plasma-framework/applet.h

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/*
* Copyright 2006-2007 by Aaron Seigo <aseigo@kde.org>
* Copyright 2007 by Riccardo Iaconelli <riccardo@kde.org>
* Copyright 2008 by Ménard Alexis <darktears31@gmail.com>
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details
*
* You should have received a copy of the GNU Library General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef PLASMA_APPLET_H
#define PLASMA_APPLET_H
#include <QtGui/QGraphicsItem>
#include <QtGui/QGraphicsWidget>
#include <QtGui/QIcon>
#include <kconfiggroup.h>
#include <kgenericfactory.h>
#include <kplugininfo.h>
#include <kshortcut.h>
#include <plasma/configloader.h>
#include <plasma/packagestructure.h>
#include <plasma/plasma.h>
#include <plasma/animator.h>
#include <plasma/version.h>
class QWidget;
class KConfigDialog;
class QGraphicsView;
class KActionCollection;
namespace Plasma
{
class AppletPrivate;
class Containment;
class Context;
class DataEngine;
class Extender;
class ExtenderItem;
class Package;
/**
* @class Applet plasma/applet.h <Plasma/Applet>
*
* @short The base Applet class
*
* Applet provides several important roles for add-ons widgets in Plasma.
*
* First, it is the base class for the plugin system and therefore is the
* interface to applets for host applications. It also handles the life time
* management of data engines (e.g. all data engines accessed via
* Applet::dataEngine(const QString&) are properly deref'd on Applet
* destruction), background painting (allowing for consistent and complex
* look and feel in just one line of code for applets), loading and starting
* of scripting support for each applet, providing access to the associated
* plasmoid package (if any) and access to configuration data.
*
* See techbase.kde.org for tutorial on writing Applets using this class.
*/
class PLASMA_EXPORT Applet : public QGraphicsWidget
{
Q_OBJECT
Q_PROPERTY(bool hasConfigurationInterface READ hasConfigurationInterface)
Q_PROPERTY(QString name READ name)
Q_PROPERTY(QString category READ category)
Q_PROPERTY(ImmutabilityType immutability READ immutability WRITE setImmutability)
Q_PROPERTY(bool hasFailedToLaunch READ hasFailedToLaunch WRITE setFailedToLaunch)
Q_PROPERTY(bool isBusy READ isBusy WRITE setBusy)
Q_PROPERTY(bool configurationRequired READ configurationRequired WRITE setConfigurationRequired)
Q_PROPERTY(QRectF geometry READ geometry WRITE setGeometry)
Q_PROPERTY(bool shouldConserveResources READ shouldConserveResources)
public:
typedef QList<Applet*> List;
typedef QHash<QString, Applet*> Dict;
/**
* Description on how draw a background for the applet
*/
enum BackgroundHint {
NoBackground = 0, /**< Not drawing a background under the
applet, the applet has its own implementation */
StandardBackground = 1, /**< The standard background from the theme is drawn */
TranslucentBackground = 2, /**< An alternate version of the background is drawn,
usually more translucent */
DefaultBackground = StandardBackground /**< Default settings:
both standard background */
};
Q_DECLARE_FLAGS(BackgroundHints, BackgroundHint)
~Applet();
/**
* @return a package structure representing a Theme
*/
static PackageStructure::Ptr packageStructure();
/**
* @return the id of this applet
*/
uint id() const;
/**
* Returns the KConfigGroup to access the applets configuration.
*
* This config object will write to an instance
* specific config file named \<appletname\>\<instanceid\>rc
* in the Plasma appdata directory.
**/
KConfigGroup config() const;
/**
* Returns a config group with the name provided. This ensures
* that the group name is properly namespaced to avoid collision
* with other applets that may be sharing this config file
*
* @param group the name of the group to access
**/
KConfigGroup config(const QString &group) const;
/**
* Saves state information about this applet that will
* be accessed when next instantiated in the restore(KConfigGroup&) method.
