Bug 88878 [Preferences] File and Content Type pages should link to one another
There should be some mention of the relationship between content type and file association pages.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/ContentTypesPreferencePage.java
for (Iterator i = elements.iterator(); i.hasNext();) {
                                Spec spec = (Spec) i.next();
                                if (spec.isPredefined)
                                    enabled = false;
                            }
                            removeButton.setEnabled(enabled);
                        }
                    });
        }
        {
            Composite buttonArea = new Composite(composite, SWT.NONE);
            GridLayout layout = new GridLayout(1, false);
            layout.marginHeight = layout.marginWidth = 0;
            buttonArea.setLayout(layout);
            GridData data = new GridData(GridData.VERTICAL_ALIGN_BEGINNING);
            buttonArea.setLayoutData(data);
            addButton = new Button(buttonArea, SWT.PUSH);
            addButton.setFont(composite.getFont());
            setButtonLayoutData(addButton);
            addButton
                    .setText(IDEWorkbenchMessages.ContentTypes_fileAssociationsAddLabel);
            addButton.setEnabled(false);
            addButton.addSelectionListener(new SelectionAdapter() {
                /*
                 * (non-Javadoc)
                 * 
                 * @see org.eclipse.swt.events.SelectionAdapter#widgetSelected(org.eclipse.swt.events.SelectionEvent)
                 */
                public void widgetSelected(SelectionEvent e) {
                    Shell shell = e.widget.getDisplay().getActiveShell();