public class

TabActivity

extends ActivityGroup
java.lang.Object
   ↳ android.content.Context
     ↳ android.content.ContextWrapper
       ↳ android.view.ContextThemeWrapper
         ↳ android.app.Activity
           ↳ android.app.ActivityGroup
             ↳ android.app.TabActivity

Class Overview

An activity that contains and runs multiple embedded activities or views.

Summary

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Inherited Constants
From class android.app.Activity
From class android.content.Context
Public Constructors
TabActivity()
Public Methods
TabHost getTabHost()
Returns the TabHost the activity is using to host its tabs.
TabWidget getTabWidget()
Returns the TabWidget the activity is using to draw the actual tabs.
void onContentChanged()
Updates the screen state (current list and other views) when the content changes.
void setDefaultTab(String tag)
Sets the default tab that is the first tab highlighted.
void setDefaultTab(int index)
Sets the default tab that is the first tab highlighted.
Protected Methods
void onChildTitleChanged(Activity childActivity, CharSequence title)
void onPostCreate(Bundle icicle)
Called when activity start-up is complete (after onStart() and onRestoreInstanceState(Bundle) have been called).
void onRestoreInstanceState(Bundle state)
This method is called after onStart() when the activity is being re-initialized from a previously saved state, given here in state.
void onSaveInstanceState(Bundle outState)
Called to retrieve per-instance state from an activity before being killed so that the state can be restored in onCreate(Bundle) or onRestoreInstanceState(Bundle) (the Bundle populated by this method will be passed to both).
[Expand]
Inherited Methods
From class android.app.ActivityGroup
From class android.app.Activity
From class android.view.ContextThemeWrapper
From class android.content.ContextWrapper
From class android.content.Context
From class java.lang.Object
From interface android.content.ComponentCallbacks
From interface android.view.KeyEvent.Callback
From interface android.view.LayoutInflater.Factory
From interface android.view.View.OnCreateContextMenuListener
From interface android.view.Window.Callback

Public Constructors

public TabActivity ()

Since: API Level 1

Public Methods

public TabHost getTabHost ()

Since: API Level 1

Returns the TabHost the activity is using to host its tabs.

Returns
  • the TabHost the activity is using to host its tabs.

public TabWidget getTabWidget ()

Since: API Level 1

Returns the TabWidget the activity is using to draw the actual tabs.

Returns
  • the TabWidget the activity is using to draw the actual tabs.

public void onContentChanged ()

Since: API Level 1

Updates the screen state (current list and other views) when the content changes.

public void setDefaultTab (String tag)

Since: API Level 1

Sets the default tab that is the first tab highlighted.

Parameters
tag the name of the default tab

public void setDefaultTab (int index)

Since: API Level 1

Sets the default tab that is the first tab highlighted.

Parameters
index the index of the default tab

Protected Methods

protected void onChildTitleChanged (Activity childActivity, CharSequence title)

Since: API Level 1

protected void onPostCreate (Bundle icicle)

Since: API Level 1

Called when activity start-up is complete (after onStart() and onRestoreInstanceState(Bundle) have been called). Applications will generally not implement this method; it is intended for system classes to do final initialization after application code has run.

Derived classes must call through to the super class's implementation of this method. If they do not, an exception will be thrown.

Parameters
icicle If the activity is being re-initialized after previously being shut down then this Bundle contains the data it most recently supplied in onSaveInstanceState(Bundle). Note: Otherwise it is null.

protected void onRestoreInstanceState (Bundle state)

Since: API Level 1

This method is called after onStart() when the activity is being re-initialized from a previously saved state, given here in state. Most implementations will simply use onCreate(Bundle) to restore their state, but it is sometimes convenient to do it here after all of the initialization has been done or to allow subclasses to decide whether to use your default implementation. The default implementation of this method performs a restore of any view state that had previously been frozen by onSaveInstanceState(Bundle).

This method is called between onStart() and onPostCreate(Bundle).

Parameters
state the data most recently supplied in onSaveInstanceState(Bundle).

protected void onSaveInstanceState (Bundle outState)

Since: API Level 1

Called to retrieve per-instance state from an activity before being killed so that the state can be restored in onCreate(Bundle) or onRestoreInstanceState(Bundle) (the Bundle populated by this method will be passed to both).

This method is called before an activity may be killed so that when it comes back some time in the future it can restore its state. For example, if activity B is launched in front of activity A, and at some point activity A is killed to reclaim resources, activity A will have a chance to save the current state of its user interface via this method so that when the user returns to activity A, the state of the user interface can be restored via onCreate(Bundle) or onRestoreInstanceState(Bundle).

Do not confuse this method with activity lifecycle callbacks such as onPause(), which is always called when an activity is being placed in the background or on its way to destruction, or onStop() which is called before destruction. One example of when onPause() and onStop() is called and not this method is when a user navigates back from activity B to activity A: there is no need to call onSaveInstanceState(Bundle) on B because that particular instance will never be restored, so the system avoids calling it. An example when onPause() is called and not onSaveInstanceState(Bundle) is when activity B is launched in front of activity A: the system may avoid calling onSaveInstanceState(Bundle) on activity A if it isn't killed during the lifetime of B since the state of the user interface of A will stay intact.

The default implementation takes care of most of the UI per-instance state for you by calling onSaveInstanceState() on each view in the hierarchy that has an id, and by saving the id of the currently focused view (all of which is restored by the default implementation of onRestoreInstanceState(Bundle)). If you override this method to save additional information not captured by each individual view, you will likely want to call through to the default implementation, otherwise be prepared to save all of the state of each view yourself.

If called, this method will occur before onStop(). There are no guarantees about whether it will occur before or after onPause().

Parameters
outState Bundle in which to place your saved state.