Develop Reference

How can I show options after LongClick?

I need to program something like the image:
When I long click a item in a ListView two options appear in the toolbar, to delete the item or cancel the action.
I want to make exactly like that, I do not want a context menu (which I know how to do).
Is it possible to do this with simple code? If no, can I accomplish that manipulating the toolbar? How can I do that?
PS: I can only use native code.

You need to use contextual Action Mode Over Toolbar.For Using Action Mode we need to extend our class with ActionMode.Callback. Its a Callback interface for action modes. Supplied to startSupportActionMode(Callback) (Callback)}, a Callback configures and handles events raised by a user’s interaction with an action mode.You need to override following method.
onCreateActionMode(ActionMode, Menu) once on initial creation.
onPrepareActionMode(ActionMode, Menu) after creation and any time the ActionMode is
invalidated.
onActionItemClicked(ActionMode, MenuItem) any time a contextual action button is
clicked.
onDestroyActionMode(ActionMode) when the action mode is closed.

Android: Hide 3 dots from Navigation view header at right

How to hide 3 dots from Navigation header which comes in the right of header? This could be repeated question. I found few similar questions and their answers but they were for older version of Android. I am using Android sdk 21.
Any idea how to hide that 3 dot button?

Just Remove Override Method like this
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.search_and_add, menu);
return true;
}
This Override Method is responsible to for creating three dote as you mention it's really OptionMenu. If you don't want it, don't override onCreateOptionsMenumethod.
Alternative
Don't Inflate the menu xml. Just block the line like this
//getMenuInflater().inflate(R.menu.search_and_add, menu);
other code can remain same. No problem at all..

Those "3 Dots" are the "Overflow" menu, and is created when you establish a menu using a file in the menu resources directory.
If you have buttons or functionality you are wanting to expose via you action bar, you will need to have the overflow buttons (or instead, you can choose to have your buttons exposed at the top level inside the Action bar.
If you really don't want a menu, get rid of the menu.xml file describing this menu, and then get rid of the onCreateOptionsMenu() from your Activity.
Here are the official docs, which describe how this works.

I think you are speaking about the options menu, to get rid of it remove the override of the method onCreateOptionsMenu

In your menu folder the xmlfile that is used by your activity, change the app:showAsAction="never" to app:showAsAction="always" or some other you can see the options that are availabe by pressing ctrl+space.
Or else to get rid of it completely just remove the whole code and it's corresponding usages.

Best practices for Android action bar

I'm new to so and fairly new to android development too, and have already developed some bad habits.
Basically I've coded up an app, using an old learning source as a reference which did not cover fragments. As such I have several standard activities which I am in the process of converting to fragments.
One thing that I have not been able to find information on is the best practices for the action bar; is it best to define the action bar in the activity, or in the fragment?
I notice that calling onCreateOptionsMenu(Menu menu, MenuInflater inflater) results in subtle changes from calling the same method in the activity, would it be possible to have advice on where it is best to call this and what benefits it provides?
Thanks

Yep, this method is a little bit different for fragment:
void onCreateOptionsMenu(Menu menu, MenuInflater inflater)
and activity:
boolean onCreateOptionsMenu(Menu menu)
The logic is quite simple: if you are going to have the same Action Bar (the same number of actions) across all the fragments, it's better to define it in the activity. If Action Bar layout depends on fragment, it's better to define it there.

What does onPrepareOptionsMenu do?

I want to make Option Menu for Android, I have visit this site. In their script, I found onPrepareOptionsMenu, I try to compile and run using Android 2.3.3 compiler with and without onPrepareOptionsMenu, both works, but I didn't see any difference.
public boolean onCreateOptionsMenu(Menu menu){
//code here
}
public boolean onOptionsItemSelected(MenuItem item){
//code here
}
public boolean onPrepareOptionsMenu(Menu menu){
//code here
}
What is actually onPrepareOptionsMenu method do? Is that method important? Could I just delete the method?
Addition
Oh, I also hear about Action Bar in Android 3.0, it says that Action Bar is the alternative way for make Option Menu, and it using onPrepareOptionsMenu. Is that right?
Thank you...

Take a look in the API:
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.

If you want to alter the menu before it's shown to the user, you can put code to do that into onPrepareOptionsMenu. I've used that dynamically to disable some menu options in some circumstances.
As an example of when one might want to disable a menu option, I had an app where there was a way of specifying a destination. One of my menu options was to calculate a route to the destination. However, if a destination wasn't specified, that option didn't apply, so I used onPrepareOptionsMenu to disable that menu option when it wasn't applicable.
From Android 3.0 and beyond, there's the ActionBar, which is a menu bar. The most important items go into the ActionBar itself, but then there's an overflow for when there's not enough room on the action bar. One can specify that menu items should always be in the overflow menu and never on the action bar itself. On some devices, the action bar overflow corresponds to the permanent menu button on the device, whereas on other devices which don't have a menu button the overflow menu is seen on the right hand side of the action bar as three vertical dots.

onCreateOptionsMenu is called once, when your activity is first created. If it returns false, no option menu is shown and onPrepareOptionsMenu is never called.
If onCreateOptionsMenu returns true, onPrepareOptionsMenu is also called before the activity is displayed, and also every time the options menu is invalidated. Use onPrepareOptionsMenu if you need to enable/disable, show/hide, or add/remove items after creating it.
If your menu does not change, use onCreateOptionsMenu.

example
#Override
public void onPrepareOptionsMenu(#NonNull Menu menu) {
super.onPrepareOptionsMenu(menu);
if(!URLUtil.isValidUrl(news.geturl())){
menu.findItem(R.id.share).setVisible(false);
}
}

How to add menuItem to actionbarsherlock dialog?

I am using Theme Theme.Sherlock.Dialog tho show a dialog. Now, how can I add menu items at the top right corner of that dialog?
I use this code but I can't.
#Override
public boolean onCreateOptionsMenu(Menu menu) {
menu.add("Close")
.setIcon(R.drawable.button_close)
.setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
return true;
}

That is not possible. The action bar of the dialog has none of the features of the normal action bar.
Words of the ActionBarSherlock developer in this question.

please check if you are setting holo theme correctly and make sure you have initialized the actionbar in oncreate of activity. Above code works fine if you have followed the steps correctly