first draft of the ScriptEngine plugin

svn path=/trunk/KDE/kdebase/workspace/libs/plasma/; revision=691244

applet.cpp

@@ -36,6 +36,7 @@
 #include "plasma/package.h"
 #include "plasma/packages_p.h"
 #include "plasma/plasma.h"
+#include "plasma/scriptengine.h"
 #include "plasma/svg.h"
 
 #include "plasma/widgets/widget.h"
@@ -67,22 +68,6 @@ public:
         if (appletId > s_maxAppletId) {
             s_maxAppletId = appletId;
         }
-
-        if (appletDescription.isValid() &&
-            !appletDescription.property("X-Plasma-Language").toString().isEmpty()) {
-            QString path = KStandardDirs::locate("appdata",
-                                                 "plasmoids/" +
-                                                 appletDescription.pluginName());
-            if (!path.isEmpty()) {
-                package = new Package(path,
-                        appletDescription.pluginName(),
-                        PlasmoidStructure());
-                if (!package->isValid()) {
-                    delete package;
-                    package = 0;
-                }
-            }
-        }
     }
 
     ~Private()
@@ -100,9 +85,44 @@ public:
             applet->setFailedToLaunch(true);
         }
 
+        QString language = appletDescription.property("X-Plasma-Language").toString();
+
+        // we have a scripted plasmoid
+        if (!language.isEmpty()) {
+            // find where the Package is
+            QString path = KStandardDirs::locate("appdata",
+                                                 "plasmoids/" +
+                                                 appletDescription.pluginName());
+
+            if (!path.isEmpty()) {
+                // create the package and see if we have something real
+                package = new Package(path,
+                                      appletDescription.pluginName(),
+                                      PlasmoidStructure());
+                if (package->isValid()) {
+                    // now we try and set up the script engine.
+                    // it will be parented to this applet and so will get
+                    // deleted when the applet does
+
+                    //TODO: do we need to hold on to the engine for later use?
+                    ScriptEngine* engine = ScriptEngine::load(language, applet);
+                    if (!engine) {
+                        delete package;
+                        package = 0;
+                    }
+                } else {
+                    delete package;
+                    package = 0;
+                }
+
+                if (!package) {
+                    applet->setFailedToLaunch(true);
+                }
+            }
+        }
+
         applet->setImmutable(applet->globalConfig().isImmutable() ||
                              applet->config().isImmutable());
-
     }
 
     static uint nextId()

applet.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2005 by Aaron Seigo <aseigo@kde.org>
+ *   Copyright (C) 2006-2007 by Aaron Seigo <aseigo@kde.org>
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU Library General Public License version 2 as

includes/ScriptEngine

@@ -0,0 +1 @@
+#include "../../plasma/scriptengine.h"

