Extends applets to allow detachable parts. More...

#include <extender.h>

Inheritance diagram for Plasma::Extender:

Public Types
enum	Appearance { NoBorders = 0, BottomUpStacked = 1, TopDownStacked = 2 }
Signals
void	geometryChanged ()
void	itemAttached (Plasma::ExtenderItem *)
void	itemDetached (Plasma::ExtenderItem *)
Public Member Functions
	Extender (Applet *applet)
	~Extender ()
Appearance	appearance () const
Applet *	applet () const
QList< ExtenderItem * >	attachedItems () const
QList< ExtenderItem * >	detachedItems () const
QString	emptyExtenderMessage () const
Q_INVOKABLE ExtenderGroup *	group (const QString &name) const
QList< ExtenderGroup * >	groups () const
Q_INVOKABLE bool	hasItem (const QString &name) const
bool	isEmpty () const
Q_INVOKABLE ExtenderItem *	item (const QString &name) const
QList< ExtenderItem * >	items () const
void	setAppearance (Appearance appearance)
void	setEmptyExtenderMessage (const QString &message)
Protected Member Functions
void	dragEnterEvent (QGraphicsSceneDragDropEvent *event)
void	dragLeaveEvent (QGraphicsSceneDragDropEvent *event)
void	dragMoveEvent (QGraphicsSceneDragDropEvent *event)
void	dropEvent (QGraphicsSceneDragDropEvent *event)
virtual FrameSvg::EnabledBorders	enabledBordersForItem (ExtenderItem *item) const
virtual void	itemAddedEvent (ExtenderItem *item, const QPointF &pos=QPointF(-1,-1))
QVariant	itemChange (GraphicsItemChange change, const QVariant &value)
virtual void	itemHoverEnterEvent (ExtenderItem *item)
virtual void	itemHoverLeaveEvent (ExtenderItem *item)
virtual void	itemHoverMoveEvent (ExtenderItem *item, const QPointF &pos)
virtual void	itemRemovedEvent (ExtenderItem *item)
void	mousePressEvent (QGraphicsSceneMouseEvent *event)
void	resizeEvent (QGraphicsSceneResizeEvent *event)
virtual void	saveState ()
Properties
QList< ExtenderItem * >	attachedItems
QList< ExtenderItem * >	detachedItems
bool	empty
QString	emptyExtenderMessage
QList< ExtenderGroup * >	groups
QList< ExtenderItem * >	items

Detailed Description

Extends applets to allow detachable parts.

An Extender is a widget that visually extends the normal contents of an applet with additional dynamic widgets called ExtenderItems. These ExtenderItems can be detached by the user and dropped either on another Extender or on the canvas directly.

This widget allows using ExtenderItems in your applet. Extender takes care of the presentation of a collection of ExtenderItems and keeps track of ExtenderItems that originate in it.

The default Extender implementation displays extender items in a vertical layout with spacers that appear when dropping an ExtenderItem over it.

If you wish to have a different presentation of extender items, you can choose to subclass Extender and reimplement the extenderItem* events and, optionally, the saveState function.

To use an Extender in you applet, you'll have to instantiate one. A call to extender() in your applet will create an extender on your applet if you haven't got one already. Every applet can contain only one extender. Think of it as a decorator that adds some functionality to applets that require it. Never instantiate an Extender before init() in your applet. This won't work correctly since a scene is required when an Extender is instantiated.

As soon as an Extender is instantiated, ExtenderItems contained previously in this Extender are restored using the initExtenderItem function from the applet the items originally came from. For more information on how this works and how to use ExtenderItems in general, see the ExtenderItem API documentation.

Definition at line 65 of file extender.h.

Member Enumeration Documentation

enum Plasma::Extender::Appearance

Description on how to render the extender's items.

Enumerator:

NoBorders

Draws no borders on the extender's items.

When placed in an applet on the desktop, use this setting and use the standard margins of the applet containing this extender.

BottomUpStacked

Draws no borders on the topmost extenderitem, but draws the left, top and right border on subsequent items.

When margins of the containing dialog are set to 0, except for the top margin, this leads to the 'stacked' look, recommended for extenders of applet's contained in a panel at the bottom of the screen.

TopDownStacked

Draws no borders on the bottom extenderitem, but draws the left, bottom and right border on subsequent items.

When margins of the containing dialog are set to 0, except for the bottom margin, this leads to the 'stacked' look, recommended for extenders of applet's contained in a panel at the top of the screen.

