public class

Activity

extends ContextThemeWrapper
implements ComponentCallbacks2 KeyEvent.Callback LayoutInflater.Factory2 View.OnCreateContextMenuListener Window.Callback

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

Known Direct Subclasses

AccountAuthenticatorActivity, ActivityGroup, AliasActivity, ExpandableListActivity, FragmentActivity, ListActivity, NativeActivity

Known Indirect Subclasses

ActionBarActivity, LauncherActivity, PreferenceActivity, TabActivity

Class Overview

An activity is a single, focused thing that the user can do. Almost all activities interact with the user, so the Activity class takes care of creating a window for you in which you can place your UI with setContentView(View). While activities are often presented to the user as full-screen windows, they can also be used in other ways: as floating windows (via a theme with windowIsFloating set) or embedded inside of another activity (using ActivityGroup). There are two methods almost all subclasses of Activity will implement:

onCreate(Bundle) is where you initialize your activity. Most importantly, here you will usually call setContentView(int) with a layout resource defining your UI, and using findViewById(int) to retrieve the widgets in that UI that you need to interact with programmatically.
onPause() is where you deal with the user leaving your activity. Most importantly, any changes made by the user should at this point be committed (usually to the ContentProvider holding the data).

To be of use with Context.startActivity(), all activity classes must have a corresponding <activity> declaration in their package's AndroidManifest.xml.
Topics covered here:

Developer Guides

The Activity class is an important part of an application's overall lifecycle, and the way activities are launched and put together is a fundamental part of the platform's application model. For a detailed perspective on the structure of an Android application and how activities behave, please read the Application Fundamentals and Tasks and Back Stack developer guides.
You can also find a detailed discussion about how to create activities in the Activities developer guide.

Fragments

Starting with HONEYCOMB, Activity implementations can make use of the Fragment class to better modularize their code, build more sophisticated user interfaces for larger screens, and help scale their application between small and large screens.

Activity Lifecycle

Activities in the system are managed as an activity stack. When a new activity is started, it is placed on the top of the stack and becomes the running activity -- the previous activity always remains below it in the stack, and will not come to the foreground again until the new activity exits.
An activity has essentially four states:

If an activity in the foreground of the screen (at the top of the stack), it is active or running.
If an activity has lost focus but is still visible (that is, a new non-full-sized or transparent activity has focus on top of your activity), it is paused. A paused activity is completely alive (it maintains all state and member information and remains attached to the window manager), but can be killed by the system in extreme low memory situations.
If an activity is completely obscured by another activity, it is stopped. It still retains all state and member information, however, it is no longer visible to the user so its window is hidden and it will often be killed by the system when memory is needed elsewhere.
If an activity is paused or stopped, the system can drop the activity from memory by either asking it to finish, or simply killing its process. When it is displayed again to the user, it must be completely restarted and restored to its previous state.

The following diagram shows the important state paths of an Activity. The square rectangles represent callback methods you can implement to perform operations when the Activity moves between states. The colored ovals are major states the Activity can be in.
State diagram for an Android Activity Lifecycle.

State diagram for an Android Activity Lifecycle.

There are three key loops you may be interested in monitoring within your activity:

The entire lifetime of an activity happens between the first call to onCreate(Bundle) through to a single final call to onDestroy(). An activity will do all setup of "global" state in onCreate(), and release all remaining resources in onDestroy(). For example, if it has a thread running in the background to download data from the network, it may create that thread in onCreate() and then stop the thread in onDestroy().
The visible lifetime of an activity happens between a call to onStart() until a corresponding call to onStop(). During this time the user can see the activity on-screen, though it may not be in the foreground and interacting with the user. Between these two methods you can maintain resources that are needed to show the activity to the user. For example, you can register a BroadcastReceiver in onStart() to monitor for changes that impact your UI, and unregister it in onStop() when the user no longer sees what you are displaying. The onStart() and onStop() methods can be called multiple times, as the activity becomes visible and hidden to the user.
The foreground lifetime of an activity happens between a call to onResume() until a corresponding call to onPause(). During this time the activity is in front of all other activities and interacting with the user. An activity can frequently go between the resumed and paused states -- for example when the device goes to sleep, when an activity result is delivered, when a new intent is delivered -- so the code in these methods should be fairly lightweight.

The entire lifecycle of an activity is defined by the following Activity methods. All of these are hooks that you can override to do appropriate work when the activity changes state. All activities will implement onCreate(Bundle) to do their initial setup; many will also implement onPause() to commit changes to data and otherwise prepare to stop interacting with the user. You should always call up to your superclass when implementing these methods.

 public class Activity extends ApplicationContext {
     protected void onCreate(Bundle savedInstanceState);

     protected void onStart();
     
     protected void onRestart();

     protected void onResume();

     protected void onPause();

     protected void onStop();

     protected void onDestroy();
 }

In general the movement through an activity's lifecycle looks like this:

Method			Description	Killable?	Next
`onCreate()`			Called when the activity is first created. This is where you should do all of your normal static set up: create views, bind data to lists, etc. This method also provides you with a Bundle containing the activity's previously frozen state, if there was one. Always followed by `onStart()`.	No	`onStart()`
	`onRestart()`		Called after your activity has been stopped, prior to it being started again. Always followed by `onStart()`	No	`onStart()`
	`onStart()`		Called when the activity is becoming visible to the user. Followed by `onResume()` if the activity comes to the foreground, or `onStop()` if it becomes hidden.	No	`onResume()` or `onStop()`
		`onResume()`	Called when the activity will start interacting with the user. At this point your activity is at the top of the activity stack, with user input going to it. Always followed by `onPause()`.	No	`onPause()`
		`onPause()`	Called when the system is about to start resuming a previous activity. This is typically used to commit unsaved changes to persistent data, stop animations and other things that may be consuming CPU, etc. Implementations of this method must be very quick because the next activity will not be resumed until this method returns. Followed by either `onResume()` if the activity returns back to the front, or `onStop()` if it becomes invisible to the user.	Pre-`HONEYCOMB`	`onResume()` or `onStop()`
	`onStop()`		Called when the activity is no longer visible to the user, because another activity has been resumed and is covering this one. This may happen either because a new activity is being started, an existing one is being brought in front of this one, or this one is being destroyed. Followed by either `onRestart()` if this activity is coming back to interact with the user, or `onDestroy()` if this activity is going away.	Yes	`onRestart()` or `onDestroy()`
`onDestroy()`			The final call you receive before your activity is destroyed. This can happen either because the activity is finishing (someone called `finish()` on it, or because the system is temporarily destroying this instance of the activity to save space. You can distinguish between these two scenarios with the `isFinishing()` method.	Yes	nothing

