Moving Plasma::Applet::listAppletInfo into the PluginLoader logic. Also implemented internalAppletNames which, if implemented, will return a QStringList of the available applets' names. PluginLoader::listAppletInfo will then search for .desktop files in $APPDATA/plasma/applets/ which match the applets' names (ie. $APPDATA/plasma/applets/org.skrooge.report.desktop), and add them to the KPluginInfo::List returned by PluginLoader::listAppletInfo and subsequently Plasma::Applet::listAppletInfo.

Since the applets are dynamically loaded, the .desktop files don't need an X-KDE-Library entries, but the others will be used, for example X-KDE-PluginInfo-Name (which will be the value given to PluginLoader::internalAppletLoad, so it is really important), Icon, Type, ServiceTypes...

svn path=/trunk/KDE/kdelibs/; revision=1154551

applet.cpp

@@ -2160,30 +2160,7 @@ QString AppletPrivate::parentAppConstraint(const QString &parentApp)
 
 KPluginInfo::List Applet::listAppletInfo(const QString &category, const QString &parentApp)
 {
-    QString constraint = AppletPrivate::parentAppConstraint(parentApp);
-
-    //note: constraint guaranteed non-empty from here down
-    if (category.isEmpty()) { //use all but the excluded categories
-        KConfigGroup group(KGlobal::config(), "General");
-        QStringList excluded = group.readEntry("ExcludeCategories", QStringList());
-        foreach (const QString &category, excluded) {
-            constraint.append(" and [X-KDE-PluginInfo-Category] != '").append(category).append("'");
-        }
-    } else { //specific category (this could be an excluded one - is that bad?)
-        constraint.append(" and ").append("[X-KDE-PluginInfo-Category] == '").append(category).append("'");
-        if (category == "Miscellaneous") {
-            constraint.append(" or (not exist [X-KDE-PluginInfo-Category] or [X-KDE-PluginInfo-Category] == '')");
-        }
-    }
-
-    KService::List offers = KServiceTypeTrader::self()->query("Plasma/Applet", constraint);
-
-    //now we have to do some manual filtering because the constraint can't handle everything
-    AppletPrivate::filterOffers(offers);
-
-    //kDebug() << "Applet::listAppletInfo constraint was '" << constraint
-    //         << "' which got us " << offers.count() << " matches";
-    return KPluginInfo::fromServices(offers);
+   return PluginLoader::pluginLoader()->listAppletInfo(category, parentApp); 
 }
 
 KPluginInfo::List Applet::listAppletInfoForMimetype(const QString &mimetype)

pluginloader.cpp

@@ -23,6 +23,7 @@
 #include <kglobal.h>
 #include <kservice.h>
 #include <kservicetypetrader.h>
+#include <kplugininfo.h>
 
 #include "applet.h"
 #include "containment.h"
@@ -224,6 +225,48 @@ Service *PluginLoader::loadService(const QString &name, const QVariantList &args
     return service;
 }
 
+KPluginInfo::List PluginLoader::listAppletInfo( const QString &category, const QString &parentApp )
+{
+    KPluginInfo::List list = KPluginInfo::List();
+
+    if(PluginLoader::pluginLoader()){
+        QStringList appletNames = internalAppletNames(category);
+        foreach ( QString appletName, appletNames ) {
+            KService::Ptr service = KService::serviceByStorageId( appletName );
+
+            if ( !service.isNull() ) {
+                KPluginInfo info( service );
+                list.append(info);
+            }
+        }
+    }
+
+    QString constraint = AppletPrivate::parentAppConstraint(parentApp);
+
+    //note: constraint guaranteed non-empty from here down
+    if (category.isEmpty()) { //use all but the excluded categories
+        KConfigGroup group(KGlobal::config(), "General");
+        QStringList excluded = group.readEntry("ExcludeCategories", QStringList());
+        foreach (const QString &category, excluded) {
+            constraint.append(" and [X-KDE-PluginInfo-Category] != '").append(category).append("'");
+        }
+    } else { //specific category (this could be an excluded one - is that bad?)
+        constraint.append(" and ").append("[X-KDE-PluginInfo-Category] == '").append(category).append("'");
+        if (category == "Miscellaneous") {
+            constraint.append(" or (not exist [X-KDE-PluginInfo-Category] or [X-KDE-PluginInfo-Category] == '')");
+        }
+    }
+
+    KService::List offers = KServiceTypeTrader::self()->query("Plasma/Applet", constraint);
+
+    //now we have to do some manual filtering because the constraint can't handle everything
+    AppletPrivate::filterOffers(offers);
+
+    //kDebug() << "Applet::listAppletInfo constraint was '" << constraint
+    //         << "' which got us " << offers.count() << " matches";
+    return KPluginInfo::fromServices(offers);
+}
+
 Applet* PluginLoader::internalLoadApplet(const QString &name, uint appletId, const QVariantList &args)
 { 
     Q_UNUSED(name)
@@ -246,5 +289,12 @@ Service* PluginLoader::internalLoadService(const QString &name, const QVariantLi
     return 0;
 }
 
+QStringList PluginLoader::internalAppletNames(const QString &category)
+{
+    Q_UNUSED(category)
+
+    return QStringList();
+}
+
 } // Plasma Namespace
 

pluginloader.h

@@ -21,6 +21,7 @@
 #define PLUGIN_LOADER_H
 
 #include <plasma/plasma.h>
+#include <kplugininfo.h>
 
 namespace Plasma {
 
@@ -77,6 +78,8 @@ public:
      **/
     Service *loadService(const QString &name, const QVariantList &args, QObject *parent = 0);
 
+    KPluginInfo::List listAppletInfo( const QString &category, const QString &parentApp );
+
     /**
      * Set the plugin loader which will be queried for all loads.
      * 
@@ -134,11 +137,34 @@ protected:
      **/
     virtual Service *internalLoadService(const QString &name, const QVariantList &args, QObject *parent = 0);
 
+    /**
+     * A re-implementable method that allows subclasses to provide additional applets
+     * for listAppletInfo. If the application has no applets to give to the application, 
+     * then the implementation should return QStringList().
+     * This method is called by listAppletInfo prior to generating the list of applets installed
+     * on the system using the standard Plasma plugin mechanisms, and will try to find .desktop
+     * files for your 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
+     **/
+    QStringList internalAppletNames(const QString &category);
+
+
 private:
     PluginLoaderPrivate * const d;
 };
 
 }
-Q_DECLARE_METATYPE( Plasma::PluginLoader* ) // so that it can be wrapped in QVariants, etc
 
 #endif