Definition at line 79 of file extender.h.

Constructor & Destructor Documentation

Plasma::Extender::Extender ( Applet * applet ) [explicit]

Creates an extender.

Note that extender expects applet to have a config(), and needs a scene because of that. So you should only instantiate an extender in init() or later, not in an applet's constructor. The constructor also takes care of restoring ExtenderItems that were contained in this extender before, so ExtenderItems are persistent between sessions. Note that a call to extender() in an applet will instantiate an Extender for you if one isn't already associated with your applet.

Parameters:

applet The applet this extender is part of. Null is not allowed here.

Definition at line 89 of file extender.cpp.

Plasma::Extender::~Extender ( )

Definition at line 134 of file extender.cpp.

Member Function Documentation

Extender::Appearance Plasma::Extender::appearance ( ) const

Returns:: the current way of rendering extender items that is used.

Definition at line 340 of file extender.cpp.

Applet * Plasma::Extender::applet ( ) const

Returns:: the Applet this Extender is associated with

Since:: 4.4

Definition at line 359 of file extender.cpp.

QList<ExtenderItem*> Plasma::Extender::attachedItems ( ) const

Returns:: a list of all attached extender items.

QList<ExtenderItem*> Plasma::Extender::detachedItems ( ) const

Returns:: a list of all detached extender items.

void Plasma::Extender::dragEnterEvent ( QGraphicsSceneDragDropEvent * event ) [protected]

Reimplemented from QGraphicsWidget.

Definition at line 400 of file extender.cpp.

void Plasma::Extender::dragLeaveEvent ( QGraphicsSceneDragDropEvent * event ) [protected]

Reimplemented from QGraphicsWidget.

Definition at line 433 of file extender.cpp.

void Plasma::Extender::dragMoveEvent ( QGraphicsSceneDragDropEvent * event ) [protected]

Reimplemented from QGraphicsWidget.

Definition at line 419 of file extender.cpp.

void Plasma::Extender::dropEvent ( QGraphicsSceneDragDropEvent * event ) [protected]

Reimplemented from QGraphicsWidget.

Definition at line 477 of file extender.cpp.

QString Plasma::Extender::emptyExtenderMessage ( ) const

Returns:: The text to be shown whenever the applet's layout is empty.

FrameSvg::EnabledBorders Plasma::Extender::enabledBordersForItem ( ExtenderItem * item ) const [protected, virtual]

This function get's called on every item to determine which background border's to render.

Parameters:

item	the item for which its position or extender has changed.

Returns:: the borders that have to be enabled on its background.

Definition at line 606 of file extender.cpp.

void Plasma::Extender::geometryChanged ( ) [signal]

Fires when an extender's preferred size changes.

ExtenderGroup * Plasma::Extender::group ( const QString & name ) const

Extra convenience function for obtaining groups specified by name.

This will avoid needed to call item and casting to ExtenderGroup, which is otherwise quite common.

Returns:: the requested group

Since:: 4.3

Definition at line 294 of file extender.cpp.

QList<ExtenderGroup*> Plasma::Extender::groups ( ) const

Returns:: a list of groups that are contained in this extender.

Since:: 4.3

bool Plasma::Extender::hasItem ( const QString & name ) const

This function can be used for easily determining if a certain item is already displayed in an extender item somewhere, so your applet doesn't duplicate this item.

This is needed because ExtenderItems are persistent, so you can't blindly add new extender items in all cases.

Returns:: whether or not this item already exists.

Since:: 4.3

Definition at line 299 of file extender.cpp.

bool Plasma::Extender::isEmpty ( ) const

Returns:: true if the Extender is visually empty (though it may have items such as empty groups or detached items associatd with it)

Definition at line 924 of file extender.cpp.

ExtenderItem * Plasma::Extender::item ( const QString & name ) const

This function can be used for obtaining the extender item specified by name.

For checking whether or not an item already exists, you should use hasItem instead: while plasma is starting up, not all detached items might have been instantiated yet. hasItem returns true even if the requested item isn't instantiated yet.

Returns:: the requested item

Definition at line 242 of file extender.cpp.

void Plasma::Extender::itemAddedEvent	(	ExtenderItem *	item,
		const QPointF &	pos = `QPointF(-1, -1)`
	)		`[protected, virtual]`

Get's called after an item has been added to this extender.

