plasma-framework/wallpaper.h
Aaron J. Seigo b2138871bd add a fairly useful detail to the apidox on this method
svn path=/trunk/KDE/kdelibs/; revision=952061
2009-04-10 19:52:16 +00:00

444 lines
16 KiB
C++

/*
* Copyright 2008 by Aaron Seigo <aseigo@kde.org>
* Copyright 2008 by Petri Damsten <damu@iki.fi>
* 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_WALLPAPER_H
#define PLASMA_WALLPAPER_H
#include <kplugininfo.h>
#include <plasma/plasma.h>
#include <plasma/packagestructure.h>
#include <plasma/version.h>
namespace Plasma
{
class DataEngine;
class WallpaperPrivate;
/**
* @class Wallpaper plasma/wallpaper.h <Plasma/Wallpaper>
*
* @short The base Wallpaper class
*
* "Wallpapers" are components that paint the background for Containments that
* do not provide their own background rendering.
*
* Wallpaper plugins are registered using .desktop files. These files should be
* named using the following naming scheme:
*
* plasma-wallpaper-\<pluginname\>.desktop
*
* If a wallpaper plugin provides more than on mode (e.g. Single Image, Wallpaper)
* it should include a Actions= entry in the .desktop file, listing the possible
* actions. An actions group should be included to provide for translatable names.
*/
class PLASMA_EXPORT Wallpaper : public QObject
{
Q_OBJECT
Q_PROPERTY(QRectF boundingRect READ boundingRect WRITE setBoundingRect)
Q_PROPERTY(QString name READ name)
Q_PROPERTY(QString pluginName READ pluginName)
Q_PROPERTY(QString icon READ icon)
Q_PROPERTY(KServiceAction renderingMode READ renderingMode)
Q_PROPERTY(QList<KServiceAction> listRenderingModes READ listRenderingModes)
public:
/**
* Various resize modes supported by the built in image renderer
*/
enum ResizeMethod {
ScaledResize /**< Scales the image to fit the full area*/,
CenteredResize /**< Centers the image within the area */,
ScaledAndCroppedResize /**< Scales and crops the image, preserving the aspect ratio */,
TiledResize /**< Tiles the image to fill the area */,
CenterTiledResize /**< Tiles the image to fill the area, starting with a centered tile */,
MaxpectResize /**< Best fit resize */
};
Q_ENUMS(ResizeMethod)
/**
* Default constructor for an empty or null wallpaper
*/
explicit Wallpaper(QObject * parent = 0);
~Wallpaper();
/**
* Returns a list of all known wallpapers.
*
* @return list of wallpapers
**/
static KPluginInfo::List listWallpaperInfo(const QString &formFactor = QString());
/**
* Attempts to load an wallpaper
*
* Returns a pointer to the wallpaper if successful.
* The caller takes responsibility for the wallpaper, including
* deleting it when no longer needed.
*
* @param name the plugin name, as returned by KPluginInfo::pluginName()
* @param args to send the wallpaper extra arguments
* @return a pointer to the loaded wallpaper, or 0 on load failure
**/
static Wallpaper *load(const QString &name, const QVariantList &args = QVariantList());
/**
* Attempts to load an wallpaper
*
* Returns a pointer to the wallpaper if successful.
* The caller takes responsibility for the wallpaper, including
* deleting it when no longer needed.
*
* @param info KPluginInfo object for the desired wallpaper
* @param args to send the wallpaper extra arguments
* @return a pointer to the loaded wallpaper, or 0 on load failure
**/
static Wallpaper *load(const KPluginInfo &info, const QVariantList &args = QVariantList());
/**
* Returns the Package specialization for wallpapers. May be queried for 'preferred'
* which will return the preferred wallpaper image path given the associated Wallpaper
* object, if any.
*
* @param paper the Wallpaper object to associated the PackageStructure with,
* which will then use the Wallpaper object to define things such as
* default size and resize methods.
