for the observed widget.

Parameters

keyEvent Key event

See also: eventFilter(), widgetKeyReleaseEvent()

◆ widgetMouseMoveEvent()

void QwtPanner::widgetMouseMoveEvent ( QMouseEvent * mouseEvent )

protectedvirtual

Handle a mouse move event for the observed widget.

Parameters

mouseEvent Mouse event

See also: eventFilter(), widgetMousePressEvent(), widgetMouseReleaseEvent()

◆ widgetMousePressEvent()

void QwtPanner::widgetMousePressEvent ( QMouseEvent * mouseEvent )

protectedvirtual

Handle a mouse press event for the observed widget.

Parameters

mouseEvent Mouse event

See also: eventFilter(), widgetMouseReleaseEvent(), widgetMouseMoveEvent(),

◆ widgetMouseReleaseEvent()

void QwtPanner::widgetMouseReleaseEvent ( QMouseEvent * mouseEvent )

protectedvirtual

Handle a mouse release event for the observed widget.

Parameters

mouseEvent Mouse event

See also: eventFilter(), widgetMousePressEvent(), widgetMouseMoveEvent(),

Signals

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ QwtPanner()

Member Function Documentation

◆ contentsMask()

◆ cursor()

◆ eventFilter()

◆ grab()

◆ isEnabled()

◆ isOrientationEnabled()

◆ moved

◆ paintEvent()

◆ panned

◆ setAbortKey()

◆ setCursor()

◆ setEnabled()

◆ setMouseButton()

◆ setOrientations()

◆ widgetKeyPressEvent()

◆ widgetKeyReleaseEvent()

◆ widgetMouseMoveEvent()

◆ widgetMousePressEvent()

◆ widgetMouseReleaseEvent()