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public
class
WallpaperService.Engine
extends Object
java.lang.Object | |
↳ | android.service.wallpaper.WallpaperService.Engine |
The actual implementation of a wallpaper. A wallpaper service may
have multiple instances running (for example as a real wallpaper
and as a preview), each of which is represented by its own Engine
instance. You must implement WallpaperService#onCreateEngine()
to return your concrete Engine implementation.
Public constructors | |
---|---|
Engine()
Default constructor |
Public methods | |
---|---|
int
|
getDesiredMinimumHeight()
Convenience for |
int
|
getDesiredMinimumWidth()
Convenience for |
Context
|
getDisplayContext()
The |
SurfaceHolder
|
getSurfaceHolder()
Provides access to the surface in which this wallpaper is drawn. |
boolean
|
isPreview()
Returns true if this engine is running in preview mode -- that is, it is being shown to the user before they select it as the actual wallpaper. |
boolean
|
isVisible()
Return whether the wallpaper is currently visible to the user,
this is the last value supplied to
|
void
|
notifyColorsChanged()
Notifies the engine that wallpaper colors changed significantly. |
void
|
onApplyWindowInsets(WindowInsets insets)
Called with the current insets that are in effect for the wallpaper. |
Bundle
|
onCommand(String action, int x, int y, int z, Bundle extras, boolean resultRequested)
Process a command that was sent to the wallpaper with
|
WallpaperColors
|
onComputeColors()
Called by the system when it needs to know what colors the wallpaper is using. |
void
|
onCreate(SurfaceHolder surfaceHolder)
Called once to initialize the engine. |
void
|
onDesiredSizeChanged(int desiredWidth, int desiredHeight)
Called when an application has changed the desired virtual size of the wallpaper. |
void
|
onDestroy()
Called right before the engine is going away. |
void
|
onOffsetsChanged(float xOffset, float yOffset, float xOffsetStep, float yOffsetStep, int xPixelOffset, int yPixelOffset)
Called to inform you of the wallpaper's offsets changing
within its contain, corresponding to the container's
call to |
void
|
onSurfaceChanged(SurfaceHolder holder, int format, int width, int height)
Convenience for |
void
|
onSurfaceCreated(SurfaceHolder holder)
Convenience for |
void
|
onSurfaceDestroyed(SurfaceHolder holder)
Convenience for |
void
|
onSurfaceRedrawNeeded(SurfaceHolder holder)
Convenience for |
void
|
onTouchEvent(MotionEvent event)
Called as the user performs touch-screen interaction with the window that is currently showing this wallpaper. |
void
|
onVisibilityChanged(boolean visible)
Called to inform you of the wallpaper becoming visible or hidden. |
void
|
onZoomChanged(float zoom)
Called when the zoom level of the wallpaper changed. |
void
|
setOffsetNotificationsEnabled(boolean enabled)
Control whether this wallpaper will receive notifications when the wallpaper has been scrolled. |
void
|
setTouchEventsEnabled(boolean enabled)
Control whether this wallpaper will receive raw touch events from the window manager as the user interacts with the window that is currently displaying the wallpaper. |
Protected methods | |
---|---|
void
|
dump(String prefix, FileDescriptor fd, PrintWriter out, String[] args)
|
Inherited methods | |
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public Engine ()
Default constructor
public int getDesiredMinimumHeight ()
Convenience for WallpaperManager.getDesiredMinimumHeight()
, returning the height
that the system would like this wallpaper to run in.
Returns | |
---|---|
int |
public int getDesiredMinimumWidth ()
Convenience for WallpaperManager.getDesiredMinimumWidth()
, returning the width
that the system would like this wallpaper to run in.
Returns | |
---|---|
int |
public Context getDisplayContext ()
The Context
with resources that match the current display the wallpaper is on.
For multiple display environment, multiple engines can be created to render on each
display, but these displays may have different densities. Use this context to get the
corresponding resources for currently display, avoiding the context of the service.
The display context will never be null
after
Engine#onCreate(SurfaceHolder)
has been called.
Returns | |
---|---|
Context |
A Context for current display. |
public SurfaceHolder getSurfaceHolder ()
Provides access to the surface in which this wallpaper is drawn.
Returns | |
---|---|
SurfaceHolder |
public boolean isPreview ()
Returns true if this engine is running in preview mode -- that is, it is being shown to the user before they select it as the actual wallpaper.
Returns | |
---|---|
boolean |
public boolean isVisible ()
Return whether the wallpaper is currently visible to the user,
this is the last value supplied to
onVisibilityChanged(boolean)
.
Returns | |
---|---|
boolean |
public void notifyColorsChanged ()
Notifies the engine that wallpaper colors changed significantly.
This will trigger a onComputeColors()
call.
public void onApplyWindowInsets (WindowInsets insets)
Called with the current insets that are in effect for the wallpaper. This gives you the part of the overall wallpaper surface that will generally be visible to the user (ignoring position offsets applied to it).
