QwtCachePanner provides panning of a widget. More...

#include <qwt_cache_panner.h>

Inheritance diagram for QwtCachePanner:

Classes
class	PrivateData

Signals
void	panned (int dx, int dy)
	Signal emitted, when panning is done.

void	moved (int dx, int dy)
	Signal emitted, while the widget moved, but panning is not finished.

Public Member Functions
	QwtCachePanner (QWidget *parent)
	Creates an panner that is enabled for the left mouse button.

virtual	~QwtCachePanner ()
	Destructor.

void	setEnabled (bool)
	En/disable the panner.

bool	isEnabled () const

void	setMouseButton (Qt::MouseButton, Qt::KeyboardModifiers=Qt::NoModifier)
	Change the mouse button and modifiers used for panning The defaults are Qt::LeftButton and 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)
	Change the abort key The defaults are Qt::Key_Escape and Qt::NoModifiers.

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

void	setCursor (const QCursor &)
	Change the cursor, that is active while panning The default is the cursor of the parent widget.

const QCursor	cursor () const

void	setOrientations (Qt::Orientations)
	Set the orientations, where panning is enabled The default value is in both directions: Qt::Horizontal \| Qt::Vertical.

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

bool	isOrientationEnabled (Qt::Orientation) const

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

Protected Member Functions
virtual void	widgetMousePressEvent (QMouseEvent *)
	Handle a mouse press event for the observed widget.

virtual void	widgetMouseReleaseEvent (QMouseEvent *)
	Handle a mouse release event for the observed widget.

virtual void	widgetMouseMoveEvent (QMouseEvent *)
	Handle a mouse move event for the observed widget.

virtual void	widgetKeyPressEvent (QKeyEvent *)
	Handle a key press event for the observed widget.

virtual void	widgetKeyReleaseEvent (QKeyEvent *)
	Handle a key release event for the observed widget.

virtual void	paintEvent (QPaintEvent *) QWT_OVERRIDE
	Paint event.

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

virtual QPixmap	grab () const
	Grab the widget into a pixmap.

Detailed Description

QwtCachePanner provides panning of a widget.

QwtCachePanner 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.

QwtCachePanner 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

◆ QwtCachePanner()

QwtCachePanner::QwtCachePanner ( QWidget * parent )

explicit

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

Parameters

parent Parent widget to be panned

Member Function Documentation

◆ contentsMask()

QBitmap QwtCachePanner::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 QwtPlotCachePanner.

◆ cursor()

const QCursor QwtCachePanner::cursor ( ) const

Returns: Cursor that is active while panning

See also: setCursor()

◆ eventFilter()

bool QwtCachePanner::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 QwtCachePanner::grab ( ) const

protectedvirtual

Grab the widget into a pixmap.

Returns: Grabbed pixmap

Reimplemented in QwtPlotCachePanner.

◆ isEnabled()

bool QwtCachePanner::isEnabled ( ) const

Returns: true when enabled, false otherwise

See also: setEnabled, eventFilter()

◆ isOrientationEnabled()

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

Returns: True if an orientation is enabled

See also: orientations(), setOrientations()

◆ moved

void QwtCachePanner::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 QwtCachePanner::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 QwtCachePanner::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 QwtCachePanner::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 QwtCachePanner::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 QwtCachePanner::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()

◆ setOrientations()

void QwtCachePanner::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 QwtCachePanner::widgetKeyPressEvent ( QKeyEvent * keyEvent )

protectedvirtual

Handle a key press event for the observed widget.

Parameters

keyEvent Key event

See also: eventFilter(), widgetKeyReleaseEvent()

◆ widgetKeyReleaseEvent()

void QwtCachePanner::widgetKeyReleaseEvent ( QKeyEvent * keyEvent )

protectedvirtual

Handle a key release event for the observed widget.

Parameters

keyEvent Key event

See also: eventFilter(), widgetKeyReleaseEvent()

◆ widgetMouseMoveEvent()

void QwtCachePanner::widgetMouseMoveEvent ( QMouseEvent * mouseEvent )

protectedvirtual

Handle a mouse move event for the observed widget.

Parameters

mouseEvent Mouse event

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

◆ widgetMousePressEvent()

void QwtCachePanner::widgetMousePressEvent ( QMouseEvent * mouseEvent )

protectedvirtual

Handle a mouse press event for the observed widget.

Parameters

mouseEvent Mouse event

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

Reimplemented in QwtPolarCachePanner.

◆ widgetMouseReleaseEvent()

void QwtCachePanner::widgetMouseReleaseEvent ( QMouseEvent * mouseEvent )

protectedvirtual

Handle a mouse release event for the observed widget.

Parameters

mouseEvent Mouse event

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

The documentation for this class was generated from the following files:

/home/runner/work/QWT/QWT/src/qwt_cache_panner.h
/home/runner/work/QWT/QWT/src/qwt_cache_panner.cpp

Classes

Signals

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ QwtCachePanner()

Member Function Documentation

◆ contentsMask()

◆ cursor()

◆ eventFilter()

◆ grab()

◆ isEnabled()

◆ isOrientationEnabled()

◆ moved

◆ paintEvent()

◆ panned

◆ setAbortKey()

◆ setCursor()

◆ setEnabled()

◆ setOrientations()

◆ widgetKeyPressEvent()

◆ widgetKeyReleaseEvent()

◆ widgetMouseMoveEvent()

◆ widgetMousePressEvent()

◆ widgetMouseReleaseEvent()