Index: /trunk/src/org/openstreetmap/josm/actions/mapmode/DeleteAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/mapmode/DeleteAction.java	(revision 1378)
+++ /trunk/src/org/openstreetmap/josm/actions/mapmode/DeleteAction.java	(revision 1379)
@@ -15,4 +15,6 @@
 import org.openstreetmap.josm.data.osm.WaySegment;
 import org.openstreetmap.josm.gui.MapFrame;
+import org.openstreetmap.josm.gui.layer.Layer;
+import org.openstreetmap.josm.gui.layer.OsmDataLayer;
 import org.openstreetmap.josm.tools.ImageProvider;
 import org.openstreetmap.josm.tools.Shortcut;
@@ -129,3 +131,7 @@
         return tr("Click to delete. Shift: delete way segment. Alt: don't delete unused nodes when deleting a way. Ctrl: delete referring objects.");
     }
+    
+    @Override public boolean layerIsSupported(Layer l) {
+        return l instanceof OsmDataLayer;
+    }
 }
Index: /trunk/src/org/openstreetmap/josm/actions/mapmode/DrawAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/mapmode/DrawAction.java	(revision 1378)
+++ /trunk/src/org/openstreetmap/josm/actions/mapmode/DrawAction.java	(revision 1379)
@@ -50,4 +50,6 @@
 import org.openstreetmap.josm.gui.MapView;
 import org.openstreetmap.josm.gui.layer.MapViewPaintable;
+import org.openstreetmap.josm.gui.layer.Layer;
+import org.openstreetmap.josm.gui.layer.OsmDataLayer;
 import org.openstreetmap.josm.tools.ImageProvider;
 import org.openstreetmap.josm.tools.Pair;
@@ -647,3 +649,7 @@
         return rv.toString();
     }
+    
+    @Override public boolean layerIsSupported(Layer l) {
+        return l instanceof OsmDataLayer;
+    }
 }
Index: /trunk/src/org/openstreetmap/josm/actions/mapmode/ExtrudeAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/mapmode/ExtrudeAction.java	(revision 1378)
+++ /trunk/src/org/openstreetmap/josm/actions/mapmode/ExtrudeAction.java	(revision 1379)
@@ -29,4 +29,6 @@
 import org.openstreetmap.josm.gui.MapView;
 import org.openstreetmap.josm.gui.layer.MapViewPaintable;
+import org.openstreetmap.josm.gui.layer.Layer;
+import org.openstreetmap.josm.gui.layer.OsmDataLayer;
 import org.openstreetmap.josm.tools.ImageProvider;
 import org.openstreetmap.josm.tools.Shortcut;
@@ -257,3 +259,7 @@
         }
     }
+		
+		@Override public boolean layerIsSupported(Layer l) {
+				return l instanceof OsmDataLayer;
+		}
 }
Index: /trunk/src/org/openstreetmap/josm/actions/mapmode/MapMode.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/mapmode/MapMode.java	(revision 1378)
+++ /trunk/src/org/openstreetmap/josm/actions/mapmode/MapMode.java	(revision 1379)
@@ -10,4 +10,5 @@
 import org.openstreetmap.josm.Main;
 import org.openstreetmap.josm.actions.JosmAction;
+import org.openstreetmap.josm.gui.layer.Layer;
 import org.openstreetmap.josm.gui.MapFrame;
 import org.openstreetmap.josm.tools.ImageProvider;
@@ -71,4 +72,10 @@
             Main.map.selectMapMode(this);
     }
+    
+    // By default, all tools will work with all layers. Can be overwritten to require
+    // a special type of layer
+    public boolean layerIsSupported(Layer l) {
+        return true;
+    }
 
     public void mouseReleased(MouseEvent e) {}
Index: /trunk/src/org/openstreetmap/josm/actions/mapmode/SelectAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/mapmode/SelectAction.java	(revision 1378)
+++ /trunk/src/org/openstreetmap/josm/actions/mapmode/SelectAction.java	(revision 1379)
@@ -32,4 +32,6 @@
 import org.openstreetmap.josm.data.osm.visitor.AllNodesVisitor;
 import org.openstreetmap.josm.data.osm.visitor.SimplePaintVisitor;
+import org.openstreetmap.josm.gui.layer.Layer;
+import org.openstreetmap.josm.gui.layer.OsmDataLayer;
 import org.openstreetmap.josm.gui.MapFrame;
 import org.openstreetmap.josm.gui.MapView;
@@ -395,3 +397,7 @@
         }
     }
+    
+    @Override public boolean layerIsSupported(Layer l) {
+        return l instanceof OsmDataLayer;
+    }
 }
Index: /trunk/src/org/openstreetmap/josm/gui/MapView.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/MapView.java	(revision 1378)
+++ /trunk/src/org/openstreetmap/josm/gui/MapView.java	(revision 1379)
@@ -15,8 +15,10 @@
 import java.awt.image.BufferedImage;
 import java.util.ArrayList;
+import java.util.Enumeration;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedList;
 
+import javax.swing.AbstractButton;
 import javax.swing.JComponent;
 import javax.swing.JOptionPane;
@@ -25,4 +27,5 @@
 import org.openstreetmap.josm.actions.AutoScaleAction;
 import org.openstreetmap.josm.actions.JosmAction;
+import org.openstreetmap.josm.actions.mapmode.MapMode;
 import org.openstreetmap.josm.actions.MoveAction;
 import org.openstreetmap.josm.data.Bounds;
@@ -357,4 +360,13 @@
                 l.activeLayerChange(old, layer);
         }
+        
+        /* This only makes the buttons look disabled. Disabling the actions as well requires
+         * the user to re-select the tool after i.e. moving a layer. While testing I found
+         * that I switch layers and actions at the same time and it was annoying to mind the
+         * order. This way it works as visual clue for new users */
+        for (Enumeration e = Main.map.toolGroup.getElements() ; e.hasMoreElements() ;) {
+            AbstractButton x=(AbstractButton)e.nextElement();
+            x.setEnabled(((MapMode)x.getAction()).layerIsSupported(layer));
+        }
         repaint();
     }