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DreamService

public class DreamService
extends Service implements Window.Callback

java.lang.Object
   ↳ android.content.Context
     ↳ android.content.ContextWrapper
       ↳ android.app.Service
         ↳ android.service.dreams.DreamService


Extend this class to implement a custom dream (available to the user as a "Daydream").

Dreams are interactive screensavers launched when a charging device is idle, or docked in a desk dock. Dreams provide another modality for apps to express themselves, tailored for an exhibition/lean-back experience.

The DreamService lifecycle is as follows:

  1. onAttachedToWindow()

    Use this for initial setup, such as calling setContentView().

  2. onDreamingStarted()

    Your dream has started, so you should begin animations or other behaviors here.

  3. onDreamingStopped()

    Use this to stop the things you started in onDreamingStarted().

  4. onDetachedFromWindow()

    Use this to dismantle resources (for example, detach from handlers and listeners).

In addition, onCreate and onDestroy (from the Service interface) will also be called, but initialization and teardown should be done by overriding the hooks above.

To be available to the system, your DreamService should be declared in the manifest as follows:

 <service
     android:name=".MyDream"
     android:exported="true"
     android:icon="@drawable/my_icon"
     android:label="@string/my_dream_label" >

     <intent-filter>
         <action android:name="android.service.dreams.DreamService" />
         <category android:name="android.intent.category.DEFAULT" />
     </intent-filter>

     <!-- Point to additional information for this dream (optional) -->
     <meta-data
         android:name="android.service.dream"
         android:resource="@xml/my_dream" />
 </service>
 

If specified with the <meta-data> element, additional information for the dream is defined using the <dream> element in a separate XML file. Currently, the only addtional information you can provide is for a settings activity that allows the user to configure the dream behavior. For example:

res/xml/my_dream.xml

 <dream xmlns:android="http://schemas.android.com/apk/res/android"
     android:settingsActivity="com.example.app/.MyDreamSettingsActivity" />
 

This makes a Settings button available alongside your dream's listing in the system settings, which when pressed opens the specified activity.

To specify your dream layout, call setContentView(View), typically during the onAttachedToWindow() callback. For example:

 public class MyDream extends DreamService {

     @Override
     public void onAttachedToWindow() {
         super.onAttachedToWindow();

         // Exit dream upon user touch
         setInteractive(false);
         // Hide system UI
         setFullscreen(true);
         // Set the dream layout
         setContentView(R.layout.dream);
     }
 }
 

When targeting api level 21 and above, you must declare the service in your manifest file with the BIND_DREAM_SERVICE permission. For example:

 <service
     android:name=".MyDream"
     android:exported="true"
     android:icon="@drawable/my_icon"
     android:label="@string/my_dream_label"
     android:permission="android.permission.BIND_DREAM_SERVICE">
   <intent-filter>
     <action android:name=”android.service.dreams.DreamService” />
     <category android:name=”android.intent.category.DEFAULT” />
   </intent-filter>
 </service>
 

Summary

Constants

String DREAM_META_DATA

Name under which a Dream publishes information about itself.

String SERVICE_INTERFACE

The Intent that must be declared as handled by the service.

Inherited constants

From class android.app.Service
From class android.content.Context
From interface android.content.ComponentCallbacks2

Public constructors

DreamService()

Public methods

void addContentView(View view, ViewGroup.LayoutParams params)

Adds a view to the Dream's window, leaving other content views in place.

boolean dispatchGenericMotionEvent(MotionEvent event)

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 AccessibilityEvents.

boolean dispatchTouchEvent(MotionEvent event)

Called to process touch screen events.

boolean dispatchTrackballEvent(MotionEvent event)

Called to process trackball events.

View findViewById(int id)

Finds a view that was identified by the id attribute from the XML that was processed in onCreate().

final void finish()

Stops the dream and detaches from the window.

Window getWindow()

Retrieves the current Window for the dream.

