/**
* Inflate a menu hierarchy from the specified XML resource. Throws {@link InflateException} if
* there is an error.
*
* @param menuRes Resource ID for an XML layout resource to load (e.g., <code>R.menu.main_activity
* </code>)
* @param menu The Menu to inflate into. The items and submenus will be added to this Menu.
*/
public void inflate(int menuRes, Menu menu) {
XmlResourceParser parser = null;
try {
parser = mContext.getResources().getLayout(menuRes);
AttributeSet attrs = Xml.asAttributeSet(parser);
parseMenu(parser, attrs, menu);
} catch (XmlPullParserException e) {
throw new InflateException("Error inflating menu XML", e);
} catch (IOException e) {
throw new InflateException("Error inflating menu XML", e);
} finally {
if (parser != null) parser.close();
}
}
/**
* Called internally to fill the given menu. If a sub menu is seen, it will call this recursively.
*/
private void parseMenu(XmlPullParser parser, AttributeSet attrs, Menu menu)
throws XmlPullParserException, IOException {
MenuState menuState = new MenuState(menu);
int eventType = parser.getEventType();
String tagName;
boolean lookingForEndOfUnknownTag = false;
String unknownTagName = null;
// This loop will skip to the menu start tag
do {
if (eventType == XmlPullParser.START_TAG) {
tagName = parser.getName();
if (tagName.equals(XML_MENU)) {
// Go to next tag
eventType = parser.next();
break;
}
throw new RuntimeException("Expecting menu, got " + tagName);
}
eventType = parser.next();
} while (eventType != XmlPullParser.END_DOCUMENT);
boolean reachedEndOfMenu = false;
while (!reachedEndOfMenu) {
switch (eventType) {
case XmlPullParser.START_TAG:
if (lookingForEndOfUnknownTag) {
break;
}
tagName = parser.getName();
if (tagName.equals(XML_GROUP)) {
menuState.readGroup(attrs);
} else if (tagName.equals(XML_ITEM)) {
menuState.readItem(attrs);
} else if (tagName.equals(XML_MENU)) {
// A menu start tag denotes a submenu for an item
SubMenu subMenu = menuState.addSubMenuItem();
// Parse the submenu into returned SubMenu
parseMenu(parser, attrs, subMenu);
} else {
lookingForEndOfUnknownTag = true;
unknownTagName = tagName;
}
break;
case XmlPullParser.END_TAG:
tagName = parser.getName();
if (lookingForEndOfUnknownTag && tagName.equals(unknownTagName)) {
lookingForEndOfUnknownTag = false;
unknownTagName = null;
} else if (tagName.equals(XML_GROUP)) {
menuState.resetGroup();
} else if (tagName.equals(XML_ITEM)) {
// Add the item if it hasn't been added (if the item was
// a submenu, it would have been added already)
if (!menuState.hasAddedItem()) {
if (menuState.itemActionProvider != null
&& menuState.itemActionProvider.hasSubMenu()) {
menuState.addSubMenuItem();
} else {
menuState.addItem();
}
}
} else if (tagName.equals(XML_MENU)) {
reachedEndOfMenu = true;
}
break;
case XmlPullParser.END_DOCUMENT:
throw new RuntimeException("Unexpected end of document");
}
eventType = parser.next();
}
}