I have a simple 2 activity application. The main activity populates a listFragment, and the second activity populates a fragment with fields to add a custom object (list items) to the main activity.
In the second activity I have a "save" icon in the action bar. I'm trying to figure out how to listen for this button click in the fragment, so I can package up the textFields and pass it back to the activity via the interface.
I tried to override onOptionItemSelectedbut it doesn't ever hit. How would I handle this?
Okay, so the trick is in the fragments onCreate method, you have to call
setHasOptionsMenu(true);
then all you have to do is override the onOptionsItemSelected in the fragment, and handle the action bar click there!!
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_save : {
Log.i(TAG, "Save from fragment");
return true;
}
}
return super.onOptionsItemSelected(item);
}
Related
I have an activity (AppCompatActivity) (called Activity) and two fragments (called Fragment A and Fragment B).
When Activity is lunched, I use setContentView and Fragment A was generated.
When I try to start Activity with specific parameter I lunch Fragment B.
Fragment A and Fragment B has the same layout, I change only the data to be rendered.
In Fragment A, I have a menu with 1 item, this one performs an action on my view: change list to a grid layout.
In fragment B, I have this menu too, but, when I click on the item nothing changes. So I've tried this in debug mode. I've seen that when I press item in the menu, for Fragment B, this called menu action of Fragment A.
How can I resolve this cycle?
When you select a menu item, the system will dispatch that event to the active Activity as well as all currently active Fragments. The event will be dispatched to the Fragments in the order they were added to the Activity.
If Fragment A and Fragment B both include an onOptionsItemSelected() implementation that handles the same R.id constant, this will cause the problem you're seeing.
For example, imagine Fragment A has this code:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.action_settings) {
// do some Fragment A thing
}
...
}
And imagine Fragment B has this code:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.action_settings) {
// do some Fragment B thing
}
...
}
Even if the user clicks on R.id.action_settings inside Fragment B, the system will dispatch the event to Fragment A, and Fragment A will happily handle it!
There are a few different solutions to this problem.
First, you could change your menus in your two fragments so that they have the same text labels but use different android:id attributes (and then update your Fragment code accordingly). Now only the "right" fragment will be able to handle the item selection event.
Second, you could update your onOptionsItemSelected() code to determine whether the Fragment is currently active, and ignore the event if it is not:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (!isAdded() || !isVisible()) {
return false;
}
if (item.getItemId() == R.id.action_settings) {
// do some Fragment A thing
}
}
Finally, you could use dynamically-generated IDs for your menu items. I'd recommend against this approach as it is much more complicated than the others.
I have 2 xml one main xml and one menu xml. I want to get the click event from menu xml to main xml activity. is there is any way to solve this problem.
Main Home Page
Menu Page
Now click on the menu page button event i want in my main home activity page.
I done Like this
View otherLayout = LayoutInflater.from(this).inflate(R.layout.menu_layout,null);
Button tstclick = (Button) otherLayout.findViewById(R.id.textclick);
tstclick.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//Your thing
System.exit(0);
}
});
The Activity class provides us two methods to inflate/show menu items and work with them or assign some tasks to them. They are:
onCreateOptionsMenu(Menu menu)
onOptionsItemSelected(MenuItem item)
The onCreateOptionsMenu() method is responsible for creating and inflating the menu by help of MenuInflater class.
The onOptionsItemSelected() method is responsible for assigning tasks to each menu item. Each menu item is identified by help of its unique ID.
In order to show and work with menu's in any Activity, both the methods needs to be overridden as shown below:
public class MainActivity extends AppCompatActivity {
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem menuItem) {
switch (menuItem.getItemId()) {
// All your menu items will come here. Each menu item ID will become a separate case in the Switch case
default:
return super.onOptionsItemSelected(menuItem);
}
}
}
As soon as the user clicks or taps on any menu item, the onOptionsItemSelected() method is called by the Android OS and then the ID for that particular menu item will be matched in the method. The group of statements specified in the respective case will then be executed.
For more info visit the following links:
http://developer.android.com/guide/topics/ui/menus.html
http://developer.android.com/reference/android/view/MenuInflater.html
In my activity the action bar shows only the left arrow and the title of the activity.
When I press the left arrow the activity goes back to the previous activity, but no event is registered in the onKeyUp, OnkeyDown and OnBackPressed methods.
But when I press the Back key on the phone (at the bottom) the activity goes back to the previous one and all the methods onKeyUp, OnKeyDown and OnBackPressed register an event (in the logcat).