WindowManager getWindowManager()

Retrieves the current WindowManager for the dream.

boolean isFullscreen()

Returns whether or not this dream is in fullscreen mode.

boolean isInteractive()

Returns whether or not this dream is interactive.

boolean isScreenBright()

Returns whether or not this dream keeps the screen bright while dreaming.

void onActionModeFinished(ActionMode mode)

Called when an action mode has been finished.

void onActionModeStarted(ActionMode mode)

Called when an action mode has been started.

void onAttachedToWindow()

Called when the window has been attached to the window manager.

final IBinder onBind(Intent intent)

Return the communication channel to the service.

void onContentChanged()

This hook is called whenever the content view of the screen changes (due to a call to Window.setContentView or Window.addContentView).

void onCreate()

Called when this Dream is constructed.

boolean onCreatePanelMenu(int featureId, Menu menu)

Initialize the contents of the menu for panel 'featureId'.

View onCreatePanelView(int featureId)

Instantiate the view to display in the panel for 'featureId'.

void onDestroy()

Called by the system to notify a Service that it is no longer used and is being removed.

void onDetachedFromWindow()

Called when the window has been attached to the window manager.

void onDreamingStarted()

Called when the dream's window has been created and is visible and animation may now begin.

void onDreamingStopped()

Called when this Dream is stopped, either by external request or by calling finish(), before the window has been removed.

boolean onMenuItemSelected(int featureId, MenuItem item)

Called when a panel's menu item has been selected by the user.

boolean onMenuOpened(int featureId, Menu menu)

Called when a panel's menu is opened by the user.

void onPanelClosed(int featureId, Menu menu)

Called when a panel is being closed.

boolean onPreparePanel(int featureId, View view, Menu menu)

Prepare a panel to be displayed.

boolean onSearchRequested()

Called when the user signals the desire to start a search.

boolean onSearchRequested(SearchEvent event)

Called when the user signals the desire to start a search.

void onWakeUp()

Called when the dream is being asked to stop itself and wake.

void onWindowAttributesChanged(WindowManager.LayoutParams attrs)

This is called whenever the current window attributes change.

void onWindowFocusChanged(boolean hasFocus)

This hook is called whenever the window focus changes.

ActionMode onWindowStartingActionMode(ActionMode.Callback callback)

Called when an action mode is being started for this window.

ActionMode onWindowStartingActionMode(ActionMode.Callback callback, int type)

Called when an action mode is being started for this window.

void setContentView(View view)

Sets a view to be the content view for this Dream.

void setContentView(int layoutResID)

Inflates a layout resource and set it to be the content view for this Dream.

void setContentView(View view, ViewGroup.LayoutParams params)

Sets a view to be the content view for this Dream.

void setFullscreen(boolean fullscreen)

Controls FLAG_FULLSCREEN on the dream's window.

void setInteractive(boolean interactive)

Marks this dream as interactive to receive input events.

void setScreenBright(boolean screenBright)

Marks this dream as keeping the screen bright while dreaming.

final void wakeUp()

Wakes the dream up gently.

Protected methods

void dump(FileDescriptor fd, PrintWriter pw, String[] args)

Print the Service's state into the given stream.

Inherited methods

From class android.app.Service
From class android.content.ContextWrapper
From class android.content.Context
From class java.lang.Object
From interface android.content.ComponentCallbacks2
From interface android.view.Window.Callback
From interface android.content.ComponentCallbacks

Constants

DREAM_META_DATA

Added in API level 17
String DREAM_META_DATA

Name under which a Dream publishes information about itself. This meta-data must reference an XML resource containing a <dream> tag.

Constant Value: "android.service.dream"

SERVICE_INTERFACE

Added in API level 17
String SERVICE_INTERFACE

The Intent that must be declared as handled by the service.

Constant Value: "android.service.dreams.DreamService"

Public constructors

DreamService

Added in API level 17
DreamService ()

Public methods

addContentView

Added in API level 17
void addContentView (View view, 
                ViewGroup.LayoutParams params)

Adds a view to the Dream's window, leaving other content views in place.

Note: Requires a window, do not call before onAttachedToWindow()

Parameters
view View: The desired content to display.
params ViewGroup.LayoutParams: Layout parameters for the view.

dispatchGenericMotionEvent

Added in API level 17
boolean dispatchGenericMotionEvent (MotionEvent event)

Called to process generic motion events. At the very least your implementation must call superDispatchGenericMotionEvent(MotionEvent) to do the standard processing.

Parameters
event MotionEvent: The generic motion event.
Returns
boolean boolean Return true if this event was consumed.

dispatchKeyEvent

Added in API level 17
boolean dispatchKeyEvent (KeyEvent event)

Called to process key events. At the very least your implementation must call superDispatchKeyEvent(KeyEvent) to do the standard key processing.

