public
final
class
Display
extends Object
java.lang.Object | |
↳ | android.view.Display |
Provides information about the size and density of a logical display.
The display area is described in two different ways.
getSize(Point)
, getRectSize(Rect)
and getMetrics(DisplayMetrics)
.getRealSize(Point)
, getRealMetrics(DisplayMetrics)
.A logical display does not necessarily represent a particular physical display device such as the built-in screen or an external monitor. The contents of a logical display may be presented on one or more physical displays according to the devices that are currently attached and whether mirroring has been enabled.
Nested classes | |
---|---|
class |
Display.HdrCapabilities
Encapsulates the HDR capabilities of a given display. |
class |
Display.Mode
A mode supported by a given display. |
Constants | |
---|---|
int |
DEFAULT_DISPLAY
The default Display id, which is the id of the built-in primary display assuming there is one. |
int |
FLAG_PRESENTATION
Display flag: Indicates that the display is a presentation display. |
int |
FLAG_PRIVATE
Display flag: Indicates that the display is private. |
int |
FLAG_ROUND
Display flag: Indicates that the display has a round shape. |
int |
FLAG_SECURE
Display flag: Indicates that the display has a secure video output and supports compositing secure surfaces. |
int |
FLAG_SUPPORTS_PROTECTED_BUFFERS
Display flag: Indicates that the display supports compositing content that is stored in protected graphics buffers. |
int |
INVALID_DISPLAY
Invalid display id. |
int |
STATE_DOZE
Display state: The display is dozing in a low power state; it is still on but is optimized for showing system-provided content while the device is non-interactive. |
int |
STATE_DOZE_SUSPEND
Display state: The display is dozing in a suspended low power state; it is still on but is optimized for showing static system-provided content while the device is non-interactive. |
int |
STATE_OFF
Display state: The display is off. |
int |
STATE_ON
Display state: The display is on. |
int |
STATE_UNKNOWN
Display state: The display state is unknown. |
Public methods | |
---|---|
long
|
getAppVsyncOffsetNanos()
Gets the app VSYNC offset, in nanoseconds. |
void
|
getCurrentSizeRange(Point outSmallestSize, Point outLargestSize)
Return the range of display sizes an application can expect to encounter under normal operation, as long as there is no physical change in screen size. |
int
|
getDisplayId()
Gets the display id. |
int
|
getFlags()
Returns a combination of flags that describe the capabilities of the display. |
Display.HdrCapabilities
|
getHdrCapabilities()
Returns the display's HDR capabilities. |
int
|
getHeight()
This method was deprecated
in API level 13.
Use |
void
|
getMetrics(DisplayMetrics outMetrics)
Gets display metrics that describe the size and density of this display. |
Display.Mode
|
getMode()
Returns the active mode of the display. |
String
|
getName()
Gets the name of the display. |
int
|
getOrientation()
This method was deprecated
in API level 8.
use |
int
|
getPixelFormat()
This method was deprecated
in API level 17.
This method is no longer supported.
The result is always |
long
|
getPresentationDeadlineNanos()
This is how far in advance a buffer must be queued for presentation at a given time. |
void
|
getRealMetrics(DisplayMetrics outMetrics)
Gets display metrics based on the real size of this display. |
void
|
getRealSize(Point outSize)
Gets the real size of the display without subtracting any window decor or applying any compatibility scale factors. |
void
|
getRectSize(Rect outSize)
Gets the size of the display as a rectangle, in pixels. |
float
|
getRefreshRate()
Gets the refresh rate of this display in frames per second. |
int
|
getRotation()
Returns the rotation of the screen from its "natural" orientation. |
void
|
getSize(Point outSize)
Gets the size of the display, in pixels. |
int
|
getState()
Gets the state of the display, such as whether it is on or off. |
Mode[]
|
getSupportedModes()
Gets the supported modes of this display. |
float[]
|
getSupportedRefreshRates()
This method was deprecated
in API level 23.
use |
int
|
getWidth()
This method was deprecated
in API level 13.
