Develop Reference

How to replace menu dynamically with another in Android

I have a ListActivity (SherlockListActivity) and its content can be dynamically changed by the user. When the content changes, the options menu should be replaced.
As I learned, instead of onCreateOptionsMenu I should use onPrepareOptionsMenu that is (supposed to be) called every time the user selects the menu.
This is called right before the menu is shown, every time it is shown.
I have the following code:
#Override
public boolean onPrepareOptionsMenu(Menu menu)
{
menu.clear();
if (UserOption == UserOption1)
getSupportMenuInflater().inflate(R.menu.menu_option1, menu);
else
getSupportMenuInflater().inflate(R.menu.menu_option2, menu);
return super.onPrepareOptionsMenu(menu);
}
It is called only once during debug, so I always have the same menu.
What should I set to make it work?

Create and prepare the options menu for changing and its item selection method
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
menu.clear();
MenuInflater inflater = getMenuInflater();
if(menuString=="red"){
inflater.inflate(R.menu.red_menu, menu);
}else if(menuString=="green"){
inflater.inflate(R.menu.green_menu, menu);
}
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.new_game:
return true;
case R.id.help:
return true;
default:
return super.onOptionsItemSelected(item);
}
}
Like whenever you want to change menu call
String menuString="red or green";
invalidateOptionsMenu();
Like others told, if you want to have static menu use onCreateOptionsMenu, and if you want to change its visibility dynamically use onPrepareOptionsMenu along with onCreateOptionsMenu

Open menu thing on android

on android phones there is a button at the bottom left. this usually opens up a menu. what is the code for this. Its okay to lead me to another post instead of posting a long answer here. sorry Im asking. I understand if there are other posts like this one. I just couldnt seem to find one. ill delete this one when done. Thanks.

Check out the developer guide on menu :) http://developer.android.com/guide/topics/ui/menus.html

To specify the options menu for an activity, override onCreateOptionsMenu() (fragments provide their own onCreateOptionsMenu() callback). In this method, you can inflate your menu resource (defined in XML) into the Menu provided in the callback. For example:
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.game_menu, menu);
return true;
}
To handle click events:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.new_game:
newGame();
return true;
case R.id.help:
showHelp();
return true;
default:
return super.onOptionsItemSelected(item);
}
}

option menu not clicked at first time in sherlockfragment

I have used option menu in my fragment.The problem is that when i go first time to fragment ,the option menu click event is not called.But when i go to another fragment.and again revist that fragment then the option menu click event is called...
following is the code
//Creating the option menu
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater)
{
super.onCreateOptionsMenu(menu, inflater);
inflater.inflate(R.menu.newcarmenu, menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
//super.onOptionsItemSelected(item);
switch(item.getItemId())
{
case R.id.menuNewCar:
_menuClickCallback.onMenuSelected();
break;
}
return super.onOptionsItemSelected(item);
}
please tell me why this happen?

Right now, you are returning super.onOptionsItemSelected(item) every time, so the selection is being passed on. You need to return true when your MenuItem has been selected. Try this instead:
switch(item.getItemId())
{
case R.id.menuNewCar:
_menuClickCallback.onMenuSelected();
return true;
default:
return super.onOptionsItemSelected(item);
}

Android - Enabling MenuItems by code

I need to enable a MenuItem when a previous screen (Activity) returns.
I tried this code:
...
((MenuItem)findViewById(R.id.menu_how)).setEnabled(true);
...
but a null pointer exception is launched.
BTW, the menu_how is set to false in xml; and the code is part of onActivityResult(int requestCode, int resultCode, Intent data) call.

Try using menu.findItem(R.id.menu_how) in onCreateOptionsMenu and save a reference for later use.
This should work fine with enabled, however, I've found that setting a menu item to invisible in the XML means you can't show/hide it programmatically.

