Handler for modifying one or more QWidget and/or QwtPlotMarker with mouse or keyboard. More...

#include <SelectionMoveResizer.h>

Public Slots
void	add (Legend *target)
	Add target to the list of items to be moved/resized together.
void	add (ArrowMarker *target)
	Add target to the list of items to be moved/resized together.
void	add (ImageMarker *target)
	Add target to the list of items to be moved/resized together.
void	add (QWidget *target)
	Add target to the list of items to be moved/resized together.
void	recalcBoundingRect ()
	Calculate d_bounding_rect based on the bounding rectangles of all targets.
int	removeAll (Legend *target)
	Remove target from the list of items to be moved/resized together and returns the number of occurences removed.
int	removeAll (ArrowMarker *target)
	Remove target from the list of items to be moved/resized together and returns the number of occurences removed.
int	removeAll (ImageMarker *target)
	Remove target from the list of items to be moved/resized together and returns the number of occurences removed.
int	removeAll (QWidget *target)
	Remove target from the list of items to be moved/resized together and returns the number of occurences removed.

Signals
void	targetsChanged ()
	Emitted when the targets are modified (moved or resized).

Public Member Functions
bool	contains (QWidget *w) const
	Returns true if w is one of targets, false else.
bool	contains (Legend *m) const
	Returns true if m is one of targets, false else.
bool	contains (ArrowMarker *m) const
	Returns true if m is one of targets, false else.
bool	contains (ImageMarker *m) const
	Returns true if m is one of targets, false else.
virtual bool	eventFilter (QObject o, QEvent e)
	React on geometry changes of parent and targets.
	SelectionMoveResizer (Legend *target)
	Construct a new MoveResizer with the given marker as the only target.
	SelectionMoveResizer (ArrowMarker *target)
	Construct a new MoveResizer with the given marker as the only target.
	SelectionMoveResizer (ImageMarker *target)
	Construct a new MoveResizer with the given marker as the only target.
	SelectionMoveResizer (QWidget *target)
	Construct a new MoveResizer with the given widget as the only target.
	~SelectionMoveResizer ()
	Clean up after myself.

Protected Types
enum	Operation { None = -2, Move, Resize_N, Resize_NE, Resize_E, Resize_SE, Resize_S, Resize_SW, Resize_W, Resize_NW }
	Available modes of operation. More...

Protected Member Functions
virtual void	keyPressEvent (QKeyEvent *e)
	Allow keyboard-based moving of the selection.
virtual void	mouseDoubleClickEvent (QMouseEvent *e)
	Ignore double-clicks so that they can be used by my parent.
virtual void	mouseMoveEvent (QMouseEvent *e)
	Mouse movements need to be monitored for updating the frame during operation.
virtual void	mousePressEvent (QMouseEvent *e)
	Mouse button presses start move/resize operations.
virtual void	mouseReleaseEvent (QMouseEvent *e)
	Mouse releases end the current operation and apply it to the targets.
virtual void	paintEvent (QPaintEvent *e)
	Draw frame and resize handlers.

Private Slots
void	removeWidget (QObject *w)
	A non-typesafe version of remvoveAll(QWidget*) needed for QObject::destroyed().

Private Member Functions
QRect	boundingRectOf (QwtPlotMarker *target) const
	Get the bounding rectangle of a marker in paint coordinates.
void	init ()
	The initialization part common to all constructors.
QRect	operateOn (const QRect in)
	Apply operation specified by d_op and d_op_dp to in.
void	operateOnTargets ()
	Apply operation specified by d_op and d_op_dp to all targets.

Static Private Member Functions
static const QRect	handlerRect (QRect rect, Operation op)
	Return one of the rectangles to be filled for starting resize operations.

Private Attributes
QRect	d_bounding_rect
	Bounding rectangle of all targets taken together, in drawing coordinates.
QList< ImageMarker * >	d_image_markers
	Target markers I'm handling.
QList< Legend * >	d_legend_markers
	Target markers I'm handling.
QList< ArrowMarker * >	d_line_markers
	Target markers I'm handling.
Operation	d_op
	The type of operation currently in progress.
QPoint	d_op_dp
	Difference between current and start position during operation.
QPoint	d_op_start
	Mouse position where an operation started; (-1,-1) means started by keyboard.
QList< QWidget * >	d_widgets
	Target widgets I'm handling.

