Android Layout Editor cannot open file

Question

I am working through the Android Google Maps tutorial here http://developer.android.com/resources/tutorials/views/hello-mapview.html using Eclipse 3.6 and Google API's 10 revision 1.

However, whenever I try to edit the 'Main.xml' file, the following error is thrown by the editor:

java.lang.NullPointerException
    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.renderWithBridge(Unknown Source)
    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.recomputeLayout(Unknown Source)
    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.activated(Unknown Source)
    at com.android.ide.eclipse.adt.internal.editors.layout.LayoutEditor.pageChange(Unknown Source)
    at org.eclipse.ui.part.MultiPageEditorPart.setActivePage(MultiPageEditorPart.java:1067)
    at org.eclipse.ui.forms.editor.FormEditor.setActivePage(FormEditor.java:607)
    at org.eclipse.ui.part.MultiPageEditorPart.createPartControl(MultiPageEditorPart.java:352)
    at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:670)
    at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:465)
    at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
    at org.eclipse.ui.internal.EditorReference.getEditor(EditorReference.java:289)
    at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2863)
    at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2768)
    at org.eclipse.ui.internal.WorkbenchPage.access$11(WorkbenchPage.java:2760)
    at org.eclipse.ui.internal.WorkbenchPage$10.run(WorkbenchPage.java:2711)
    at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
    at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2707)
    at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2691)
    at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2674)
    at org.eclipse.ui.ide.IDE.openEditor(IDE.java:683)
    at com.android.ide.eclipse.adt.internal.wizards.newxmlfile.NewXmlFileWizard.performFinish(Unknown Source)
    at org.eclipse.jface.wizard.WizardDialog.finishPressed(WizardDialog.java:811)
    at org.eclipse.jface.wizard.WizardDialog.buttonPressed(WizardDialog.java:430)
    at org.eclipse.jface.dialogs.Dialog$2.widgetSelected(Dialog.java:624)
    at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:234)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
    at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4066)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3657)
    at org.eclipse.jface.window.Window.runEventLoop(Window.java:825)
    at org.eclipse.jface.window.Window.open(Window.java:801)
    at org.eclipse.ui.internal.handlers.WizardHandler$New.executeHandler(WizardHandler.java:254)
    at org.eclipse.ui.internal.handlers.WizardHandler.execute(WizardHandler.java:274)
    at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:293)
    at org.eclipse.core.commands.Command.executeWithChecks(Command.java:476)
    at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:508)
    at org.eclipse.ui.internal.handlers.HandlerService.executeCommand(HandlerService.java:169)
    at org.eclipse.ui.internal.handlers.SlaveHandlerService.executeCommand(SlaveHandlerService.java:241)
    at org.eclipse.ui.internal.actions.CommandAction.runWithEvent(CommandAction.java:157)
    at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:584)
    at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:501)
    at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:411)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
    at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4066)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3657)
    at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2640)
    at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2604)
    at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2438)
    at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:671)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:664)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:115)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:369)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:619)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:574)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1407)

Any clues on what I am doing wrong/possible fixes would be much appreciated.

Thanks

NigelT

Answer 1

I just had some similar issues. It turns out I didn't have all of the web tool plugins installed properly. Look into installing the Web Tools: http://download.eclipse.org/webtools/repository/indigo/

(or .../helios/ , if that's your Eclipse flavor)

If you did like me and installed only portions of the web tools, you may have problems later. If you want to load the full thing, go back and uninstall the partially-installed plugin first.

Uninstall Navigation:

[Eclipse (Mac) || Help (Win)] -> About Eclipse SDK -> Installation Details -> Select Plugin -> Uninstall...

Install Navigation:

Help -> Install New Software... -> Work with: <install URL>

Answer 2

hmmm, i dunno what is causing the problem but it looks like it is an issue with the graphical xml editor in eclipse. As a quick workaround, have you tried right-clicking main.xml in the package explorer, and doing 'Open With -> Text Editor' ?