Note the "Killable" column in the above table -- for those methods that are marked as being killable, after that method returns the process hosting the activity may killed by the system at any time without another line of its code being executed. Because of this, you should use the onPause() method to write any persistent data (such as user edits) to storage. In addition, the method onSaveInstanceState(Bundle) is called before placing the activity in such a background state, allowing you to save away any dynamic instance state in your activity into the given Bundle, to be later received in onCreate(Bundle) if the activity needs to be re-created. See the Process Lifecycle section for more information on how the lifecycle of a process is tied to the activities it is hosting. Note that it is important to save persistent data in onPause() instead of onSaveInstanceState(Bundle) because the latter is not part of the lifecycle callbacks, so will not be called in every situation as described in its documentation.

Be aware that these semantics will change slightly between applications targeting platforms starting with HONEYCOMB vs. those targeting prior platforms. Starting with Honeycomb, an application is not in the killable state until its onStop() has returned. This impacts when onSaveInstanceState(Bundle) may be called (it may be safely called after onPause() and allows and application to safely wait until onStop() to save persistent state.

For those methods that are not marked as being killable, the activity's process will not be killed by the system starting from the time the method is called and continuing after it returns. Thus an activity is in the killable state, for example, between after onPause() to the start of onResume().

Configuration Changes

If the configuration of the device (as defined by the Resources.Configuration class) changes, then anything displaying a user interface will need to update to match that configuration. Because Activity is the primary mechanism for interacting with the user, it includes special support for handling configuration changes.
Unless you specify otherwise, a configuration change (such as a change in screen orientation, language, input devices, etc) will cause your current activity to be destroyed, going through the normal activity lifecycle process of onPause(), onStop(), and onDestroy() as appropriate. If the activity had been in the foreground or visible to the user, once onDestroy() is called in that instance then a new instance of the activity will be created, with whatever savedInstanceState the previous instance had generated from onSaveInstanceState(Bundle).
This is done because any application resource, including layout files, can change based on any configuration value. Thus the only safe way to handle a configuration change is to re-retrieve all resources, including layouts, drawables, and strings. Because activities must already know how to save their state and re-create themselves from that state, this is a convenient way to have an activity restart itself with a new configuration.
In some special cases, you may want to bypass restarting of your activity based on one or more types of configuration changes. This is done with the android:configChanges attribute in its manifest. For any types of configuration changes you say that you handle there, you will receive a call to your current activity's onConfigurationChanged(Configuration) method instead of being restarted. If a configuration change involves any that you do not handle, however, the activity will still be restarted and onConfigurationChanged(Configuration) will not be called.

Starting Activities and Getting Results

The startActivity(Intent) method is used to start a new activity, which will be placed at the top of the activity stack. It takes a single argument, an Intent, which describes the activity to be executed.
Sometimes you want to get a result back from an activity when it ends. For example, you may start an activity that lets the user pick a person in a list of contacts; when it ends, it returns the person that was selected. To do this, you call the startActivityForResult(Intent, int) version with a second integer parameter identifying the call. The result will come back through your onActivityResult(int, int, Intent) method.
When an activity exits, it can call setResult(int) to return data back to its parent. It must always supply a result code, which can be the standard results RESULT_CANCELED, RESULT_OK, or any custom values starting at RESULT_FIRST_USER. In addition, it can optionally return back an Intent containing any additional data it wants. All of this information appears back on the parent's Activity.onActivityResult(), along with the integer identifier it originally supplied.
If a child activity fails for any reason (such as crashing), the parent activity will receive a result with the code RESULT_CANCELED.

 public class MyActivity extends Activity {
     ...

     static final int PICK_CONTACT_REQUEST = 0;

     protected boolean onKeyDown(int keyCode, KeyEvent event) {
         if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
             // When the user center presses, let them pick a contact.
             startActivityForResult(
                 new Intent(Intent.ACTION_PICK,
                 new Uri("content://contacts")),
                 PICK_CONTACT_REQUEST);
            return true;
         }
         return false;
     }

     protected void onActivityResult(int requestCode, int resultCode,
             Intent data) {
         if (requestCode == PICK_CONTACT_REQUEST) {
             if (resultCode == RESULT_OK) {
                 // A contact was picked.  Here we will just display it
                 // to the user.
                 startActivity(new Intent(Intent.ACTION_VIEW, data));
             }
         }
     }
 }

Saving Persistent State

There are generally two kinds of persistent state than an activity will deal with: shared document-like data (typically stored in a SQLite database using a content provider) and internal state such as user preferences.
For content provider data, we suggest that activities use a "edit in place" user model. That is, any edits a user makes are effectively made immediately without requiring an additional confirmation step. Supporting this model is generally a simple matter of following two rules:

When creating a new document, the backing database entry or file for it is created immediately. For example, if the user chooses to write a new e-mail, a new entry for that e-mail is created as soon as they start entering data, so that if they go to any other activity after that point this e-mail will now appear in the list of drafts.
When an activity's onPause() method is called, it should commit to the backing content provider or file any changes the user has made. This ensures that those changes will be seen by any other activity that is about to run. You will probably want to commit your data even more aggressively at key times during your activity's lifecycle: for example before starting a new activity, before finishing your own activity, when the user switches between input fields, etc.

