Android introduced Action bar's in API level 11 i.e in HoneyComb 3.0. Native implementation is posted
here. There is no backward compatibility as of now. This leads to our point of discussion.
In some cases where our action bar needs to be compatible from Android SDK version 2.1. In such cases we can go with
Sherlock API.
Steps to implement Sherlock action bar include.
- Download Sherlock source.
- UnZip the source and find "actionbarsherlock" folder, which is the library project for implementing Sherlock ActionBar.
- Import the library project into the workspace.
- Create a new Android Project.
- Click on properties of the project and add "actionbarsherlock" as library project.
Now, we are ready to implement our action bar.
1) Extend your class with SherlockActivity
public class SherlockAtionBar extends SherlockActivity
2) Override onCreate and setTheme as one of the sherlock theme before calling super.onCreate()
@Override
protected void onCreate(Bundle savedInstanceState) {
setTheme(R.style.Theme_Sherlock);
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
}
3) Override onCreateOptionsMenu()
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Collapsible Action Item
menu.add("Search").setIcon(R.drawable.ic_search)
.setActionView(R.layout.collapsible_edittext)
.setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS |
MenuItem.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW);
// OverFlow menu in actionbar.
SubMenu submenu = menu.addSubMenu("");
submenu.setIcon( R.drawable.abs__ic_menu_moreoverflow_normal_holo_dark);
submenu.add(1, 0, 1, "Cut");
submenu.add(1, 1, 2, "Copy");
submenu.add(1, 2, 3, "Paste");
submenu.getItem(). setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS|
MenuItem.SHOW_AS_ACTION_WITH_TEXT);
// end overflow menu
return true;
}
My collapsible_edittext layout looks like
<EditText xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="Search"/>
That's it ..... our action bar with menu items and action view is ready. Snapshot of output is shown below.
 |
| Sherlock action bar with Action view, menu item's and sub menu item's |
I will now explain code in
OnCreateMenuOptions(). First with the submenu thing.
If we add menu items to Menu directly using Menu.add(), Actionbar will have different UI for different OS versions of Android. For 3.0 and above it will be shown as overflow menu like in the above picture. For Android OS version's less than 3.0, action bar's overflow type of menu is overrided by the default menu's(at the bottom). I think you got my point... For consistent behaviour of overflow menu's, we have to use SubMenu instead of Menu. Don't forget to add setShowAction() property for the sub menu item. This property will change the style of the menu's to overflow.
We also have some default things for an activity such as Search. Considering these functionalities, concept of ActionViews is introduced. In the above discussed
OnCreateMenuOptions(), we have added
search menu item to Menu and provided collapsible_edittext layout for the ActionView. Upon click of search Menu Item the layout appears on the top of action bar like ..
 |
| Sherlock ActionBar with Action View. |
As per our layout edit text appears with hint as Search.
Split ActionBar :
We can split the action bar based on the space availability. Just add a tag
android:uiOptions = "splitActionBarWhenNarrow".
Observe the change in the below output by using this tag.
 |
| Split action bar in Android Phone |
|
The split behavior is different in large screens. See the below output in Nexus 10 device.
From this observation, we can judge that split behavior comes into act when there is no real estate to display on action bar .
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