Package org.jline.terminal.impl

Class DumbTerminal

java.lang.Object

org.jline.terminal.impl.AbstractTerminal

org.jline.terminal.impl.DumbTerminal

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable, TerminalExt, Terminal

public class DumbTerminal
extends AbstractTerminal

A minimal terminal implementation with limited capabilities.

The DumbTerminal class provides a basic terminal implementation that works in environments where a full-featured terminal is not available or not supported. It has minimal capabilities and does not support features like cursor movement, color output, or advanced input processing.

This terminal type is often used as a fallback when more capable terminal implementations cannot be created, such as in non-interactive environments, redirected I/O scenarios, or when running inside IDEs or other tools that don't provide full terminal emulation.

The DumbTerminal supports two variants:

• Standard dumb terminal (Terminal.TYPE_DUMB) - No color support
• Color dumb terminal (Terminal.TYPE_DUMB_COLOR) - Basic color support

While limited in capabilities, the DumbTerminal still provides the core terminal functionality such as reading input and writing output, making it suitable for basic console applications that don't require advanced terminal features.

See Also:

• Terminal.TYPE_DUMB
• Terminal.TYPE_DUMB_COLOR
• AbstractTerminal

Nested Class Summary

Nested classes/interfaces inherited from interface org.jline.terminal.Terminal

Terminal.MouseTracking, Terminal.Signal, Terminal.SignalHandler

Field Summary

Fields inherited from class org.jline.terminal.impl.AbstractTerminal

bools, currentMouseTracking, encoding, handlers, ints, name, onClose, palette, status, strings, type

Fields inherited from interface org.jline.terminal.Terminal

TYPE_DUMB, TYPE_DUMB_COLOR

Constructor Summary

Constructors

Constructor	Description
DumbTerminal(InputStream in, OutputStream out)
DumbTerminal(String name, String type, InputStream in, OutputStream out, Charset encoding)
DumbTerminal(TerminalProvider provider, SystemStream systemStream, String name, String type, InputStream in, OutputStream out, Charset encoding, Terminal.SignalHandler signalHandler)

Method Summary

Modifier and Type	Method	Description
Attributes	getAttributes()	Returns the current terminal attributes.
TerminalProvider	getProvider()	Returns the terminal provider that created this terminal.
Size	getSize()	Retrieve the size of the visible window
SystemStream	getSystemStream()	Returns the system stream associated with this terminal, if any.
InputStream	input()	Retrieve the input stream for this terminal.
OutputStream	output()	Retrieve the output stream for this terminal.
NonBlockingReader	reader()	Retrieve the Reader for this terminal.
void	setAttributes(Attributes attr)	Sets the terminal attributes to the specified values.
void	setSize(Size sz)	Sets the size of the terminal.
PrintWriter	writer()	Retrieve the Writer for this terminal.

Methods inherited from class org.jline.terminal.impl.AbstractTerminal

canPauseResume, checkInterrupted, close, doClose, echo, echo, echoSignal, encoding, enterRawMode, flush, getBooleanCapability, getCurrentMouseTracking, getCursorPosition, getDefaultBackgroundColor, getDefaultForegroundColor, getKind, getName, getNumericCapability, getPalette, getStatus, getStatus, getStringCapability, getType, handle, hasFocusSupport, hasMouseSupport, parseInfoCmp, pause, pause, paused, puts, raise, readMouseEvent, readMouseEvent, readMouseEvent, readMouseEvent, resume, setOnClose, toString, trackFocus, trackMouse

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jline.terminal.Terminal

getBufferSize, getHeight, getWidth

Constructor Details

DumbTerminal

public DumbTerminal(InputStream in,
 OutputStream out)
             throws IOException

Throws:

IOException

DumbTerminal

public DumbTerminal(String name,
 String type,
 InputStream in,
 OutputStream out,
 Charset encoding)
             throws IOException

Throws:

IOException

DumbTerminal

public DumbTerminal(TerminalProvider provider,
 SystemStream systemStream,
 String name,
 String type,
 InputStream in,
 OutputStream out,
 Charset encoding,
 Terminal.SignalHandler signalHandler)
             throws IOException

Throws:

IOException

Method Details

reader

public NonBlockingReader reader()

Description copied from interface: Terminal

Retrieve the Reader for this terminal. This is the standard way to read input from this terminal. The reader is non blocking.

Returns:

The non blocking reader

writer

public PrintWriter writer()

Description copied from interface: Terminal

Retrieve the Writer for this terminal. This is the standard way to write to this terminal.

Returns:

The writer

input

public InputStream input()

Description copied from interface: Terminal

Retrieve the input stream for this terminal. In some rare cases, there may be a need to access the terminal input stream directly. In the usual cases, use the Terminal.reader() instead.

Returns:

The input stream

See Also:

• Terminal.reader()

output

public OutputStream output()

Description copied from interface: Terminal

Retrieve the output stream for this terminal. In some rare cases, there may be a need to access the terminal output stream directly. In the usual cases, use the Terminal.writer() instead.

