Provides a window onto a section of a terminal screen. More...

#include "ScreenWindow.h"

Inheritance diagram for ScreenWindow:

Collaboration diagram for ScreenWindow:

Public Types
enum	RelativeScrollMode { ScrollLines, ScrollPages }

Public Slots
void	notifyOutputChanged ()
	Notifies the window that the contents of the associated terminal screen have changed.

Signals
void	outputChanged ()
	Emitted when the contents of the associated terminal screen ( see screen() ) changes.
void	scrolled (int line)
	Emitted when the screen window is scrolled to a different position.
void	selectionChanged ()
	Emitted when the selection is changed.

Public Member Functions
	ScreenWindow (QObject *parent=0)
	Constructs a new screen window with the given parent.
virtual	~ScreenWindow ()
bool	atEndOfOutput () const
	Convenience method.
void	clearSelection ()
	Clears the current selection.
int	columnCount () const
	Returns the total number of columns in the screen.
int	currentLine () const
	Returns the index of the line which is currently at the top of this window.
QPoint	cursorPosition () const
	Returns the position of the cursor within the window.
Character *	getImage ()
	Returns the image of characters which are currently visible through this window onto the screen.
QVector< LineProperty >	getLineProperties ()
	Returns the line attributes associated with the lines of characters which are currently visible through this window.
void	getSelectionEnd (int &column, int &line)
	Retrieves the end of the selection within the window.
void	getSelectionStart (int &column, int &line)
	Retrieves the start of the selection within the window.
bool	isSelected (int column, int line)
	Returns true if the character at `line` , `column` is part of the selection.
int	lineCount () const
	Returns the total number of lines in the screen.
void	resetScrollCount ()
	Resets the count of scrolled lines returned by scrollCount()
Screen *	screen () const
	Returns the screen which this window looks onto.
void	scrollBy (RelativeScrollMode mode, int amount)
	Scrolls the window relative to its current position on the screen.
int	scrollCount () const
	Returns the number of lines which the region of the window specified by scrollRegion() has been scrolled by since the last call to resetScrollCount().
QRect	scrollRegion () const
	Returns the area of the window which was last scrolled, this is usually the whole window area.
void	scrollTo (int line)
	Scrolls the window so that `line` is at the top of the window.
QString	selectedText (bool preserveLineBreaks) const
	Returns the text which is currently selected.
void	setScreen (Screen *screen)
	Sets the screen which this window looks onto.
void	setSelectionEnd (int column, int line)
	Sets the end of the selection to the given `line` and `column` within the window.
void	setSelectionStart (int column, int line, bool columnMode)
	Sets the start of the selection to the given `line` and `column` within the window.
void	setTrackOutput (bool trackOutput)
	Specifies whether the window should automatically move to the bottom of the screen when new output is added.
void	setWindowLines (int lines)
	Sets the number of lines in the window.
bool	trackOutput () const
	Returns whether the window automatically moves to the bottom of the screen as new output is added.
int	windowColumns () const
	Returns the number of columns in the window.
int	windowLines () const
	Returns the number of lines in the window.

Private Member Functions
int	endWindowLine () const
void	fillUnusedArea ()

Private Attributes
bool	_bufferNeedsUpdate
int	_currentLine
Screen *	_screen
int	_scrollCount
bool	_trackOutput
Character *	_windowBuffer
int	_windowBufferSize
int	_windowLines

Detailed Description

Provides a window onto a section of a terminal screen.

This window can then be rendered by a terminal display widget ( TerminalDisplay ).

To use the screen window, create a new ScreenWindow() instance and associated it with a terminal screen using setScreen(). Use the scrollTo() method to scroll the window up and down on the screen. Call the getImage() method to retrieve the character image which is currently visible in the window.

setTrackOutput() controls whether the window moves to the bottom of the associated screen when new lines are added to it.

Whenever the output from the underlying screen is changed, the notifyOutputChanged() slot should be called. This in turn will update the window's position and emit the outputChanged() signal if necessary.

Definition at line 51 of file ScreenWindow.h.

Member Enumeration Documentation

enum ScreenWindow::RelativeScrollMode

Enumerator:

ScrollLines
ScrollPages

Definition at line 172 of file ScreenWindow.h.

Constructor & Destructor Documentation

ScreenWindow::ScreenWindow ( QObject * parent = 0 )

Constructs a new screen window with the given parent.

A screen must be specified by calling setScreen() before calling getImage() or getLineProperties().

You should not call this constructor directly, instead use the Emulation::createWindow() method to create a window on the emulation which you wish to view. This allows the emulation to notify the window when the associated screen has changed and synchronize selection updates between all views on a session.