How can I capture that left arrow (I think it is called the UP button)?
The reason I need to capture the key is to know in the onPause method that the activity is destroyed by the user and not by the system (for example, if the user switches to another activity).
By further investigating he matter I found out that the UP button gives an event that is captured by the onOptionsItemSelected method and since there is no other button on the menu I know it is this button.
see http://developer.android.com/guide/topics/ui/actionbar.html#Handling
Handling clicks on action items
When the user presses an action, the system calls your activity's onOptionsItemSelected() method. Using the MenuItem passed to this method, you can identify the action by calling getItemId(). This returns the unique ID provided by the tag's id attribute so you can perform the appropriate action. For example:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle presses on the action bar items
switch (item.getItemId()) {
case android.R.id.home:
onUpButtonPressed();
return true;
case R.id.action_search:
openSearch();
return true;
case R.id.action_compose:
composeMessage();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
Note: If you inflate menu items from a fragment, via the Fragment
class's onCreateOptionsMenu() callback, the system calls
onOptionsItemSelected() for that fragment when the user selects one of
those items. However, the activity gets a chance to handle the event
first, so the system first calls onOptionsItemSelected() on the
activity, before calling the same callback for the fragment. To ensure
that any fragments in the activity also have a chance to handle the
callback, always pass the call to the superclass as the default
behavior instead of returning false when you do not handle the item.
To enable the app icon as an Up button, call setDisplayHomeAsUpEnabled(). For example:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_details);
ActionBar actionBar = getSupportActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
...
}
Yes you are right, you can detect if the up button was pressed in the onOptionsItemSelected method. This should work:
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// Do something here. This is the event fired when up button is pressed.
return true;
}
return super.onOptionsItemSelected(item);
}
I am creating an android application with three tabs using PageSlidingtabStrip as a library to create a swipe view.And it has three fragments.Each fragments has a list view.When the item of the listview is clicked it opens an activity and display the details.
The problem is how can i come back to the fragment in the main screen using back button in actionbar in the activity
And how can i go to the corresponding Fragment(Tab)
Try something like this :
#Override
public void onBackPressed() {
// TODO Auto-generated method stub
super.onBackPressed();
Intent intent = new Intent(YourCurrentClass.this , ClassThatYouWantToGo.class);
startActivity(intent)
}
Or actually like #TommyTopas said, you can just Override onBackPressed and put this.finish();.
EDIT
As I've understood you want to use a button on your AcitonBar, then you have tod o something like this :
First set the HomeButton enabled doing :
getActionBar().setDisplayHomeAsUpEnabled(true); Then Override onOptionsItemSelected
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// or onBackPressed();
this.finish()
}
return true;
}
As I understand, when you return to the "Tab" Activity, you want to display the same tab in which the list item had been clicked. What you can do is, when a list item in any tab is clicked, save the tab number in onSavedInstanceState(), and when the Activity is recreated, then set the previously selected tab (if one was selected previously). You will get the savedInstanceState that you saved in onSavedInstanceState() back in the onCreate() of the same Activity.
You can provide an Up navigation by writing getActionBar().setDisplayHomeAsUpEnabled(true); and then in the onOptionsItemSelected method in the activity, if the item's id is android.R.id.home call the activity's method onBackPressed(); which will close your current activity and come back to your fragment
I'm using a navigation drawer in a main activity with many fragments
For example :
I have fragment 1 for presentation
And fragment2 that contains a listView.
If I click an item in the listView it will launch another activity
When i click the action bar back button i want to go to the main activity fragment2
But the fragment1 is used
How can I use the second fragment
Thanks for your answers
In your second activity's onCreate, put(although i think you already have) :
getActionBar().setDisplayHomeAsUpEnabled(true);
and inside second activity's options handling(i think you've done this too) :
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case android.R.id.home:
//perhaps use intent if needed but i'm sure there's a specific intent action for up you can use to handle
finish();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
and inside your first activity's onCreate's intent handler for example :
if(Intent.ACTION_VIEW.equals(action))
you set the current page of the viewpager with viewpager.setCurrentItem(position). If you want to change the page for different items you could use intent.putExtra() in your second activity and then retrieve it in your first activity.
I have added the code below in my second activity :
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// TODO Auto-generated method stub
onBackPressed();
return true;
}
It's working as I expected
is it a clean solution ?
Thanks