Returns:

The output stream

See Also:

• Terminal.writer()

getAttributes

public Attributes getAttributes()

Description copied from interface: Terminal

Returns the current terminal attributes.

Terminal attributes control various aspects of terminal behavior, including:

• Input processing - How input characters are processed (e.g., character mapping, parity checking)
• Output processing - How output characters are processed (e.g., newline translation)
• Control settings - Hardware settings like baud rate and character size
• Local settings - Terminal behavior settings like echo, canonical mode, and signal generation
• Control characters - Special characters like EOF, interrupt, and erase

The returned Attributes object is a copy of the terminal's current attributes and can be safely modified without affecting the terminal until it is applied using Terminal.setAttributes(Attributes). This allows for making multiple changes to the attributes before applying them all at once.

Example usage:

 Terminal terminal = TerminalBuilder.terminal();

 // Get current attributes
 Attributes attrs = terminal.getAttributes();

 // Modify attributes
 attrs.setLocalFlag(LocalFlag.ECHO, false);      // Disable echo
 attrs.setInputFlag(InputFlag.ICRNL, false);     // Disable CR to NL mapping
 attrs.setControlChar(ControlChar.VMIN, 1);      // Set minimum input to 1 character
 attrs.setControlChar(ControlChar.VTIME, 0);     // Set timeout to 0 deciseconds

 // Apply modified attributes
 terminal.setAttributes(attrs);
 

Returns:

a copy of the terminal's current attributes

See Also:

• Terminal.setAttributes(Attributes)
• Attributes
• Terminal.enterRawMode()

setAttributes

public void setAttributes(Attributes attr)

Description copied from interface: Terminal

Sets the terminal attributes to the specified values.

This method applies the specified attributes to the terminal, changing its behavior according to the settings in the Attributes object. The terminal makes a copy of the provided attributes, so further modifications to the attr object will not affect the terminal until this method is called again.

Terminal attributes control various aspects of terminal behavior, including input and output processing, control settings, local settings, and special control characters. Changing these attributes allows for fine-grained control over how the terminal processes input and output.

Common attribute modifications include:

• Disabling echo for password input
• Enabling/disabling canonical mode for line-by-line or character-by-character input
• Disabling signal generation for custom handling of Ctrl+C and other control sequences
• Changing control characters like the interrupt character or end-of-file character

For convenience, the Terminal.enterRawMode() method provides a pre-configured set of attributes suitable for full-screen interactive applications.

Example usage:

 Terminal terminal = TerminalBuilder.terminal();

 // Save original attributes for later restoration
 Attributes originalAttrs = terminal.getAttributes();

 try {
     // Create and configure new attributes
     Attributes attrs = new Attributes(originalAttrs);
     attrs.setLocalFlag(LocalFlag.ECHO, false);      // Disable echo for password input
     attrs.setLocalFlag(LocalFlag.ICANON, false);    // Disable canonical mode

     // Apply the new attributes
     terminal.setAttributes(attrs);

     // Use terminal with modified attributes...
 } finally {
     // Restore original attributes
     terminal.setAttributes(originalAttrs);
 }
 

Parameters:

attr - the attributes to apply to the terminal

See Also:

• Terminal.getAttributes()
• Attributes
• Terminal.enterRawMode()

getSize

public Size getSize()

Description copied from interface: Terminal

Retrieve the size of the visible window

Returns:

the visible terminal size

See Also:

• Terminal.getBufferSize()

setSize

public void setSize(Size sz)

Description copied from interface: Terminal

Sets the size of the terminal.

This method attempts to resize the terminal to the specified dimensions. Note that not all terminals support resizing, and the actual size after this operation may differ from the requested size depending on terminal capabilities and constraints.

For virtual terminals or terminal emulators, this may update the internal size representation. For physical terminals, this may send appropriate escape sequences to adjust the viewable area.

Parameters:

sz - the new terminal size (columns and rows)

See Also:

• Terminal.getSize()

getProvider

public TerminalProvider getProvider()

Description copied from interface: TerminalExt

Returns the terminal provider that created this terminal.

The terminal provider is responsible for creating and managing terminal instances on a specific platform. This method allows access to the provider that created this terminal, which can be useful for accessing provider-specific functionality or for creating additional terminals with the same provider.

Returns:

the TerminalProvider that created this terminal, or null if the terminal was created with no provider

See Also:

• TerminalProvider

getSystemStream

public SystemStream getSystemStream()

Description copied from interface: TerminalExt

Returns the system stream associated with this terminal, if any.

This method indicates whether the terminal is bound to a standard system stream (standard input, standard output, or standard error). Terminals that are connected to system streams typically represent the actual terminal window or console that the application is running in.

Returns:

the underlying system stream, which may be SystemStream.Input, SystemStream.Output, SystemStream.Error, or null if this terminal is not bound to a system stream

See Also:

• SystemStream