ev3dev.hardware.display

Class LinuxFramebuffer

java.lang.Object

ev3dev.hardware.display.LinuxFramebuffer

All Implemented Interfaces:

JavaFramebuffer, java.io.Closeable, java.lang.AutoCloseable

Direct Known Subclasses:

BitFramebuffer, RGBFramebuffer

public abstract class LinuxFramebuffer
extends java.lang.Object
implements JavaFramebuffer

Linux Java2D framebuffer.

Since:

2.4.7

Field Summary

Fields

Modifier and Type	Field and Description
private byte[]	backup Framebuffer backup for VT switches.
private java.awt.image.BufferedImage	blank Cache blank image.
private boolean	closeDevice Whether to close the nativeframebuffer device when closing this framebuffer.
private NativeFramebuffer	device Underlying native Linux device.
private DisplayInterface	display Display manager
private NativeFramebuffer.fb_fix_screeninfo	fixinfo Underlying fixed framebuffer info.
private boolean	flushEnabled Whether to enable display output.
private NativeFramebuffer.fb_var_screeninfo	varinfo Underlying variable framebuffer info.
private Pointer	videomem Memory-mapped memory from Linux framebuffer device.

Constructor Summary

Constructors

Constructor and Description
LinuxFramebuffer(NativeFramebuffer fb, DisplayInterface disp) Create and initialize new Linux-based Java2D framebuffer.

Method Summary

Modifier and Type	Method and Description
void	clear() Clear the hardware framebuffer.
void	close()
java.awt.image.BufferedImage	createCompatibleBuffer() Create full-screen buffer.
abstract java.awt.image.BufferedImage	createCompatibleBuffer(int width, int height) Create pixel-compatible buffer with a specified size.
java.awt.image.BufferedImage	createCompatibleBuffer(int width, int height, int stride) Create pixel-compatible buffer with a specified size and stride.
abstract java.awt.image.BufferedImage	createCompatibleBuffer(int width, int height, int stride, byte[] backed) Create pixel-compatible buffer with a specified size and stride.
void	flushScreen(java.awt.image.BufferedImage compatible) Write full-screen buffer into the framebuffer.
long	getBufferSize() Get video memory size.
NativeFramebuffer	getDevice() Get the underlying native device.
DisplayInterface	getDisplay() Get the associated display manager.
NativeFramebuffer.fb_fix_screeninfo	getFixedInfo() Get Linux framebuffer fixed info.
int	getHeight() Query framebuffer height.
Pointer	getMemory() Get direct access to the video memory.
int	getStride() Query framebuffer scanline stride, e.g.
NativeFramebuffer.fb_var_screeninfo	getVariableInfo() Get Linux framebuffer variable info.
int	getWidth() Query framebuffer width.
protected void	initializeMemory()
void	restoreData() Restore original hardware framebuffer state.
protected void	setDeviceClose(boolean rly) Set whether to close the underlying device on exit.
void	setFlushEnabled(boolean rly) Controls whether JavaFramebuffer.flushScreen(BufferedImage) has effect or not.
void	storeData() Store current hardware framebuffer state.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

fixinfo

private NativeFramebuffer.fb_fix_screeninfo fixinfo

Underlying fixed framebuffer info.

varinfo

private NativeFramebuffer.fb_var_screeninfo varinfo

Underlying variable framebuffer info.

device

private NativeFramebuffer device

Underlying native Linux device.

videomem

private Pointer videomem

Memory-mapped memory from Linux framebuffer device.

flushEnabled

private boolean flushEnabled

Whether to enable display output.

backup

private byte[] backup

Framebuffer backup for VT switches.

blank

private java.awt.image.BufferedImage blank

Cache blank image.

closeDevice

private boolean closeDevice

Whether to close the nativeframebuffer device when closing this framebuffer.

display

private DisplayInterface display

Display manager

Constructor Detail

LinuxFramebuffer

public LinuxFramebuffer(NativeFramebuffer fb,
                        DisplayInterface disp)
                 throws LastErrorException

Create and initialize new Linux-based Java2D framebuffer.

Parameters:

fb - Framebuffer device (e.g. /dev/fb0)

disp - Display manager (e.g. /dev/tty)

Throws:

LastErrorException

Method Detail

initializeMemory

protected void initializeMemory()
                         throws LastErrorException

Throws:

LastErrorException

close

public void close()
           throws LastErrorException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Throws:

LastErrorException

getWidth

public int getWidth()

Description copied from interface: JavaFramebuffer

Query framebuffer width.

