Index: applications/editors/josm/plugins/walkingpapers/build.xml
===================================================================
--- applications/editors/josm/plugins/walkingpapers/build.xml	(revision 19073)
+++ applications/editors/josm/plugins/walkingpapers/build.xml	(revision 19074)
@@ -1,56 +1,176 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+** This is the build.xml for the walkingpaper plugin
+**
+** Usage
+** =====
+** To build it run
+**
+**    > ant  dist
+**
+** To install the generated plugin locally (in your default plugin directory) run
+**
+**    > ant  install
+**
+** To build against the core in ../../core, create a correct manifest and deploy to
+** SVN, 
+**    set the properties commit.message and plugin.main.version
+** and run
+**    > ant  publish
+**
+**
+-->
 <project name="walkingpapers" default="dist" basedir=".">
-    <property name="josm"                   location="../../core/dist/josm-custom.jar"/>
-    <property name="plugin.dist.dir"        value="../../dist"/>
-    <property name="plugin.build.dir"       value="build"/>
-    <property name="plugin.jar"             value="${plugin.dist.dir}/${ant.project.name}.jar"/>
-    <property name="ant.build.javac.target" value="1.5"/>
-    <target name="init">
-        <mkdir dir="${plugin.build.dir}"/>
-    </target>
-    <target name="compile" depends="init">
-        <echo message="creating ${plugin.jar}"/>
-        <javac srcdir="src" classpath="${josm}" debug="true" destdir="${plugin.build.dir}">
-            <compilerarg value="-Xlint:deprecation"/>
-            <compilerarg value="-Xlint:unchecked"/>
-        </javac>
-    </target>
-    <target name="dist" depends="compile,revision">
-        <copy todir="${plugin.build.dir}/images">
-            <fileset dir="images"/>
-        </copy>
-        <jar destfile="${plugin.jar}" basedir="${plugin.build.dir}">
-            <manifest>
-                <attribute name="Author" value="Frederik Ramm"/>
-                <attribute name="Plugin-Class" value="org.openstreetmap.josm.plugins.walkingpapers.WalkingPapersPlugin"/>
-                <attribute name="Plugin-Date" value="${version.entry.commit.date}"/>
-                <attribute name="Plugin-Description" value="Supports downloading tiled, scanned maps from walking-papers.org. This plugin is still under early development and may be buggy."/>
-                <attribute name="Plugin-Link" value="http://wiki.openstreetmap.org/index.php/JOSM/Plugins/WalkingPapers"/>
-                <attribute name="Plugin-Mainversion" value="2620"/>
-                <attribute name="Plugin-Version" value="${version.entry.commit.revision}"/>
-            </manifest>
-        </jar>
-    </target>
-    <target name="revision">
-        <exec append="false" output="REVISION" executable="svn" failifexecutionfails="false">
-            <env key="LANG" value="C"/>
-            <arg value="info"/>
-            <arg value="--xml"/>
-            <arg value="."/>
-        </exec>
-        <xmlproperty file="REVISION" prefix="version" keepRoot="false" collapseAttributes="true"/>
-        <delete file="REVISION"/>
-    </target>
-    <target name="clean">
-        <delete dir="${plugin.build.dir}"/>
-        <delete file="${plugin.jar}"/>
-    </target>
-    <target name="install" depends="dist">
-        <property environment="env"/>
-        <condition property="josm.plugins.dir" value="${env.APPDATA}/JOSM/plugins" else="${user.home}/.josm/plugins">
-            <and>
-                <os family="windows"/>
-            </and>
-        </condition>
