Project: Eclipse_Platform_UI
Bug 144225 [FieldAssist] NullPointerException in ContentProposalAdapter$ContentProposalPopup.open()
Reported: 2006-05-29 09:51:59 | Status: verified fixed

I am using Eclipse 3.2RC6 and was playing around with the org.eclipse.jface.fieldassist package. I wanted to implement a simple auto-complete textfield with the ContentProposalAdapter class. But if the first letter which is entered in the textfield does not yield any proposals, the call to getSelectedProposal() in line 859 of ContentProposalAdapter.java returns null and therefore a NPE is thrown, rather than just not showing the popup at all. The following snippet shows this behaviour (just type any letter except "p"): import org.eclipse.jface.fieldassist.ContentProposalAdapter; import org.eclipse.jface.fieldassist.IContentProposal; import org.eclipse.jface.fieldassist.IContentProposalProvider; import org.eclipse.jface.fieldassist.TextContentAdapter; import org.eclipse.swt.SWT; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Text; public class ExampleSnippet { public static void main(String[] args) { Display display = new Display(); Shell shell = new Shell(display); shell.setLayout(new FillLayout()); Text text = new Text(shell, SWT.NONE); ContentProposalAdapter adapter = new ContentProposalAdapter(text, new TextContentAdapter(), new TextProposalProvider(), null, null); adapter.setProposalAcceptanceStyle(ContentProposalAdapter.PROPOSAL_REPLACE); shell.setSize(200, text.getSize().y); shell.open(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) display.sleep(); } display.dispose(); } } class TextProposalProvider implements IContentProposalProvider { private String str = "Proposal"; public IContentProposal[] getProposals(String contents, int position) { IContentProposal[] proposals; if (str.toLowerCase().startsWith(contents.toLowerCase())) { proposals = new IContentProposal[1]; proposals[0] = new IContentProposal() { public String getContent() { return str; } public int getCursorPosition() { return str.length(); } public String getDescription() { return null; } public String getLabel() { return null; } }; } else { proposals = new IContentProposal[0]; } return proposals; } }

Files changed in fix:
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java