This model is designed to prevent data loss when a user is navigating between activities, and allows the system to safely kill an activity (because system resources are needed somewhere else) at any time after it has been paused. Note this implies that the user pressing BACK from your activity does not mean "cancel" -- it means to leave the activity with its current contents saved away. Canceling edits in an activity must be provided through some other mechanism, such as an explicit "revert" or "undo" option.
See the content package for more information about content providers. These are a key aspect of how different activities invoke and propagate data between themselves.
The Activity class also provides an API for managing internal persistent state associated with an activity. This can be used, for example, to remember the user's preferred initial display in a calendar (day view or week view) or the user's default home page in a web browser.
Activity persistent state is managed with the method getPreferences(int), allowing you to retrieve and modify a set of name/value pairs associated with the activity. To use preferences that are shared across multiple application components (activities, receivers, services, providers), you can use the underlying Context.getSharedPreferences() method to retrieve a preferences object stored under a specific name. (Note that it is not possible to share settings data across application packages -- for that you will need a content provider.)
Here is an excerpt from a calendar activity that stores the user's preferred view mode in its persistent settings:

 public class CalendarActivity extends Activity {
     ...

     static final int DAY_VIEW_MODE = 0;
     static final int WEEK_VIEW_MODE = 1;

     private SharedPreferences mPrefs;
     private int mCurViewMode;

     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         SharedPreferences mPrefs = getSharedPreferences();
         mCurViewMode = mPrefs.getInt("view_mode", DAY_VIEW_MODE);
     }

     protected void onPause() {
         super.onPause();
 
         SharedPreferences.Editor ed = mPrefs.edit();
         ed.putInt("view_mode", mCurViewMode);
         ed.commit();
     }
 }

Permissions

The ability to start a particular Activity can be enforced when it is declared in its manifest's <activity> tag. By doing so, other applications will need to declare a corresponding <uses-permission> element in their own manifest to be able to start that activity.
When starting an Activity you can set Intent.FLAG_GRANT_READ_URI_PERMISSION and/or Intent.FLAG_GRANT_WRITE_URI_PERMISSION on the Intent. This will grant the Activity access to the specific URIs in the Intent. Access will remain until the Activity has finished (it will remain across the hosting process being killed and other temporary destruction). As of GINGERBREAD, if the Activity was already created and a new Intent is being delivered to onNewIntent(Intent), any newly granted URI permissions will be added to the existing ones it holds.
See the Security and Permissions document for more information on permissions and security in general.

Process Lifecycle

The Android system attempts to keep application process around for as long as possible, but eventually will need to remove old processes when memory runs low. As described in Activity Lifecycle, the decision about which process to remove is intimately tied to the state of the user's interaction with it. In general, there are four states a process can be in based on the activities running in it, listed here in order of importance. The system will kill less important processes (the last ones) before it resorts to killing more important processes (the first ones).

The foreground activity (the activity at the top of the screen that the user is currently interacting with) is considered the most important. Its process will only be killed as a last resort, if it uses more memory than is available on the device. Generally at this point the device has reached a memory paging state, so this is required in order to keep the user interface responsive.
A visible activity (an activity that is visible to the user but not in the foreground, such as one sitting behind a foreground dialog) is considered extremely important and will not be killed unless that is required to keep the foreground activity running.
A background activity (an activity that is not visible to the user and has been paused) is no longer critical, so the system may safely kill its process to reclaim memory for other foreground or visible processes. If its process needs to be killed, when the user navigates back to the activity (making it visible on the screen again), its onCreate(Bundle) method will be called with the savedInstanceState it had previously supplied in onSaveInstanceState(Bundle) so that it can restart itself in the same state as the user last left it.
An empty process is one hosting no activities or other application components (such as Service or BroadcastReceiver classes). These are killed very quickly by the system as memory becomes low. For this reason, any background operation you do outside of an activity must be executed in the context of an activity BroadcastReceiver or Service to ensure that the system knows it needs to keep your process around.

Sometimes an Activity may need to do a long-running operation that exists independently of the activity lifecycle itself. An example may be a camera application that allows you to upload a picture to a web site. The upload may take a long time, and the application should allow the user to leave the application will it is executing. To accomplish this, your Activity should start a Service in which the upload takes place. This allows the system to properly prioritize your process (considering it to be more important than other non-visible applications) for the duration of the upload, independent of whether the original activity is paused, stopped, or finished.

Summary

Constants
int	DEFAULT_KEYS_DIALER	Use with `setDefaultKeyMode(int)` to launch the dialer during default key handling.
int	DEFAULT_KEYS_DISABLE	Use with `setDefaultKeyMode(int)` to turn off default handling of keys.
int	DEFAULT_KEYS_SEARCH_GLOBAL	Use with `setDefaultKeyMode(int)` to specify that unhandled keystrokes will start a global search (typically web search, but some platforms may define alternate methods for global search) See `android.app.SearchManager` for more details.
int	DEFAULT_KEYS_SEARCH_LOCAL	Use with `setDefaultKeyMode(int)` to specify that unhandled keystrokes will start an application-defined search.
int	DEFAULT_KEYS_SHORTCUT	Use with `setDefaultKeyMode(int)` to execute a menu shortcut in default key handling.
int	RESULT_CANCELED	Standard activity result: operation canceled.
int	RESULT_FIRST_USER	Start of user-defined activity results.
int	RESULT_OK	Standard activity result: operation succeeded.