*/
static PackageStructure::Ptr packageStructure(Wallpaper *paper = 0);
/**
* Returns the user-visible name for the wallpaper, as specified in the
* .desktop file.
*
* @return the user-visible name for the wallpaper.
**/
QString name() const;
/**
* Returns the plugin name for the wallpaper
*/
QString pluginName() const;
/**
* Returns the icon related to this wallpaper
**/
QString icon() const;
/**
* @return the currently active rendering mode
*/
KServiceAction renderingMode() const;
/**
* Sets the rendering mode for this wallpaper.
* @param mode One of the modes supported by the plugin,
* or an empty string for the default mode.
*/
void setRenderingMode(const QString &mode);
/**
* Returns modes the wallpaper has, as specified in the
* .desktop file.
*/
QList<KServiceAction> listRenderingModes() const;
/**
* @return true if initialized (usually by calling retore), false otherwise
*/
bool isInitialized() const;
/**
* Returns bounding rectangle
*/
QRectF boundingRect() const;
/**
* Sets bounding rectangle
*/
void setBoundingRect(const QRectF &boundingRect);
/**
* This method is called when the wallpaper should be painted.
*
* @param painter the QPainter to use to do the painting
* @param exposedRect the rect to paint within
**/
virtual void paint(QPainter *painter, const QRectF &exposedRect) = 0;
/**
* This method should be called once the wallpaper is loaded or mode is changed.
* @param config Config group to load settings
* @see init
**/
void restore(const KConfigGroup &config);
/**
* This method is called when settings need to be saved.
* @param config Config group to save settings
**/
virtual void save(KConfigGroup &config);
/**
* Returns widget for configuration dialog.
*/
virtual QWidget *createConfigurationInterface(QWidget *parent);
/**
* Mouse move event. To prevent further propagation of the event,
* the event must be accepted.
*
* @param event the mouse event object
*/
virtual void mouseMoveEvent(QGraphicsSceneMouseEvent *event);
/**
* Mouse press event. To prevent further propagation of the even,
* and to receive mouseMoveEvents, the event must be accepted.
*
* @param event the mouse event object
*/
virtual void mousePressEvent(QGraphicsSceneMouseEvent *event);
/**
* Mouse release event. To prevent further propagation of the event,
* the event must be accepted.
*
* @param event the mouse event object
*/
virtual void mouseReleaseEvent(QGraphicsSceneMouseEvent *event);
/**
* Mouse wheel event. To prevent further propagation of the event,
* the event must be accepted.
*
* @param event the wheel event object
*/
virtual void wheelEvent(QGraphicsSceneWheelEvent *event);
/**
* 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
*
* @since 4.3
*/
Q_INVOKABLE DataEngine *dataEngine(const QString &name) const;
/**
* @return true if the wallpaper currently needs to be configured,
* otherwise, false
* @since 4.3
*/
bool configurationRequired() const;
/**
* @return true if disk caching is turned on.
* @since 4.3
*/
bool isUsingDiskCache() const;
/**
* Allows one to set rendering hints that may differ from the actualities of the
* Wallpaper's current state, allowing for better selection of papers from packages,
* for instance.
*
* @arg resizeMethod The resize method to assume will be used for future wallpaper
* scaling; may later be changed by calls to render()
*
* @since 4.3
*/
void setResizeMethodHint(Wallpaper::ResizeMethod resizeMethod);
/*
* Allows one to set rendering hints that may differ from the actualities of the
* Wallpaper's current state, allowing for better selection of papers from packages,
* for instance.
*
* @arg targetSize The size to assume will be used for future wallpaper scaling
*
* @since 4.3
*/
void setTargetSizeHint(const QSizeF &targetSize);
Q_SIGNALS:
/**
* This signal indicates that wallpaper needs to be repainted.
*/
void update(const QRectF &exposedArea);
/**
* Emitted when the user wants to configure/change the wallpaper.
* @since 4.3
*/
void configureRequested();
/**
* Emitted when the state of the wallpaper requiring configuration
* changes.
