jcurzez.peer.ansi
Class PeerScreen

java.lang.Object
  |
  +--jcurzez.peer.ansi.PeerScreen

All Implemented Interfaces:

ScreenPeer

public final class PeerScreen

extends java.lang.Object

implements ScreenPeer

This is the ansi implementation of jcurzez. There are no native calls, thus this implementation should work on any platform that supports Java and ansi.

For retrieving size of the screen, we use four system properties:

• jcurzez.term.columns
• jcurzez.term.lines
• jcurzez.term.x
• jcurzez.term.y

Those properties can be set on JVM invocation using tput(1), or environment variables COLUMNS and LINES. If they are not set, they default to 80, 24 (or 25 for Windows) and 0, 0.

Version:

0.0.4

Author:

Thomas Girard

Field Summary

private int	columns Number of columns the screen has.
private int	lines Number of lines the screen has.
private Cell	previousCell To optimize, we keep the last cell.
private int	previousX To optimize cursor motion, we store previous cursor position.
private int	previousY To optimize cursor motion, we store previous cursor position.
private java.lang.StringBuffer	text Current representation of the content of the screen.

Constructor Summary

PeerScreen()
Constructs a new ANSI PeerScreen.

Method Summary

private void	attributeToEscapeSequence(Attribute a) Computes the representation of the attribute a, and appends this representation to text.
void	beep() Emits an audio beep.
void	end() Does nothing.
int	getColumns() Relies on the jcurzez.term.columns property, or defaults to 80 if this property is not set.
int	getFirstX() Retrieves the x coordinate by the time the screen object is created.
int	getFirstY() Retrieves the y coordinate by the time the screen object is created.
int	getLines() Retrieves the number of lines the screen has.
void	gotoXY(int x, int y) Moves the cursor on the physical screen at specified position.
void	printCell(int x, int y, Cell cell) Prints the cell cell on the physical screen at specified position.
void	setCursorVisibility(int v) Does nothing for the ansi implementation.
void	update() Updates the physical screen.

Methods inherited from class java.lang.Object

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

Field Detail

columns

private int columns

Number of columns the screen has.

lines

private int lines

Number of lines the screen has.

previousX

private int previousX

To optimize cursor motion, we store previous cursor position.

previousY

private int previousY

To optimize cursor motion, we store previous cursor position.

text

private java.lang.StringBuffer text

Current representation of the content of the screen.

previousCell

private Cell previousCell

To optimize, we keep the last cell. If the next adjacent cell has the same decoration, we won't send escape sequences again.

Constructor Detail

PeerScreen

public PeerScreen()

Constructs a new ANSI PeerScreen. Then sets colors' real objects (using Color.setRealColor(java.lang.Object)) which, for the ansi implementation, are escape sequences.

Method Detail

gotoXY

public void gotoXY(int x,
                   int y)

Description copied from interface: ScreenPeer

Moves the cursor on the physical screen at specified position. This method must not be called directly. x and y should be consistent. This method is used by refresh to move the cursor where it is supposed to be.

Specified by:

gotoXY in interface ScreenPeer

Following copied from interface: jcurzez.peer.ScreenPeer

Parameters:

x - x coordinate where to send the cursor. This is an absolute coordinate.

y - y coordinate where to send the cursor. This is an absolute coordinate.

See Also:

AbstractWindow.refresh()

attributeToEscapeSequence

private void attributeToEscapeSequence(Attribute a)

Computes the representation of the attribute a, and appends this representation to text.

Parameters:

a - the attribute we want to use.

printCell

public void printCell(int x,
                      int y,
                      Cell cell)

Description copied from interface: ScreenPeer

Prints the cell cell on the physical screen at specified position.

Specified by:

printCell in interface ScreenPeer

Following copied from interface: jcurzez.peer.ScreenPeer

Parameters:

x - x coordinate where to send the cursor. This is an absolute coordinate.

y - y coordinate where to send the cursor. This is an absolute coordinate.

cell - the cell to print at this position.

See Also:

Cell

getColumns

public int getColumns()

Relies on the jcurzez.term.columns property, or defaults to 80 if this property is not set.

Specified by:

getColumns in interface ScreenPeer

Following copied from interface: jcurzez.peer.ScreenPeer

Returns:

the number of columns the screen has.

getLines

public int getLines()

Description copied from interface: ScreenPeer

Retrieves the number of lines the screen has. This is often 25, but it may be different if you use a xterm, a different screen mode, or frame buffering.

Specified by:

getLines in interface ScreenPeer

Following copied from interface: jcurzez.peer.ScreenPeer

Returns:

the number of lines the screen has.

getFirstX

public int getFirstX()

Description copied from interface: ScreenPeer

Retrieves the x coordinate by the time the screen object is created.

Specified by:

getFirstX in interface ScreenPeer

Following copied from interface: jcurzez.peer.ScreenPeer

Returns:

the x coordinate at the beginning.

getFirstY

public int getFirstY()

Description copied from interface: ScreenPeer

Retrieves the y coordinate by the time the screen object is created.

Specified by:

getFirstY in interface ScreenPeer

Following copied from interface: jcurzez.peer.ScreenPeer

Returns:

the y coordinate at the beginning.

update

public void update()

Description copied from interface: ScreenPeer

Updates the physical screen. This method provides a way for a peer to optimize its display. It is called when all needed cells have been printed, and before the cursor is moved back - using ScreenPeer.gotoXY(int, int) - to where it should be.

Specified by:

update in interface ScreenPeer

Following copied from interface: jcurzez.peer.ScreenPeer

See Also:

AbstractWindow.refresh()

setCursorVisibility

public void setCursorVisibility(int v)

Does nothing for the ansi implementation.

Specified by:

setCursorVisibility in interface ScreenPeer

Following copied from interface: jcurzez.peer.ScreenPeer

Parameters:

v - visibility of the cursor. One of NORMAL, INVISIBLE, VERY_VISIBLE.

See Also:

Cursor

beep

public void beep()

Description copied from interface: ScreenPeer

Emits an audio beep.

Specified by:

beep in interface ScreenPeer

end

public void end()

Does nothing.

Specified by:

end in interface ScreenPeer