[Expand] Inherited Constants
From class android.content.Context
From interface android.content.ComponentCallbacks2

Fields
protected static final int[]	FOCUSED_STATE_SET

Public Constructors
	Activity()

Public Methods
void	addContentView(View view, ViewGroup.LayoutParams params) Add an additional content view to the activity.
void	closeContextMenu() Programmatically closes the most recently opened context menu, if showing.
void	closeOptionsMenu() Progammatically closes the options menu.
PendingIntent	createPendingResult(int requestCode, Intent data, int flags) Create a new PendingIntent object which you can hand to others for them to use to send result data back to your `onActivityResult(int, int, Intent)` callback.
final void	dismissDialog(int id) This method was deprecated in API level 13. Use the new `DialogFragment` class with `FragmentManager` instead; this is also available on older platforms through the Android compatibility package.
boolean	dispatchGenericMotionEvent(MotionEvent ev) Called to process generic motion events.
boolean	dispatchKeyEvent(KeyEvent event) Called to process key events.
boolean	dispatchKeyShortcutEvent(KeyEvent event) Called to process a key shortcut event.
boolean	dispatchPopulateAccessibilityEvent(AccessibilityEvent event) Called to process population of `AccessibilityEvent`s.
boolean	dispatchTouchEvent(MotionEvent ev) Called to process touch screen events.
boolean	dispatchTrackballEvent(MotionEvent ev) Called to process trackball events.
void	dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) Print the Activity's state into the given stream.
View	findViewById(int id) Finds a view that was identified by the id attribute from the XML that was processed in `onCreate(Bundle)`.
void	finish() Call this when your activity is done and should be closed.
void	finishActivity(int requestCode) Force finish another activity that you had previously started with `startActivityForResult(Intent, int)`.
void	finishActivityFromChild(Activity child, int requestCode) This is called when a child activity of this one calls its finishActivity().
void	finishAffinity() Finish this activity as well as all activities immediately below it in the current task that have the same affinity.
void	finishFromChild(Activity child) This is called when a child activity of this one calls its `finish()` method.
ActionBar	getActionBar() Retrieve a reference to this activity's ActionBar.
final Application	getApplication() Return the application that owns this activity.
ComponentName	getCallingActivity() Return the name of the activity that invoked this activity.
String	getCallingPackage() Return the name of the package that invoked this activity.
int	getChangingConfigurations() If this activity is being destroyed because it can not handle a configuration parameter being changed (and thus its `onConfigurationChanged(Configuration)` method is not being called), then you can use this method to discover the set of changes that have occurred while in the process of being destroyed.
ComponentName	getComponentName() Returns complete component name of this activity.
View	getCurrentFocus() Calls `getCurrentFocus()` on the Window of this Activity to return the currently focused view.
FragmentManager	getFragmentManager() Return the FragmentManager for interacting with fragments associated with this activity.
Intent	getIntent() Return the intent that started this activity.
Object	getLastNonConfigurationInstance() This method was deprecated in API level 13. Use the new `Fragment` API `setRetainInstance(boolean)` instead; this is also available on older platforms through the Android compatibility package.
LayoutInflater	getLayoutInflater() Convenience for calling `getLayoutInflater()`.
LoaderManager	getLoaderManager() Return the LoaderManager for this fragment, creating it if needed.
String	getLocalClassName() Returns class name for this activity with the package prefix removed.
MenuInflater	getMenuInflater() Returns a `MenuInflater` with this context.
final Activity	getParent() Return the parent activity if this view is an embedded child.
Intent	getParentActivityIntent() Obtain an `Intent` that will launch an explicit target activity specified by this activity's logical parent.
SharedPreferences	getPreferences(int mode) Retrieve a `SharedPreferences` object for accessing preferences that are private to this activity.
int	getRequestedOrientation() Return the current requested orientation of the activity.
Object	getSystemService(String name) Return the handle to a system-level service by name.
int	getTaskId() Return the identifier of the task this activity is in.
final CharSequence	getTitle()
final int	getTitleColor()
final int	getVolumeControlStream() Gets the suggested audio stream whose volume should be changed by the harwdare volume controls.
Window	getWindow() Retrieve the current `Window` for the activity.
WindowManager	getWindowManager() Retrieve the window manager for showing custom windows.
boolean	hasWindowFocus() Returns true if this activity's main window currently has window focus.
void	invalidateOptionsMenu() Declare that the options menu has changed, so should be recreated.
boolean	isChangingConfigurations() Check to see whether this activity is in the process of being destroyed in order to be recreated with a new configuration.
final boolean	isChild() Is this activity embedded inside of another activity?
boolean	isDestroyed() Returns true if the final `onDestroy()` call has been made on the Activity, so this instance is now dead.
boolean	isFinishing() Check to see whether this activity is in the process of finishing, either because you called `finish()` on it or someone else has requested that it finished.
boolean	isImmersive() Bit indicating that this activity is "immersive" and should not be interrupted by notifications if possible.
boolean	isTaskRoot() Return whether this activity is the root of a task.
final Cursor	managedQuery(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) This method was deprecated in API level 11. Use `CursorLoader` instead.
boolean	moveTaskToBack(boolean nonRoot) Move the task containing this activity to the back of the activity stack.
boolean	navigateUpTo(Intent upIntent) Navigate from this activity to the activity specified by upIntent, finishing this activity in the process.
boolean	navigateUpToFromChild(Activity child, Intent upIntent) This is called when a child activity of this one calls its `navigateUpTo(Intent)` method.
void	onActionModeFinished(ActionMode mode) Notifies the activity that an action mode has finished.
void	onActionModeStarted(ActionMode mode) Notifies the Activity that an action mode has been started.
void	onAttachFragment(Fragment fragment) Called when a Fragment is being attached to this activity, immediately after the call to its `Fragment.onAttach()` method and before `Fragment.onCreate()`.
void	onAttachedToWindow() Called when the main window associated with the activity has been attached to the window manager.
void	onBackPressed() Called when the activity has detected the user's press of the back key.
void	onConfigurationChanged(Configuration newConfig) Called by the system when the device configuration changes while your activity is running.
void	onContentChanged() This hook is called whenever the content view of the screen changes (due to a call to `Window.setContentView` or `Window.addContentView`).
boolean	onContextItemSelected(MenuItem item) This hook is called whenever an item in a context menu is selected.
void	onContextMenuClosed(Menu menu) This hook is called whenever the context menu is being closed (either by the user canceling the menu with the back/menu button, or when an item is selected).
void	onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) Called when a context menu for the `view` is about to be shown.
CharSequence	onCreateDescription() Generate a new description for this activity.
void	onCreateNavigateUpTaskStack(TaskStackBuilder builder) Define the synthetic task stack that will be generated during Up navigation from a different task.
boolean	onCreateOptionsMenu(Menu menu) Initialize the contents of the Activity's standard options menu.
boolean	onCreatePanelMenu(int featureId, Menu menu) Default implementation of `onCreatePanelMenu(int, Menu)` for activities.
View	onCreatePanelView(int featureId) Default implementation of `onCreatePanelView(int)` for activities.
boolean	onCreateThumbnail(Bitmap outBitmap, Canvas canvas) Generate a new thumbnail for this activity.
View	onCreateView(View parent, String name, Context context, AttributeSet attrs) Standard implementation of `onCreateView(View, String, Context, AttributeSet)` used when inflating with the LayoutInflater returned by `getSystemService(String)`.
View	onCreateView(String name, Context context, AttributeSet attrs) Standard implementation of `onCreateView(String, Context, AttributeSet)` used when inflating with the LayoutInflater returned by `getSystemService(String)`.
void	onDetachedFromWindow() Called when the main window associated with the activity has been detached from the window manager.
boolean	onGenericMotionEvent(MotionEvent event) Called when a generic motion event was not handled by any of the views inside of the activity.
boolean	onKeyDown(int keyCode, KeyEvent event) Called when a key was pressed down and not handled by any of the views inside of the activity.
boolean	onKeyLongPress(int keyCode, KeyEvent event) Default implementation of `KeyEvent.Callback.onKeyLongPress()`: always returns false (doesn't handle the event).
boolean	onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) Default implementation of `KeyEvent.Callback.onKeyMultiple()`: always returns false (doesn't handle the event).
boolean	onKeyShortcut(int keyCode, KeyEvent event) Called when a key shortcut event is not handled by any of the views in the Activity.
boolean	onKeyUp(int keyCode, KeyEvent event) Called when a key was released and not handled by any of the views inside of the activity.
void	onLowMemory() This is called when the overall system is running low on memory, and would like actively running process to try to tighten their belt.
boolean	onMenuItemSelected(int featureId, MenuItem item) Default implementation of `onMenuItemSelected(int, MenuItem)` for activities.
boolean	onMenuOpened(int featureId, Menu menu) Called when a panel's menu is opened by the user.
boolean	onNavigateUp() This method is called whenever the user chooses to navigate Up within your application's activity hierarchy from the action bar.
boolean	onNavigateUpFromChild(Activity child) This is called when a child activity of this one attempts to navigate up.
boolean	onOptionsItemSelected(MenuItem item) This hook is called whenever an item in your options menu is selected.
void	onOptionsMenuClosed(Menu menu) This hook is called whenever the options menu is being closed (either by the user canceling the menu with the back/menu button, or when an item is selected).