Static Private Attributes
static const int	handler_size = 10
	Size of resize handle in pixels.

Detailed Description

Handler for modifying one or more QWidget and/or QwtPlotMarker with mouse or keyboard.

During initialization, the SelectionMoveResizer adds itself as a new child widget to the target's parentWidget() or QwtPlotCanvas. Because Qt 4.1 and beyond propagate a widget's background by default, frame and resize handlers can then simply be drawn on top of the usual content of the parent. Also, the SelectionMoveResizer gets to see mouse and key events first without the need to filter events for its parent. Note however that the latter must still be done in order to catch geometry changes and stay the same size as the parent.

At every point in time, the list of managed targets must be non-empty, so that the SelectionMoveResizer has a well-defined bounding rectangle. When there are no more selected targets, it deletes itself, so references to a SelectionMoveResizer should be maintained by QPointer and checked for validity before use.

QWidget targets are automatically removed when they are deleted (possibly also deleting the SelectionMoveResizer), using the QObject::destroyed() signal. With QwtPlotMarker, this is not possible since it's not a QObject. Thus, care has to be taken to remove them before or shortly after deletion, lest the wrath of Segmentation Fault shall come upon you.

Design Ideas

Keep as much of the select/move/resize code as possible in one class to ease maintanance.
Use the same class for layer and marker handling to avoid duplicating code. Good for bugfixing and for maintaining a consistent user interface.
Keep this class generic so that it can later be used for other parents (than MultiLayer's canvas QWidget and Plot's QwtPlotCanvas) and/or targets (e.g. new QwtPlotMarker subclasses) with little to no modifications.
Differentiate between move/resize, which are generic operations, and editing (like moving the endpoints of a ArrowMarker), which requires detailed knowledge about the target. This way, new types of markers or MultiLayer children support moving/resizing without further work. Editing can then be implemented in the targets themselves, as shown in ArrowMarker.

Future Plans

See the documentation of ImageMarker for ideas about replacing QwtPlotMarker with a new QwtPlotItem subclass. For SelectionMoveResizer this would mean supporting new enrichments without modifications and being able to automatically remove them upon deletion (if the new class inherits QObject). Not to mention that the implementation would be a lot cleaner if we would only have to handle two target classes instead of four.

Think about turning SelectionMoveResizer into an input method for general affine transformations. Particularly, this would add rotation, flipping and shearing. Markers could implement this using QPainter's coordinate transformations. Definitely not a priority, though.

Member Enumeration Documentation

enum SelectionMoveResizer::Operation

protected

Available modes of operation.

Enumerator:

None
Move
Resize_N
Resize_NE
Resize_E
Resize_SE
Resize_S
Resize_SW
Resize_W
Resize_NW

Constructor & Destructor Documentation

SelectionMoveResizer::SelectionMoveResizer ( Legend * target )

Construct a new MoveResizer with the given marker as the only target.

References add(), and init().

SelectionMoveResizer::SelectionMoveResizer ( ArrowMarker * target )

Construct a new MoveResizer with the given marker as the only target.

References add(), and init().

SelectionMoveResizer::SelectionMoveResizer ( ImageMarker * target )

Construct a new MoveResizer with the given marker as the only target.

References add(), and init().

SelectionMoveResizer::SelectionMoveResizer ( QWidget * target )

Construct a new MoveResizer with the given widget as the only target.

References add(), and init().

SelectionMoveResizer::~SelectionMoveResizer ( )

Clean up after myself.

Member Function Documentation

void SelectionMoveResizer::add ( Legend * target )

slot

Add target to the list of items to be moved/resized together.

References boundingRectOf(), d_bounding_rect, and d_legend_markers.

Referenced by SelectionMoveResizer().

void SelectionMoveResizer::add ( ArrowMarker * target )

slot

Add target to the list of items to be moved/resized together.

References boundingRectOf(), d_bounding_rect, and d_line_markers.

void SelectionMoveResizer::add ( ImageMarker * target )

slot

Add target to the list of items to be moved/resized together.

References boundingRectOf(), d_bounding_rect, and d_image_markers.

void SelectionMoveResizer::add ( QWidget * target )

slot

Add target to the list of items to be moved/resized together.