Specified by:

getWidth in interface JavaFramebuffer

Returns:

Screen width in pixels.

getHeight

public int getHeight()

Description copied from interface: JavaFramebuffer

Query framebuffer height.

Specified by:

getHeight in interface JavaFramebuffer

Returns:

Screen height in pixels.

getStride

public int getStride()

Description copied from interface: JavaFramebuffer

Query framebuffer scanline stride, e.g. real row length in bytes.

Specified by:

getStride in interface JavaFramebuffer

Returns:

Screen scanline stride in bytes

createCompatibleBuffer

public java.awt.image.BufferedImage createCompatibleBuffer()

Description copied from interface: JavaFramebuffer

Create full-screen buffer.

Specified by:

createCompatibleBuffer in interface JavaFramebuffer

Returns:

BufferedImage with correct settings.

createCompatibleBuffer

public abstract java.awt.image.BufferedImage createCompatibleBuffer(int width,
                                                                    int height)

Description copied from interface: JavaFramebuffer

Create pixel-compatible buffer with a specified size.

Specified by:

createCompatibleBuffer in interface JavaFramebuffer

Parameters:

width - Requested image width.

height - Requested image height.

Returns:

BufferedImage with correct settings.

createCompatibleBuffer

public java.awt.image.BufferedImage createCompatibleBuffer(int width,
                                                           int height,
                                                           int stride)

Description copied from interface: JavaFramebuffer

Create pixel-compatible buffer with a specified size and stride.

Specified by:

createCompatibleBuffer in interface JavaFramebuffer

Parameters:

width - Requested image width.

height - Requested image height.

stride - Requested scanline stride.

Returns:

BufferedImage with correct settings.

createCompatibleBuffer

public abstract java.awt.image.BufferedImage createCompatibleBuffer(int width,
                                                                    int height,
                                                                    int stride,
                                                                    byte[] backed)

Description copied from interface: JavaFramebuffer

Create pixel-compatible buffer with a specified size and stride. This buffer will be backed by existing byte array.

Specified by:

createCompatibleBuffer in interface JavaFramebuffer

Parameters:

width - Requested image width.

height - Requested image height.

stride - Requested scanline stride.

Returns:

BufferedImage with correct settings.

flushScreen

public void flushScreen(java.awt.image.BufferedImage compatible)

Description copied from interface: JavaFramebuffer

Write full-screen buffer into the framebuffer.

Specified by:

flushScreen in interface JavaFramebuffer

Parameters:

compatible - What to draw onto the screen.

setFlushEnabled

public void setFlushEnabled(boolean rly)

Description copied from interface: JavaFramebuffer

Controls whether JavaFramebuffer.flushScreen(BufferedImage) has effect or not.

Specified by:

setFlushEnabled in interface JavaFramebuffer

Parameters:

rly - Whether flushing should be enabled or not.

storeData

public void storeData()

Description copied from interface: JavaFramebuffer

Store current hardware framebuffer state.

Specified by:

storeData in interface JavaFramebuffer

restoreData

public void restoreData()

Description copied from interface: JavaFramebuffer

Restore original hardware framebuffer state.

Specified by:

restoreData in interface JavaFramebuffer

clear

public void clear()

Description copied from interface: JavaFramebuffer

Clear the hardware framebuffer.

Specified by:

clear in interface JavaFramebuffer

getDisplay

public DisplayInterface getDisplay()

Description copied from interface: JavaFramebuffer

Get the associated display manager.

Specified by:

getDisplay in interface JavaFramebuffer

Returns:

reference to display manager

getFixedInfo

public NativeFramebuffer.fb_fix_screeninfo getFixedInfo()

Get Linux framebuffer fixed info.

Returns:

Fixed information about the framebuffer.

getVariableInfo

public NativeFramebuffer.fb_var_screeninfo getVariableInfo()

Get Linux framebuffer variable info.

Returns:

Variable information about the framebuffer.

getDevice

public NativeFramebuffer getDevice()

Get the underlying native device.

Returns:

Linux device

getMemory

public Pointer getMemory()

Get direct access to the video memory.

Returns:

JNA pointer to the framebuffer

See Also:

for memory size.

getBufferSize

public long getBufferSize()

Get video memory size.

Returns:

Size of video memory in bytes.

See Also:

for memory pointer.

setDeviceClose

protected void setDeviceClose(boolean rly)

Set whether to close the underlying device on exit.