void	onPanelClosed(int featureId, Menu menu) Default implementation of `onPanelClosed(int, Menu)` for activities.
void	onPrepareNavigateUpTaskStack(TaskStackBuilder builder) Prepare the synthetic task stack that will be generated during Up navigation from a different task.
boolean	onPrepareOptionsMenu(Menu menu) Prepare the Screen's standard options menu to be displayed.
boolean	onPreparePanel(int featureId, View view, Menu menu) Default implementation of `onPreparePanel(int, View, Menu)` for activities.
void	onProvideAssistData(Bundle data) This is called when the user is requesting an assist, to build a full `ACTION_ASSIST` Intent with all of the context of the current application.
Object	onRetainNonConfigurationInstance() This method was deprecated in API level 13. Use the new `Fragment` API `setRetainInstance(boolean)` instead; this is also available on older platforms through the Android compatibility package.
boolean	onSearchRequested() This hook is called when the user signals the desire to start a search.
boolean	onTouchEvent(MotionEvent event) Called when a touch screen event was not handled by any of the views under it.
boolean	onTrackballEvent(MotionEvent event) Called when the trackball was moved and not handled by any of the views inside of the activity.
void	onTrimMemory(int level) Called when the operating system has determined that it is a good time for a process to trim unneeded memory from its process.
void	onUserInteraction() Called whenever a key, touch, or trackball event is dispatched to the activity.
void	onWindowAttributesChanged(WindowManager.LayoutParams params) This is called whenever the current window attributes change.
void	onWindowFocusChanged(boolean hasFocus) Called when the current `Window` of the activity gains or loses focus.
ActionMode	onWindowStartingActionMode(ActionMode.Callback callback) Give the Activity a chance to control the UI for an action mode requested by the system.
void	openContextMenu(View view) Programmatically opens the context menu for a particular `view`.
void	openOptionsMenu() Programmatically opens the options menu.
void	overridePendingTransition(int enterAnim, int exitAnim) Call immediately after one of the flavors of `startActivity(Intent)` or `finish()` to specify an explicit transition animation to perform next.
void	recreate() Cause this Activity to be recreated with a new instance.
void	registerForContextMenu(View view) Registers a context menu to be shown for the given view (multiple views can show the context menu).
final void	removeDialog(int id) This method was deprecated in API level 13. Use the new `DialogFragment` class with `FragmentManager` instead; this is also available on older platforms through the Android compatibility package.
final boolean	requestWindowFeature(int featureId) Enable extended window features.
final void	runOnUiThread(Runnable action) Runs the specified action on the UI thread.
void	setContentView(int layoutResID) Set the activity content from a layout resource.
void	setContentView(View view) Set the activity content to an explicit view.
void	setContentView(View view, ViewGroup.LayoutParams params) Set the activity content to an explicit view.
final void	setDefaultKeyMode(int mode) Select the default key handling for this activity.
final void	setFeatureDrawable(int featureId, Drawable drawable) Convenience for calling `setFeatureDrawable(int, Drawable)`.
final void	setFeatureDrawableAlpha(int featureId, int alpha) Convenience for calling `setFeatureDrawableAlpha(int, int)`.
final void	setFeatureDrawableResource(int featureId, int resId) Convenience for calling `setFeatureDrawableResource(int, int)`.
final void	setFeatureDrawableUri(int featureId, Uri uri) Convenience for calling `setFeatureDrawableUri(int, Uri)`.
void	setFinishOnTouchOutside(boolean finish) Sets whether this activity is finished when touched outside its window's bounds.
void	setImmersive(boolean i) Adjust the current immersive mode setting.
void	setIntent(Intent newIntent) Change the intent returned by `getIntent()`.
final void	setProgress(int progress) Sets the progress for the progress bars in the title.
final void	setProgressBarIndeterminate(boolean indeterminate) Sets whether the horizontal progress bar in the title should be indeterminate (the circular is always indeterminate).
final void	setProgressBarIndeterminateVisibility(boolean visible) Sets the visibility of the indeterminate progress bar in the title.
final void	setProgressBarVisibility(boolean visible) Sets the visibility of the progress bar in the title.
void	setRequestedOrientation(int requestedOrientation) Change the desired orientation of this activity.
final void	setResult(int resultCode) Call this to set the result that your activity will return to its caller.
final void	setResult(int resultCode, Intent data) Call this to set the result that your activity will return to its caller.
final void	setSecondaryProgress(int secondaryProgress) Sets the secondary progress for the progress bar in the title.
void	setTitle(int titleId) Change the title associated with this activity.
void	setTitle(CharSequence title) Change the title associated with this activity.
void	setTitleColor(int textColor)
void	setVisible(boolean visible) Control whether this activity's main window is visible.
final void	setVolumeControlStream(int streamType) Suggests an audio stream whose volume should be changed by the hardware volume controls.
boolean	shouldUpRecreateTask(Intent targetIntent) Returns true if the app should recreate the task when navigating 'up' from this activity by using targetIntent.
final boolean	showDialog(int id, Bundle args) This method was deprecated in API level 13. Use the new `DialogFragment` class with `FragmentManager` instead; this is also available on older platforms through the Android compatibility package.
final void	showDialog(int id) This method was deprecated in API level 13. Use the new `DialogFragment` class with `FragmentManager` instead; this is also available on older platforms through the Android compatibility package.
ActionMode	startActionMode(ActionMode.Callback callback) Start an action mode.
void	startActivities(Intent[] intents, Bundle options) Launch a new activity.
void	startActivities(Intent[] intents) Same as `startActivities(Intent[], Bundle)` with no options specified.
void	startActivity(Intent intent) Same as `startActivity(Intent, Bundle)` with no options specified.
void	startActivity(Intent intent, Bundle options) Launch a new activity.
void	startActivityForResult(Intent intent, int requestCode) Same as calling `startActivityForResult(Intent, int, Bundle)` with no options.
void	startActivityForResult(Intent intent, int requestCode, Bundle options) Launch an activity for which you would like a result when it finished.
void	startActivityFromChild(Activity child, Intent intent, int requestCode, Bundle options) This is called when a child activity of this one calls its `startActivity(Intent)` or `startActivityForResult(Intent, int)` method.
void	startActivityFromChild(Activity child, Intent intent, int requestCode) Same as calling `startActivityFromChild(Activity, Intent, int, Bundle)` with no options.
void	startActivityFromFragment(Fragment fragment, Intent intent, int requestCode, Bundle options) This is called when a Fragment in this activity calls its `startActivity(Intent)` or `startActivityForResult(Intent, int)` method.
void	startActivityFromFragment(Fragment fragment, Intent intent, int requestCode) Same as calling `startActivityFromFragment(Fragment, Intent, int, Bundle)` with no options.
boolean	startActivityIfNeeded(Intent intent, int requestCode, Bundle options) A special variation to launch an activity only if a new activity instance is needed to handle the given Intent.
boolean	startActivityIfNeeded(Intent intent, int requestCode) Same as calling `startActivityIfNeeded(Intent, int, Bundle)` with no options.
void	startIntentSender(IntentSender intent, Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags, Bundle options) Like `startActivity(Intent, Bundle)`, but taking a IntentSender to start; see `startIntentSenderForResult(IntentSender, int, Intent, int, int, int, Bundle)` for more information.
void	startIntentSender(IntentSender intent, Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags) Same as calling `startIntentSender(IntentSender, Intent, int, int, int, Bundle)` with no options.
void	startIntentSenderForResult(IntentSender intent, int requestCode, Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags, Bundle options) Like `startActivityForResult(Intent, int)`, but allowing you to use a IntentSender to describe the activity to be started.
void	startIntentSenderForResult(IntentSender intent, int requestCode, Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags) Same as calling `startIntentSenderForResult(IntentSender, int, Intent, int, int, int, Bundle)` with no options.
void	startIntentSenderFromChild(Activity child, IntentSender intent, int requestCode, Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags) Same as calling `startIntentSenderFromChild(Activity, IntentSender, int, Intent, int, int, int, Bundle)` with no options.
void	startIntentSenderFromChild(Activity child, IntentSender intent, int requestCode, Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags, Bundle options) Like `startActivityFromChild(Activity, Intent, int)`, but taking a IntentSender; see `startIntentSenderForResult(IntentSender, int, Intent, int, int, int)` for more information.
void	startManagingCursor(Cursor c) This method was deprecated in API level 11. Use the new `CursorLoader` class with `LoaderManager` instead; this is also available on older platforms through the Android compatibility package.
boolean	startNextMatchingActivity(Intent intent) Same as calling `startNextMatchingActivity(Intent, Bundle)` with no options.
boolean	startNextMatchingActivity(Intent intent, Bundle options) Special version of starting an activity, for use when you are replacing other activity components.
void	startSearch(String initialQuery, boolean selectInitialQuery, Bundle appSearchData, boolean globalSearch) This hook is called to launch the search UI.
void	stopManagingCursor(Cursor c) This method was deprecated in API level 11. Use the new `CursorLoader` class with `LoaderManager` instead; this is also available on older platforms through the Android compatibility package.
void	takeKeyEvents(boolean get) Request that key events come to this activity.
void	triggerSearch(String query, Bundle appSearchData) Similar to `startSearch(String, boolean, Bundle, boolean)`, but actually fires off the search query after invoking the search dialog.
void	unregisterForContextMenu(View view) Prevents a context menu to be shown for the given view.