*
* This method does not need to be reimplmented by Applet
* subclasses, but can be useful for Applet specializations
* (such as Containment) to do so.
*
* Applet subclasses may instead want to reimplement saveState().
**/
virtual void save(KConfigGroup &group) const;
/**
* Restores state information about this applet saved previously
* in save(KConfigGroup&).
*
* This method does not need to be reimplmented by Applet
* subclasses, but can be useful for Applet specializations
* (such as Containment) to do so.
**/
virtual void restore(KConfigGroup &group);
/**
* Returns a KConfigGroup object to be shared by all applets of this
* type.
*
* This config object will write to an applet-specific config object
* named plasma_\<appletname\>rc in the local config directory.
*/
KConfigGroup globalConfig() const;
/**
* Returns the config skeleton object from this applet's package,
* if any.
*
* @return config skeleton object, or 0 if none
**/
ConfigLoader *configScheme() const;
/**
* Loads the given DataEngine
*
* Tries to load the data engine given by @p name. Each engine is
* only loaded once, and that instance is re-used on all subsequent
* requests.
*
* If the data engine was not found, an invalid data engine is returned
* (see DataEngine::isValid()).
*
* Note that you should <em>not</em> delete the returned engine.
*
* @param name Name of the data engine to load
* @return pointer to the data engine if it was loaded,
* or an invalid data engine if the requested engine
* could not be loaded
*/
Q_INVOKABLE DataEngine *dataEngine(const QString &name) const;
/**
* Accessor for the associated Package object if any.
* Generally, only Plasmoids come in a Package.
*
* @return the Package object, or 0 if none
**/
const Package *package() const;
/**
* Returns the view this widget is visible on, or 0 if none can be found.
* @warning do NOT assume this will always return a view!
* a null view probably means that either plasma isn't finished loading, or your applet is
* on an activity that's not being shown anywhere.
*/
QGraphicsView *view() const;
/**
* Maps a QRect from a view's coordinates to local coordinates.
* @param view the view from which rect should be mapped
* @param rect the rect to be mapped
*/
QRectF mapFromView(const QGraphicsView *view, const QRect &rect) const;
/**
* Maps a QRectF from local coordinates to a view's coordinates.
* @param view the view to which rect should be mapped
* @param rect the rect to be mapped
*/
QRect mapToView(const QGraphicsView *view, const QRectF &rect) const;
/**
* Reccomended position for a popup window like a menu or a tooltip
* given its size
* @param s size of the popup
* @returns reccomended position
*/
QPoint popupPosition(const QSize &s) const;
/**
* Called when any of the geometry constraints have been updated.
* This method calls constraintsEvent, which may be reimplemented,
* once the Applet has been prepared for updating the constraints.
*
* @param constraints the type of constraints that were updated
*/
void updateConstraints(Plasma::Constraints constraints = Plasma::AllConstraints);
/**
* Returns the current form factor the applet is being displayed in.
*
* @see Plasma::FormFactor
*/
virtual FormFactor formFactor() const;
/**
* Returns the location of the scene which is displaying applet.
*
* @see Plasma::Location
*/
virtual Location location() const;
/**
* Returns the workspace context which the applet is operating in
*/
Context *context() const;
/**
* @return the preferred aspect ratio mode for placement and resizing
*/
Plasma::AspectRatioMode aspectRatioMode() const;
/**
* Sets the preferred aspect ratio mode for placement and resizing
*/
void setAspectRatioMode(Plasma::AspectRatioMode);
/**
* Returns a list of all known applets.
*
* @param category Only applets matchin this category will be returned.
* Useful in conjunction with knownCategories.
* If "Misc" is passed in, then applets without a
* Categories= entry are also returned.
* If an empty string is passed in, all applets are
* returned.
* @param parentApp the application to filter applets on. Uses the
* X-KDE-ParentApp entry (if any) in the plugin info.
* The default value of QString() will result in a
* list containing only applets not specifically
* registered to an application.