Parameters | |
---|---|
insets |
WindowInsets : Insets to apply. |
public Bundle onCommand (String action, int x, int y, int z, Bundle extras, boolean resultRequested)
Process a command that was sent to the wallpaper with
WallpaperManager#sendWallpaperCommand
.
The default implementation does nothing, and always returns null
as the result.
Parameters | |
---|---|
action |
String : The name of the command to perform. This tells you
what to do and how to interpret the rest of the arguments. |
x |
int : Generic integer parameter. |
y |
int : Generic integer parameter. |
z |
int : Generic integer parameter. |
extras |
Bundle : Any additional parameters. |
resultRequested |
boolean : If true, the caller is requesting that
a result, appropriate for the command, be returned back. |
Returns | |
---|---|
Bundle |
If returning a result, create a Bundle and place the result data in to it. Otherwise return null. |
public WallpaperColors onComputeColors ()
Called by the system when it needs to know what colors the wallpaper is using.
You might return null if no color information is available at the moment.
In that case you might want to call notifyColorsChanged()
when
color information becomes available.
The simplest way of creating a WallpaperColors
object is by using
WallpaperColors.fromBitmap(Bitmap)
or
WallpaperColors.fromDrawable(Drawable)
, but you can also specify
your main colors by constructing a WallpaperColors
object manually.
Returns | |
---|---|
WallpaperColors |
Wallpaper colors. |
public void onCreate (SurfaceHolder surfaceHolder)
Called once to initialize the engine. After returning, the engine's surface will be created by the framework.
Parameters | |
---|---|
surfaceHolder |
SurfaceHolder |
public void onDesiredSizeChanged (int desiredWidth, int desiredHeight)
Called when an application has changed the desired virtual size of the wallpaper.
Parameters | |
---|---|
desiredWidth |
int |
desiredHeight |
int |
public void onDestroy ()
Called right before the engine is going away. After this the surface will be destroyed and this Engine object is no longer valid.
public void onOffsetsChanged (float xOffset, float yOffset, float xOffsetStep, float yOffsetStep, int xPixelOffset, int yPixelOffset)
Called to inform you of the wallpaper's offsets changing
within its contain, corresponding to the container's
call to WallpaperManager.setWallpaperOffsets()
.
Parameters | |
---|---|
xOffset |
float |
yOffset |
float |
xOffsetStep |
float |
yOffsetStep |
float |
xPixelOffset |
int |
yPixelOffset |
int |
public void onSurfaceChanged (SurfaceHolder holder, int format, int width, int height)
Convenience for SurfaceHolder.Callback.surfaceChanged()
.
Parameters | |
---|---|
holder |
SurfaceHolder |
format |
int |
width |
int |
height |
int |
public void onSurfaceCreated (SurfaceHolder holder)
Convenience for SurfaceHolder.Callback.surfaceCreated()
.
Parameters | |
---|---|
holder |
SurfaceHolder |
public void onSurfaceDestroyed (SurfaceHolder holder)
Convenience for SurfaceHolder.Callback.surfaceDestroyed()
.
Parameters | |
---|---|
holder |
SurfaceHolder |
public void onSurfaceRedrawNeeded (SurfaceHolder holder)
Convenience for SurfaceHolder.Callback.surfaceRedrawNeeded()
.
Parameters | |
---|---|
holder |
SurfaceHolder |
public void onTouchEvent (MotionEvent event)
Called as the user performs touch-screen interaction with the window that is currently showing this wallpaper. Note that the events you receive here are driven by the actual application the user is interacting with, so if it is slow you will get fewer move events.
Parameters | |
---|---|
event |
MotionEvent |
public void onVisibilityChanged (boolean visible)
Called to inform you of the wallpaper becoming visible or hidden. It is very important that a wallpaper only use CPU while it is visible..
Parameters | |
---|---|
visible |
boolean |
public void onZoomChanged (float zoom)
Called when the zoom level of the wallpaper changed. This method will be called with the initial zoom level when the surface is created.
Parameters | |
---|---|
zoom |
float : the zoom level, between 0 indicating fully zoomed in and 1 indicating fully
zoomed out.
Value is between 0f and 1f inclusive |
public void setOffsetNotificationsEnabled (boolean enabled)
Control whether this wallpaper will receive notifications when the wallpaper has been scrolled. By default, wallpapers will receive notifications, although the default static image wallpapers do not. It is a performance optimization to set this to false.
Parameters | |
---|---|
enabled |
boolean : whether the wallpaper wants to receive offset notifications |
public void setTouchEventsEnabled (boolean enabled)
Control whether this wallpaper will receive raw touch events
from the window manager as the user interacts with the window
that is currently displaying the wallpaper. By default they
are turned off. If enabled, the events will be received in
onTouchEvent(android.view.MotionEvent)
.
Parameters | |
---|---|
enabled |
boolean |
protected void dump (String prefix, FileDescriptor fd, PrintWriter out, String[] args)
Parameters | |
---|---|
prefix |
String |
fd |
FileDescriptor |
out |
PrintWriter |
args |
String |