* @since 4.3
*/
void configurationRequired(bool needsConfig);
/**
* Emitted when the configuration of the wallpaper needs to be saved
* to disk.
* @since 4.3
*/
void configNeedsSaving();
/**
* Emitted when a wallpaper image render is completed.
* @since 4.3
*/
void renderCompleted(const QImage &image);
/**
* @internal
*/
void renderHintsChanged();
protected:
/**
* This constructor is to be used with the plugin loading systems
* found in KPluginInfo and KService. The argument list is expected
* to have one element: the KService service ID for the desktop entry.
*
* @param parent a QObject parent; you probably want to pass in 0
* @param args a list of strings containing one entry: the service id
*/
Wallpaper(QObject *parent, const QVariantList &args);
/**
* This method is called once the wallpaper is loaded or mode is changed.
*
* The mode can be retrieved using the renderingMode() method.
*
* @param config Config group to load settings
**/
virtual void init(const KConfigGroup &config);
/**
* When the wallpaper needs to be configured before being usable, this
* method can be called to denote that action is required
*
* @param needsConfiguring true if the applet needs to be configured,
* or false if it doesn't
* @param reason a translated message for the user explaining that the
* applet needs configuring; this should note what needs
* to be configured
* @since 4.3
*/
void setConfigurationRequired(bool needsConfiguring, const QString &reason = QString());
/**
* Renders the wallpaper asyncronously with the given parameters. When the rendering is
* complete, the renderCompleted signal is emitted.
*
* @param sourceImagePath the path to the image file on disk. Common image formats such as
* PNG, JPEG and SVG are supported
* @param size the size to render the image as
* @param resizeMethod the method to use when resizing the image to fit size, @see
* ResizeMethod
* @param color the color to use to pad the rendered image if it doesn't take up the
* entire size with the given ResizeMethod
* @since 4.3
*/
void render(const QString &sourceImagePath, const QSize &size,
Wallpaper::ResizeMethod resizeMethod = ScaledResize,
const QColor &color = QColor(0, 0, 0));
/**
* Sets whether or not to cache on disk the results of calls to render. If the wallpaper
* changes often or is innexpensive to render, then it's probably best not to cache them.
*
* The default is not to cache.
*
* @see render
* @param useCache true to cache rendered papers on disk, false not to cache
* @since 4.3
*/
void setUsingDiskCache(bool useCache);
/**
* Tries to load pixmap with the specified key from cache.
*
* @param key the name to use in the cache for this image
* @param image the image object to populate with the resulting data if found
* @param lastModified if non-zero, the time stamp is also checked on the file,
* and must be newer than the timestamp to be loaded
*
* @return true when pixmap was found and loaded from cache, false otherwise
* @since 4.3
**/
bool findInCache(const QString &key, QImage &image, unsigned int lastModified = 0);
/**
* Insert specified pixmap into the cache if usingDiskCache.
* If the cache already contains pixmap with the specified key then it is
* overwritten.
*
* @param key the name use in the cache for this image; if the image is specific
* to this wallpaper plugin, consider including the name() as part of
* the cache key to avoid collisions with other plugins.
* @param image the image to store in the cache; passing in a null image will cause
* the cached image to be removed from the cache
*
* @since 4.3
**/
void insertIntoCache(const QString& key, const QImage &image);
private:
Q_PRIVATE_SLOT(d, void renderCompleted(int token, const QImage &image,
const QString &sourceImagePath, const QSize &size,
int resizeMethod, const QColor &color))
friend class WallpaperPackage;
friend class WallpaperPrivate;
WallpaperPrivate *const d;
};
} // Plasma namespace
/**
* Register an wallpaper when it is contained in a loadable module
*/
#define K_EXPORT_PLASMA_WALLPAPER(libname, classname) \
K_PLUGIN_FACTORY(factory, registerPlugin<classname>();) \
K_EXPORT_PLUGIN(factory("plasma_wallpaper_" #libname)) \
K_EXPORT_PLUGIN_VERSION(PLASMA_VERSION)
#endif // multiple inclusion guard