From 9250bd82b49f8cf755af19bc54edccaee24eaa55 Mon Sep 17 00:00:00 2001
From: "Aaron J. Seigo" <aseigo@kde.org>
Date: Thu, 24 Apr 2008 20:16:21 +0000
Subject: [PATCH] put sourceLimit back in, add an accessor as well. used by
 akonadi

svn path=/trunk/KDE/kdebase/workspace/libs/plasma/; revision=800769
---
 dataengine.cpp                 | 20 ++++++++++++++++++++
 dataengine.h                   | 17 +++++++++++++++++
 scripting/dataenginescript.cpp |  7 +++++++
 scripting/dataenginescript.h   |  1 +
 4 files changed, 45 insertions(+)

diff --git a/dataengine.cpp b/dataengine.cpp
index 52bb65eb3..215dee67b 100644
--- a/dataengine.cpp
+++ b/dataengine.cpp
@@ -418,6 +418,26 @@ void DataEngine::addSource(DataContainer* source)
     emit sourceAdded(source->objectName());
 }
 
+void DataEngine::setSourceLimit(uint limit)
+{
+    if (d->limit == limit) {
+        return;
+    }
+
+    d->limit = limit;
+
+    if (d->limit > 0) {
+        d->trimQueue();
+    } else {
+        d->sourceQueue.clear();
+    }
+}
+
+uint DataEngine::sourceLimit() const
+{
+    return d->limit;
+}
+
 void DataEngine::setMinimumPollingInterval(int minimumMs)
 {
     d->minPollingInterval = minimumMs;
diff --git a/dataengine.h b/dataengine.h
index 5b4fc27e9..5e462aeaf 100644
--- a/dataengine.h
+++ b/dataengine.h
@@ -196,6 +196,14 @@ class PLASMA_EXPORT DataEngine : public QObject
          */
         bool isEmpty() const;
 
+        /**
+         * Returns the maximum number of sources this DataEngine will list
+         * at any given time.
+         *
+         * @return the maximum number of sources; zero means no limit.
+         */
+        uint sourceLimit() const;
+
         /**
          * @return the name of the icon for this data engine; and empty string
          *         is returned if there is no associated icon.
@@ -307,6 +315,15 @@ class PLASMA_EXPORT DataEngine : public QObject
          **/
         void addSource(DataContainer* source);
 
+        /**
+         * Sets an upper limit on the number of data sources to keep in this engine.
+         * If the limit is exceeded, then the oldest data source, as defined by last
+         * update, is dropped.
+         *
+         * @param limit the maximum number of sources to keep active
+         **/
+        void setSourceLimit(uint limit);
+
         /**
          * Sets the minimum amount of time, in milliseconds, that must pass between
          * successive updates of data. This can help prevent too many updates happening
diff --git a/scripting/dataenginescript.cpp b/scripting/dataenginescript.cpp
index 701ad8c37..c2ff49046 100644
--- a/scripting/dataenginescript.cpp
+++ b/scripting/dataenginescript.cpp
@@ -92,6 +92,13 @@ void DataEngineScript::removeData(const QString& source, const QString& key)
     }
 }
 
+void DataEngineScript::setSourceLimit(uint limit)
+{
+    if (d->dataEngine) {
+        d->dataEngine->setSourceLimit(limit);
+    }
+}
+
 void DataEngineScript::setMinimumPollingInterval(int minimumMs)
 {
     if (d->dataEngine) {
diff --git a/scripting/dataenginescript.h b/scripting/dataenginescript.h
index 13c85eb80..4d42bd4af 100644
--- a/scripting/dataenginescript.h
+++ b/scripting/dataenginescript.h
@@ -80,6 +80,7 @@ protected:
     void setData(const QString &source, const QVariant &value);
     void clearData(const QString& source);
     void removeData(const QString& source, const QString& key);
+    void setSourceLimit(uint limit);
     void setMinimumPollingInterval(int minimumMs);
     int  minimumPollingInterval() const;
     void setPollingInterval(uint frequency);