QwtPanner Class Reference

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.
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 panning is enabled.
bool	isOrientationEnabled (Qt::Orientation) const
virtual bool	eventFilter (QObject *, QEvent *) override
	Event filter.

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 *) override
	Paint event.
virtual QBitmap	contentsMask () const
	Calculate a mask for the contents of the panned widget.
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.

Definition at line 35 of file qwt_panner.h.

Constructor & Destructor Documentation

QwtPanner()

QwtPanner::QwtPanner ( QWidget * parent )

explicit

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

Parameters

parent

Parent widget to be panned

Definition at line 87 of file qwt_panner.cpp.

~QwtPanner()

QwtPanner::~QwtPanner ( )

virtual

Destructor.

Definition at line 101 of file qwt_panner.cpp.

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.

Definition at line 297 of file qwt_panner.cpp.

cursor()

const QCursor QwtPanner::cursor

(

)

const

Returns

Cursor that is active while panning

See also

setCursor()

Definition at line 167 of file qwt_panner.cpp.

eventFilter()

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

overridevirtual

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()

Definition at line 330 of file qwt_panner.cpp.

getAbortKey()

void QwtPanner::getAbortKey	(	int &	key,
		Qt::KeyboardModifiers &	modifiers ) const

Get the abort key and modifiers.

Definition at line 140 of file qwt_panner.cpp.

getMouseButton()

void QwtPanner::getMouseButton	(	Qt::MouseButton &	button,
		Qt::KeyboardModifiers &	modifiers ) const

Get mouse button and modifiers used for panning.

Definition at line 118 of file qwt_panner.cpp.

grab()

QPixmap QwtPanner::grab ( ) const

protectedvirtual

Grab the widget into a pixmap.

Returns

Grabbed pixmap

Reimplemented in QwtPlotPanner.

Definition at line 306 of file qwt_panner.cpp.

isEnabled()

bool QwtPanner::isEnabled

(

)

const

Returns

true when enabled, false otherwise

See also

setEnabled, eventFilter()

Definition at line 240 of file qwt_panner.cpp.

isOrientationEnabled()

bool QwtPanner::isOrientationEnabled

(

Qt::Orientation

o

)

const

Returns

True if an orientation is enabled

See also

orientations(), setOrientations()

Definition at line 231 of file qwt_panner.cpp.

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

orientations()

Qt::Orientations QwtPanner::orientations

(

)

const

Return the orientation, where panning is enabled.

Definition at line 222 of file qwt_panner.cpp.

paintEvent()

void QwtPanner::paintEvent ( QPaintEvent * event )

overrideprotectedvirtual

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

Definition at line 253 of file qwt_panner.cpp.

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

Definition at line 132 of file qwt_panner.cpp.

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()

Definition at line 156 of file qwt_panner.cpp.

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()

Definition at line 188 of file qwt_panner.cpp.

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

Definition at line 110 of file qwt_panner.cpp.

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

Definition at line 216 of file qwt_panner.cpp.

widgetKeyPressEvent()

void QwtPanner::widgetKeyPressEvent ( QKeyEvent * keyEvent )

protectedvirtual

Handle a key press event for the observed widget.

Parameters

keyEvent

Key event

See also

eventFilter(), widgetKeyReleaseEvent()

Definition at line 482 of file qwt_panner.cpp.

widgetKeyReleaseEvent()

void QwtPanner::widgetKeyReleaseEvent ( QKeyEvent * keyEvent )

protectedvirtual

Handle a key release event for the observed widget.

Parameters

keyEvent

Key event

See also

eventFilter(), widgetKeyReleaseEvent()

Definition at line 502 of file qwt_panner.cpp.

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()

Definition at line 421 of file qwt_panner.cpp.

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(),

Reimplemented in QwtPolarPanner.

Definition at line 381 of file qwt_panner.cpp.

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(),

Definition at line 449 of file qwt_panner.cpp.