-        <copy file="${plugin.jar}" todir="${josm.plugins.dir}"/>
-    </target>
+
+	<!-- 
+	** update before publishing 
+	-->
+	<property name="commit.message" value="Updated to JOSM 2621" />
+	<property name="plugin.main.version" value="2621" />
+
+	
+	<property name="josm"                   location="../../core/dist/josm-custom.jar"/>
+	<property name="plugin.dist.dir"        value="../../dist"/>
+	<property name="plugin.build.dir"       value="build"/>
+	<property name="plugin.jar"             value="${plugin.dist.dir}/${ant.project.name}.jar"/>
+	<property name="ant.build.javac.target" value="1.5"/>
+	<target name="init">
+		<mkdir dir="${plugin.build.dir}"/>
+	</target>
+	<target name="compile" depends="init">
+		<echo message="creating ${plugin.jar}"/>
+		<javac srcdir="src" classpath="${josm}" debug="true" destdir="${plugin.build.dir}">
+			<compilerarg value="-Xlint:deprecation"/>
+			<compilerarg value="-Xlint:unchecked"/>
+		</javac>
+	</target>
+	<target name="dist" depends="compile,revision">
+		<copy todir="${plugin.build.dir}/images">
+			<fileset dir="images"/>
+		</copy>
+		<jar destfile="${plugin.jar}" basedir="${plugin.build.dir}">
+			<manifest>
+				<attribute name="Author" value="Frederik Ramm"/>
+				<attribute name="Plugin-Class" value="org.openstreetmap.josm.plugins.walkingpapers.WalkingPapersPlugin"/>
+				<attribute name="Plugin-Date" value="${version.entry.commit.date}"/>
+				<attribute name="Plugin-Description" value="Supports downloading tiled, scanned maps from walking-papers.org. This plugin is still under early development and may be buggy."/>
+				<attribute name="Plugin-Link" value="http://wiki.openstreetmap.org/index.php/JOSM/Plugins/WalkingPapers"/>
+				<attribute name="Plugin-Mainversion" value="${plugin.main.version}"/>
+				<attribute name="Plugin-Version" value="${version.entry.commit.revision}"/>
+			</manifest>
+		</jar>
+	</target>
+	<target name="revision">
+		<exec append="false" output="REVISION" executable="svn" failifexecutionfails="false">
+			<env key="LANG" value="C"/>
+			<arg value="info"/>
+			<arg value="--xml"/>
+			<arg value="."/>
+		</exec>
+		<xmlproperty file="REVISION" prefix="version" keepRoot="false" collapseAttributes="true"/>
+		<delete file="REVISION"/>
+	</target>
+	<target name="clean">
+		<delete dir="${plugin.build.dir}"/>
+		<delete file="${plugin.jar}"/>
+	</target>
+	<target name="install" depends="dist">
+		<property environment="env"/>
+		<condition property="josm.plugins.dir" value="${env.APPDATA}/JOSM/plugins" else="${user.home}/.josm/plugins">
+			<and>
+				<os family="windows"/>
+			</and>
+		</condition>
+		<copy file="${plugin.jar}" todir="${josm.plugins.dir}"/>
+	</target>
+
+	<!--
+		 ************************** Publishing the plugin *********************************** 
+		-->
+	<!--
+		** extracts the JOSM release for the JOSM version in ../core and saves it in the 
+		** property ${coreversion.info.entry.revision}
+		**
+		-->
+	<target name="core-info">
+		<exec append="false" output="core.info.xml" executable="svn" failifexecutionfails="false">
+			<env key="LANG" value="C"/>
+			<arg value="info"/>
+			<arg value="--xml"/>
+			<arg value="../../core"/>
+		</exec>
+		<xmlproperty file="core.info.xml" prefix="coreversion" keepRoot="true" collapseAttributes="true"/>
+		<echo>Building against core revision ${coreversion.info.entry.revision}.</echo>
+		<echo>Plugin-Mainversion is set to ${plugin.main.version}.</echo>
+		<delete file="core.info.xml" />
+	</target>
+
+	<!--
+		** commits the source tree for this plugin
+		-->