The bookkeeping has already been done when this function get's called. The only thing left to do is put it somewhere appropriate. The default implementation adds the extenderItem to the appropriate place in a QGraphicsLinearLayout.

Parameters:

item	The item that has just been added.
pos	The location the item has been dropped in local coordinates.

Definition at line 491 of file extender.cpp.

void Plasma::Extender::itemAttached ( Plasma::ExtenderItem * ) [signal]

Fires when an extender item is added to this extender.

QVariant Plasma::Extender::itemChange	(	GraphicsItemChange	change,
		const QVariant &	value
	)		`[protected]`

Reimplemented from QGraphicsWidget.

Definition at line 371 of file extender.cpp.

void Plasma::Extender::itemDetached ( Plasma::ExtenderItem * ) [signal]

Fires when an extender item is removed from this extender.

void Plasma::Extender::itemHoverEnterEvent ( ExtenderItem * item ) [protected, virtual]

Get's called when an ExtenderItem that get's dragged enters this extender.

Default implementation does nothing.

Definition at line 553 of file extender.cpp.

void Plasma::Extender::itemHoverLeaveEvent ( ExtenderItem * item ) [protected, virtual]

Get's called when an ExtenderItem that was previously hovering over this extender moves away from this extender.

The default implementation removes any spacer from the layout.

Definition at line 590 of file extender.cpp.

void Plasma::Extender::itemHoverMoveEvent	(	ExtenderItem *	item,
		const QPointF &	pos
	)		`[protected, virtual]`

Gets called when an ExtenderItem is hovering over this extender.

Implement this function to give some visual feedback about what will happen when the mouse button is released at that position. The default implementation shows a spacer at the appropriate location in the layout.

Parameters:

item	The item that's hovering over this extender. Most useful for obtaining the size of the spacer.
pos	The location the item is hovering.

Definition at line 558 of file extender.cpp.

void Plasma::Extender::itemRemovedEvent ( ExtenderItem * item ) [protected, virtual]

Get's called after an item has been removed from this extender.

All bookkeeping has already been done when this function get's called.

Parameters:

item	The item that has just been removed.

Definition at line 526 of file extender.cpp.

QList<ExtenderItem*> Plasma::Extender::items ( ) const

Returns:: a list of all extender items (attached AND detached) where the source applet is this applet.

void Plasma::Extender::mousePressEvent ( QGraphicsSceneMouseEvent * event ) [protected]

Reimplemented from QGraphicsWidget.

Definition at line 386 of file extender.cpp.

void Plasma::Extender::resizeEvent ( QGraphicsSceneResizeEvent * event ) [protected]

Reimplemented from QGraphicsWidget.

Definition at line 380 of file extender.cpp.

void Plasma::Extender::saveState ( ) [protected, virtual]

This function get's called for every extender when plasma exits.

Implement this function to store the current state of this extender (position in a layout for example), so this can be restored when applet starts again. The default implementation stores the y coordinate of every extender item in the config field extenderItemPos.

Definition at line 364 of file extender.cpp.

void Plasma::Extender::setAppearance ( Appearance appearance )

Use this function to instruct the extender on how to render its items.

Usually you will want to call this function in your applet's constraintsEvent, allthough this is already done for you when using PopupApplet as base class for your applet. Defaults to NoBorders.

Parameters:

appearance the way this extender should look.

Definition at line 330 of file extender.cpp.

void Plasma::Extender::setEmptyExtenderMessage ( const QString & message )

Parameters:

message The text to be shown whenever the applet's extender is empty.

Definition at line 164 of file extender.cpp.

Property Documentation

QList< ExtenderItem * > Plasma::Extender::attachedItems [read]

Definition at line 70 of file extender.h.

QList< ExtenderItem * > Plasma::Extender::detachedItems [read]

Definition at line 71 of file extender.h.

bool Plasma::Extender::empty [read]

Definition at line 73 of file extender.h.

QString Plasma::Extender::emptyExtenderMessage [read, write]

Definition at line 68 of file extender.h.

QList< ExtenderGroup * > Plasma::Extender::groups [read]

Definition at line 72 of file extender.h.

QList< ExtenderItem * > Plasma::Extender::items [read]

Definition at line 69 of file extender.h.

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

Plasma

Plasma::Extender Class Reference

Public Types

Signals

Public Member Functions

Protected Member Functions

Properties

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Property Documentation

Plasma

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