the Action Bar
Previously, we have learn how to :
Now we see how to overlay the action bar.
By default, the action bar appears at the top of your
activity window, slightly reducing the amount of space available for the rest
of your activity's layout. If, during the course of user interaction, you want
to hide and show the action bar, you can do so by calling hide() and show() on the
ActionBar. However, this causes your activity to recompute and redraw the
layout based on its new size.
To avoid resizing your layout when the action bar hides and
shows, you can enable overlay mode
for the action bar. When in overlay mode, your activity layout uses all the
space available as if the action bar is not there and the system draws the
action bar in front of your layout. This obscures some of the layout at the
top, but now when the action bar hides or appears, the system does not need to
resize your layout and the transition is seamless.
To enable overlay mode for the action bar, you need to
create a custom theme that extends an existing action bar theme and set the android:windowActionBarOverlay property
If your minSdkVersion
is set to 11 or higher, your custom theme should use Theme.Holo theme (or one of its descendants) as your parent theme.
<!-- the theme
applied to the application or activity -->
action bar is in overlay mode, it might obscure some of your layout that should
remain visible. To ensure that such items remain below the action bar at all
times, add either margin or padding
to the top of the view(s) using the height specified by actionBarSize. For example:
If you're using the Support Library for the action bar, you
need to remove the android: prefix. For example:
<!-- Support library compatibility -->
In this case, the ?attr/actionBarSize value without the
prefix works on all versions, including Android 3.0 and higher.
This post is referred from Google docs Overlaying the Action Bar