Bug 90569 combobox needs to remember more items
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/search/JavaSearchPage.java
public void widgetSelected(SelectionEvent e) {
				handlePatternSelected();
				updateOKStatus();
			}
		});
		fPattern.addModifyListener(new ModifyListener() {
			public void modifyText(ModifyEvent e) {
				doPatternModified();
				updateOKStatus();
			}
		});
		GridData data= new GridData(GridData.FILL, GridData.FILL, true, false, 1, 1);
		data.widthHint= convertWidthInCharsToPixels(50);
		fPattern.setLayoutData(data);
				
		fCaseSensitive= new Button(result, SWT.CHECK);
		fCaseSensitive.setText(SearchMessages.getString("SearchPage.expression.caseSensitive")); 
		fCaseSensitive.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent e) {
				fIsCaseSensitive= fCaseSensitive.getSelection();
			}
		});
		fCaseSensitive.setLayoutData(new GridData(GridData.FILL, GridData.FILL, false, false, 1, 1));
		
		return result;
	}
	
	final void updateOKStatus() {
		boolean isValid= isValidSearchPattern();
		getContainer().setPerformActionEnabled(isValid);