* Before you can display the content of this buffered screen to the real underlying terminal, you must call the * {@code startScreen()} method. This will ask the terminal to enter private mode (which is required for Screens to * work properly). Similarly, when you are done, you should call {@code stopScreen()} which will exit private mode. * * @param terminal Terminal object to create the DefaultScreen on top of * @throws java.io.IOException If there was an underlying I/O error when querying the size of the terminal */ public TerminalScreen(Terminal terminal) throws IOException { this(terminal, DEFAULT_CHARACTER); } /** * Creates a new Screen on top of a supplied terminal, will query the terminal for its size. The screen is initially * blank. The default character used for unused space (the newly initialized state of the screen and new areas after * expanding the terminal size) will be a blank space in 'default' ANSI front- and background color. *
* Before you can display the content of this buffered screen to the real underlying terminal, you must call the
* {@code startScreen()} method. This will ask the terminal to enter private mode (which is required for Screens to
* work properly). Similarly, when you are done, you should call {@code stopScreen()} which will exit private mode.
*
* @param terminal Terminal object to create the DefaultScreen on top of.
* @param defaultCharacter What character to use for the initial state of the screen and expanded areas
* @throws java.io.IOException If there was an underlying I/O error when querying the size of the terminal
*/
public TerminalScreen(Terminal terminal, TextCharacter defaultCharacter) throws IOException {
super(terminal.getTerminalSize(), defaultCharacter);
this.terminal = terminal;
this.terminal.addResizeListener(new TerminalScreenResizeListener());
this.isStarted = false;
this.fullRedrawHint = true;
}
@Override
public synchronized void startScreen() throws IOException {
if(isStarted) {
return;
}
isStarted = true;
getTerminal().enterPrivateMode();
getTerminal().getTerminalSize();
getTerminal().clearScreen();
this.fullRedrawHint = true;
TerminalPosition cursorPosition = getCursorPosition();
if(cursorPosition != null) {
getTerminal().setCursorVisible(true);
getTerminal().setCursorPosition(cursorPosition.getColumn(), cursorPosition.getRow());
} else {
getTerminal().setCursorVisible(false);
}
}
@Override
public void stopScreen() throws IOException {
stopScreen(true);
}
public synchronized void stopScreen(boolean flushInput) throws IOException {
if(!isStarted) {
return;
}
if (flushInput) {
//Drain the input queue
KeyStroke keyStroke;
do {
keyStroke = pollInput();
}
while(keyStroke != null && keyStroke.getKeyType() != KeyType.EOF);
}
getTerminal().exitPrivateMode();
isStarted = false;
}
@Override
public synchronized void refresh(RefreshType refreshType) throws IOException {
if(!isStarted) {
return;
}
if((refreshType == RefreshType.AUTOMATIC && fullRedrawHint) || refreshType == RefreshType.COMPLETE) {
refreshFull();
fullRedrawHint = false;
}
else if(refreshType == RefreshType.AUTOMATIC &&
(scrollHint == null || scrollHint == ScrollHint.INVALID)) {
double threshold = getTerminalSize().getRows() * getTerminalSize().getColumns() * 0.75;
if(getBackBuffer().isVeryDifferent(getFrontBuffer(), (int) threshold)) {
refreshFull();
}
else {
refreshByDelta();
}
}
else {
refreshByDelta();
}
getBackBuffer().copyTo(getFrontBuffer());
TerminalPosition cursorPosition = getCursorPosition();
if(cursorPosition != null) {
getTerminal().setCursorVisible(true);
//If we are trying to move the cursor to the padding of a CJK character, put it on the actual character instead
if(cursorPosition.getColumn() > 0 && TerminalTextUtils.isCharCJK(getFrontBuffer().getCharacterAt(cursorPosition.withRelativeColumn(-1)).getCharacter())) {
getTerminal().setCursorPosition(cursorPosition.getColumn() - 1, cursorPosition.getRow());
}
else {
getTerminal().setCursorPosition(cursorPosition.getColumn(), cursorPosition.getRow());
}
} else {
getTerminal().setCursorVisible(false);
}
getTerminal().flush();
}
private void useScrollHint() throws IOException {
if (scrollHint == null) { return; }
try {
if (scrollHint == ScrollHint.INVALID) { return; }
Terminal term = getTerminal();
if (term instanceof Scrollable) {
// just try and see if it cares:
scrollHint.applyTo( (Scrollable)term );
// if that didn't throw, then update front buffer:
scrollHint.applyTo( getFrontBuffer() );
}
}
catch (UnsupportedOperationException uoe) { /* ignore */ }
finally { scrollHint = null; }
}
private void refreshByDelta() throws IOException {
Map
* Be aware: directly modifying the underlying terminal will most likely result in unexpected behaviour if
* you then go on and try to interact with the Screen. The Screen's back-buffer/front-buffer will not know about
* the operations you are going on the Terminal and won't be able to properly generate a refresh unless you enforce
* a {@code Screen.RefreshType.COMPLETE}, at which the entire terminal area will be repainted according to the
* back-buffer of the {@code Screen}.
* @return Underlying terminal used by the screen
*/
@SuppressWarnings("WeakerAccess")
public Terminal getTerminal() {
return terminal;
}
@Override
public KeyStroke readInput() throws IOException {
return terminal.readInput();
}
@Override
public KeyStroke pollInput() throws IOException {
return terminal.pollInput();
}
@Override
public synchronized void clear() {
super.clear();
fullRedrawHint = true;
scrollHint = ScrollHint.INVALID;
}
@Override
public synchronized TerminalSize doResizeIfNecessary() {
TerminalSize newSize = super.doResizeIfNecessary();
if(newSize != null) {
fullRedrawHint = true;
}
return newSize;
}
/**
* Perform the scrolling and save scroll-range and distance in order
* to be able to optimize Terminal-update later.
*/
@Override
public void scrollLines(int firstLine, int lastLine, int distance) {
// just ignore certain kinds of garbage:
if (distance == 0 || firstLine > lastLine) { return; }
super.scrollLines(firstLine, lastLine, distance);
// Save scroll hint for next refresh:
ScrollHint newHint = new ScrollHint(firstLine,lastLine,distance);
if (scrollHint == null) {
// no scroll hint yet: use the new one:
scrollHint = newHint;
} else //noinspection StatementWithEmptyBody
if (scrollHint == ScrollHint.INVALID) {
// scroll ranges already inconsistent since latest refresh!
// leave at INVALID
} else if (scrollHint.matches(newHint)) {
// same range: just accumulate distance:
scrollHint.distance += newHint.distance;
} else {
// different scroll range: no scroll-optimization for next refresh
this.scrollHint = ScrollHint.INVALID;
}
}
private class TerminalScreenResizeListener implements TerminalResizeListener {
@Override
public void onResized(Terminal terminal, TerminalSize newSize) {
addResizeRequest(newSize);
}
}
private static class ScreenPointComparator implements Comparator