Protected Methods
void	onActivityResult(int requestCode, int resultCode, Intent data) Called when an activity you launched exits, giving you the requestCode you started it with, the resultCode it returned, and any additional data from it.
void	onApplyThemeResource(Resources.Theme theme, int resid, boolean first) Called by `setTheme(int)` and `getTheme()` to apply a theme resource to the current Theme object.
void	onChildTitleChanged(Activity childActivity, CharSequence title)
void	onCreate(Bundle savedInstanceState) Called when the activity is starting.
Dialog	onCreateDialog(int id) This method was deprecated in API level 8. Old no-arguments version of `onCreateDialog(int, Bundle)`.
Dialog	onCreateDialog(int id, Bundle args) This method was deprecated in API level 13. Use the new `DialogFragment` class with `FragmentManager` instead; this is also available on older platforms through the Android compatibility package.
void	onDestroy() Perform any final cleanup before an activity is destroyed.
void	onNewIntent(Intent intent) This is called for activities that set launchMode to "singleTop" in their package, or if a client used the `FLAG_ACTIVITY_SINGLE_TOP` flag when calling `startActivity(Intent)`.
void	onPause() Called as part of the activity lifecycle when an activity is going into the background, but has not (yet) been killed.
void	onPostCreate(Bundle savedInstanceState) Called when activity start-up is complete (after `onStart()` and `onRestoreInstanceState(Bundle)` have been called).
void	onPostResume() Called when activity resume is complete (after `onResume()` has been called).
void	onPrepareDialog(int id, Dialog dialog) This method was deprecated in API level 8. Old no-arguments version of `onPrepareDialog(int, Dialog, Bundle)`.
void	onPrepareDialog(int id, Dialog dialog, Bundle args) This method was deprecated in API level 13. Use the new `DialogFragment` class with `FragmentManager` instead; this is also available on older platforms through the Android compatibility package.
void	onRestart() Called after `onStop()` when the current activity is being re-displayed to the user (the user has navigated back to it).
void	onRestoreInstanceState(Bundle savedInstanceState) This method is called after `onStart()` when the activity is being re-initialized from a previously saved state, given here in `savedInstanceState`.
void	onResume() Called after `onRestoreInstanceState(Bundle)`, `onRestart()`, or `onPause()`, for your activity to start interacting with the user.
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).
void	onStart() Called after `onCreate(Bundle)` — or after `onRestart()` when the activity had been stopped, but is now again being displayed to the user.
void	onStop() Called when you are no longer visible to the user.
void	onTitleChanged(CharSequence title, int color)
void	onUserLeaveHint() Called as part of the activity lifecycle when an activity is about to go into the background as the result of user choice.

