Android APIs
public class

ActivityManager

extends Object
java.lang.Object
   ↳ android.app.ActivityManager

Class Overview

Interact with the overall activities running in the system.

Summary

Nested Classes
class ActivityManager.AppTask The AppTask allows you to manage your own application's tasks. 
class ActivityManager.MemoryInfo Information you can retrieve about the available memory through getMemoryInfo(ActivityManager.MemoryInfo)
class ActivityManager.ProcessErrorStateInfo Information you can retrieve about any processes that are in an error condition. 
class ActivityManager.RecentTaskInfo Information you can retrieve about tasks that the user has most recently started or visited. 
class ActivityManager.RunningAppProcessInfo Information you can retrieve about a running process. 
class ActivityManager.RunningServiceInfo Information you can retrieve about a particular Service that is currently running in the system. 
class ActivityManager.RunningTaskInfo Information you can retrieve about a particular task that is currently "running" in the system. 
class ActivityManager.TaskDescription Information you can set and retrieve about the current activity within the recent task list. 
Constants
String ACTION_REPORT_HEAP_LIMIT Action an app can implement to handle reports from setWatchHeapLimit(long).
int LOCK_TASK_MODE_LOCKED Full lock task mode is active.
int LOCK_TASK_MODE_NONE Lock task mode is not active.
int LOCK_TASK_MODE_PINNED App pinning mode is active.
String META_HOME_ALTERNATE <meta-data> name for a 'home' Activity that declares a package that is to be uninstalled in lieu of the declaring one.
int MOVE_TASK_NO_USER_ACTION Flag for moveTaskToFront(int, int): don't count this as a user-instigated action, so the current activity will not receive a hint that the user is leaving.
int MOVE_TASK_WITH_HOME Flag for moveTaskToFront(int, int): also move the "home" activity along with the task, so it is positioned immediately behind the task.
int RECENT_IGNORE_UNAVAILABLE Provides a list that does not contain any recent tasks that currently are not available to the user.
int RECENT_WITH_EXCLUDED Flag for use with getRecentTasks(int, int): return all tasks, even those that have set their FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS flag.
Public Methods
int addAppTask(Activity activity, Intent intent, ActivityManager.TaskDescription description, Bitmap thumbnail)
Add a new ActivityManager.AppTask for the calling application.
boolean clearApplicationUserData()
Permits an application to erase its own data from disk.
void clearWatchHeapLimit()
Clear a heap watch limit previously set by setWatchHeapLimit(long).
void dumpPackageState(FileDescriptor fd, String packageName)
Perform a system dump of various state associated with the given application package name.
Size getAppTaskThumbnailSize()
Return the current design dimensions for ActivityManager.AppTask thumbnails, for use with addAppTask(Activity, Intent, ActivityManager.TaskDescription, Bitmap).
List<ActivityManager.AppTask> getAppTasks()
Get the list of tasks associated with the calling application.
ConfigurationInfo getDeviceConfigurationInfo()
Get the device configuration attributes.
int getLargeMemoryClass()
Return the approximate per-application memory class of the current device when an application is running with a large heap.
int getLauncherLargeIconDensity()
Get the preferred density of icons for the launcher.
int getLauncherLargeIconSize()
Get the preferred launcher icon size.
int getLockTaskModeState()
Return the current state of task locking.
int getMemoryClass()
Return the approximate per-application memory class of the current device.
void getMemoryInfo(ActivityManager.MemoryInfo outInfo)
Return general information about the memory state of the system.
static void getMyMemoryState(ActivityManager.RunningAppProcessInfo outState)
Return global memory state information for the calling process.
MemoryInfo[] getProcessMemoryInfo(int[] pids)
Return information about the memory usage of one or more processes.
List<ActivityManager.ProcessErrorStateInfo> getProcessesInErrorState()
Returns a list of any processes that are currently in an error condition.
List<ActivityManager.RecentTaskInfo> getRecentTasks(int maxNum, int flags)
This method was deprecated in API level 21. As of LOLLIPOP, this method is no longer available to third party applications: the introduction of document-centric recents means it can leak personal information to the caller. For backwards compatibility, it will still return a small subset of its data: at least the caller's own tasks (though see getAppTasks() for the correct supported way to retrieve that information), and possibly some other tasks such as home that are known to not be sensitive.
List<ActivityManager.RunningAppProcessInfo> getRunningAppProcesses()
Returns a list of application processes that are running on the device.
PendingIntent getRunningServiceControlPanel(ComponentName service)
Returns a PendingIntent you can start to show a control panel for the given running service.
List<ActivityManager.RunningServiceInfo> getRunningServices(int maxNum)
Return a list of the services that are currently running.
List<ActivityManager.RunningTaskInfo> getRunningTasks(int maxNum)
This method was deprecated in API level 21. As of LOLLIPOP, this method is no longer available to third party applications: the introduction of document-centric recents means it can leak person information to the caller. For backwards compatibility, it will still retu rn a small subset of its data: at least the caller's own tasks, and possibly some other tasks such as home that are known to not be sensitive.
boolean isInLockTaskMode()
This method was deprecated in API level 23. Use getLockTaskModeState() instead.
boolean isLowRamDevice()
Returns true if this is a low-RAM device.
static boolean isRunningInTestHarness()
Returns "true" if device is running in a test harness.
static boolean isUserAMonkey()
Returns "true" if the user interface is currently being messed with by a monkey.
void killBackgroundProcesses(String packageName)
Have the system immediately kill all background processes associated with the given package.
void moveTaskToFront(int taskId, int flags, Bundle options)
Ask that the task associated with a given task ID be moved to the front of the stack, so it is now visible to the user.
void moveTaskToFront(int taskId, int flags)
Equivalent to calling moveTaskToFront(int, int, Bundle) with a null options argument.
void restartPackage(String packageName)
This method was deprecated in API level 8. This is now just a wrapper for killBackgroundProcesses(String); the previous behavior here is no longer available to applications because it allows them to break other applications by removing their alarms, stopping their services, etc.
void setWatchHeapLimit(long pssSize)
Request that the system start watching for the calling process to exceed a pss size as given here.
[Expand]
Inherited Methods
From class java.lang.Object