Parameters
event KeyEvent: The key event.
Returns
boolean boolean Return true if this event was consumed.

dispatchKeyShortcutEvent

Added in API level 17
boolean dispatchKeyShortcutEvent (KeyEvent event)

Called to process a key shortcut event. At the very least your implementation must call superDispatchKeyShortcutEvent(KeyEvent) to do the standard key shortcut processing.

Parameters
event KeyEvent: The key shortcut event.
Returns
boolean True if this event was consumed.

dispatchPopulateAccessibilityEvent

Added in API level 17
boolean dispatchPopulateAccessibilityEvent (AccessibilityEvent event)

Called to process population of AccessibilityEvents.

Parameters
event AccessibilityEvent: The event.
Returns
boolean boolean Return true if event population was completed.

dispatchTouchEvent

Added in API level 17
boolean dispatchTouchEvent (MotionEvent event)

Called to process touch screen events. At the very least your implementation must call superDispatchTouchEvent(MotionEvent) to do the standard touch screen processing.

Parameters
event MotionEvent: The touch screen event.
Returns
boolean boolean Return true if this event was consumed.

dispatchTrackballEvent

Added in API level 17
boolean dispatchTrackballEvent (MotionEvent event)

Called to process trackball events. At the very least your implementation must call superDispatchTrackballEvent(MotionEvent) to do the standard trackball processing.

Parameters
event MotionEvent: The trackball event.
Returns
boolean boolean Return true if this event was consumed.

findViewById

Added in API level 17
View findViewById (int id)

Finds a view that was identified by the id attribute from the XML that was processed in onCreate().

Note: Requires a window, do not call before onAttachedToWindow()

Parameters
id int
Returns
View The view if found or null otherwise.

finish

Added in API level 17
void finish ()

Stops the dream and detaches from the window.

When the dream ends, the system will be allowed to go to sleep fully unless there is a reason for it to be awake such as recent user activity or wake locks being held.

getWindow

Added in API level 17
Window getWindow ()

Retrieves the current Window for the dream. Behaves similarly to getWindow().

Returns
Window The current window, or null if the dream is not started.

getWindowManager

Added in API level 17
WindowManager getWindowManager ()

Retrieves the current WindowManager for the dream. Behaves similarly to getWindowManager().

Returns
WindowManager The current window manager, or null if the dream is not started.

isFullscreen

Added in API level 17
boolean isFullscreen ()

Returns whether or not this dream is in fullscreen mode. Defaults to false.

Returns
boolean

See also:

isInteractive

Added in API level 17
boolean isInteractive ()

Returns whether or not this dream is interactive. Defaults to false.

Returns
boolean

See also:

isScreenBright

Added in API level 17
boolean isScreenBright ()

Returns whether or not this dream keeps the screen bright while dreaming. Defaults to false, allowing the screen to dim if necessary.

Returns
boolean

See also:

onActionModeFinished

Added in API level 17
void onActionModeFinished (ActionMode mode)

Called when an action mode has been finished. The appropriate mode callback method will have already been invoked.

Parameters
mode ActionMode: The mode that was just finished.

onActionModeStarted

Added in API level 17
void onActionModeStarted (ActionMode mode)

Called when an action mode has been started. The appropriate mode callback method will have already been invoked.

Parameters
mode ActionMode: The new mode that has just been started.

onAttachedToWindow

Added in API level 17
void onAttachedToWindow ()

Called when the window has been attached to the window manager. See View.onAttachedToWindow() for more information.

onBind

Added in API level 17
IBinder onBind (Intent intent)

Return the communication channel to the service. May return null if clients can not bind to the service. The returned IBinder is usually for a complex interface that has been described using aidl.

Note that unlike other application components, calls on to the IBinder interface returned here may not happen on the main thread of the process. More information about the main thread can be found in Processes and Threads.