* @return list of applets
**/
static KPluginInfo::List listAppletInfo(const QString &category = QString(),
const QString &parentApp = QString());
/**
* Returns a list of all known applets associated with a certain mimetype.
*
* @return list of applets
**/
static KPluginInfo::List listAppletInfoForMimetype(const QString &mimetype);
/**
* Returns a list of all the categories used by
* installed applets.
*
* @param parentApp the application to filter applets on. Uses the
* X-KDE-ParentApp entry (if any) in the plugin info.
* The default value of QString() will result in a
* list containing only applets not specifically
* registered to an application.
* @return list of categories
* @param visibleOnly true if it should only return applets that are marked as visible
*/
static QStringList listCategories(const QString &parentApp = QString(),
bool visibleOnly = true);
/**
* Attempts to load an applet
*
* Returns a pointer to the applet if successful.
* The caller takes responsibility for the applet, including
* deleting it when no longer needed.
*
* @param name the plugin name, as returned by KPluginInfo::pluginName()
* @param appletId unique ID to assign the applet, or zero to have one
* assigned automatically.
* @param args to send the applet extra arguments
* @return a pointer to the loaded applet, or 0 on load failure
**/
static Applet *load(const QString &name, uint appletId = 0,
const QVariantList &args = QVariantList());
/**
* Attempts to load an applet
*
* Returns a pointer to the applet if successful.
* The caller takes responsibility for the applet, including
* deleting it when no longer needed.
*
* @param info KPluginInfo object for the desired applet
* @param appletId unique ID to assign the applet, or zero to have one
* assigned automatically.
* @param args to send the applet extra arguments
* @return a pointer to the loaded applet, or 0 on load failure
**/
static Applet *load(const KPluginInfo &info, uint appletId = 0,
const QVariantList &args = QVariantList());
/**
* Get the category of the given applet
*
* @param applet a KPluginInfo object for the applet
*/
static QString category(const KPluginInfo &applet);
/**
* Get the category of the given applet
*
* @param appletName the name of the applet
*/
static QString category(const QString &appletName);
/**
* This method is called when the interface should be painted.
*
* @param painter the QPainter to use to do the paintiner
* @param option the style options object
* @param contentsRect the rect to paint within; automatically adjusted for
* the background, if any
**/
virtual void paintInterface(QPainter *painter,
const QStyleOptionGraphicsItem *option,
const QRect &contentsRect);
/**
* Returns the user-visible name for the applet, as specified in the
* .desktop file.
*
* @return the user-visible name for the applet.
**/
QString name() const;
/**
* @return the font currently set for this widget
**/
QFont font() const;
/**
* Returns the plugin name for the applet
*/
QString pluginName() const;
/**
* Whether the applet should conserve resources. If true, try to avoid doing stuff which
* is computationally heavy. Try to conserve power and resources.
*
* @return true if it should conserve resources, false if it does not.
*/
bool shouldConserveResources() const;
/**
* Returns the icon related to this applet
**/
QString icon() const;
/**
* Returns the category the applet is in, as specified in the
* .desktop file.
*/
QString category() const;
/**
* @return The type of immutability of this applet
*/
ImmutabilityType immutability() const;
void paintWindowFrame(QPainter *painter,
const QStyleOptionGraphicsItem *option, QWidget *widget);
/**
* If for some reason, the applet fails to get up on its feet (the
* library couldn't be loaded, necessary hardware support wasn't found,
* etc..) this method returns true
**/
bool hasFailedToLaunch() const;
/**
* @return true if the applet is busy and is showing an indicator widget for that
*/
bool isBusy() const;
/**
* @return true if the applet currently needs to be configured,
* otherwise, false
*/
bool configurationRequired() const;
/**
* @return true if this plasmoid provides a GUI configuration
**/
bool hasConfigurationInterface() const;
/**
* Returns a list of context-related QAction instances.
*
* This is used e.g. within the \a DesktopView to display a
* contextmenu.
*
* @return A list of actions. The default implementation returns an
* empty list.