Use |
boolean
|
isValid()
Returns true if this display is still valid, false if the display has been removed. |
String
|
toString()
Returns a string representation of the object. |
Inherited methods | |
---|---|
From
class
java.lang.Object
|
int DEFAULT_DISPLAY
The default Display id, which is the id of the built-in primary display assuming there is one.
Constant Value: 0 (0x00000000)
int FLAG_PRESENTATION
Display flag: Indicates that the display is a presentation display.
This flag identifies secondary displays that are suitable for use as presentation displays such as HDMI or Wireless displays. Applications may automatically project their content to presentation displays to provide richer second screen experiences.
See also:
Constant Value: 8 (0x00000008)
int FLAG_PRIVATE
Display flag: Indicates that the display is private. Only the application that owns the display can create windows on it.
See also:
Constant Value: 4 (0x00000004)
int FLAG_ROUND
Display flag: Indicates that the display has a round shape.
This flag identifies displays that are circular, elliptical or otherwise do not permit the user to see all the way to the logical corners of the display.
See also:
Constant Value: 16 (0x00000010)
int FLAG_SECURE
Display flag: Indicates that the display has a secure video output and supports compositing secure surfaces.
If this flag is set then the display device has a secure video output
and is capable of showing secure surfaces. It may also be capable of
showing protected buffers
.
If this flag is not set then the display device may not have a secure video output; the user may see a blank region on the screen instead of the contents of secure surfaces or protected buffers.
Secure surfaces are used to prevent content rendered into those surfaces by applications from appearing in screenshots or from being viewed on non-secure displays. Protected buffers are used by secure video decoders for a similar purpose.
An application creates a window with a secure surface by specifying the
FLAG_SECURE
window flag.
Likewise, an application creates a SurfaceView
with a secure surface
by calling setSecure(boolean)
before attaching the secure view to
its containing window.
An application can use the absence of this flag as a hint that it should not create secure surfaces or protected buffers on this display because the content may not be visible. For example, if the flag is not set then the application may choose not to show content on this display, show an informative error message, select an alternate content stream or adopt a different strategy for decoding content that does not rely on secure surfaces or protected buffers.
See also:
Constant Value: 2 (0x00000002)
int FLAG_SUPPORTS_PROTECTED_BUFFERS
Display flag: Indicates that the display supports compositing content that is stored in protected graphics buffers.
If this flag is set then the display device supports compositing protected buffers.
If this flag is not set then the display device may not support compositing protected buffers; the user may see a blank region on the screen instead of the protected content.
Secure (DRM) video decoders may allocate protected graphics buffers to request that a hardware-protected path be provided between the video decoder and the external display sink. If a hardware-protected path is not available, then content stored in protected graphics buffers may not be composited.
An application can use the absence of this flag as a hint that it should not use protected buffers for this display because the content may not be visible. For example, if the flag is not set then the application may choose not to show content on this display, show an informative error message, select an alternate content stream or adopt a different strategy for decoding content that does not rely on protected buffers.
See also:
Constant Value: 1 (0x00000001)
int INVALID_DISPLAY
Invalid display id.
Constant Value: -1 (0xffffffff)
int STATE_DOZE
Display state: The display is dozing in a low power state; it is still on but is optimized for showing system-provided content while the device is non-interactive.
See also:
Constant Value: 3 (0x00000003)
int STATE_DOZE_SUSPEND
Display state: The display is dozing in a suspended low power state; it is still on but is optimized for showing static system-provided content while the device is non-interactive. This mode may be used to conserve even more power by allowing the hardware to stop applying frame buffer updates from the graphics subsystem or to take over the display and manage it autonomously to implement low power always-on display functionality.
See also:
Constant Value: 4 (0x00000004)
int STATE_OFF
Display state: The display is off.
See also:
Constant Value: 1 (0x00000001)
int STATE_ON
Display state: The display is on.
See also:
Constant Value: 2 (0x00000002)
int STATE_UNKNOWN
Display state: The display state is unknown.
See also:
Constant Value: 0 (0x00000000)
long getAppVsyncOffsetNanos ()
Gets the app VSYNC offset, in nanoseconds. This is a positive value indicating the phase offset of the VSYNC events provided by Choreographer relative to the display refresh. For example, if Choreographer reports that the refresh occurred at time N, it actually occurred at (N - appVsyncOffset).