Parameters
intent Intent: The Intent that was used to bind to this service, as given to Context.bindService. Note that any extras that were included with the Intent at that point will not be seen here.
Returns
IBinder Return an IBinder through which clients can call on to the service.

onContentChanged

Added in API level 17
void onContentChanged ()

This hook is called whenever the content view of the screen changes (due to a call to Window.setContentView or Window.addContentView).

onCreate

Added in API level 17
void onCreate ()

Called when this Dream is constructed.

onCreatePanelMenu

Added in API level 17
boolean onCreatePanelMenu (int featureId, 
                Menu menu)

Initialize the contents of the menu for panel 'featureId'. This is called if onCreatePanelView() returns null, giving you a standard menu in which you can place your items. It is only called once for the panel, the first time it is shown.

You can safely hold on to menu (and any items created from it), making modifications to it as desired, until the next time onCreatePanelMenu() is called for this feature.

Parameters
featureId int: The panel being created.
menu Menu: The menu inside the panel.
Returns
boolean boolean You must return true for the panel to be displayed; if you return false it will not be shown.

onCreatePanelView

Added in API level 17
View onCreatePanelView (int featureId)

Instantiate the view to display in the panel for 'featureId'. You can return null, in which case the default content (typically a menu) will be created for you.

Parameters
featureId int: Which panel is being created.
Returns
View view The top-level view to place in the panel.

onDestroy

Added in API level 17
void onDestroy ()

Called by the system to notify a Service that it is no longer used and is being removed. The service should clean up any resources it holds (threads, registered receivers, etc) at this point. Upon return, there will be no more calls in to this Service object and it is effectively dead. Do not call this method directly.

onDetachedFromWindow

Added in API level 17
void onDetachedFromWindow ()

Called when the window has been attached to the window manager. See View.onDetachedFromWindow() for more information.

onDreamingStarted

Added in API level 17
void onDreamingStarted ()

Called when the dream's window has been created and is visible and animation may now begin.

onDreamingStopped

Added in API level 17
void onDreamingStopped ()

Called when this Dream is stopped, either by external request or by calling finish(), before the window has been removed.

onMenuItemSelected

Added in API level 17
boolean onMenuItemSelected (int featureId, 
                MenuItem item)

Called when a panel's menu item has been selected by the user.

Parameters
featureId int: The panel that the menu is in.
item MenuItem: The menu item that was selected.
Returns
boolean boolean Return true to finish processing of selection, or false to perform the normal menu handling (calling its Runnable or sending a Message to its target Handler).

onMenuOpened

Added in API level 17
boolean onMenuOpened (int featureId, 
                Menu menu)

Called when a panel's menu is opened by the user. This may also be called when the menu is changing from one type to another (for example, from the icon menu to the expanded menu).

Parameters
featureId int: The panel that the menu is in.
menu Menu: The menu that is opened.
Returns
boolean Return true to allow the menu to open, or false to prevent the menu from opening.

onPanelClosed

Added in API level 17
void onPanelClosed (int featureId, 
                Menu menu)

Called when a panel is being closed. If another logical subsequent panel is being opened (and this panel is being closed to make room for the subsequent panel), this method will NOT be called.

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

onPreparePanel

Added in API level 17
boolean onPreparePanel (int featureId, 
                View view, 
                Menu menu)

Prepare a panel to be displayed. This is called right before the panel window is shown, every time it is shown.

Parameters
featureId int: The panel that is being displayed.
view View: The View that was returned by onCreatePanelView().
menu Menu: If onCreatePanelView() returned null, this is the Menu being displayed in the panel.
Returns
boolean boolean You must return true for the panel to be displayed; if you return false it will not be shown.

onSearchRequested

Added in API level 17
boolean onSearchRequested ()

Called when the user signals the desire to start a search.

Returns
boolean true if search launched, false if activity refuses (blocks)

onSearchRequested

Added in API level 23
boolean onSearchRequested (SearchEvent event)

Called when the user signals the desire to start a search.

Parameters
event SearchEvent: A SearchEvent describing the signal to start a search.
Returns
boolean true if search launched, false if activity refuses (blocks)

onWakeUp

Added in API level 21
void onWakeUp ()

Called when the dream is being asked to stop itself and wake.

The default implementation simply calls finish() which ends the dream immediately. Subclasses may override this function to perform a smooth exit transition then call finish() afterwards.

Note that the dream will only be given a short period of time (currently about five seconds) to wake up. If the dream does not finish itself in a timely manner then the system will forcibly finish it once the time allowance is up.

onWindowAttributesChanged

Added in API level 17
void onWindowAttributesChanged (WindowManager.LayoutParams attrs)

This is called whenever the current window attributes change.

