buildings_tools: Check for OSM data layer before enter mode

[OliverW]

Select building_mode leads to NP exception, if no data layer is present (see stack trace below).

Expected behaviour: Issue error message

Repository Root: ​http://josm.openstreetmap.de/svn
Build-Date: 2010-04-24 01:31:33
Last Changed Author: stoecker
Revision: 3201
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
URL: ​http://josm.openstreetmap.de/svn/trunk
Last Changed Date: 2010-04-23 23:09:20 +0200 (Fri, 23 Apr 2010)
Last Changed Rev: 3201

Memory Usage: 142 MB / 508 MB (43 MB allocated, but free)
Java version: 1.6.0_17, Sun Microsystems Inc., Java HotSpot(TM) Client VM
Operating system: Windows XP

Plugins: AddrInterpolation,ColumbusCSV,DirectUpload,ElevationProfile,ImageWayPoint,PicLayer,buildings_tools,colorscheme,editgpx,livegps,measurement,openvisible,plastic_laf,slippymap,terracer
Plugin plastic_laf (Version: 19469)
Plugin PicLayer (Version: 20217)
Plugin ImageWayPoint (Version: 19444)
Plugin slippymap (Version: 19887)
Plugin ElevationProfile (Version: 288)
Plugin livegps (Version: 20431)
Plugin AddrInterpolation (Version: 19422)
Plugin terracer (Version: 20956)
Plugin measurement (Version: 19681)
Plugin ColumbusCSV (Version: 299)
Plugin colorscheme (Version: 19426)
Plugin editgpx (Version: 19683)
Plugin openvisible (Version: 20067)
Plugin DirectUpload (Version: 20881)
Plugin buildings_tools (Version: 20269)

java.lang.NullPointerException

at buildings_tools.DrawBuildingAction.enterMode(DrawBuildingAction.java:140)
at org.openstreetmap.josm.gui.MapFrame.selectMapMode(MapFrame.java:265)
at org.openstreetmap.josm.actions.mapmode.MapMode.actionPerformed(MapMode.java:72)
at javax.swing.SwingUtilities.notifyAction(Unknown Source)
at javax.swing.JComponent.processKeyBinding(Unknown Source)
at javax.swing.KeyboardManager.fireBinding(Unknown Source)
at javax.swing.KeyboardManager.fireKeyboardAction(Unknown Source)
at javax.swing.JComponent.processKeyBindingsForAllComponents(Unknown Source)
at javax.swing.JComponent.processKeyBindings(Unknown Source)
at javax.swing.JComponent.processKeyEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.KeyboardFocusManager.redispatchEvent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.dispatchEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

[Upliner]

How have you done this? Drawing tools should be disabled when there's no dataset.

[Upliner]

Fixed

[OliverW]

I pressed the 'W' key