References d_bounding_rect, d_widgets, and removeWidget().

QRect SelectionMoveResizer::boundingRectOf ( QwtPlotMarker * target ) const

private

Get the bounding rectangle of a marker in paint coordinates.

Referenced by add(), and recalcBoundingRect().

bool SelectionMoveResizer::contains ( QWidget * w ) const

inline

Returns true if w is one of targets, false else.

References d_widgets.

Referenced by mouseMoveEvent(), and mousePressEvent().

bool SelectionMoveResizer::contains ( Legend * m ) const

inline

Returns true if m is one of targets, false else.

References d_legend_markers.

bool SelectionMoveResizer::contains ( ArrowMarker * m ) const

inline

Returns true if m is one of targets, false else.

References d_line_markers.

bool SelectionMoveResizer::contains ( ImageMarker * m ) const

inline

Returns true if m is one of targets, false else.

References d_image_markers.

bool SelectionMoveResizer::eventFilter	(	QObject *	o,
		QEvent *	e
	)

virtual

React on geometry changes of parent and targets.

References recalcBoundingRect().

const QRect SelectionMoveResizer::handlerRect	(	QRect	rect,
		Operation	op
	)

staticprivate

Return one of the rectangles to be filled for starting resize operations.

References handler_size, Resize_E, Resize_N, Resize_NE, Resize_NW, Resize_S, Resize_SE, Resize_SW, and Resize_W.

Referenced by mouseMoveEvent(), mousePressEvent(), and paintEvent().

void SelectionMoveResizer::init ( )

private

The initialization part common to all constructors.

References d_bounding_rect, d_op, d_op_dp, d_op_start, and None.

Referenced by SelectionMoveResizer().

void SelectionMoveResizer::keyPressEvent ( QKeyEvent * e )

protectedvirtual

Allow keyboard-based moving of the selection.

Unused keys are passed on to the parent.

References d_op, d_op_dp, d_op_start, Move, None, and operateOnTargets().

void SelectionMoveResizer::mouseDoubleClickEvent ( QMouseEvent * e )

protectedvirtual

Ignore double-clicks so that they can be used by my parent.

void SelectionMoveResizer::mouseMoveEvent ( QMouseEvent * e )

protectedvirtual

Mouse movements need to be monitored for updating the frame during operation.

When no operation is in progress, the mouse cursor is updated based on its position before the event is passed on to the parent.

References contains(), d_bounding_rect, d_op, d_op_dp, d_op_start, handlerRect(), Move, None, Resize_E, Resize_N, Resize_NE, Resize_NW, Resize_S, Resize_SE, Resize_SW, and Resize_W.

void SelectionMoveResizer::mousePressEvent ( QMouseEvent * e )

protectedvirtual

Mouse button presses start move/resize operations.

Clicks outside of d_bounding_rect or with anything else than the left button are propagated to the parent as usual.

References contains(), d_bounding_rect, d_op, d_op_start, handlerRect(), and Move.

void SelectionMoveResizer::mouseReleaseEvent ( QMouseEvent * e )

protectedvirtual

Mouse releases end the current operation and apply it to the targets.

When there is no operation in progress, the event is passed on to the parent.

References d_op, d_op_dp, d_op_start, None, and operateOnTargets().

QRect SelectionMoveResizer::operateOn ( const QRect in )

private

Apply operation specified by d_op and d_op_dp to in.

References d_bounding_rect, d_op, d_op_dp, Move, Resize_E, Resize_N, Resize_NE, Resize_NW, Resize_S, Resize_SE, Resize_SW, and Resize_W.

Referenced by operateOnTargets(), and paintEvent().

void SelectionMoveResizer::operateOnTargets ( )

private

Apply operation specified by d_op and d_op_dp to all targets.

References d_image_markers, d_legend_markers, d_line_markers, d_op_dp, d_op_start, d_widgets, ArrowMarker::endPoint(), Legend::font(), operateOn(), Graph::plotWidget(), recalcBoundingRect(), Legend::rect(), ImageMarker::rect(), ArrowMarker::rect(), ArrowMarker::setEndPoint(), Legend::setFont(), Legend::setOrigin(), ImageMarker::setOrigin(), ImageMarker::setSize(), ArrowMarker::setStartPoint(), ArrowMarker::startPoint(), targetsChanged(), and Legend::text().

