plasma-framework/applet.h
Aaron J. Seigo 4381fdfafa they beginning of keyboard focus possibilities; hardly works at the moment, but this is the groundwork
svn path=/trunk/KDE/kdebase/workspace/libs/plasma/; revision=797091
2008-04-14 21:50:41 +00:00

768 lines
26 KiB
C++

/*
* 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/QWidget>
#include <QtGui/QGraphicsWidget>
#include <KDE/KPluginInfo>
#include <KDE/KGenericFactory>
#include <plasma/configxml.h>
#include <plasma/packagestructure.h>
#include <plasma/plasma.h>
class KConfigDialog;
class QGraphicsView;
namespace Plasma
{
class Containment;
class DataEngine;
class Package;
/**
* @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 WRITE setHasConfigurationInterface)
Q_PROPERTY(QString name READ name)
Q_PROPERTY(QString category READ category)
Q_PROPERTY(bool immutable READ isImmutable WRITE setImmutable)
Q_PROPERTY(bool drawStandardBackground READ drawStandardBackground WRITE setDrawStandardBackground)
Q_PROPERTY(bool failedToLaunch READ failedToLaunch WRITE setFailedToLaunch)
Q_PROPERTY(bool needsConfiguring READ needsConfiguring WRITE setNeedsConfiguring)
Q_PROPERTY(QRectF geometry READ geometry WRITE setGeometry)
Q_PROPERTY(bool shouldConserveResources READ shouldConserveResources)
Q_PROPERTY(Qt::AspectRatioMode aspectRatioMode READ aspectRatioMode WRITE setAspectRatioMode)
public:
typedef QList<Applet*> List;
typedef QHash<QString, Applet*> Dict;
/**
* @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);
/**
* 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);
~Applet();
/**
* @return a package structure representing a Theme
*/
static PackageStructure::Ptr packageStructure();
/**
* 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.
**/
virtual void init();
/**
* @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.
**/
void save(KConfigGroup* group) const;
/**
* Restores state information about this applet.
**/
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
**/
ConfigXml* configXml() 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
*/
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;
/**
* Recomended position for a popup window like a menu or a tooltip
* given its size
* @param s size of the popup
* @returns recomended position
*/
QPoint popupPosition(const QSize &s) const;
/**
* Called when any of the geometry constraints have been updated.
* This method calls constraintsUpdated, 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);
/**
* 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 constraintsUpdated(Plasma::Constraints constraints);
/**
* 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;
/**
* @return the prefered aspect ratio mode for placement and resizing
*/
Qt::AspectRatioMode aspectRatioMode() const;
/**
* Sets the prefered aspect ratio mode for placement and resizing
*/
void setAspectRatioMode(Qt::AspectRatioMode);
/**
* @return whether or not to keep this applet square.
*/
bool remainSquare() const;
/**
* Sets whether or not this applet should be kept square.
*
* @param square true if the applet should always be square in shape.
*/
void setRemainSquare(bool square);
/**
* 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 knownApplets(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 knownAppletsForMimetype(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 knownCategories(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;
/**
* Returns the color corresponding to the applet's category.
*/
QColor color() const;
/**
* @return true if this applet is immutable
**/
bool isImmutable() const;
/**
* @return true if this applet is immutable due to Kiosk settings
*/
bool isKioskImmutable() const;
/**
* @return returns whether or not the applet is using the standard
* background
**/
bool drawStandardBackground() const;
/**
* Sets whether the applet should automatically draw the standard
* background.
*
* Defaults to true
**/
void setDrawStandardBackground(bool drawBackground);
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 failedToLaunch() const;
/**
* 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());
/**
* @return true if the applet currently needs to be configured,
* otherwise, false
*/
bool needsConfiguring() const;
/**
* 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
*
* 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 needsConfiguring true if the applet needs to be configured,
* or false if it doesn't
*/
void setNeedsConfiguring(bool needsConfiguring);
/**
* @return true if this plasmoid provides a GUI configuration
**/
bool hasConfigurationInterface();
/**
* 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 showConfigurationInterface()
*
* @param hasInterface whether or not there is a user interface available
**/
void setHasConfigurationInterface(bool hasInterface);
/**
* 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*> contextActions();
/**
* Sets shadow for the given applet.
*/
void setShadowShown(bool);
/**
* Returns true if the given item has a shadow shown.