Parameters
attrs WindowManager.LayoutParams

onWindowFocusChanged

Added in API level 17
void onWindowFocusChanged (boolean hasFocus)

This hook is called whenever the window focus changes. See View.onWindowFocusChangedNotLocked(boolean) for more information.

Parameters
hasFocus boolean: Whether the window now has focus.

onWindowStartingActionMode

Added in API level 17
ActionMode onWindowStartingActionMode (ActionMode.Callback callback)

Called when an action mode is being started for this window. Gives the callback an opportunity to handle the action mode in its own unique and beautiful way. If this method returns null the system can choose a way to present the mode or choose not to start the mode at all. This is equivalent to onWindowStartingActionMode(android.view.ActionMode.Callback, int) with type TYPE_PRIMARY.

Parameters
callback ActionMode.Callback: Callback to control the lifecycle of this action mode
Returns
ActionMode The ActionMode that was started, or null if the system should present it

onWindowStartingActionMode

Added in API level 23
ActionMode onWindowStartingActionMode (ActionMode.Callback callback, 
                int type)

Called when an action mode is being started for this window. Gives the callback an opportunity to handle the action mode in its own unique and beautiful way. If this method returns null the system can choose a way to present the mode or choose not to start the mode at all.

Parameters
callback ActionMode.Callback: Callback to control the lifecycle of this action mode
type int: One of TYPE_PRIMARY or TYPE_FLOATING.
Returns
ActionMode The ActionMode that was started, or null if the system should present it

setContentView

Added in API level 17
void setContentView (View view)

Sets a view to be the content view for this Dream. Behaves similarly to setContentView(android.view.View) in an activity, including using MATCH_PARENT as the layout height and width of the view.

Note: This requires a window, so you should usually call it during onAttachedToWindow() and never earlier (you cannot call it during onCreate()).

Parameters
view View

See also:

setContentView

Added in API level 17
void setContentView (int layoutResID)

Inflates a layout resource and set it to be the content view for this Dream. Behaves similarly to setContentView(int).

Note: Requires a window, do not call before onAttachedToWindow()

Parameters
layoutResID int: Resource ID to be inflated.

See also:

setContentView

Added in API level 17
void setContentView (View view, 
                ViewGroup.LayoutParams params)

Sets a view to be the content view for this Dream. Behaves similarly to setContentView(android.view.View, android.view.ViewGroup.LayoutParams) in an activity.

Note: This requires a window, so you should usually call it during onAttachedToWindow() and never earlier (you cannot call it during onCreate()).

Parameters
view View: The desired content to display.
params ViewGroup.LayoutParams: Layout parameters for the view.

See also:

setFullscreen

Added in API level 17
void setFullscreen (boolean fullscreen)

Controls FLAG_FULLSCREEN on the dream's window.

Parameters
fullscreen boolean: If true, the fullscreen flag will be set; else it will be cleared.

setInteractive

Added in API level 17
void setInteractive (boolean interactive)

Marks this dream as interactive to receive input events.

Non-interactive dreams (default) will dismiss on the first input event.

Interactive dreams should call finish() to dismiss themselves.

Parameters
interactive boolean: True if this dream will handle input events.

setScreenBright

Added in API level 17
void setScreenBright (boolean screenBright)

Marks this dream as keeping the screen bright while dreaming.

Parameters
screenBright boolean: True to keep the screen bright while dreaming.

wakeUp

Added in API level 21
void wakeUp ()

Wakes the dream up gently.

Calls onWakeUp() to give the dream a chance to perform an exit transition. When the transition is over, the dream should call finish().

Protected methods

dump

Added in API level 17
void dump (FileDescriptor fd, 
                PrintWriter pw, 
                String[] args)

Print the Service's state into the given stream. This gets invoked if you run "adb shell dumpsys activity service <yourservicename>" (note that for this command to work, the service must be running, and you must specify a fully-qualified service name). This is distinct from "dumpsys <servicename>", which only works for named system services and which invokes the dump(FileDescriptor, String[]) method on the IBinder interface registered with ServiceManager.

Parameters
fd FileDescriptor: The raw file descriptor that the dump is being sent to.
pw PrintWriter: The PrintWriter to which you should dump your state. This will be closed for you after you return.
args String: additional arguments to the dump request.
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