Referenced by keyPressEvent(), and mouseReleaseEvent().

void SelectionMoveResizer::paintEvent ( QPaintEvent * e )

protectedvirtual

Draw frame and resize handlers.

Besides managing resize operations, this also provides a visual feedback on the selection state.

References d_bounding_rect, handlerRect(), and operateOn().

void SelectionMoveResizer::recalcBoundingRect ( )

slot

Calculate d_bounding_rect based on the bounding rectangles of all targets.

References boundingRectOf(), d_bounding_rect, d_image_markers, d_legend_markers, d_line_markers, and d_widgets.

Referenced by eventFilter(), operateOnTargets(), and removeAll().

int SelectionMoveResizer::removeAll ( Legend * target )

slot

Remove target from the list of items to be moved/resized together and returns the number of occurences removed.

References d_image_markers, d_legend_markers, d_line_markers, d_widgets, and recalcBoundingRect().

Referenced by removeWidget().

int SelectionMoveResizer::removeAll ( ArrowMarker * target )

slot

Remove target from the list of items to be moved/resized together and returns the number of occurences removed.

References d_image_markers, d_legend_markers, d_line_markers, d_widgets, and recalcBoundingRect().

int SelectionMoveResizer::removeAll ( ImageMarker * target )

slot

Remove target from the list of items to be moved/resized together and returns the number of occurences removed.

References d_image_markers, d_legend_markers, d_line_markers, d_widgets, and recalcBoundingRect().

int SelectionMoveResizer::removeAll ( QWidget * target )

slot

Remove target from the list of items to be moved/resized together and returns the number of occurences removed.

References d_image_markers, d_legend_markers, d_line_markers, d_widgets, and recalcBoundingRect().

void SelectionMoveResizer::removeWidget ( QObject * w )

inlineprivateslot

A non-typesafe version of remvoveAll(QWidget*) needed for QObject::destroyed().

References removeAll().

Referenced by add().

void SelectionMoveResizer::targetsChanged ( )

signal

Emitted when the targets are modified (moved or resized).

Referenced by operateOnTargets().

Member Data Documentation

QRect SelectionMoveResizer::d_bounding_rect

private

Bounding rectangle of all targets taken together, in drawing coordinates.

Referenced by add(), init(), mouseMoveEvent(), mousePressEvent(), operateOn(), paintEvent(), and recalcBoundingRect().

QList<ImageMarker *> SelectionMoveResizer::d_image_markers

private

Target markers I'm handling.

Referenced by add(), contains(), operateOnTargets(), recalcBoundingRect(), and removeAll().

QList<Legend *> SelectionMoveResizer::d_legend_markers

private

Target markers I'm handling.

Referenced by add(), contains(), operateOnTargets(), recalcBoundingRect(), and removeAll().

QList<ArrowMarker *> SelectionMoveResizer::d_line_markers

private

Target markers I'm handling.

Referenced by add(), contains(), operateOnTargets(), recalcBoundingRect(), and removeAll().

Operation SelectionMoveResizer::d_op

private

The type of operation currently in progress.

Referenced by init(), keyPressEvent(), mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), and operateOn().

QPoint SelectionMoveResizer::d_op_dp

private

Difference between current and start position during operation.

Referenced by init(), keyPressEvent(), mouseMoveEvent(), mouseReleaseEvent(), operateOn(), and operateOnTargets().

QPoint SelectionMoveResizer::d_op_start

private

Mouse position where an operation started; (-1,-1) means started by keyboard.

Referenced by init(), keyPressEvent(), mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), and operateOnTargets().

QList<QWidget *> SelectionMoveResizer::d_widgets

private

Target widgets I'm handling.

Referenced by add(), contains(), operateOnTargets(), recalcBoundingRect(), and removeAll().

const int SelectionMoveResizer::handler_size = 10

staticprivate

Size of resize handle in pixels.

Referenced by handlerRect().

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

scidavis/src/SelectionMoveResizer.h
scidavis/src/SelectionMoveResizer.cpp

Public Slots

Signals

Public Member Functions

Protected Types

Protected Member Functions

Private Slots

Private Member Functions

Static Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Design Ideas

Future Plans

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation