From 00a8b22ad6dbb03eea18090f6d9f578101632752 Mon Sep 17 00:00:00 2001
Message-Id: <00a8b22ad6dbb03eea18090f6d9f578101632752.1313007841.git.kevin.kofler@chello.at>
From: Kevin Kofler <kevin.kofler@chello.at>
Date: Wed, 10 Aug 2011 21:48:19 +0200
Subject: [PATCH] Trigger installation of missing components when installing a
 package.

For script engines, the existing metadata (X-Plasma-API) is sufficient.

For data engines, we introduce a new metadata entry:
X-Plasma-RequiredDataEngines. Third-party packages will have to add this entry
to benefit from this feature at this time. Automatic support for scanning
package source code on installation (at least for some languages) is planned,
but the metadata entry is definitely the most efficient method.
---
 plasma/package.cpp         |   39 +++++++++++++++++++++++++++++++++++++++
 plasma/packagemetadata.cpp |   13 +++++++++++++
 plasma/packagemetadata.h   |    7 +++++++
 3 files changed, 59 insertions(+), 0 deletions(-)

diff --git a/plasma/package.cpp b/plasma/package.cpp
index 4c00d36..0a45c87 100644
--- a/plasma/package.cpp
+++ b/plasma/package.cpp
@@ -49,8 +49,11 @@
 #include <kdebug.h>
 
 #include "authorizationmanager.h"
+#include "dataenginemanager.h"
 #include "packagemetadata.h"
+#include "scripting/scriptengine.h"
 #include "private/authorizationmanager_p.h"
+#include "private/componentinstaller_p.h"
 #include "private/package_p.h"
 #include "private/plasmoidservice_p.h"
 #include "private/service_p.h"
@@ -603,6 +606,42 @@ bool Package::installPackage(const QString &package,
         tempdir.setAutoRemove(false);
     }
 
+    // check for missing dependencies
+    QString requiredScriptEngine = meta.implementationApi();
+    if (!requiredScriptEngine.isEmpty()) {
+        // figure out the component type to query for
+        ComponentTypes componentTypes = static_cast<ComponentTypes>(0);
+        QStringList serviceTypes = meta.serviceType().split(',');
+        if (serviceTypes.contains("Plasma/Applet")) {
+            componentTypes |= AppletComponent;
+        }
+        if (serviceTypes.contains("Plasma/DataEngine")) {
+            componentTypes |= DataEngineComponent;
+        }
+        if (serviceTypes.contains("Plasma/Runner")) {
+            componentTypes |= RunnerComponent;
+        }
+        if (serviceTypes.contains("Plasma/Wallpaper")) {
+            componentTypes |= WallpaperComponent;
+        }
+        if (!knownLanguages(componentTypes).contains(requiredScriptEngine)) {
+            // install the missing script engine
+            // force prompting because the user has just explicitly installed a widget
+            ComponentInstaller::self()->installMissingComponent("scriptengine", requiredScriptEngine, 0, true);
+        }
+    }
+    QStringList requiredDataEngines = meta.requiredDataEngines();
+    if (!requiredDataEngines.isEmpty()) {
+        QStringList knownDataEngines = DataEngineManager::self()->listAllEngines(meta.application());
+        foreach (const QString &requiredDataEngine, requiredDataEngines) {
+            if (!knownDataEngines.contains(requiredDataEngine)) {
+                // install the missing data engine
+                // force prompting because the user has just explicitly installed a widget
+                ComponentInstaller::self()->installMissingComponent("dataengine", requiredDataEngine, 0, true);
+            }
+        }
+    }
+
     if (!servicePrefix.isEmpty()) {
         // and now we register it as a service =)
         QString metaPath = targetName + "/metadata.desktop";
diff --git a/plasma/packagemetadata.cpp b/plasma/packagemetadata.cpp
index 59163b2..8cfaf64 100644
--- a/plasma/packagemetadata.cpp
+++ b/plasma/packagemetadata.cpp
@@ -52,6 +52,7 @@ class PackageMetadataPrivate
         QString serviceType;
         QString api;
         KUrl location;
+        QStringList requiredDataEngines;
 };
 
 PackageMetadata::PackageMetadata(const PackageMetadata &other)
@@ -106,6 +107,7 @@ void PackageMetadata::write(const QString &filename) const
     config.writeEntry("X-KDE-ParentApp", d->app);
     config.writeEntry("Type", d->type);
     config.writeEntry("X-Plasma-RemoteLocation", d->location);
+    config.writeEntry("X-Plasma-RequiredDataEngines", d->requiredDataEngines);
 }
 
 void PackageMetadata::read(const QString &filename)
@@ -133,6 +135,7 @@ void PackageMetadata::read(const QString &filename)
     d->app = config.readEntry("X-KDE-ParentApp", d->app);
     d->type = config.readEntry("Type", d->type);
     d->location = config.readEntry("X-Plasma-RemoteLocation", d->location);
+    d->requiredDataEngines = config.readEntry("X-Plasma-RequiredDataEngines", d->requiredDataEngines);
 }
 
 QString PackageMetadata::name() const
@@ -225,6 +228,11 @@ QString PackageMetadata::implementationApi() const
     return d->api;
 }
 
+QStringList PackageMetadata::requiredDataEngines() const
+{
+    return d->requiredDataEngines;
+}
+
 void PackageMetadata::setImplementationApi(const QString &api)
 {
     d->api = api;
@@ -300,6 +308,11 @@ void PackageMetadata::setRemoteLocation(const KUrl &location)
     d->location = location;
 }
 
+void PackageMetadata::setRequiredDataEngines(const QStringList &requiredDataEngines)
+{
+    d->requiredDataEngines = requiredDataEngines;
+}
+
 void PackageMetadata::setType(const QString &type)
 {
     d->type = type;
diff --git a/plasma/packagemetadata.h b/plasma/packagemetadata.h
index b10f0e4..ec396a6 100644
--- a/plasma/packagemetadata.h
+++ b/plasma/packagemetadata.h
@@ -21,6 +21,7 @@
 #define PLASMA_PACKAGEMETADATA_H
 
 #include <QtCore/QString>
+#include <QtCore/QStringList>
 
 #include <plasma/plasma_export.h>
 
@@ -92,6 +93,7 @@ public:
     QString pluginName() const;
     QString implementationApi() const;
     KUrl remoteLocation() const;
+    QStringList requiredDataEngines() const;
 
     QString type() const;
 
@@ -205,6 +207,11 @@ public:
      */
     void setImplementationApi(const QString &api);
 
+    /**
+     * Set the required data engines for this package.
+     */
+    void setRequiredDataEngines(const QStringList &);
+
 private:
     PackageMetadataPrivate * const d;
 };
-- 
1.7.4.4