diff -r e5618cc85d74 -r 6c158198356e javamanager/javainstaller/installer/javasrc.s60/com/nokia/mj/impl/installer/utils/PropertyProvider.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/javamanager/javainstaller/installer/javasrc.s60/com/nokia/mj/impl/installer/utils/PropertyProvider.java	Thu Aug 19 09:48:13 2010 +0300
@@ -0,0 +1,179 @@
+/*
+* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+*
+*/
+
+
+package com.nokia.mj.impl.installer.utils;
+
+/**
+ * Provides notifications whenever the subscribed property value changes.
+ * <br>
+ * One PropertyProvider instance can be used to subscribe events
+ * for only one property. If events for more properties are needed
+ * use separate PropertyProvider instance for each property.
+ *
+ * @see PropertyListener
+ */
+public class PropertyProvider
+{
+    /** Property category. */
+    private int iCategory = 0;
+    /** Property key. */
+    private int iKey = 0;
+    /** Property listener. */
+    private PropertyListener iListener = null;
+    /** Handle to native object. */
+    private int iHandle = 0;
+
+    /**
+     * Constructor.
+     */
+    public PropertyProvider()
+    {
+    }
+
+    /**
+     * Subscribe to listen changes of specified property value.
+     * One PropertyListener can subscribe to only one property
+     * value at a time.
+     *
+     * @param aCategory property category
+     * @param aKey property key
+     * @param aListener listener to be notified.
+     */
+    public void subscribe(int aCategory, int aKey, PropertyListener aListener)
+    {
+        if (iHandle != 0)
+        {
+            InstallerException.internalError("PropertyProvider already in use.");
+        }
+        iCategory = aCategory;
+        iKey = aKey;
+        iListener = aListener;
+        // Start a new thread which blocks until unsubscribe is called.
+        final PropertyProvider provider = this;
+        new Thread(new Runnable()
+        {
+            public void run()
+            {
+                synchronized (provider)
+                {
+                    iHandle = _subscribe(iCategory, iKey);
+                    // Notify subscribe method after subscription
+                    // result is available.
+                    provider.notify();
+                }
+                if (iHandle > 0)
+                {
+                    // Subscription succeeded, start to process events.
+                    _processEvents(iHandle, provider);
+                }
+            }
+        }, "PropertyProviderThread").start();
+        synchronized (this)
+        {
+            try
+            {
+                if (iHandle == 0)
+                {
+                    // Wait until subscription has been completed.
+                    wait();
+                }
+            }
+            catch (InterruptedException ie)
+            {
+            }
+        }
+        // Check if subscription failed.
+        if (iHandle < 0)
+        {
+            Log.logError("PropertyProvider.subscribe failed with code " + iHandle);
+            iHandle = 0;
+        }
+    }
+
+    /**
+     * Unubscribe from listening changes.
+     */
+    public void unsubscribe()
+    {
+        final PropertyProvider provider = this;
+        new Thread(new Runnable()
+        {
+            public void run()
+            {
+                synchronized (provider)
+                {
+                    if (iHandle <= 0)
+                    {
+                        Log.logWarning(
+                            "PropertyProvider.unsubscribe: no subscription.");
+                        return;
+                    }
+                    int err = _unsubscribe(iHandle);
+                    if (err < 0)
+                    {
+                        Log.logError(
+                            "PropertyProvider.unsubscribe failed with code " +
+                            err);
+                    }
+                    else
+                    {
+                        iHandle = 0;
+                    }
+                }
+            }
+        }, "PropertyProviderUnsubscribeThread").start();
+    }
+
+    /**
+     * Called from native when value for the subscribed property changes.
+     */
+    private void valueChanged(int aValue)
+    {
+        if (iListener != null)
+        {
+            iListener.valueChanged(iCategory, iKey, aValue);
+        }
+    }
+
+    /**
+     * Subscribe to listen changes of specified property value.
+     *
+     * @param aCategory property category
+     * @param aKey property key
+     * @return handle to native side object or Symbian error
+     * code (negative number)
+     */
+    private static native int _subscribe(int aCategory, int aKey);
+
+    /**
+     * Starts to process events. This call blocks until unsubscribe is called.
+     *
+     * @param aHandle handle to native side object
+     * @param aProvider PropertyProvider class instance to be notified
+     * @return 0 or Symbian error code (negative number)
+     */
+    private static native int _processEvents(int aHandle, PropertyProvider aProvider);
+
+    /**
+     * Unubscribe from listening changes.
+     *
+     * @param aHandle handle to native side object
+     * @return 0 or Symbian error code (negative number)
+     */
+    private static native int _unsubscribe(int aHandle);
+}