[Expand] Inherited Methods
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.content.ComponentCallbacks2
From interface android.view.KeyEvent.Callback
From interface android.view.LayoutInflater.Factory
From interface android.view.LayoutInflater.Factory2
From interface android.view.View.OnCreateContextMenuListener
From interface android.view.Window.Callback

Constants

public static final int DEFAULT_KEYS_DIALER

Added in API level 1

Use with setDefaultKeyMode(int) to launch the dialer during default key handling.

public static final int DEFAULT_KEYS_DISABLE

Added in API level 1

Use with setDefaultKeyMode(int) to turn off default handling of keys.

public static final int DEFAULT_KEYS_SEARCH_GLOBAL

Added in API level 1

Use with setDefaultKeyMode(int) to specify that unhandled keystrokes will start a global search (typically web search, but some platforms may define alternate methods for global search)
See android.app.SearchManager for more details.

public static final int DEFAULT_KEYS_SEARCH_LOCAL

Added in API level 1

Use with setDefaultKeyMode(int) to specify that unhandled keystrokes will start an application-defined search. (If the application or activity does not actually define a search, the the keys will be ignored.)
See android.app.SearchManager for more details.

public static final int DEFAULT_KEYS_SHORTCUT

Added in API level 1

Use with setDefaultKeyMode(int) to execute a menu shortcut in default key handling.
That is, the user does not need to hold down the menu key to execute menu shortcuts.

public static final int RESULT_CANCELED

Added in API level 1

Standard activity result: operation canceled.

Constant Value: 0 (0x00000000)

public static final int RESULT_FIRST_USER

Added in API level 1

Start of user-defined activity results.

Constant Value: 1 (0x00000001)

public static final int RESULT_OK

Added in API level 1

Standard activity result: operation succeeded.

Constant Value: -1 (0xffffffff)

Fields

protected static final int[] FOCUSED_STATE_SET

Added in API level 1

view	The desired content to display.
params	Layout parameters for the view.

requestCode	Private request code for the sender that will be associated with the result data when it is returned. The sender can not modify this value, allowing you to identify incoming results.
data	Default data to supply in the result, which may be modified by the sender.
flags	May be `PendingIntent.FLAG_ONE_SHOT`, `PendingIntent.FLAG_NO_CREATE`, `PendingIntent.FLAG_CANCEL_CURRENT`, `PendingIntent.FLAG_UPDATE_CURRENT`, or any of the flags as supported by `Intent.fillIn()` to control which unspecified parts of the intent that can be supplied when the actual send happens.

prefix	Desired prefix to prepend at each line of output.
fd	The raw file descriptor that the dump is being sent to.
writer	The PrintWriter to which you should dump your state. This will be closed for you after you return.
args	additional arguments to the dump request.

child	The activity making the call.
requestCode	Request code that had been used to start the activity.

uri	The URI of the content provider to query.
projection	List of columns to return.
selection	SQL WHERE clause.
selectionArgs	The arguments to selection, if any ?s are pesent
sortOrder	SQL ORDER BY clause.

child	The activity making the call.
upIntent	An intent representing the target destination for up navigation

menu	The context menu that is being built
v	The view for which the context menu is being built
menuInfo	Extra information about the item for which the context menu should be shown. This information will vary depending on the class of v.

featureId	The panel being created.
menu	The menu inside the panel.

outBitmap	The bitmap to contain the thumbnail.
canvas	Can be used to render into the bitmap.

parent	The parent that the created view will be placed in; note that this may be null.
name	Tag name to be inflated.
context	The context the view is being created in.
attrs	Inflation attributes as specified in XML file.

keyCode	The value in event.getKeyCode().
event	Description of the key event.