**/
virtual QList<QAction*> contextualActions();
/**
* Returns the QAction with the given name from our collection
*/
QAction *action(QString name) const;
/**
* Adds the action to our collection under the given name
*/
void addAction(QString name, QAction *action);
/**
* Sets the BackgroundHints for this applet @see BackgroundHint
*
* @param hints the BackgroundHint combination for this applet
*/
void setBackgroundHints(const BackgroundHints hints);
/**
* @return BackgroundHints flags combination telling if the standard background is shown
* and if it has a drop shadow
*/
BackgroundHints backgroundHints() const;
/**
* @return true if this Applet is currently being used as a Containment, false otherwise
*/
bool isContainment() const;
/**
* This method returns screen coordinates for the widget; this method can be somewhat
* expensive and should ONLY be called when screen coordinates are required. For
* example when positioning top level widgets on top of the view to create the
* appearance of unit. This should NOT be used for popups (@see popupPosition) or
* for normal widget use (use Plasma:: widgets or QGraphicsProxyWidget instead).
*
* @return a rect of the applet in screen coordinates.
*/
QRect screenRect() const;
/**
* Reimplemented from QGraphicsItem
**/
int type() const;
enum {
Type = Plasma::AppletType
};
/**
* @return the Containment, if any, this applet belongs to
**/
Containment *containment() const;
/**
* Sets the global shorcut to associate with this widget.
*/
void setGlobalShortcut(const KShortcut &shortcut);
/**
* @return the global shortcut associated with this wiget, or
* an empty shortcut if no global shortcut is associated.
*/
KShortcut globalShortcut() const;
/**
* @return true is there is a popup assoiated with this Applet
* showing, such as the dialog of a PopupApplet. May be reimplemented
* for custom popup implementations.
*/
virtual bool isPopupShowing() const;
/**
* associate actions with this widget, including ones added after this call.
* needed to make keyboard shortcuts work.
*/
virtual void addAssociatedWidget(QWidget *widget);
/**
* un-associate actions from this widget, including ones added after this call.
* needed to make keyboard shortcuts work.
*/
virtual void removeAssociatedWidget(QWidget *widget);
/**
* Gets called when and extender item has to be initialized after a plasma restart. If you
* create ExtenderItems in your applet, you should implement this function to again create
* the widget that should be shown in this extender item. This function might look something
* like this:
*
* @code
* SuperCoolWidget *widget = new SuperCoolWidget();
* dataEngine("engine")->connectSource(item->config("dataSourceName"), widget);
* item->setWidget(widget);
* @endcode
*
* You can also add one or more custom qactions to this extender item in this function.
*
* Note that by default, not all ExtenderItems are persistent. Only items that are detached,
* will have their configuration stored when plasma exits.
*/
virtual void initExtenderItem(ExtenderItem *item);
/**
* @param parent the QGraphicsItem this applet is parented to
* @param serviceId the name of the .desktop file containing the
* information about the widget
* @param appletId a unique id used to differentiate between multiple
* instances of the same Applet type
*/
explicit Applet(QGraphicsItem *parent = 0,
const QString &serviceId = QString(),
uint appletId = 0);
/**
* @return true if destroy() was called; useful for Applets which should avoid
* certain tasks if they are about to be deleted permanently
*/
bool destroyed() const;
Q_SIGNALS:
/**
* This signal indicates that an application launch, window
* creation or window focus event was triggered. This is used, for instance,
* to ensure that the Dashboard view in Plasma hides when such an event is
* triggered by an item it is displaying.
*/
void releaseVisualFocus();
/**
* Emitted whenever the applet makes a geometry change, so that views
* can coordinate themselves with these changes if they desire.
*/
void geometryChanged();
/**
* Emitted by Applet subclasses when they change a sizeHint and wants to announce the change
*/
void sizeHintChanged(Qt::SizeHint which);
/**
* Emitted when an applet has changed values in its configuration
* and wishes for them to be saved at the next save point. As this implies
* disk activity, this signal should be used with care.
*
* @note This does not need to be emitted from saveState by individual
* applets.