+	<target name="commit-current">
+		<echo>Commiting the plugin source with message '${commit.message}' ...</echo>
+		<exec append="true" output="svn.log" executable="svn" failifexecutionfails="false">
+			<env key="LANG" value="C"/>
+			<arg value="-m '${commit.message}'"/>
+			<arg value="commit"/>
+			<arg value="."/>
+		</exec>
+	</target>
+
+	<!--
+		** updates (svn up) the source tree for this plugin
+		-->
+	<target name="update-current">
+		<echo>Updating plugin source ...</echo>
+		<exec append="true" output="svn.log" executable="svn" failifexecutionfails="false">
+			<env key="LANG" value="C"/>
+			<arg value="up"/>
+			<arg value="."/>
+		</exec>
+		<echo>Updating ${plugin.jar} ...</echo>
+		<exec append="true" output="svn.log" executable="svn" failifexecutionfails="false">
+			<env key="LANG" value="C"/>
+			<arg value="up"/>
+			<arg value="../dist/${plugin.jar}"/>
+		</exec>
+	</target>
+
+	<!--
+		** commits the plugin.jar 
+		-->
+	<target name="commit-dist">
+		<echo>
+	***** Properties of published ${plugin.jar} *****
+	Commit message    : '${commit.message}'					
+	Plugin-Mainversion: ${plugin.main.version}
+	JOSM build version: ${coreversion.info.entry.revision}
+	Plugin-Version    : ${version.entry.commit.revision}
+	***** / Properties of published ${plugin.jar} *****					
+						
+	Now commiting ${plugin.jar} ...
+	</echo>
+		<exec append="true" output="svn.log" executable="svn" failifexecutionfails="false">
+			<env key="LANG" value="C"/>
+			<arg value="-m '${commit.message}'"/>
+			<arg value="commit"/>
+			<arg value="${plugin.jar}"/>
+		</exec>
+	</target>
+
+	<!-- ** make sure svn is present as a command line tool ** -->
+	<target name="ensure-svn-present">
+		<exec append="true" output="svn.log" executable="svn" failonerror="false" resultproperty="svn.exit.code">
+			<env key="LANG" value="C" />
+			<arg value="--version" />
+		</exec>
+		<fail message="Fatal: command 'svn' not found. Please make sure svn is installed on your system.">
+			<condition>
+				<isfailure code="${svn.exit.code}" />
+			</condition>
+		</fail>
+	</target>
+
+	<target name="publish" depends="ensure-svn-present,core-info,commit-current,update-current,clean,dist,commit-dist">
+	</target>
 </project>
Index: applications/editors/josm/plugins/walkingpapers/src/org/openstreetmap/josm/plugins/walkingpapers/WalkingPapersLayer.java
===================================================================
--- applications/editors/josm/plugins/walkingpapers/src/org/openstreetmap/josm/plugins/walkingpapers/WalkingPapersLayer.java	(revision 19073)
+++ applications/editors/josm/plugins/walkingpapers/src/org/openstreetmap/josm/plugins/walkingpapers/WalkingPapersLayer.java	(revision 19074)
@@ -23,4 +23,5 @@
 import org.openstreetmap.josm.data.osm.visitor.BoundingXYVisitor;
 import org.openstreetmap.josm.gui.MapView;
+import org.openstreetmap.josm.gui.MapView.LayerChangeListener;
 import org.openstreetmap.josm.gui.dialogs.LayerListDialog;
 import org.openstreetmap.josm.gui.dialogs.LayerListPopup;
@@ -69,5 +70,5 @@
 		clearTileStorage();
 
-	    Layer.addLayerChangeListener(new LayerChangeListener() {
+	    MapView.addLayerChangeListener(new LayerChangeListener() {
 	        public void activeLayerChange(Layer oldLayer, Layer newLayer) {
 	        	// if user changes to a walking papers layer, zoom there just as if
@@ -86,5 +87,7 @@
 
 	        public void layerRemoved(Layer oldLayer) {
-	        	//
+	        	if (oldLayer == WalkingPapersLayer.this) {
+	        		MapView.removeLayerChangeListener(this);
+	        	}
 	        }
 	    });