keyCode	The value in event.getKeyCode().
repeatCount	Number of pairs as returned by event.getRepeatCount().
event	Description of the key event.

featureId	The panel that the menu is in.
item	The menu item that was selected.

featureId	The panel that is being displayed.
menu	If onCreatePanelView() returned null, this is the Menu being displayed in the panel.

enterAnim	A resource ID of the animation resource to use for the incoming activity. Use 0 for no animation.
exitAnim	A resource ID of the animation resource to use for the outgoing activity. Use 0 for no animation.

resultCode	The result code to propagate back to the originating activity, often RESULT_CANCELED or RESULT_OK
data	The data to propagate back to the originating activity.

id	The id of the managed dialog.
args	Arguments to pass through to the dialog. These will be saved and restored for you. Note that if the dialog is already created, `onCreateDialog(int, Bundle)` will not be called with the new arguments but `onPrepareDialog(int, Dialog, Bundle)` will be. If you need to rebuild the dialog, call `removeDialog(int)` first.

intents	The intents to start.
options	Additional options for how the Activity should be started. See `Context.startActivity(Intent, Bundle)` for more details.

intent	The intent to start.
options	Additional options for how the Activity should be started. See `Context.startActivity(Intent, Bundle)` for more details.

fragment	The fragment making the call.
intent	The intent to start.
requestCode	Reply request code. < 0 if reply is not requested.
options	Additional options for how the Activity should be started. See `Context.startActivity(Intent, Bundle)` for more details.

Menu

Monday, 2 September 2013

Android activity class

Activity

Class Overview

Developer Guides

Fragments

Activity Lifecycle

Configuration Changes

Starting Activities and Getting Results

Saving Persistent State

Permissions

Process Lifecycle

Summary

Constants

public static final int DEFAULT_KEYS_DIALER

See Also

public static final int DEFAULT_KEYS_DISABLE

See Also

public static final int DEFAULT_KEYS_SEARCH_GLOBAL

See Also

public static final int DEFAULT_KEYS_SEARCH_LOCAL

See Also

public static final int DEFAULT_KEYS_SHORTCUT

See Also

public static final int RESULT_CANCELED

public static final int RESULT_FIRST_USER

public static final int RESULT_OK

Fields

protected static final int[] FOCUSED_STATE_SET

Public Constructors

public Activity ()

Public Methods

public void addContentView (View view, ViewGroup.LayoutParams params)

Parameters

public void closeContextMenu ()

public void closeOptionsMenu ()

public PendingIntent createPendingResult (int requestCode, Intent data, int flags)

Parameters

Returns

See Also

public final void dismissDialog (int id)

Parameters

Throws

See Also

public boolean dispatchGenericMotionEvent (MotionEvent ev)

Parameters

Returns

public boolean dispatchKeyEvent (KeyEvent event)

Parameters

Returns

public boolean dispatchKeyShortcutEvent (KeyEvent event)

Parameters

Returns

public boolean dispatchPopulateAccessibilityEvent (AccessibilityEvent event)

Parameters

Returns

public boolean dispatchTouchEvent (MotionEvent ev)

Parameters

Returns

public boolean dispatchTrackballEvent (MotionEvent ev)

Parameters

Returns

public void dump (String prefix, FileDescriptor fd, PrintWriter writer, String[] args)

Parameters

public View findViewById (int id)

Returns

public void finish ()

public void finishActivity (int requestCode)

Parameters

public void finishActivityFromChild (Activity child, int requestCode)

Parameters

public void finishAffinity ()

public void finishFromChild (Activity child)

Parameters

See Also

public ActionBar getActionBar ()

Returns

public final Application getApplication ()

public ComponentName getCallingActivity ()

intent	The IntentSender to launch.
fillInIntent	If non-null, this will be provided as the intent parameter to `sendIntent(Context, int, Intent, IntentSender.OnFinished, Handler)`.
flagsMask	Intent flags in the original IntentSender that you would like to change.
flagsValues	Desired values for any bits set in `flagsMask`
extraFlags	Always set to 0.
options	Additional options for how the Activity should be started. See `Context.startActivity(Intent, Bundle)` for more details. If options have also been supplied by the IntentSender, options given here will override any that conflict with those given by the IntentSender.

intent	The intent to dispatch to the next activity. For correct behavior, this must be the same as the Intent that started your own activity; the only changes you can make are to the extras inside of it.
options	Additional options for how the Activity should be started. See `Context.startActivity(Intent, Bundle)` for more details.

initialQuery	Any non-null non-empty string will be inserted as pre-entered text in the search query box.
selectInitialQuery	If true, the intial query will be preselected, which means that any further typing will replace it. This is useful for cases where an entire pre-formed query is being inserted. If false, the selection point will be placed at the end of the inserted query. This is useful when the inserted query is text that the user entered, and the user would expect to be able to keep typing. This parameter is only meaningful if initialQuery is a non-empty string.
appSearchData	An application can insert application-specific context here, in order to improve quality or specificity of its own searches. This data will be returned with SEARCH intent(s). Null if no extra data is required.
globalSearch	If false, this will only launch the search that has been specifically defined by the application (which is usually defined as a local search). If no default search is defined in the current application or activity, global search will be launched. If true, this will always launch a platform-global (e.g. web-based) search instead.

query	The query to trigger. If empty, the request will be ignored.
appSearchData	An application can insert application-specific context here, in order to improve quality or specificity of its own searches. This data will be returned with SEARCH intent(s). Null if no extra data is required.

requestCode	The integer request code originally supplied to startActivityForResult(), allowing you to identify who this result came from.
resultCode	The integer result code returned by the child activity through its setResult().
data	An Intent, which can return result data to the caller (various data can be attached to Intent "extras").

theme	The Theme object being modified.
resid	The theme style resource being applied to `theme`.
first	Set to true if this is the first time a style is being applied to `theme`.

id	The id of the dialog.
args	The dialog arguments provided to `showDialog(int, Bundle)`.

id	The id of the managed dialog.
dialog	The dialog.
args	The dialog arguments provided to `showDialog(int, Bundle)`.