From a452da7dd2f328f540fb90b1f3ea8cc6c172caa7 Mon Sep 17 00:00:00 2001
From: "Aaron J. Seigo" <aseigo@kde.org>
Date: Sun, 17 Jun 2007 17:38:54 +0000
Subject: [PATCH] * removeData method added to DataEngine which allows one to,
 well, remove data from a source * passing a null or invalid QVariant to
 DataSource::setData now results in the removal of the entry if it exists

svn path=/trunk/KDE/kdebase/workspace/libs/plasma/; revision=676783
---
 dataengine.cpp |  9 +++++++++
 dataengine.h   |  8 ++++++++
 datasource.cpp | 11 ++++++++++-
 datasource.h   |  4 +++-
 4 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/dataengine.cpp b/dataengine.cpp
index ba451afbb..47842d374 100644
--- a/dataengine.cpp
+++ b/dataengine.cpp
@@ -218,6 +218,15 @@ void DataEngine::setData(const QString& source, const QString& key, const QVaria
     d->queueUpdate();
 }
 
+void DataEngine::removeData(const QString& source, const QString& key)
+{
+    DataSource* s = d->source(source, false);
+    if (s) {
+        s->setData(key, QVariant());
+        d->queueUpdate();
+    }
+}
+
 void DataEngine::addSource(DataSource* source)
 {
     SourceDict::const_iterator it = d->sources.find(source->objectName());
diff --git a/dataengine.h b/dataengine.h
index eb9689684..3e694b917 100644
--- a/dataengine.h
+++ b/dataengine.h
@@ -205,6 +205,14 @@ class PLASMA_EXPORT DataEngine : public QObject
          **/
         void setData(const QString& source, const QString& key, const QVariant& value);
 
+        /**
+         * Removes a data entry from a source
+         *
+         * @param source the name of the data source
+         * @param key the data entry to remove
+         **/
+        void removeData(const QString& source, const QString& key);
+
         /**
          * Adds an already constructed data source. The DataEngine takes
          * ownership of the DataSource object.
diff --git a/datasource.cpp b/datasource.cpp
index e761f83f8..0a699962d 100644
--- a/datasource.cpp
+++ b/datasource.cpp
@@ -56,7 +56,16 @@ const DataEngine::Data DataSource::data() const
 
 void DataSource::setData(const QString& key, const QVariant& value)
 {
-    d->data[key] = value;
+    if (value.isNull() || !value.isValid()) {
+        if (!d->data.contains(key)) {
+            return;
+        }
+
+        d->data.remove(key);
+    } else {
+        d->data[key] = value;
+    }
+
     d->dirty = true;
 }
 
diff --git a/datasource.h b/datasource.h
index 4aed80be5..73ab71831 100644
--- a/datasource.h
+++ b/datasource.h
@@ -63,7 +63,9 @@ class PLASMA_EXPORT DataSource : public QObject
          * is done by the engine. This allows for batching updates.
          *
          * @param key a string used as the key for the data
-         * @param value a QVariant holding the actual data
+         * @param value a QVariant holding the actual data. If a null or invalid
+         *              QVariant is passed in and the key currently exists in the
+         *              data, then the data entry is removed
          **/
         void setData(const QString& key, const QVariant& value);