Develop Reference

Questions regarding the setting button, action bar and the title changing

I am a noob in android development and I follow the tutoral of the android website.
1. In the part of "Starting Another Activity", I just copied the code and tried to run it, but I found after the activity is changed (changed to new page), the title of action bar will change to the name of the class of that activity.
2. When it talks about the respond of the action button, the code is written as:
public boolean onOptionsItemSelected(MenuItem item) {
// Handle presses on the action bar items
switch (item.getItemId()) {
case R.id.action_search:
openSearch();
return true;
case R.id.action_settings:
openSettings();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
However, in the default code:
`public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}`
It only return true which contains no method to respond(no openSettings()), but a "setting" word still pop out when I press it.
3. How do I remove the action bar and make it full screen?

Don't fully understand your question (you really didn't ask one specifically) but I think this is what you're asking
How to change the title of a new activity?
Here: How do I change the android actionbar title and icon
How does settings open up?
Android does this automatically, if the onCreateOptionsMenu(Menu menu) is called.
How do i make a full screen activity?
Here: Fullscreen Activity in Android?
In the future, be sure to look through Google and StackOverflow for you answers, most likely someone has already asked a similar question

The Name of the activity is, in your case, is declared in AndroidManifest.xml. Check the android:label attribute of your activity. You can manipulate it through java code if you want. See this SO question.
Check the menu file under res/menu/your_menu_file.xml. I think it contains something like
<item
android:id="#+id/action_settings"
android:orderInCategory="100"
android:showAsAction="never"
android:title="#string/action_settings"/>
The displayed icon is NOT setting icon, but overflow icon. If the overflow icon is clicked, it lists all menu items. In your case only one (i.e Setting)
To hide the action bar, include these in your onCreate() method
//getWindow().requestWindowFeature(Window.FEATURE_NO_TITLE);
getActionBar().hide();
You can also do it via xml. Look at this SO question.

Menu onClick attribute and method argument

I'm practising adding menu items and trying to react to menu item clicks. According to the developer's guide, it says:
Tip: Android 3.0 adds the ability for you to define the on-click behavior for a menu item in XML, using the android:onClick attribute. The value for the attribute must be the name of a method defined by the activity using the menu. The method must be public and accept a single MenuItem parameter—when the system calls this method, it passes the menu item selected. For more information and an example, see the Menu Resource document.
However, the sample code in the same page doesn't follow the rule: the methods do not pass the MenuItem parameter. The sample code is:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.new_game:
newGame();
return true;
case R.id.help:
showHelp();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
My question is: Shouldn't method calls be newGame(MenuItem item) and showHelp(MenuItem item), instead of newGame() and showHelp()? When I tested my own, (MenuItem item) argument was needed in fact, otherwise, the app was crashing, even though it compiles correctly.
Any help would be appreciated.

onOptionsItemSelected is the alternative to defining onClick attributes and what is available prior to Android 3.0 (important if you want to be backward compatible). It is simply a different way of providing the same process flow. Of course, onClick has the potential to crash your application on runtime, rather than onOptionsItemSelected not handling a menu item (simply causing it to do nothing).

Android no menu items showing in Action Bar

I am developing an Android app and I am trying to put a menu item into the ActionBar.
It has enough space, so it shouldn't be on the overflow or anything.
In my menu.xml I have added that item + android:showAsAction="ifRoom|withText"
However, no matter how large the screen is, that damn menu will not show up on the ActionBar (although it is present in the menu, if the user presses a key).
Unfortunately I cannot post any full-code since I am under a non-disclosure agreement, but I will answer all questions.
The section where I inflate the menu:
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.drinks, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
case R.id.done:
//stuff
}
return super.onOptionsItemSelected(item);
}

Since you have only a menu item, use this attribute instead: android:showAsAction="always".
EDIT Above works all the time if you're running the code on post Honeycomb. But, in order to run on pre-Honeycomb, according to developer article, you need to extend from ActionBarActivity, that means adding compatibility support v4 & v7 and set the following theme for your activity:
<activity android:theme="#style/Theme.AppCompat.Light" ... >
... or a Them.AppCompat theme. Or use one of your own that extends from these.

ActionBarSherlock: OnOptionsItemSelected doesn't recognize R.id.home

I'm using the ActionBarSherlock library and I'm following the exact steps as suggested here and here to enable navigation to the previous screen.
My code looks like this:
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
and
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// This callback is used only when mSoloFragment == true (see
// onActivityCreated above)
switch (item.getItemId()) {
case android.R.id.home:
// App icon in Action Bar clicked; go up
Intent intent = new Intent(this, MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); // Reuse the
// existing
// instance
startActivity(intent);
return true;
default:
return super.onOptionsItemSelected(item);
}
But R.id.home is not recognized and home shows up in red. :-/ If I use the native actionbar the home declaration takes me to ids.xml file. But here the declaration is not found while I use the ActionBarSherlock Activity. Am I missing something?

just replace this
android.R.id.home
to
R.id.home
and check your code... run it
because
R.layout.* are layouts you provide (in res/layout, for example).
android.R.layout.* are layouts that ship with the Android SDK.

I know this is an old question but I believe the right answer is missing.
It should be be android.R.id.home because it is a platform resource, so your code is fine.
Make sure your minSdkVersion is 11 or higher since home was introduced in 11.

I remeber running into this problem and apparently its quite frequent a quick google or search through stack overflow should've given you some insight anyways check this thread out R cannot be resolved - Android error
Im pretty sure your running into same problem

Android - keep options menu open

I have an Options menu up and running in my Android application and I've overridden the onCreateOptionsMenu, onOptionsItemSelected and onPrepareOptionsMenu methods to customize the menu a little.
My question is related to keeping the Options menu open after the user clicks on a menu item. Basically, I'd like to be able to hide the menu until the user clicks on the device menu key. Once the user clicks on this key, I'd like to be able to hold the menu in place regardless of how many times the user clicks on menu items. If the user wants to hide the Options menu, they'd just need to click on the device menu key again.
Is this type of interaction supported (or even advisable). If this interaction is not supported, any alternative suggestions are more than welcome.
Cheers!
Sean

This will not be possible with onCreateOptionsMenu and the other methods. They always act that way.
But you can do it another way. But there you have to program the whole menu yourself. Basically add the Menu in your layout.xml and let it be hidden (visibility = gone). Then you overwrite the methods onKeyDown. There you check if it is the Menu key. if the menu is not yet open yes, then you show the menu. If it is open already, you hide it.
should not be too difficult. Good thing as well is, that you can make the menu look exactly the way you want and as well let it react the way you want.

For anybody like me, who found this question in google:
To keep menu open after selecting item, you need this code:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
item.setChecked(!item.isChecked());
item.setShowAsAction(MenuItem.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW);
item.setActionView(new View(this));
item.setOnActionExpandListener(new MenuItem.OnActionExpandListener() {
#Override
public boolean onMenuItemActionExpand(MenuItem item) {
return false;
}
#Override
public boolean onMenuItemActionCollapse(MenuItem item) {
return false;
}
});
return false;
}
Important to return false in onOptionsItemSelected and methods of OnActionExpandListener
This solution from #MayurGajra. More details here: How to hold the overflow menu after I click it？