Constants

public static final String ACTION_REPORT_HEAP_LIMIT

Added in API level 23

Action an app can implement to handle reports from setWatchHeapLimit(long). If your package has an activity handling this action, it will be launched with the heap data provided to it the same way as ACTION_SEND. Note that to match the activty must support this action and a MIME type of "*/*".

Constant Value: "android.app.action.REPORT_HEAP_LIMIT"

public static final int LOCK_TASK_MODE_LOCKED

Added in API level 23

Full lock task mode is active.

Constant Value: 1 (0x00000001)

public static final int LOCK_TASK_MODE_NONE

Added in API level 23

Lock task mode is not active.

Constant Value: 0 (0x00000000)

public static final int LOCK_TASK_MODE_PINNED

Added in API level 23

App pinning mode is active.

Constant Value: 2 (0x00000002)

public static final String META_HOME_ALTERNATE

Added in API level 19

<meta-data> name for a 'home' Activity that declares a package that is to be uninstalled in lieu of the declaring one. The package named here must be signed with the same certificate as the one declaring the <meta-data>.

Constant Value: "android.app.home.alternate"

public static final int MOVE_TASK_NO_USER_ACTION

Added in API level 12

Flag for moveTaskToFront(int, int): don't count this as a user-instigated action, so the current activity will not receive a hint that the user is leaving.

Constant Value: 2 (0x00000002)

public static final int MOVE_TASK_WITH_HOME

Added in API level 11

Flag for moveTaskToFront(int, int): also move the "home" activity along with the task, so it is positioned immediately behind the task.

Constant Value: 1 (0x00000001)

public static final int RECENT_IGNORE_UNAVAILABLE

Added in API level 11

Provides a list that does not contain any recent tasks that currently are not available to the user.

Constant Value: 2 (0x00000002)

public static final int RECENT_WITH_EXCLUDED

Added in API level 1

Flag for use with getRecentTasks(int, int): return all tasks, even those that have set their FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS flag.

Constant Value: 1 (0x00000001)

Public Methods

public int addAppTask (Activity activity, Intent intent, ActivityManager.TaskDescription description, Bitmap thumbnail)

Added in API level 21

Add a new ActivityManager.AppTask for the calling application. This will create a new recents entry that is added to the end of all existing recents.

