Develop Reference

Android: hide action bar menu views regardless the menu items

I am using navigation drawer to switch between fragments.
And my action bar menu items are different regarding to the fragments.
I want to hide the menu item views when drawer is opened.
Referring to the doc, it suggest to find the menu item by ID and hide the item.
However, my menu items are different with fragments, so, how can I simply hide/show the menu item views on the action bar? Is there some flag to control it?
By the way, I see in the DOC it says I can return false in onPrepareOptionsMenu() to make it not displayed, however I tried and ended up in vain. Did I misunderstand it?
public boolean onPrepareOptionsMenu (Menu menu)
Added in API level 1
Prepare the Screen's standard options menu to be displayed. This is called right before the menu is shown, every time it is shown. You can use this method to efficiently enable/disable items or otherwise dynamically modify the contents.
The default implementation updates the system menu items based on the activity's state. Deriving classes should always call through to the base class implementation.
Parameters
menu The options menu as last shown or first initialized by onCreateOptionsMenu().
Returns
You must return true for the menu to be displayed; if you return false it will not be shown.

If people are still visiting the link, this is how we disable the options menu or options menu items for a fragment.
1) In the onCreateView() method of fragment add the following code
setHasOptionsMenu(true);// then only we can work with the menu items.Without this onPrepareOptionsMenu() method is not called
.
Now override the onPreparedOptionsMenu() method and hide the menu items. If you hide all the menu items the menu will not at all be shown. or use menu.clear() to clear all the menu items
#Override
public void onPrepareOptionsMenu(Menu menu) {
super.onPrepareOptionsMenu(menu);
menu.findItem(R.id.menu_contacts).setVisible(false);
--------------
}

Show and Hide action bar buttons outside onPrepareOptionsMenu

In the overrided public boolean onPrepareOptionsMenu(Menu menu) I can easily hide or show menu buttons simply adding true or false in this way
menu.findItem(R.id.my_action_button).setVisible(true);
but I need to do the same operation also when a different method inside the activity is called,
How could I do this?

Call:
activity.invalidateOptionsMenu();

Android: How to recreate Action bar when fragment changed

I have an activity showing a few fragments.
Activity view contains only ViewPager initialized with custom FragmentPagerAdapter.
This adapter provide navigation among 3 fragments.
All seems to work fine except Action bar.
I override onCreateOptionsMenu() method in my fragments to create individual Action bar for any fragment:
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater)
{
super.onCreateOptionsMenu(menu, inflater);
menu.clear();
//fragment specific menu creation
}
When I do swipe, new fragment appears, but Action bar stay the same for a few seconds. Probably after a few seconds this method are called and Action bar get changed.
This looks pretty bad when action bar are changed in a while after swipe is finished.
How can I recreate action bar immediately, before swipe begin?

You can ask android to re-create the actionbar before it automatically does by calling invalidateOptionsMenu();
Do this somewhere close to the point where you change fragments to try and decrease the 'lag' between the fragment and actionbar changing.
Edit
a complete solution may look like this:
class activity extends Activity{
private void switchFragment(){
...do fragment changing stuff
activity.invalidateOptionsMenu();
}
}
class someFragment extends Fragment{
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater)
{
super.onCreateOptionsMenu(menu, inflater);
menu.clear();
//fragment specific menu creation
}
}
whichever fragment is open during the
activity.invalidateOptionsMenu();
will then call its
onCreateOptionsMenu
and you can do fragment specific menu creation in there

It can be done by implementing onCreateOptionsMenu and calling setHasOptionsMenu(true) in the onAttach callback in each fragment and change the actions accordingly.
To show the fragment without any actions setHasOptionsMenu(false) in it

If you are using ActionBar tabs, You would like to see this answer:
How can I change Action Bar actions dynamically?

