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Bug 325261

Summary:	[Wizards] NullPointerException in WizardDialog.updateButtons
Product:	[Eclipse Project] Platform	Reporter:	Adriaan Peeters <apeeters>
Component:	UI	Assignee:	Platform UI Triaged <platform-ui-triaged>
Status:	RESOLVED INVALID	QA Contact:	Prakash Rangaraj <prakash>
Severity:	normal
Priority:	P3	CC:	remy.suen
Version:	3.6
Target Milestone:	---
Hardware:	All
OS:	Mac OS X - Carbon (unsup.)
Whiteboard:

Description Adriaan Peeters

2010-09-14 10:28:54 EDT

Build Identifier: 20100617-1415

When WizardDialog.updateButtons is called without a current page, a NullPointerException is thrown.

updateButtons should, similar to updateMessage, start with a null check of the currentPage variable.

Reproducible: Always

Comment 1 Prakash Rangaraj

2010-09-17 01:27:24 EDT

Do you have a stack trace? I was wondering how is updateButtons() get called without the current page set

Comment 2 Adriaan Peeters

2010-09-23 04:16:40 EDT

I do not have a concrete stack trace but I encountered this 'bug' in the following scenario.

I have a wizard that updates its buttons on changes in the underlying data model (using a listener). This data model might change before the wizard is open, hence triggering the listener which calls updateButtons. In this method currentPage is referenced, which is null.

Comment 3 Adriaan Peeters

2010-09-23 04:22:17 EDT

A simplified stack trace follows:

java.lang.NullPointerException
	at org.eclipse.jface.wizard.WizardDialog.updateButtons(WizardDialog.java:1326)
        ...
        updateButtons is called somehow during createControl
        ...
	at com.example.WizardPage.createControl(WizardPage.java:32)
	at org.eclipse.jface.wizard.Wizard.createPageControls(Wizard.java:170)
	at org.eclipse.jface.wizard.WizardDialog.createPageControls(WizardDialog.java:734)
	at org.eclipse.jface.wizard.WizardDialog.createContents(WizardDialog.java:606)
	at org.eclipse.jface.window.Window.create(Window.java:431)
	at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1089)
	at org.eclipse.jface.window.Window.open(Window.java:790)

Comment 4 Prakash Rangaraj

2010-09-29 02:21:52 EDT

The updateButtons() sets the enablement of the back/next buttons. You cannot do this before the creation of all the wizard pages. So calling the updateButtons() in the wizardPage.createControl() method is not correct.

You can probably move the logic to the setVisible() method