Parameters
activity Activity: The activity that is adding the entry. This is used to help determine the context that the new recents entry will be in.
intent Intent: The Intent that describes the recents entry. This is the same Intent that you would have used to launch the activity for it. In generally you will want to set both FLAG_ACTIVITY_NEW_DOCUMENT and FLAG_ACTIVITY_RETAIN_IN_RECENTS; the latter is required since this recents entry will exist without an activity, so it doesn't make sense to not retain it when its activity disappears. The given Intent here also must have an explicit ComponentName set on it.
description ActivityManager.TaskDescription: Optional additional description information.
thumbnail Bitmap: Thumbnail to use for the recents entry. Should be the size given by getAppTaskThumbnailSize(). If the bitmap is not that exact size, it will be recreated in your process, probably in a way you don't like, before the recents entry is added.
Returns
int Returns the task id of the newly added app task, or -1 if the add failed. The most likely cause of failure is that there is no more room for more tasks for your app.

public boolean clearApplicationUserData ()

Added in API level 19

Permits an application to erase its own data from disk. This is equivalent to the user choosing to clear the app's data from within the device settings UI. It erases all dynamic data associated with the app -- its private data and data in its private area on external storage -- but does not remove the installed application itself, nor any OBB files.

Returns
boolean true if the application successfully requested that the application's data be erased; false otherwise.

public void clearWatchHeapLimit ()

Added in API level 23

Clear a heap watch limit previously set by setWatchHeapLimit(long).

public void dumpPackageState (FileDescriptor fd, String packageName)

Added in API level 19

Perform a system dump of various state associated with the given application package name. This call blocks while the dump is being performed, so should not be done on a UI thread. The data will be written to the given file descriptor as text. An application must hold the DUMP permission to make this call.

Parameters
fd FileDescriptor: The file descriptor that the dump should be written to. The file descriptor is not closed by this function; the caller continues to own it.
packageName String: The name of the package that is to be dumped.

public Size getAppTaskThumbnailSize ()

Added in API level 21

Return the current design dimensions for ActivityManager.AppTask thumbnails, for use with addAppTask(Activity, Intent, ActivityManager.TaskDescription, Bitmap).

Returns
Size

public List<ActivityManager.AppTask> getAppTasks ()

Added in API level 21

Get the list of tasks associated with the calling application.

Returns
List<ActivityManager.AppTask> The list of tasks associated with the application making this call.
Throws
SecurityException

public ConfigurationInfo getDeviceConfigurationInfo ()

Added in API level 3

Get the device configuration attributes.

Returns
ConfigurationInfo

public int getLargeMemoryClass ()

Added in API level 11

Return the approximate per-application memory class of the current device when an application is running with a large heap. This is the space available for memory-intensive applications; most applications should not need this amount of memory, and should instead stay with the getMemoryClass() limit. The returned value is in megabytes. This may be the same size as getMemoryClass() on memory constrained devices, or it may be significantly larger on devices with a large amount of available RAM.

The is the size of the application's Dalvik heap if it has specified android:largeHeap="true" in its manifest.

Returns
int

public int getLauncherLargeIconDensity ()

Added in API level 11

Get the preferred density of icons for the launcher. This is used when custom drawables are created (e.g., for shortcuts).

Returns
int density in terms of DPI

public int getLauncherLargeIconSize ()

Added in API level 11

Get the preferred launcher icon size. This is used when custom drawables are created (e.g., for shortcuts).

Returns
int dimensions of square icons in terms of pixels

public int getLockTaskModeState ()

Added in API level 23

Return the current state of task locking. The three possible outcomes are LOCK_TASK_MODE_NONE, LOCK_TASK_MODE_LOCKED and LOCK_TASK_MODE_PINNED.

Returns
int

See also:

public int getMemoryClass ()

Added in API level 5

Return the approximate per-application memory class of the current device. This gives you an idea of how hard a memory limit you should impose on your application to let the overall system work best. The returned value is in megabytes; the baseline Android memory class is 16 (which happens to be the Java heap limit of those devices); some device with more memory may return 24 or even higher numbers.