scriptengine.cpp

@@ -0,0 +1,131 @@
+/*
+ *   Copyright 2007 by Aaron Seigo <aseigo@kde.org>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License version 2 as
+ *   published by the Free Software Foundation
+ *
+ *   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.
+ */
+
+#include "scriptengine.h"
+
+#include <KDebug>
+#include <KService>
+#include <KServiceTypeTrader>
+
+#include "applet.h"
+#include "package.h"
+
+namespace Plasma
+{
+
+class ScriptEngine::Private
+{
+public:
+    Applet* applet;
+};
+
+ScriptEngine::ScriptEngine(QObject *parent, const QStringList &args)
+    : QObject(parent),
+      d(new Private)
+{
+    Q_UNUSED(args)
+    d->applet = 0;
+}
+
+ScriptEngine::~ScriptEngine()
+{
+}
+
+void ScriptEngine::init(Applet* applet)
+{
+    d->applet = applet;
+    if (!init()) {
+        d->applet->setFailedToLaunch(true);
+    }
+}
+
+bool ScriptEngine::init()
+{
+    Q_ASSERT(d->applet);
+    return false;
+}
+
+QString ScriptEngine::mainScript() const
+{
+    Q_ASSERT(d->applet);
+    return d->applet->package()->filePath("mainscript");
+}
+
+Applet* ScriptEngine::applet()  const
+{
+    Q_ASSERT(d->applet);
+    return d->applet;
+}
+
+const Package* ScriptEngine::package() const
+{
+    Q_ASSERT(d->applet);
+    return d->applet->package();
+}
+
+QStringList ScriptEngine::knownLanguages()
+{
+    KService::List offers = KServiceTypeTrader::self()->query("Plasma/ScriptEngine");
+    //kDebug() << "Applet::knownApplets constraint was '" << constraint << "' which got us " << offers.count() << " matches" << endl;
+
+    QStringList languages;
+    foreach (KService::Ptr service, offers) {
+        QString language = service->property("X-Plasma-Language").toString();
+        if (!languages.contains(language)) {
+            languages.append(language);
+        }
+    }
+
+    return languages;
+}
+
+ScriptEngine* ScriptEngine::load(const QString &language, Applet *applet)
+{
+    if (language.isEmpty()) {
+        return 0;
+    }
+
+    QString constraint = QString("[X-Plasma-Language] == '%1'").arg(language);
+    KService::List offers = KServiceTypeTrader::self()->query("Plasma/ScriptEngine", constraint);
+
+    if (offers.isEmpty()) {
+        kDebug() << "ScriptEngine::load: no offers for \"" << language << "\"" << endl;
+        return 0;
+    }
+
+    QStringList args;
+    ScriptEngine* engine = 0;
+    foreach (KService::Ptr service, offers) {
+        engine = KService::createInstance<Plasma::ScriptEngine>(service, applet, args);
+        if (engine) {
+            break;
+        }
+    }
+
+    if (!engine) {
+        kDebug() << "Couldn't load script engine for language " << language << "!" << endl;
+    }
+
+    engine->init(applet);
+    return engine;
+}
+
+} // namespace Plasma
+
+#include <scriptengine.moc>
+

scriptengine.h

@@ -0,0 +1,111 @@
+/*
+ *   Copyright 2007 by Aaron Seigo <aseigo@kde.org>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License version 2 as
+ *   published by the Free Software Foundation
+ *
+ *   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_SCRIPTENGINE_H
+#define PLASMA_SCRIPTENGINE_H
+
+#include <QtCore/QObject>
+
+namespace Plasma
+{
+
+class Applet;
+class Package;
+
+/**
+ * @brief The base class for scripting interfaces to be used in loading
+ *        plasmoids of a given language.
+ *
+ * All ScriptEngines should export as consistent an interface as possible
+ * so that the learning curve is limited. In particular, the following
+ * API should be made available in the script environment:
+ *
+ * TODO: define the actual API ...
+ * PlasmaApplet - the applet of this plasmoid
+ * LoadUserInterface(String uiFile) - loads and returns a given UI file
+ * LoadImage - loads an image resource out of the plasmoid's package
+ * PlasmaSvg - creates and returns an Svg file
+ **/
+class ScriptEngine : public QObject
+{
+    Q_OBJECT
+
+public:
+    /**
+     * The default constructor for a ScriptEngine
+     *
+     * @param applet the Applet object that will house the plasmoid
+     **/
+    explicit ScriptEngine(QObject *parent, const QStringList &args);
+    virtual ~ScriptEngine();
+
+    void init(Applet* applet);
+
+    /**
+     * @return a list of all supported languages
+     **/
+    static QStringList knownLanguages();
+
+    /**
+     * Loads a script engine for the given language.
+     *
+     * @param language the language to load an engine for
+     * @param applet the applet for this plasmoid
+     * @return pointer to the ScriptEngine or 0 on failure
+     **/
+    static ScriptEngine* load(const QString &language, Applet *applet);
+
+protected:
+    /**
+     * Called when the script should set up the script environment and
+     * start the script itself
+     **/
+    virtual bool init();
+
+    /**
+     * @return absolute path to the main script file for this plasmoid
+     **/
+    QString mainScript() const;
+
+    /**
+     * @return the Package associated with this plasmoid which can
+     *         be used to request resources, such as images and
+     *         interface files.
+     */
+    const Package* package() const;
+
+    /**
+     * @return the Applet that contains this plasmoid
+     **/
+    Applet* applet() const;
+
+private:
+    class Private;
+    Private * const d;
+};
+
+#define K_EXPORT_PLASMA_SCRIPENGINE(libname, classname) \
+        K_EXPORT_COMPONENT_FACTORY(                \
+                        plasma_scriptengine_##libname,    \
+                        KGenericFactory<classname>("plasma_scriptengine_" #libname))
+
+
+} // namespace Plasma
+
+#endif
+