Develop Reference

How to change text content in bottomNavigationView dynamically

I've got bottomNavigationView which is already created and attach to activity. Currently I'm trying to find out how to change text in one of navigation items which are inflated from res-menu dynamically.
I've tried to look into existing threads and none of that help me (I've already tried to pick menu from onCreateOptionsMenu and change it with setTitle option later but that wouldn't change text in the activity)
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu, menu);
this.menu = menu;
return true;
}
//later update on button click (this action is performed)
menu.findItem(R.id.secondItem).setTitle("New Text");
I've expected to change text to "New Text" but it's still same as before

Okay after a while of trying I've finally figured out how to do that. Instead of taking menu during onCreateOptionsMenu I've pick menu directly from bottomNavigationView when I click on the button
//your code to invoke this action
Menu menu = bottomNavigationView.getMenu();
menu.getItem(2).setTitle("New Text");

try this method inside your activity/fragment:
public void setNavigationTitle(String title) {
MenuItem menuItem = bottomNavigationView.getMenu().findItem(R.id.action_navigation_next);
menuItem.setTitle(title);
}

Android: Change menu item from Log in to Log out

My menu has a item to Log in, but when you are logged in I want it to say Log out.
How?
If I'm going to change the item after its created, its probably through this method
#Override
public boolean onCreateOptionsMenu( Menu menu ) {
MenuInflater inflater = getMenuInflater();
inflater.inflate( R.menu.menu_main, menu );
return true;
}
Afaik the onCreateOptionsMenu() happens after the onCreate so putting any getItemId() for the menu there will give me a NullPointerException right away.
I want the app to find out if its supposed to use the string R.string.Logout if its logged in.
I dont even know what to search for for this issue. All I found was how to make a string implement names, like this answer https://stackoverflow.com/a/7646689/3064486

You should use onPrepareOptionsMenu(Menu menu) instead to update menu items
#Override
public boolean onPrepareOptionsMenu(Menu menu){
super.onPrepareOptionsMenu(menu);
MenuItem someMenuItem = menu.findItem(R.id.some_menu_item);
someMenuItem.setTitle("Log out");
return super.onPrepareOptionsMenu(menu);
}
To refresh Menu items call invalidateOptionsMenu();from Activity
From Android API guides: "If you want to modify the options menu based on events that occur during the activity lifecycle, you can do so in the onPrepareOptionsMenu() method. This method passes you the Menu object as it currently exists so you can modify it, such as add, remove, or disable items. (Fragments also provide an onPrepareOptionsMenu() callback.)"

After you inflate a menu, you can customize its items. To get each one, you must call findItem() with the item's id. In particular, you can use setTitle() to change the displayed string.
For example:
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
if (mIsLoggedIn)
menu.findItem(R.id.action_login).setTitle("Log out");
return true;
}
where action_login is the id you set for this particular menu item in the menu's xml file.

private void updateUI() {
runOnUiThread(new Runnable() {
#Override
public void run() {
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
Menu menu = navigationView.getMenu();
MenuItem nav_signin = menu.findItem(R.id.nav_signin);
nav_signin.setTitle(MyApp.signedIn ? "Sign out" : "Sign in");
}
});
}

Google Glass : OnCreateOptionsMenu

I am trying to modify the title of menu item on google glass dynamically.
As there is no hardware menu button and My activity is themed NoActionBarFullScreen,
creating and initializing the Menu menu item in onCreateOptionsMenu always give null value because onCreateOptionsMenu never called. So how to do that ?
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.gatt_services, menu);
if (!init) {
// I want to do this outside of this function also
menu.findItem(R.id.menu_connect).setTitle("Connect"); }
else {
menu.findItem(R.id.menu_connect).setTitle("Disconnect");
}
// so I initialized this variable here
this.menu = menu; // but this is always null
return true;
}
MenuItem connetItem = menu.findItem(R.id.menu_connect); // App crashes
So how do i access this menu item and change its title?

