Bug 38570 Source generation wizards; Add button to open preference page
M1 The Getter/Setter wizard should offer an access to the Code Generation Preference page: Field prefix/suffix, getter/setter body content, method comment template Add delegate, constructor and override could have a button for the method comment template The code to open a preference page programatically can be copied from TodoTaskPropertyPage.showPreferencePage
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/AddDelegateMethodsAction.java
for (int i = 0; i < nElements; i++) {
				Object curr = elements.get(i);
				if (curr instanceof IField) {
					IField fld = (IField) curr;
					if (i == 0) {
						
						cu = fld.getCompilationUnit();
						if (cu == null) {
							return null;
						}
					} else if (!cu.equals(fld.getCompilationUnit())) {
						
						return null;
					}
					try {
						if (fld.getDeclaringType().isInterface()) {
							 
							return null;
						}
					} catch (JavaModelException e) {
						JavaPlugin.log(e);
						return null;
					}
					res[i] = fld;
				} else {
					return null;
				}
			}
			return res;
		}