Apps generally do not need to be aware of this. It's only useful for fine-grained A/V synchronization.
Returns | |
---|---|
long |
void getCurrentSizeRange (Point outSmallestSize, Point outLargestSize)
Return the range of display sizes an application can expect to encounter under normal operation, as long as there is no physical change in screen size. This is basically the sizes you will see as the orientation changes, taking into account whatever screen decoration there is in each rotation. For example, the status bar is always at the top of the screen, so it will reduce the height both in landscape and portrait, and the smallest height returned here will be the smaller of the two. This is intended for applications to get an idea of the range of sizes they will encounter while going through device rotations, to provide a stable UI through rotation. The sizes here take into account all standard system decorations that reduce the size actually available to the application: the status bar, navigation bar, system bar, etc. It does not take into account more transient elements like an IME soft keyboard.
Parameters | |
---|---|
outSmallestSize |
Point :
Filled in with the smallest width and height
that the application will encounter, in pixels (not dp units). The x
(width) dimension here directly corresponds to
Configuration.smallestScreenWidthDp , except the value here is in raw
screen pixels rather than dp units. Your application may of course
still get smaller space yet if, for example, a soft keyboard is
being displayed. |
outLargestSize |
Point :
Filled in with the largest width and height
that the application will encounter, in pixels (not dp units). Your
application may of course still get larger space than this if,
for example, screen decorations like the status bar are being hidden.
|
int getDisplayId ()
Gets the display id.
Each logical display has a unique id.
The default display has id DEFAULT_DISPLAY
.
Returns | |
---|---|
int |
int getFlags ()
Returns a combination of flags that describe the capabilities of the display.
Returns | |
---|---|
int |
The display flags. |
Display.HdrCapabilities getHdrCapabilities ()
Returns the display's HDR capabilities.
Returns | |
---|---|
Display.HdrCapabilities |
int getHeight ()
This method was deprecated
in API level 13.
Use getSize(Point)
instead.
Returns | |
---|---|
int |
void getMetrics (DisplayMetrics outMetrics)
Gets display metrics that describe the size and density of this display. The size returned by this method does not necessarily represent the actual raw size (native resolution) of the display.
1. The returned size may be adjusted to exclude certain system decor elements that are always visible.
2. It may be scaled to provide compatibility with older applications that were originally designed for smaller displays.
3. It can be different depending on the WindowManager to which the display belongs.
- If requested from non-Activity context (e.g. Application context via
(WindowManager) getApplicationContext().getSystemService(Context.WINDOW_SERVICE)
)
metrics will report real size of the display based on current rotation.
- If requested from activity resulting metrics will correspond to current window metrics.
In this case the size can be smaller than physical size in multi-window mode.
Parameters | |
---|---|
outMetrics |
DisplayMetrics :
A DisplayMetrics object to receive the metrics.
|
Display.Mode getMode ()
Returns the active mode of the display.
Returns | |
---|---|
Display.Mode |
String getName ()
Gets the name of the display.
Note that some displays may be renamed by the user.
Returns | |
---|---|
String |
The display's name. |
int getOrientation ()
This method was deprecated
in API level 8.
use getRotation()
Returns | |
---|---|
int |
orientation of this display. |
int getPixelFormat ()
This method was deprecated
in API level 17.
This method is no longer supported.
The result is always RGBA_8888
.
Gets the pixel format of the display.
Returns | |
---|---|
int |
One of the constants defined in PixelFormat . |
long getPresentationDeadlineNanos ()
This is how far in advance a buffer must be queued for presentation at a given time. If you want a buffer to appear on the screen at time N, you must submit the buffer before (N - presentationDeadline).
The desired presentation time for GLES rendering may be set with
eglPresentationTimeANDROID(EGLDisplay, EGLSurface, long)
. For video decoding, use
releaseOutputBuffer(int, long)
. Times are
expressed in nanoseconds, using the system monotonic clock
(nanoTime()
).