*/
void configNeedsSaving();
/**
* Emitted when activation is requested due to, for example, a global
* keyboard shortcut. By default the wiget is given focus.
*/
void activate();
public Q_SLOTS:
/**
* Sets the immutability type for this applet (not immutable,
* user immutable or system immutable)
* @arg immutable the new immutability type of this applet
*/
void setImmutability(const ImmutabilityType immutable);
/**
* Destroys the applet; it will be removed nicely and deleted.
* Its configuration will also be deleted.
*/
virtual void destroy();
/**
* Lets the user interact with the plasmoid options.
* Called when the user selects the configure entry
* from the context menu.
*
* Unless there is good reason for overriding this method,
* Applet subclasses should actually override createConfigurationInterface
* instead. A good example of when this isn't plausible is
* when using a dialog prepared by another library, such
* as KPropertiesDialog from libkfile.
*/
virtual void showConfigurationInterface();
/**
* Causes this applet to raise above all other applets.
*/
void raise();
/**
* Causes this applet to lower below all the other applets.
*/
void lower();
/**
* Sends all pending contraints updates to the applet. Will usually
* be called automatically, but can also be called manually if needed.
*/
void flushPendingConstraintsEvents();
/**
* This method is called once the applet is loaded and added to a Corona.
* If the applet requires a QGraphicsScene or has an particularly intensive
* set of initialization routines to go through, consider implementing it
* in this method instead of the constructor.
*
* Note: paintInterface may get called before init() depending on initialization
* order. Painting is managed by the canvas (QGraphisScene), and may schedule a
* paint event prior to init() being called.
**/
virtual void init();
/**
* Called when applet configuration values has changed.
*/
virtual void configChanged();
/**
* Shows a busy indicator that overlays the applet
* @param busy show or hide the busy indicator
*/
void setBusy(bool busy);
protected:
/**
* This constructor is to be used with the plugin loading systems
* found in KPluginInfo and KService. The argument list is expected
* to have two elements: the KService service ID for the desktop entry
* and an applet ID which must be a base 10 number.
*
* @param parent a QObject parent; you probably want to pass in 0
* @param args a list of strings containing two entries: the service id
* and the applet id
*/
Applet(QObject *parent, const QVariantList &args);
/**
* Call this method when the applet fails to launch properly. An
* optional reason can be provided.
*
* Not that all children items will be deleted when this method is
* called. If you have pointers to these items, you will need to
* reset them after calling this method.
*
* @param failed true when the applet failed, false when it succeeded
* @param reason an optional reason to show the user why the applet
* failed to launch
**/
void setFailedToLaunch(bool failed, const QString &reason = QString());
/**
* When called, the Applet should write any information needed as part
* of the Applet's running state to the configuration object in config()
* and/or globalConfig().
*
* Applets that always sync their settings/state with the config
* objects when these settings/states change do not need to reimplement
* this method.
**/
virtual void saveState(KConfigGroup &config) const;
/**
* Sets whether or not this applet provides a user interface for
* configuring the applet.
*
* It defaults to false, and if true is passed in you should
* also reimplement createConfigurationInterface()
*
* @param hasInterface whether or not there is a user interface available
**/
void setHasConfigurationInterface(bool hasInterface);
/**
* When the applet needs to be configured before being usable, this
* method can be called to show a standard interface prompting the user
* to configure the applet
*
* @param needsConfiguring true if the applet needs to be configured,
* or false if it doesn't
*/
void setConfigurationRequired(bool needsConfiguring, const QString &reason = QString());
/**
* Reimplement this method so provide a configuration interface,
* parented to the supplied widget. Ownership of the widgets is passed
* to the parent widget.
*
* @param parent the dialog which is the parent of the configuration
* widgets
*/
virtual void createConfigurationInterface(KConfigDialog *parent);
/**
* Called when any of the geometry constraints have been updated.
*
* This is always called prior to painting and should be used as an
* opportunity to layout the widget, calculate sizings, etc.
