For each Fragment I will add Menu Items to provide the user with context related actions. But when switching to another Fragment, the Menu items stayed. So I can end with all options from each fragment in the menu.
How do you clean the menu item to have only the ones set up in the activity menu?
I read about invalidateOptionMenu() and onPrepareOPtionmenu() but I don't really get how they work. What is the correct way to implement it ?
Anyway, how is it that removing fragment-linked menu item when the fragment is not displayed anymore is not native Android behavior?
EDIT if instrucitons not clear enough.
I have one activity supporting Navigation_Mode_Tabs with settings as global menu item.
I start fragA that add itemA1 and itemA2. So I have setting, itemA1, itemA2. So far, so good.
Then I switch to fragB that add its own itemB. HERE, I have settings, itemA1, itemA2, itemB in the menu !
Why itemA1 and itemA2 are stuck? How to remove them?
EDIT 2 : I have try another set up of tabulation from this post and it suddenly menu items seems to be correctly remove !
It's something to see with the use of remove(R.id.container, fragment) versus the onDetach()/onAttach() that Google recommands here
I am looking at this, probably tomorrow I'll update. Please, if you know about this, share :)
you could set the menuinflater on each activity.
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.demo, menu);
return true;
}
You should add TabListener to your tabs and call supportInvalidateOptionsMenu() in onTabSelected() method. It cause call onCreateOptionsMenu(). You should override it in your activity and inflate menu for selected fragment. If you add menu items from code don't forget to clear menu for previous fragment.
Related
I am learning android and I am a bit unsure about how menu options work.Here is the set up I have,
I have a main activity which has a fragment inside it. Main activity's onCreateOptionsMenu looks like this
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
This menu_main.xml just has settings button. I was supposed to add a refresh button in the fragment so I created a new menu xml and added this code in the fragment class
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.tempfragment, menu);
}
When I ran the app and did the longpress, I saw both refresh and setting button.
My question is that when we have a menu options for main activity and for a its associated fragment, what is the flow like? Does it combine both of the menus? I can see it is combining but I am bit unsure regarding how it is getting handled internally? Can somebody explain this to me?
Edit
Here is menu file for the fragment
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto" >
<item android:id="#+id/action_refresh" android:title="action_refresh"
app:showAsAction="never"
/>
</menu>
If you have a MainActivity that inflates an options menu, menu_main.xml, then that options menu will always be present on any fragment that the MainActivity creates.
Within each fragment code, you can create options menus for that specific fragment. Say you inflate menu_friends.xml in FriendsFragment. When an instance of FriendsFragment is created by MainActivity, both menu_main.xml and menu_friends.xml will be shown. You can repeat this for all fragments.
Edit: #Kartheek is incorrect with his answer regarding calling setHasOptionsMenu(true) in a fragment cancelling out the activity's menu. All that statement does is allow a menu to be created by that fragment. Both menus will be included. See here:
Calling setHasOptionsMenu(true) from a fragment results in multiple calls to onCreateOptionsMenu in Activity
Dont forgent thet the main activity conties the fragment, and the actionbar is in the activity, so if you change the fragment its not like you change the activity...
Becuse of it the action bar not change, its just combiens between the action bar thet you have already in the activity, and the actionbar thet you have in the fragment.
Hope its help you :)
when we have a menu options for main activity and for a its associated
fragment ?
If your fragment has called the setHasOptionsMenu to true then onCreateOptionsMenu will be called in your fragment and also in your activity.It actually combines the menu items of the Activity and the Fragment.
Does it combine both of the menus?
Yes. It combines both of them it displays them in a whole.
Can somebody explain this to me?
You can declare items for the options menu from either your Activity subclass or a Fragment subclass. If both your activity and fragment(s) declare items for the options menu, they are combined in the UI. The activity's items appear first, followed by those of each fragment in the order in which each fragment is added to the activity. If necessary, you can re-order the menu items with the android:orderInCategory attribute in each <item> you need to move.
If your activity includes fragments, the system first calls onOptionsItemSelected() for the activity then for each fragment (in the order each fragment was added) until one returns true or all fragments have been called.
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);
--------------
}
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...
I'm building an application with ActionBarSherlock that uses the Dropdown list navigation style. I have it set that each dropdown list item loads a different fragment, and that works fine. What doesn't work is the menu items in the actionbar. I have setHasOptionsMenu(true) in the fragments that I want to have menu items, as well as
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
super.onCreateOptionsMenu(menu, inflater);
inflater.inflate(R.menu.fragment_menu, menu);
}
for the menus in the fragments. Every time I change fragments, I don't want the menu items appended which is what's happening. When one fragment is selected, the menu loads fine, then a different fragment is selected that isn't supposed to have menu items, and the menu items are the same as the previous fragment. Then if I go back to the first fragment, the menu items get doubled because they keep getting appended. How can I control this?
In the normal case the menu shouldn't be appended. What does your menu.xml look like? Do you have id's set? Maybe creating a menu in the Activity?
I figured it out. I wasn't using FragmentTransaction to load the fragments.
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.