Interaction between Activity and Fragments

In my application the main activity hosts two fragments and attached to acticity as ActionBarTabs. using the following code. NOTE: activity and the 2 fragments are defined in seperate xml layout files (See the picture at the bottom)
private void createActionTabs() {
ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
//Status Tab
String strStatus = getResources().getString(R.string.lblStatus);
ActionBar.Tab statusTab = actionBar.newTab();
statusTab.setText(strStatus);
TabListener<SFrag> sFTabListener = new TabListener<SFrag>(this, strStatus, SFrag.class);
statusTab.setTabListener(sFTabListener);
actionBar.addTab(statusTab);
//Controller Tab attached the same way
.....
}
The ActionBar Items (start and refresh) are added using
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main_menu, menu);
return true;
}
Now coming to my problem:
I want to update the data shown on the Status Fragment at application load, fragment resume and click of refresh menu item from the action bar. Now when I try to access the Status fragment from Main Activity using the following code
SFrag frag = (SFrag) getFragmentManager().findFragmentById(R.id.st_frag);
Log.d(TAG, "In Activity SFrag is " + (frag == null ? "null" : "not null"));
if (frag != null) {
//calls the method to update data
fragment.updateStatusData(statusInformation);
}
The getFragmentManager().findFragmentById methods always returns null. I even tried the onResume method of the activity, the fragment objects is still returned as null. So how do I access the fragment and thus accessa method of that fragment from host acticty.
Secondly, I am trying to use the action_service (its shown as Start button just for this mockup) in action bar as a toggle for satrting or stopping a background service. I can easily update the title/icon for start menu item from onOptionsItemSelected method (I save the current status running/stoppede in shared-preferences). but when I try to accees the menuItem at onStart/onResume of the activity by using
MenuItem mi = (MenuItem) findViewById (R.id.action_service);
it always returns null. So How Can I access action_service menu Item in onResume/onStart to update it.
My Application looks like this

First of all if you want to declare MenuItem, you should do it in this way :
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getSupportMenuInflater().inflate(R.menu.main_activity, menu);
MenuItem mRefresh = menu.findItem(R.id.refresh_menu_item);
return true;
}
About updating your Fragment on applications load or Activity's start, just set selected the tab which holds your Fragment and put the code which will load the data in your Fragment on it's onStart() or onActivityCreated() method. You can override onOptionsItemSelected() in your Fragment, so you can update your views not from your Activity which holds your Fragment, but from it's own class.
Edit: Here is an example how you should handle menu from your Fragment :
public class MyFragment extends Fragment {
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setHasOptionsMenu(true); // Do not forget this!!!
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
super.onCreateOptionsMenu(menu, inflater);
inflater.inflate(R.menu.first_fragment, menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
switch (item.getItemId()) {
case R.id.action_refresh:
// Do You stuff here
break;
}
return super.onOptionsItemSelected(item);
}
}
Using this you can add and use MenuItem's in your Fragment.
Hope this helps!

I can answer the MenuItem part just not the other part.
for the menu item as per the docs You can safely hold on to menu (and any items created from it), making modifications to it as desired, until the next time onCreateOptionsMenu() is called.
for example
#Override
public boolean onCreateOptionsMenu(Menu menu) {
actionMenu = menu;
return true;
}
so basically anytime you want to change one of the items you can do this
MenuItem item = actionMenu.getItem(0);

How to enable/disable MenuItem based on change in class variable

I have an options menu in an Activity with three MenuItems
create
select
delete
When there is no item currently selected I disable the MenuItem for delete.
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
final MenuInflater inflater = getMenuInflater();
inflater.inflate(R.layout.basic_menu, menu);
this.deleteCharMenu = menu.findItem(R.id.basic_menu_deletechar);
this.deleteCharMenu.setEnabled(this.current != null);
return true;
}
However onCreateOptionsMenu is not called every time the menu is opened (try and error got me this result).
So I stored the MenuItem in a class variable to be able to change its state whenever this.current changed its value.
Is there a more elegant method to ensure that the correct MenuItems are enabled and disabled? I am hoping for some kind of listener I can use?

overload the onPrepareMenu , it is called right before it's shown.