I found something at the android dev site that might be helpful (look for the section "Changing menu items at runtime")
It said that the onCreateOptionsMenu() method fired only when the the menu for the activity is created, and it happens when this activity starts. So if you want to change the menu items after the menu/activity was created, you need to override the onPrepareOptionsMenu() method instead. search the link for full details.
EDIT:
Just made it and it's working fine. I'm using one boolean var per menuItem which represents if this item should be enabled or not. This is my code:
/*************************************Game Menu**************************************/
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.game_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId())
{
case R.id.gm_new_game:
//newGame();
return true;
case R.id.gm_stand_up:
//some code when "gm_stand_up" button clicked..
return true;
case R.id.gm_forfeit:
//some code when "gm_forfeit" button clicked..
return true;
case R.id.gm_surrender:
//some code when "gm_surrender" button clicked..
return true;
case R.id.gm_exit_table:
exitTableCommand();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#Override
public boolean onPrepareOptionsMenu(Menu menu)
{
menu.findItem(R.id.gm_forfeit).setEnabled(forfeitMenuButtonIsEnabled);
menu.findItem(R.id.gm_surrender).setEnabled(surrenderMenuButtonIsEnabled);
menu.findItem(R.id.gm_new_game).setEnabled(newGameMenuButtonIsEnabled);
menu.findItem(R.id.gm_stand_up).setEnabled(standUpMenuButtonIsEnabled);
return super.onPrepareOptionsMenu(menu);
}

where are you calling this? (Sorry, didn't read carefully) I think you need to call it after the menu is inflated (usually in OnCreateOptionsMenu). To do this, you can set a variable to true when the other Activity returns, then do ((MenuItem)findViewById(R.id.menu_how)).setEnabled(mMyBooleanField) in OnCreateOptionsMenu after the call to inflater.inflate.
Edit: To accomplish this in code, it might look something like this:
At the top of the class (along with all the other class members):
Boolean mEnableMenuItem = false;
In OnCreateOptionsMenu:
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.options_main, menu);
((MenuItem)findViewById(R.id.menu_how)).setEnabled(mEnableMenuItem );
In OnActivityResult:
mEnableMenuItem = true;

Keep a reference to Menu in your activity:
private Menu mMenu;
Then:
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_note, menu);
mMenu = menu;
return true;
}
Now, to access menu items anywhere in your activity use similar code to this:
mMenu.findItem(R.id.menu_how).setVisible(false);
or
mMenu.findItem(R.id.menu_how).setEnabled(true);

Same option menu in all Activities in Android

I have 10-15 activities in my project. I want to have the option menu mostly in all Activities. Then is their any way we can do it at one place and it appears in all activities.
Also, I will like to hide the option menu in some. So, is it possible or I have to write option menu code in all activities.
Regards
Sunil

Create a Class (say BaseActivity) that extends Activity, and override onCreateOptionsMenu and onOptionsItemSelected functions.
public class BaseActivity extends Activity {
// Activity code here
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.options_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.item:
// do what you want here
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
Now, in the other 15-16 activities, instead of extending an Activity, you should extend BaseActivity.
public class FooActivity extends BaseActivity {
// Activity code here
}
This way, all your activities derive the options menu. For activities where you want the options menu disabled, you can override it again in that particular activity.
public class BarActivity extends BaseActivity {
// Activity code here
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Do Nothing
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Do Nothing
}
}
Hopefully, it doesn't give you problems in the manifest file.

The solution to this problem is in your new activity add this menu method.
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_home_page, menu);
menu.removeItem(R.id.logout);
return true;
}
In each activity this method will automatically appear.
If it doesn't then add it with the inflate call. It requires two parameters, an xml resource(the same one that you used in your original activity), and the menu object that is pass into the onCreateOptionsMenu method.
menu.removeItem will remove the menu item of whatever resource id you pass to it.
I hope this helps those who are facing this problem.
Thank you, and happy to share this post.

It is not enough to just extend the BaseActivity, you must also call super.onCreateOptionsMenu(menu) and super.onOptionsItemSelected(item) like this in your other activities:
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
//getMenuInflater().inflate(R.menu.menu_second, menu); <- remove this
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
return super.onOptionsItemSelected(item);
}