I have a settings menu item that is generated in MainActivity. All the MainActivity's job is to contain fragments that actually do the job. Those fragments have their own action bar items and they work as expected.
The settings menu item should show/hide, depending on a certain condition that is changing between fragments, so assuming the code is on MainActivity, it should be:
if (condition) menu.findItem(R.id.action_settings).setVisible(false);
else menu.findItem(R.id.action_settings).setVisible(true);
Now I'm wondering where should I place the code because the condition changes between fragments but the actual menu item is on MainActivity.
Your condition might be OK and you can put it in your Activity's onPrepareOptionsMenu().
As you said this gets called just one time when you enter the Activity (with some exceptions).
You need to force the system to recall the Activity onPrepareOptionsMenu() when switching through fragments, and that is done - from anywhere - with the line invalidateOptionsMenu() (or, if necessary, getActivity().invalidateOptionsMenu()).
Good points to paste it might be Fragments onResume(), or any other point at which you think your condition state has changed.
Depending on your libraries, there's also a support method for API<11 called supportInvalidateOptionsMenu().
This should be called each time you want your Menu to change. However, if your fragments just add some items to a base, activity menu, take a look at this.
i think it is gonna work for you
public boolean onPrepareOptionsMenu(Menu menu) {
// if nav drawer is opened, hide the action items
boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
menu.findItem(R.id.action_settings).setVisible(!drawerOpen);
return super.onPrepareOptionsMenu(menu);
}
Related
I would like to enable/disable the entire overflow menu in my Toolbar at runtime according to certain user actions. This is all within the same fragment. I tried just returning out of onPrepareOptionsMenu() if the condition holds, which hides the three dot icon as soon as the user touches it. However, I can't figure out how to then show the options menu again.
Calling getActivity().invalidateOptionsMenu() invokes onPrepareOptionsMenu() again, where you can load/not load the menu based on your conditions.
Just want to add one more thing if you want to show or hide the menu again without even inflating them. You can use oncreateoptions menu parameter like this
Menu overflow;
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.mymenu, menu);
this.overflow = menu;
return super.onCreateOptionsMenu(menu);
}
and then make a function to show or hide any menu item according to the index. for e.g.
public void hideorShowMenuItems(boolean bool){
overflow.getItem(1).setVisible(bool);
overflow.getItem(2).setVisible(bool);
overflow.getItem(3).setVisible(bool);
}
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);
--------------
}
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.
I need to make two minor changes to an Activity's ActionBar from a Fragment.
The parent FragmentActivity's onCreateOptionMenu and onPrepareOptions handle the menu across the app.
However, in the containing main Fragment view, I want the ActionBar title to change for the sake of navigation. Each time the Fragment changes.
Also, in one instance, I want to add a single menu item as defined in the layout. I rather not duplicate code for this part, do I have to override the same methods and set up entire menu again, including onOptionSelected? Or...?
Edit:
On my menu xml layout, I have this item:
<item
android:id="#+id/Add"
android:title="Add Items"/>
This item needs to be seen in the ActionBar only for one particular Fragment. The rest of the menu is identical to what should be seen for the rest of the app. In the fragment where I need this new item, do I have to also do onCreateOptionsMenu, onPrepareOptionsMenu, and onOptionsItemSelected all over again and duplicate thee OTHER menu items as well? Or can I override those in the Fragment and just pop that one extra menu item in?
1.
getActivity().getActionBar().setTitle();
or
getActivity.getSupportActionBar().setTitle();
more clarification please :)
This answered what I needed for part 2.
Putting this in onActivityCreated:
setHasOptionsMenu(true);
And then adding this too:
#Override
public void onPrepareOptionsMenu(Menu menu) {
super.onPrepareOptionsMenu(menu);
ActivityCompat.invalidateOptionsMenu(getActivity());
MenuItem Add = menu.findItem(R.id.Add);
Add.setVisible(true);
}
The parent Activity sets the R.id.Add as invisible by default.
My app uses tab navigation with Actionbar Sherlock to switch between two fragments each with their own listview. Also, each fragment has it's own options menu associated with it, so within my two fragment classes I've made use of:
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setHasOptionsMenu(true);
...
}
For one of the fragments, its important to have some of the options in its options menu greyed out depending on which items the user has selected in its list. I've done this by calling:
#Override
public void onPrepareOptionsMenu(Menu menu){
...
}
Within this method, I identify which items in the list have been checked. I've noticed that when I switch between tabs, onPrepareOptionsMenu get called right away. Then the very next time I press the menu key, onPrepareOptionsMenu is not called, and the available options in the menu are not updated. When I hit the menu button a second time, everything works fine and the available options get updated. Is there I way I can enforce onPrepareOptionsMenu gets called when the menu key is pressed following a tab switch?
I've seen notes about using invalidateOptionsMenu() to trigger onPrepareOptionsMenu, but it seems messy to override the menu key event every time while this issue only comes up the first time the user presses the menu key. Is there a better way?