Definition at line 31 of file ScreenWindow.cpp.

ScreenWindow::~ScreenWindow ( )

virtual

Definition at line 43 of file ScreenWindow.cpp.

References _windowBuffer.

Member Function Documentation

bool ScreenWindow::atEndOfOutput ( ) const

Convenience method.

Returns true if the window is currently at the bottom of the screen.

Definition at line 214 of file ScreenWindow.cpp.

References currentLine(), lineCount(), and windowLines().

Referenced by scrollRegion().

void ScreenWindow::clearSelection ( )

Clears the current selection.

Definition at line 155 of file ScreenWindow.cpp.

References _screen, Screen::clearSelection(), and selectionChanged().

int ScreenWindow::columnCount ( ) const

Returns the total number of columns in the screen.

Definition at line 182 of file ScreenWindow.cpp.

References _screen, and Screen::getColumns().

int ScreenWindow::currentLine ( ) const

Returns the index of the line which is currently at the top of this window.

Definition at line 197 of file ScreenWindow.cpp.

References _currentLine, lineCount(), and windowLines().

Referenced by atEndOfOutput(), endWindowLine(), fillUnusedArea(), getImage(), getLineProperties(), getSelectionEnd(), getSelectionStart(), isSelected(), scrollBy(), setSelectionEnd(), and setSelectionStart().

QPoint ScreenWindow::cursorPosition ( ) const

Returns the position of the cursor within the window.

Definition at line 187 of file ScreenWindow.cpp.

References _screen, Screen::getCursorX(), and Screen::getCursorY().

int ScreenWindow::endWindowLine ( ) const

private

Definition at line 104 of file ScreenWindow.cpp.

References currentLine(), lineCount(), and windowLines().

Referenced by getImage(), getLineProperties(), isSelected(), setSelectionEnd(), and setSelectionStart().

void ScreenWindow::fillUnusedArea ( )

private

Definition at line 86 of file ScreenWindow.cpp.

References _screen, _windowBuffer, _windowBufferSize, currentLine(), Screen::fillWithDefaultChar(), Screen::getHistLines(), Screen::getLines(), windowColumns(), and windowLines().

Referenced by getImage().

Character * ScreenWindow::getImage ( )

Returns the image of characters which are currently visible through this window onto the screen.

The buffer is managed by the ScreenWindow instance and does not need to be deleted by the caller.

Definition at line 59 of file ScreenWindow.cpp.

References _bufferNeedsUpdate, _screen, _windowBuffer, _windowBufferSize, currentLine(), endWindowLine(), fillUnusedArea(), Screen::getImage(), size(), windowColumns(), and windowLines().

QVector< LineProperty > ScreenWindow::getLineProperties ( )

Returns the line attributes associated with the lines of characters which are currently visible through this window.

Definition at line 109 of file ScreenWindow.cpp.

References _screen, currentLine(), endWindowLine(), Screen::getLineProperties(), and windowLines().

void ScreenWindow::getSelectionEnd	(	int &	column,
		int &	line
	)

Retrieves the end of the selection within the window.

Definition at line 129 of file ScreenWindow.cpp.

References _screen, currentLine(), and Screen::getSelectionEnd().

void ScreenWindow::getSelectionStart	(	int &	column,
		int &	line
	)

Retrieves the start of the selection within the window.

Definition at line 124 of file ScreenWindow.cpp.

References _screen, currentLine(), and Screen::getSelectionStart().

bool ScreenWindow::isSelected	(	int	column,
		int	line
	)

Returns true if the character at line , column is part of the selection.

Definition at line 150 of file ScreenWindow.cpp.

References _screen, currentLine(), endWindowLine(), and Screen::isSelected().

int ScreenWindow::lineCount ( ) const

Returns the total number of lines in the screen.

Definition at line 177 of file ScreenWindow.cpp.

References _screen, Screen::getHistLines(), and Screen::getLines().

Referenced by atEndOfOutput(), currentLine(), endWindowLine(), and scrollTo().

void ScreenWindow::notifyOutputChanged ( )

slot

Notifies the window that the contents of the associated terminal screen have changed.

This moves the window to the bottom of the screen if trackOutput() is true and causes the outputChanged() signal to be emitted.

Definition at line 266 of file ScreenWindow.cpp.

References _bufferNeedsUpdate, _currentLine, _screen, _scrollCount, _trackOutput, Screen::droppedLines(), Screen::getHistLines(), Screen::getLines(), outputChanged(), Screen::scrolledLines(), and windowLines().

void ScreenWindow::outputChanged ( )

signal

Emitted when the contents of the associated terminal screen ( see screen() ) changes.