*/
bool isShadowShown() const;
/**
* Sets whether or not this Applet is acting as a Containment
*/
void setIsContainment(bool isContainment);
/**
* @return true if this Applet is currently being used as a Containment, false otherwise
*/
bool isContainment() const;
/**
* Sets the geometry of this Plasma::Applet. Should not be used directly by
* applet subclasses.
* @param geometry the geometry to apply to this Plasma::Applet.
*/
void setGeometry(const QRectF &geometry);
/**
* Causes this applet to raise above all other applets.
*/
void raise();
/**
* Reimplemented from QGraphicsItem
**/
int type() const;
enum { Type = Plasma::AppletType };
/**
* Reimplemented from QGraphicsItem
*/
QPainterPath shape() const;
/**
* @internal
*/
void resetConfigurationObject();
/**
* @return the Containment, if any, this applet belongs to
**/
Containment* containment() const;
Q_SIGNALS:
/**
* Emitted when the applet needs to take (or lose) keyboard focus.
*
* An applet should emit this signal to ensure that autohiding
* elements stay unhidden and other bits of bookkeeping are
* performed to ensure proper function.
*
* If you call watchForFocus on your applet, then this is handled for
* the applet and it is not necessary to emit the signal directly.
*
* @param focus true if the applet is taking keyboard focus, false if
* it is giving it up
**/
void requestFocus( bool focus );
/**
* Emitted whenever the applet makes a geometry change, so that views
* can coordinate themselves with these changes if they desire.
*/
void geometryChanged();
/**
* 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();
public Q_SLOTS:
/**
* Sets whether or not this applet is immutable or not.
*
* @param immutable true if this applet should not be changeable
**/
void setImmutable(bool immutable);
/**
* Destroys the applet; it will be deleted and configurations reset.
*/
void destroy();
/**
* Lets the user interact with the plasmoid options.
* Called when the user selects the configure entry
* from the context menu.
*
* Applets should NOT reimplement this method unless there is good
* reason to do so, but instead reimplment createConfigurationInterface
*/
virtual void showConfigurationInterface();
/**
* 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);
/**
* Sends all pending contraints updates to the applet. Will usually
* be called automatically, but can also be called manually if needed.
*/
void flushUpdatedConstraints();
/**
* This method should be invoked whenever an application launch or other window
* creation of focussing event was triggered
*/
void launchActivated();
/**
* called when the Plasma::Theme has changed
*/
void themeChanged();
protected:
/**
* Called when a request to save the state of the applet is made
* during runtime
**/
virtual void saveState(KConfigGroup* config) const;
/**
* Returns the name of the applet.
*
* This will be the same for all instances of this applet.
**/
QString globalName() const;
/**
* Returns a name unique to the instance of this applet.
*
* Useful for being able to refer directly to a particular
* applet. Combines the global name with the applet id
**/
QString instanceName() const;
/**
* Register widgets that can receive keyboard focus.
*
* Calling this results in an eventFilter being placed on the widget.
*
* @param widget the widget to watch for keyboard focus
* @param watch whether to start watching the widget, or to stop doing so
*/
void watchForFocus(QObject *widget, bool watch = true);
/**
* Register the widgets that manages mouse clicks but you still want
* to be able to drag the applet around when holding the mouse pointer
* on that widgets.
*
* Calling this results in an eventFilter being places on the widget.
*
* @param widget the widget to watch for mouse move
* @param watch whether to start watching the widget, or to stop doing so
*/
void watchForMouseMove(QGraphicsItem *widget, bool watch);
/**
* Call this whenever focus is needed or not needed.
*
* You do not have to call this method for widgets that have
* been registered with watchForFocus
*
* @see watchForFocus
* @param focus whether to or not to request focus
*/
void needsFocus(bool focus);
/**
* @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);
/**
* @internal manage the mouse movement to drag the applet around
*/
void mousePressEvent(QGraphicsSceneMouseEvent *event);
/**
* Reimplemented from QGraphicsItem
*/
void focusInEvent(QFocusEvent * event);
/**
* Reimpmlemented from LayoutItem
*/
QPointF topLeft() const;
/**
* Reimplemented from QGraphicsItem
*/
QVariant itemChange(GraphicsItemChange change, const QVariant &value);
protected Q_SLOTS:
/**
* @internal used to check the immutability of the item in the config file
*/
void checkImmutability();
private:
Q_DISABLE_COPY(Applet)
/**
* Reimplemented from QGraphicsItem
**/
void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = 0);
class Private;
Private* const d;
};
} // Plasma namespace
/**
* 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))
#endif // multiple inclusion guard