Returns | |
---|---|
long |
void getRealMetrics (DisplayMetrics outMetrics)
Gets display metrics based on the real size of this display.
The size is adjusted based on the current rotation of the display.
The real size may be smaller than the physical size of the screen when the window manager is emulating a smaller display (using adb shell wm size).
Parameters | |
---|---|
outMetrics |
DisplayMetrics :
A DisplayMetrics object to receive the metrics.
|
void getRealSize (Point outSize)
Gets the real size of the display without subtracting any window decor or applying any compatibility scale factors.
The size is adjusted based on the current rotation of the display.
The real size may be smaller than the physical size of the screen when the window manager is emulating a smaller display (using adb shell am display-size).
Parameters | |
---|---|
outSize |
Point :
Set to the real size of the display.
|
void getRectSize (Rect outSize)
Gets the size of the display as a rectangle, in pixels.
Parameters | |
---|---|
outSize |
Rect :
A Rect object to receive the size information. |
See also:
float getRefreshRate ()
Gets the refresh rate of this display in frames per second.
Returns | |
---|---|
float |
int getRotation ()
Returns the rotation of the screen from its "natural" orientation.
The returned value may be Surface.ROTATION_0
(no rotation), Surface.ROTATION_90
,
Surface.ROTATION_180
, or
Surface.ROTATION_270
. For
example, if a device has a naturally tall screen, and the user has
turned it on its side to go into a landscape orientation, the value
returned here may be either Surface.ROTATION_90
or Surface.ROTATION_270
depending on
the direction it was turned. The angle is the rotation of the drawn
graphics on the screen, which is the opposite direction of the physical
rotation of the device. For example, if the device is rotated 90
degrees counter-clockwise, to compensate rendering will be rotated by
90 degrees clockwise and thus the returned value here will be
Surface.ROTATION_90
.
Returns | |
---|---|
int |
void getSize (Point outSize)
Gets the size of the display, in pixels.
Note that this value should not be used for computing layouts, since a device will typically have screen decoration (such as a status bar) along the edges of the display that reduce the amount of application space available from the size returned here. Layouts should instead use the window size.
The size is adjusted based on the current rotation of the display.
The size returned by this method does not necessarily represent the actual raw size (native resolution) of the display. The returned size may be adjusted to exclude certain system decoration elements that are always visible. It may also be scaled to provide compatibility with older applications that were originally designed for smaller displays.
Parameters | |
---|---|
outSize |
Point :
A Point object to receive the size information.
|
int getState ()
Gets the state of the display, such as whether it is on or off.
Returns | |
---|---|
int |
The state of the display: one of STATE_OFF , STATE_ON ,
STATE_DOZE , STATE_DOZE_SUSPEND , or STATE_UNKNOWN .
|
Mode[] getSupportedModes ()
Gets the supported modes of this display.
Returns | |
---|---|
Mode[] |
float[] getSupportedRefreshRates ()
This method was deprecated
in API level 23.
use getSupportedModes()
instead
Get the supported refresh rates of this display in frames per second.
This method only returns refresh rates for the display's default modes. For more options, use
getSupportedModes()
.
Returns | |
---|---|
float[] |
int getWidth ()
This method was deprecated
in API level 13.
Use getSize(Point)
instead.
Returns | |
---|---|
int |
boolean isValid ()
Returns true if this display is still valid, false if the display has been removed.
If the display is invalid, then the methods of this class will
continue to report the most recently observed display information.
However, it is unwise (and rather fruitless) to continue using a
Display
object after the display's demise.
It's possible for a display that was previously invalid to become
valid again if a display with the same id is reconnected.
Returns | |
---|---|
boolean |
True if the display is still valid. |
String toString ()
Returns a string representation of the object. In general, the
toString
method returns a string that
"textually represents" this object. The result should
be a concise but informative representation that is easy for a
person to read.
It is recommended that all subclasses override this method.
The toString
method for class Object
returns a string consisting of the name of the class of which the
object is an instance, the at-sign character `@
', and
the unsigned hexadecimal representation of the hash code of the
object. In other words, this method returns a string equal to the
value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
Returns | |
---|---|
String |
a string representation of the object. |