com.googlecode.lanterna.screen

Class Screen

java.lang.Object

com.googlecode.lanterna.screen.Screen

public class Screen
extends Object

A layer to put on top of a Terminal object, giving you a kind of screen buffer to use, which is a lot easier to work with. Drawing text or graphics to the terminal is kind of like writing to a bitmap.

Author:

Martin

Constructor Summary

Constructors

Constructor and Description
Screen(Terminal terminal) Creates a new Screen on top of a supplied terminal, will query the terminal for its size.
Screen(Terminal terminal, int terminalWidth, int terminalHeight) Creates a new Screen on top of a supplied terminal and will set the size of the screen to a supplied value.
Screen(Terminal terminal, TerminalSize terminalSize) Creates a new Screen on top of a supplied terminal and will set the size of the screen to a supplied value.

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Erases all the characters on the screen, effectively giving you a blank area.
void	completeRefresh() Clears the terminal and repaints with the whole content of the Screen.
TerminalPosition	getCursorPosition()
TabBehaviour	getTabBehaviour() Gets the behaviour for what to do about tab characters.
Terminal	getTerminal()
TerminalSize	getTerminalSize()
void	putString(int x, int y, String string, Terminal.Color foregroundColor, Terminal.Color backgroundColor, ScreenCharacterStyle... styles) Draws a string on the screen at a particular position
void	putString(int x, int y, String string, Terminal.Color foregroundColor, Terminal.Color backgroundColor, Set<ScreenCharacterStyle> styles) Draws a string on the screen at a particular position
Key	readInput() Reads the next Key from the input queue, or returns null if there is nothing on the queue.
void	refresh() Call this method to make changes done through putCharacter(...), putString(...) visible on the terminal.
boolean	resizePending() This method will check if there are any resize commands pending.
void	setCursorPosition(int column, int row) Moves the current cursor position, and if the cursor was hidden it will be visible after this call
void	setCursorPosition(TerminalPosition position) Moves the current cursor position or hides it.
void	setPaddingCharacter(char character, Terminal.Color foregroundColor, Terminal.Color backgroundColor, ScreenCharacterStyle... style)
void	setTabBehaviour(TabBehaviour tabBehaviour) Sets the behaviour for what to do about tab characters.
void	startScreen() Calling this method will put the underlying terminal in private mode, clear the screen, move the cursor and refresh.
void	stopScreen() Calling this method will make the underlying terminal leave private mode, effectively going back to whatever state the terminal was in before calling startScreen()
boolean	updateScreenSize() Calling this method will check if the terminal has changed since and in that case update the dimensions of this Screen to match.

Methods inherited from class java.lang.Object

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

Constructor Detail

Screen

public Screen(Terminal terminal)

Creates a new Screen on top of a supplied terminal, will query the terminal for its size. The screen is initially blank.

Parameters:

terminal -

Throws:

LanternaException

Screen

public Screen(Terminal terminal,
      TerminalSize terminalSize)

Creates a new Screen on top of a supplied terminal and will set the size of the screen to a supplied value. The screen is initially blank.

Parameters:

terminal -

terminalSize -

Screen

public Screen(Terminal terminal,
      int terminalWidth,
      int terminalHeight)

Creates a new Screen on top of a supplied terminal and will set the size of the screen to a supplied value. The screen is initially blank.

Parameters:

terminal -

terminalWidth - Width (number of columns) of the terminal

terminalHeight - Height (number of rows) of the terminal

Method Detail

getTerminal

public Terminal getTerminal()

Returns:

The terminal which is the backend for this screen

getCursorPosition

public TerminalPosition getCursorPosition()

Returns:

Position where the cursor will be located after the screen has been refreshed or null if the cursor is not visible

setCursorPosition

public void setCursorPosition(TerminalPosition position)

Moves the current cursor position or hides it. If the cursor is hidden and given a new position, it will be visible after this method call.

Parameters:

position - 0-indexed column and row numbers of the new position, or if null, hides the cursor

setCursorPosition

public void setCursorPosition(int column,
                     int row)

Moves the current cursor position, and if the cursor was hidden it will be visible after this call

Parameters:

column - 0-indexed column number of the new position

row - 0-indexed row number of the new position

setTabBehaviour

public void setTabBehaviour(TabBehaviour tabBehaviour)

Sets the behaviour for what to do about tab characters.

See Also:

TabBehaviour

setPaddingCharacter

public void setPaddingCharacter(char character,
                       Terminal.Color foregroundColor,
                       Terminal.Color backgroundColor,
                       ScreenCharacterStyle... style)

getTabBehaviour

public TabBehaviour getTabBehaviour()

Gets the behaviour for what to do about tab characters.

See Also:

TabBehaviour

readInput

public Key readInput()

Reads the next Key from the input queue, or returns null if there is nothing on the queue.

getTerminalSize

public TerminalSize getTerminalSize()

Returns:

Size of the screen

startScreen

public void startScreen()

Calling this method will put the underlying terminal in private mode, clear the screen, move the cursor and refresh.

Throws:

LanternaException

stopScreen

public void stopScreen()

Calling this method will make the underlying terminal leave private mode, effectively going back to whatever state the terminal was in before calling startScreen()

Throws:

LanternaException

clear

public void clear()

Erases all the characters on the screen, effectively giving you a blank area. The default background color will be used, if you want to fill the screen with a different color you will need to do this manually.

putString

public void putString(int x,
             int y,
             String string,
             Terminal.Color foregroundColor,
             Terminal.Color backgroundColor,
             ScreenCharacterStyle... styles)

Draws a string on the screen at a particular position

Parameters:

x - 0-indexed column number of where to put the first character in the string

y - 0-indexed row number of where to put the first character in the string

string - Text to put on the screen

foregroundColor - What color to use for the text

backgroundColor - What color to use for the background

styles - Additional styles to apply to the text

putString

public void putString(int x,
             int y,
             String string,
             Terminal.Color foregroundColor,
             Terminal.Color backgroundColor,
             Set<ScreenCharacterStyle> styles)

Draws a string on the screen at a particular position

Parameters:

x - 0-indexed column number of where to put the first character in the string

y - 0-indexed row number of where to put the first character in the string

string - Text to put on the screen

foregroundColor - What color to use for the text

backgroundColor - What color to use for the background

styles - Additional styles to apply to the text

resizePending

public boolean resizePending()

This method will check if there are any resize commands pending. If true, you need to call refresh() to perform the screen resize

Returns:

true if the size is the same as before, false if the screen should be resized

updateScreenSize

public boolean updateScreenSize()

Calling this method will check if the terminal has changed since and in that case update the dimensions of this Screen to match.

Returns:

Will return true if dimensions were changed, otherwise false. You probably want to clear and redraw the entire screen if this method returns true.

completeRefresh

public void completeRefresh()

Clears the terminal and repaints with the whole content of the Screen. This is useful of something has written to the terminal outside of the Screen (System.out or through direct calls to the underlying Terminal) and you want to make sure that the content of Screen is completely pushed to the terminal.

refresh

public void refresh()

Call this method to make changes done through putCharacter(...), putString(...) visible on the terminal. The screen will calculate the changes that are required and send the necessary characters and control sequences to make it so.