*
* Do not call update() from this method; an update() will be triggered
* at the appropriate time for the applet.
*
* @param constraints the type of constraints that were updated
* @property constraint
*/
virtual void constraintsEvent(Plasma::Constraints constraints);
/**
* Register the widgets that manage mouse clicks but you still want
* to be able to drag the applet around when holding the mouse pointer
* on that widget.
*
* Calling this results in an eventFilter being places on the widget.
*
* @param item the item to watch for mouse move
*/
void registerAsDragHandle(QGraphicsItem *item);
/**
* Unregister a widget registered with registerAsDragHandle.
*
* @param item the item to unregister
*/
void unregisterAsDragHandle(QGraphicsItem *item);
/**
* @param item the item to look for if it is registered or not
* @return true if it is registered, false otherwise
*/
bool isRegisteredAsDragHandle(QGraphicsItem *item);
/**
* @return the extender of this applet.
*/
Extender *extender() const;
/**
* @internal event filter; used for focus watching
**/
bool eventFilter(QObject *o, QEvent *e);
/**
* @internal scene event filter; used to manage applet dragging
*/
bool sceneEventFilter (QGraphicsItem *watched, QEvent *event);
/**
* @internal manage the mouse movement to drag the applet around
*/
void mouseMoveEvent(QGraphicsSceneMouseEvent *event);
/**
* Reimplemented from QGraphicsItem
*/
void focusInEvent(QFocusEvent *event);
/**
* Reimplemented from QGraphicsItem
*/
void resizeEvent(QGraphicsSceneResizeEvent *event);
/**
* Reimplemented from QGraphicsItem
*/
QVariant itemChange(GraphicsItemChange change, const QVariant &value);
/**
* Reimplemented from QGraphicsItem
*/
QPainterPath shape() const;
/**
* Reimplemented from QGraphicsLayoutItem
*/
QSizeF sizeHint(Qt::SizeHint which, const QSizeF & constraint = QSizeF()) const;
/**
* Reimplemented from QGraphicsLayoutItem
*/
void hoverEnterEvent(QGraphicsSceneHoverEvent *event);
/**
* Reimplemented from QGraphicsLayoutItem
*/
void hoverLeaveEvent(QGraphicsSceneHoverEvent *event);
/**
* Reimplemented from QObject
*/
void timerEvent (QTimerEvent *event);
private:
Q_PRIVATE_SLOT(d, void setFocus())
Q_PRIVATE_SLOT(d, void checkImmutability())
Q_PRIVATE_SLOT(d, void themeChanged())
Q_PRIVATE_SLOT(d, void appletAnimationComplete(QGraphicsItem *item,
Plasma::Animator::Animation anim))
Q_PRIVATE_SLOT(d, void selectItemToDestroy())
Q_PRIVATE_SLOT(d, void updateRect(const QRectF& rect))
Q_PRIVATE_SLOT(d, void destroyMessageOverlay())
Q_PRIVATE_SLOT(d, void clearShortcutEditorPtr())
/**
* Reimplemented from QGraphicsItem
**/
void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = 0);
AppletPrivate *const d;
//Corona needs to access setFailedToLaunch and init
friend class Corona;
friend class CoronaPrivate;
friend class Containment;
friend class ContainmentPrivate;
friend class AppletScript;
friend class AppletHandle;
friend class AppletPrivate;
friend class PopupApplet;
friend class PopupAppletPrivate;
friend class Extender;
friend class ExtenderItem;
};
} // Plasma namespace
Q_DECLARE_OPERATORS_FOR_FLAGS(Plasma::Applet::BackgroundHints)
/**
* Register an applet when it is contained in a loadable module
*/
#define K_EXPORT_PLASMA_APPLET(libname, classname) \
K_PLUGIN_FACTORY(factory, registerPlugin<classname>();) \
K_EXPORT_PLUGIN(factory("plasma_applet_" #libname)) \
K_EXPORT_PLUGIN_VERSION(PLASMA_VERSION)
#endif // multiple inclusion guard