Returns
int

public void getMemoryInfo (ActivityManager.MemoryInfo outInfo)

Added in API level 1

Return general information about the memory state of the system. This can be used to help decide how to manage your own memory, though note that polling is not recommended and ComponentCallbacks2.onTrimMemory(int) is the preferred way to do this. Also see getMyMemoryState(ActivityManager.RunningAppProcessInfo) for how to retrieve the current trim level of your process as needed, which gives a better hint for how to manage its memory.

Parameters
outInfo ActivityManager.MemoryInfo

public static void getMyMemoryState (ActivityManager.RunningAppProcessInfo outState)

Added in API level 16

Return global memory state information for the calling process. This does not fill in all fields of the ActivityManager.RunningAppProcessInfo. The only fields that will be filled in are pid, uid, lastTrimLevel, importance, lru, and importanceReasonCode.

Parameters
outState ActivityManager.RunningAppProcessInfo

public MemoryInfo[] getProcessMemoryInfo (int[] pids)

Added in API level 5

Return information about the memory usage of one or more processes.

Note: this method is only intended for debugging or building a user-facing process management UI.

Parameters
pids int: The pids of the processes whose memory usage is to be retrieved.
Returns
MemoryInfo[] Returns an array of memory information, one for each requested pid.

public List<ActivityManager.ProcessErrorStateInfo> getProcessesInErrorState ()

Added in API level 1

Returns a list of any processes that are currently in an error condition. The result will be null if all processes are running properly at this time.

Returns
List<ActivityManager.ProcessErrorStateInfo> Returns a list of ProcessErrorStateInfo records, or null if there are no current error conditions (it will not return an empty list). This list ordering is not specified.

public List<ActivityManager.RecentTaskInfo> getRecentTasks (int maxNum, int flags)

Added in API level 1

This method was deprecated in API level 21.
As of LOLLIPOP, this method is no longer available to third party applications: the introduction of document-centric recents means it can leak personal information to the caller. For backwards compatibility, it will still return a small subset of its data: at least the caller's own tasks (though see getAppTasks() for the correct supported way to retrieve that information), and possibly some other tasks such as home that are known to not be sensitive.

Return a list of the tasks that the user has recently launched, with the most recent being first and older ones after in order.

Note: this method is only intended for debugging and presenting task management user interfaces. This should never be used for core logic in an application, such as deciding between different behaviors based on the information found here. Such uses are not supported, and will likely break in the future. For example, if multiple applications can be actively running at the same time, assumptions made about the meaning of the data here for purposes of control flow will be incorrect.

Parameters
maxNum int: The maximum number of entries to return in the list. The actual number returned may be smaller, depending on how many tasks the user has started and the maximum number the system can remember.
flags int: Information about what to return. May be any combination of RECENT_WITH_EXCLUDED and RECENT_IGNORE_UNAVAILABLE.
Returns
List<ActivityManager.RecentTaskInfo> Returns a list of RecentTaskInfo records describing each of the recent tasks.
Throws
SecurityException

public List<ActivityManager.RunningAppProcessInfo> getRunningAppProcesses ()

Added in API level 3

Returns a list of application processes that are running on the device.

Note: this method is only intended for debugging or building a user-facing process management UI.

Returns
List<ActivityManager.RunningAppProcessInfo> Returns a list of RunningAppProcessInfo records, or null if there are no running processes (it will not return an empty list). This list ordering is not specified.

public PendingIntent getRunningServiceControlPanel (ComponentName service)

Added in API level 5

Returns a PendingIntent you can start to show a control panel for the given running service. If the service does not have a control panel, null is returned.

Parameters
service ComponentName
Returns
PendingIntent
Throws
SecurityException

public List<ActivityManager.RunningServiceInfo> getRunningServices (int maxNum)

Added in API level 1

Return a list of the services that are currently running.

Note: this method is only intended for debugging or implementing service management type user interfaces.

Parameters
maxNum int: The maximum number of entries to return in the list. The actual number returned may be smaller, depending on how many services are running.
Returns
List<ActivityManager.RunningServiceInfo> Returns a list of RunningServiceInfo records describing each of the running tasks.
Throws
SecurityException

public List<ActivityManager.RunningTaskInfo> getRunningTasks (int maxNum)

Added in API level 1

This method was deprecated in API level 21.
As of LOLLIPOP, this method is no longer available to third party applications: the introduction of document-centric recents means it can leak person information to the caller. For backwards compatibility, it will still retu rn a small subset of its data: at least the caller's own tasks, and possibly some other tasks such as home that are known to not be sensitive.