Referenced by notifyOutputChanged().

void ScreenWindow::resetScrollCount ( )

Resets the count of scrolled lines returned by scrollCount()

Definition at line 251 of file ScreenWindow.cpp.

References _scrollCount.

Screen * ScreenWindow::screen ( ) const

Returns the screen which this window looks onto.

Definition at line 54 of file ScreenWindow.cpp.

References _screen.

Referenced by setScreen().

void ScreenWindow::scrollBy	(	RelativeScrollMode	mode,
		int	amount
	)

Scrolls the window relative to its current position on the screen.

Parameters

mode	Specifies whether `amount` refers to the number of lines or the number of pages to scroll.
amount	The number of lines or pages ( depending on `mode` ) to scroll by. If this number is positive, the view is scrolled down. If this number is negative, the view is scrolled up.

Definition at line 202 of file ScreenWindow.cpp.

References currentLine(), ScrollLines, ScrollPages, scrollTo(), and windowLines().

int ScreenWindow::scrollCount ( ) const

Returns the number of lines which the region of the window specified by scrollRegion() has been scrolled by since the last call to resetScrollCount().

scrollRegion() is in most cases the whole window, but will be a smaller area in, for example, applications which provide split-screen facilities.

This is not guaranteed to be accurate, but allows views to optimise rendering by reducing the amount of costly text rendering that needs to be done when the output is scrolled.

Definition at line 246 of file ScreenWindow.cpp.

References _scrollCount.

void ScreenWindow::scrolled ( int line )

signal

Emitted when the screen window is scrolled to a different position.

Parameters

line	The line which is now at the top of the window.

Referenced by scrollTo().

QRect ScreenWindow::scrollRegion ( ) const

Returns the area of the window which was last scrolled, this is usually the whole window area.

Like scrollCount(), this is not guaranteed to be accurate, but allows views to optimise rendering.

Definition at line 256 of file ScreenWindow.cpp.

References _screen, atEndOfOutput(), Screen::getLines(), Screen::lastScrolledRegion(), windowColumns(), and windowLines().

void ScreenWindow::scrollTo ( int line )

Scrolls the window so that line is at the top of the window.

Definition at line 219 of file ScreenWindow.cpp.

References _bufferNeedsUpdate, _currentLine, _scrollCount, lineCount(), scrolled(), and windowLines().

Referenced by scrollBy().

QString ScreenWindow::selectedText ( bool preserveLineBreaks ) const

Returns the text which is currently selected.

Parameters

preserveLineBreaks See Screen::selectedText()

Definition at line 119 of file ScreenWindow.cpp.

References _screen, and Screen::selectedText().

void ScreenWindow::selectionChanged ( )

signal

Emitted when the selection is changed.

Referenced by clearSelection(), setSelectionEnd(), and setSelectionStart().

void ScreenWindow::setScreen ( Screen * screen )

Sets the screen which this window looks onto.

Definition at line 47 of file ScreenWindow.cpp.

References _screen, and screen().

Referenced by Emulation::createWindow().

void ScreenWindow::setSelectionEnd	(	int	column,
		int	line
	)

Sets the end of the selection to the given line and column within the window.

Definition at line 142 of file ScreenWindow.cpp.

References _bufferNeedsUpdate, _screen, currentLine(), endWindowLine(), selectionChanged(), and Screen::setSelectionEnd().

void ScreenWindow::setSelectionStart	(	int	column,
		int	line,
		bool	columnMode
	)

Sets the start of the selection to the given line and column within the window.

Definition at line 134 of file ScreenWindow.cpp.

References _bufferNeedsUpdate, _screen, currentLine(), endWindowLine(), selectionChanged(), and Screen::setSelectionStart().

void ScreenWindow::setTrackOutput ( bool trackOutput )

Specifies whether the window should automatically move to the bottom of the screen when new output is added.

If this is set to true, the window will be moved to the bottom of the associated screen ( see screen() ) when the notifyOutputChanged() method is called.

Definition at line 236 of file ScreenWindow.cpp.

References _trackOutput, and trackOutput().

void ScreenWindow::setWindowLines ( int lines )

Sets the number of lines in the window.

Definition at line 162 of file ScreenWindow.cpp.

References _windowLines.

Referenced by TerminalView::setScreenWindow().

bool ScreenWindow::trackOutput ( ) const

Returns whether the window automatically moves to the bottom of the screen as new output is added.

See setTrackOutput()

Definition at line 241 of file ScreenWindow.cpp.

References _trackOutput.