Finally I couldn't find any sound way to achieve this.
The best would be to make actionbar a part of fragment, not activity, but it's impossible.
I end up with clearing actionbar menu and title when swipe begins(you can set special listener in PageView) and setting menu and title again when swipe complete and new fragment are shown.
In gives some time lag and actionbar looks strangely empty during swipe, but it's best you can do.
Android API is c...

Android: Multiple Option Menus in one Activity

I have an Activity containing a ViewFlipper and would like to show a different option menu for each view in that ViewFlipper. That is, the type of menu displayed when the menu button is pressed would depend on the type of the current view.
However, onCreateOptionsMenu() is called only once (when showing the option menu for the first time), so creating the different menus can't be implemented there.
How could I solve this?

First read about onPrepareOptionsMenu(Menu menu)
Each time the user presses the Menu on their Android device while inside one of your activities, the onPrepareOptionsMenu method is called. The first time the menu is shown (i.e. only once), the onCreateOptionsMenu method is called.
Basically, the onPrepareOptionsMenu method is where you should make any changes such as enabling/disabling certain menu items, or changing the menu item text depending on the circumstances.
So do this (Don't use onCreateOptionsMenu(Menu menu) )
//Dynamically create context Menu
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
menu.clear(); //Clear view of previous menu
MenuInflater inflater = getMenuInflater();
if(condition_true)
inflater.inflate(R.menu.menu_one, menu);
else
inflater.inflate(R.menu.menu_two, menu);
return super.onPrepareOptionsMenu(menu);
}

In Android, how to change the title of a different MenuItem inside onOptionsItemSelected()

On clicking a certain MenuItem in a Options Menu in Android, I need to change the title of a different MenuItem in the same Menu. What is the way to do this?
When a MenuItem in an options menu is clicked, onOptionsItemSelected(MenuItem menuitem) is called.
You can change the title of the MenuItem which is passed as a parameter in the
onOptionsItemSelected(MenuItem menuitem), but not of any other MenuItem. I need to know how to change the title of a MenuItem that is not passed as parameter to onOptionsItemSelected(), but which belongs to the same Menu.
I did not find a way to get handle to containing Menu inside the onOptionsItemSelected method (which is called when any MenuItem is clicked).
Many Thanks.

From the Android Dev Guide: http://developer.android.com/guide/topics/ui/menus.html
Changing the menu when it opens
The onCreateOptionsMenu() method is called only the first time the Options Menu is opened. The system keeps and re-uses the Menu you define in this method until your Activity is destroyed. If you want to change the Options Menu each time it opens, you must override the onPrepareOptionsMenu() method. This passes you the Menu object as it currently exists. This is useful if you'd like to remove, add, disable, or enable menu items depending on the current state of your application.
Note: You should never change items in the Options Menu based on the View currently in focus. When in touch mode (when the user is not using a trackball or d-pad), Views cannot take focus, so you should never use focus as the basis for modifying items in the Options Menu. If you want to provide menu items that are context-sensitive to a View, use a Context Menu.

You can do it like this.
public boolean onPrepareOptionsMenu(Menu menu) {
menu.clear();
getMenuInflater().inflate(R.menu.photoviewer_menu, menu);
MenuItem item = menu.findItem(R.id.photoviewer_menu_button);
item.setTitle("title");
return super.onPrepareOptionsMenu(menu);
}

This wil work for sure try it............
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.addappointmentmenu, menu);
menu.findItem(R.id.add_appontment_menu).setTitle("Add Appointment");
//Similarly set for all your menu's has above
return true;
}

I'm not sure you can change the title, but you could remove the item and then add another one back in with the same ID with a different title.
Menu foo;
foo.removeItem(id);
foo.add(0, id, 0, R.string.a_new_title);

But when MenuItem is more than six times in the Menu resource and if you click on menu then onPrepareOptionsMenu is called either once or twice.
With a simple click on menu then the onPrepareOptionsMenu is called only once
When you click on menu and then click on the "More" option i.e. sixth option then onPrepareOptionsMenu is called twice.
I hope this will help someone.