Return a list of the tasks that are currently running, with the most recent being first and older ones after in order. Note that "running" does not mean any of the task's code is currently loaded or activity -- the task may have been frozen by the system, so that it can be restarted in its previous state when next brought to the foreground.

Note: this method is only intended for debugging and presenting task management user interfaces. This should never be used for core logic in an application, such as deciding between different behaviors based on the information found here. Such uses are not supported, and will likely break in the future. For example, if multiple applications can be actively running at the same time, assumptions made about the meaning of the data here for purposes of control flow will be incorrect.

Parameters
maxNum int: The maximum number of entries to return in the list. The actual number returned may be smaller, depending on how many tasks the user has started.
Returns
List<ActivityManager.RunningTaskInfo> Returns a list of RunningTaskInfo records describing each of the running tasks.
Throws
SecurityException

public boolean isInLockTaskMode ()

Added in API level 21

This method was deprecated in API level 23.
Use getLockTaskModeState() instead.

Return whether currently in lock task mode. When in this mode no new tasks can be created or switched to.

Returns
boolean

See also:

public boolean isLowRamDevice ()

Added in API level 19

Returns true if this is a low-RAM device. Exactly whether a device is low-RAM is ultimately up to the device configuration, but currently it generally means something in the class of a 512MB device with about a 800x480 or less screen. This is mostly intended to be used by apps to determine whether they should turn off certain features that require more RAM.

Returns
boolean

public static boolean isRunningInTestHarness ()

Added in API level 11

Returns "true" if device is running in a test harness.

Returns
boolean

public static boolean isUserAMonkey ()

Added in API level 8

Returns "true" if the user interface is currently being messed with by a monkey.

Returns
boolean

public void killBackgroundProcesses (String packageName)

Added in API level 8

Have the system immediately kill all background processes associated with the given package. This is the same as the kernel killing those processes to reclaim memory; the system will take care of restarting these processes in the future as needed.

You must hold the permission KILL_BACKGROUND_PROCESSES to be able to call this method.

Parameters
packageName String: The name of the package whose processes are to be killed.

public void moveTaskToFront (int taskId, int flags, Bundle options)

Added in API level 16

Ask that the task associated with a given task ID be moved to the front of the stack, so it is now visible to the user. Requires that the caller hold permission REORDER_TASKS or a SecurityException will be thrown.

Parameters
taskId int: The identifier of the task to be moved, as found in ActivityManager.RunningTaskInfo or ActivityManager.RecentTaskInfo.
flags int: Additional operational flags, 0 or more of MOVE_TASK_WITH_HOME, MOVE_TASK_NO_USER_ACTION.
options Bundle: Additional options for the operation, either null or as per Context.startActivity(Intent, Bundle).

public void moveTaskToFront (int taskId, int flags)

Added in API level 11

Equivalent to calling moveTaskToFront(int, int, Bundle) with a null options argument.

Parameters
taskId int: The identifier of the task to be moved, as found in ActivityManager.RunningTaskInfo or ActivityManager.RecentTaskInfo.
flags int: Additional operational flags, 0 or more of MOVE_TASK_WITH_HOME, MOVE_TASK_NO_USER_ACTION.

public void restartPackage (String packageName)

Added in API level 3

This method was deprecated in API level 8.
This is now just a wrapper for killBackgroundProcesses(String); the previous behavior here is no longer available to applications because it allows them to break other applications by removing their alarms, stopping their services, etc.

Parameters
packageName String

public void setWatchHeapLimit (long pssSize)

Added in API level 23

Request that the system start watching for the calling process to exceed a pss size as given here. Once called, the system will look for any occasions where it sees the associated process with a larger pss size and, when this happens, automatically pull a heap dump from it and allow the user to share the data. Note that this request continues running even if the process is killed and restarted. To remove the watch, use clearWatchHeapLimit().

This API only work if the calling process has been marked as FLAG_DEBUGGABLE or this is running on a debuggable (userdebug or eng) build.

Callers can optionally implement ACTION_REPORT_HEAP_LIMIT to directly handle heap limit reports themselves.

Parameters
pssSize long: The size in bytes to set the limit at.