org.crsh.text
Class VirtualScreen

java.lang.Object
  org.crsh.text.VirtualScreen

All Implemented Interfaces:

Appendable, Screenable, ScreenContext

public class VirtualScreen
extends Object
implements ScreenContext

A virtual screen that can be scrolled. This class is thread safe, as it can be used concurrently by two threads, for example one thread can provide new elements while another thread is repainting the buffer to the screen, both threads can either modify the underlying data structure. Paint could also be called concurrently by two threads, one that just provided a new element and wants to repaint the structure and another that changes the current cursor and asks for a repaint too.

Author:

Julien Viet

Constructor Summary

VirtualScreen(ScreenContext out)

Method Summary

Screenable	append(char c)
Screenable	append(CharSequence s)
Screenable	append(CharSequence csq, int start, int end)
Screenable	append(Style style)
Screenable	cls()
void	flush() Flush the stream.
int	getHeight() Returns the screen height in chars.
int	getWidth() Returns the screen width in chars.
boolean	isPainted()
boolean	isPainting()
boolean	isRefresh()
int	nextPage()
boolean	nextRow()
VirtualScreen	paint() Pain the underlying screen context.
boolean	previousRow()
boolean	update()

Methods inherited from class java.lang.Object

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

Constructor Detail

VirtualScreen

public VirtualScreen(ScreenContext out)

Method Detail

getWidth

public int getWidth()

Description copied from interface: ScreenContext

Returns the screen width in chars. When the value is not positive it means the value could not be determined.

Specified by:

getWidth in interface ScreenContext

Returns:

the term width

getHeight

public int getHeight()

Description copied from interface: ScreenContext

Returns the screen height in chars. When the value is not positive it means the value could not be determined.

Specified by:

getHeight in interface ScreenContext

Returns:

the term height

append

public Screenable append(CharSequence s)
                  throws IOException

Specified by:

append in interface Appendable

Throws:

IOException

append

public Screenable append(char c)
                  throws IOException

Specified by:

append in interface Appendable

Throws:

IOException

append

public Screenable append(CharSequence csq,
                         int start,
                         int end)
                  throws IOException

Specified by:

append in interface Appendable

Throws:

IOException

append

public Screenable append(Style style)
                  throws IOException

Specified by:

append in interface Screenable

Throws:

IOException

cls

public Screenable cls()
               throws IOException

Specified by:

cls in interface Screenable

Throws:

IOException

paint

public VirtualScreen paint()
                    throws IOException

Pain the underlying screen context.

Returns:

this screen buffer

Throws:

IOException - any io exception

previousRow

public boolean previousRow()
                    throws IOException

Throws:

IOException

isPainted

public boolean isPainted()

Returns:

true if the buffer is painted

isRefresh

public boolean isRefresh()

Returns:

true if the buffer is stale and needs a full repaint

isPainting

public boolean isPainting()

Returns:

true if the buffer is waiting for input to become painted

nextRow

public boolean nextRow()
                throws IOException

Throws:

IOException

nextPage

public int nextPage()
             throws IOException

Throws:

IOException

update

public boolean update()
               throws IOException

Throws:

IOException

flush

public void flush()
           throws IOException

Description copied from interface: ScreenContext

Flush the stream.

Specified by:

flush in interface ScreenContext

Throws:

IOException - any io exception