org.jline.utils.Status Maven / Gradle / Ivy
/*
* Copyright (c) 2002-2019, the original author(s).
*
* This software is distributable under the BSD license. See the terms of the
* BSD license in the documentation provided with this software.
*
* https://opensource.org/licenses/BSD-3-Clause
*/
package org.jline.utils;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import org.jline.terminal.Size;
import org.jline.terminal.Terminal;
import org.jline.terminal.impl.AbstractTerminal;
import org.jline.utils.InfoCmp.Capability;
public class Status {
protected final Terminal terminal;
protected final boolean supported;
protected boolean suspended = false;
protected AttributedString borderString;
protected int border = 0;
protected Display display;
protected List lines = Collections.emptyList();
protected int scrollRegion;
public static Status getStatus(Terminal terminal) {
return getStatus(terminal, true);
}
public static Optional getExistingStatus(Terminal terminal) {
return Optional.ofNullable(getStatus(terminal, false));
}
public static Status getStatus(Terminal terminal, boolean create) {
return terminal instanceof AbstractTerminal ? ((AbstractTerminal) terminal).getStatus(create) : null;
}
@SuppressWarnings("this-escape")
public Status(Terminal terminal) {
this.terminal = Objects.requireNonNull(terminal, "terminal can not be null");
this.supported = terminal.getStringCapability(Capability.change_scroll_region) != null
&& terminal.getStringCapability(Capability.save_cursor) != null
&& terminal.getStringCapability(Capability.restore_cursor) != null
&& terminal.getStringCapability(Capability.cursor_address) != null;
if (supported) {
display = new MovingCursorDisplay(terminal);
resize();
display.reset();
scrollRegion = display.rows - 1;
}
}
public void close() {
terminal.puts(Capability.save_cursor);
terminal.puts(Capability.change_scroll_region, 0, display.rows - 1);
terminal.puts(Capability.restore_cursor);
terminal.flush();
}
public void setBorder(boolean border) {
this.border = border ? 1 : 0;
}
public void resize() {
resize(terminal.getSize());
}
public void resize(Size size) {
display.resize(size.getRows(), size.getColumns());
}
public void reset() {
if (supported) {
display.reset();
scrollRegion = display.rows;
terminal.puts(Capability.change_scroll_region, 0, scrollRegion);
}
}
public void redraw() {
if (suspended) {
return;
}
update(lines);
}
public void hide() {
update(Collections.emptyList());
}
public void update(List lines) {
update(lines, true);
}
private final AttributedString ellipsis =
new AttributedStringBuilder().append("…", AttributedStyle.INVERSE).toAttributedString();
/**
* Returns true if the cursor may be misplaced and should
* be updated.
*/
public void update(List lines, boolean flush) {
if (!supported) {
return;
}
this.lines = new ArrayList<>(lines);
if (suspended) {
return;
}
lines = new ArrayList<>(lines);
// add border
int columns = display.columns;
if (border == 1 && !lines.isEmpty()) {
lines.add(0, getBorderString(columns));
}
// trim or complete lines to the full width
for (int i = 0; i < lines.size(); i++) {
AttributedString str = lines.get(i);
if (str.columnLength() > columns) {
str = new AttributedStringBuilder(columns)
.append(lines.get(i).columnSubSequence(0, columns - ellipsis.columnLength()))
.append(ellipsis)
.toAttributedString();
} else if (str.columnLength() < columns) {
str = new AttributedStringBuilder(columns)
.append(str)
.append(' ', columns - str.columnLength())
.toAttributedString();
}
lines.set(i, str);
}
List oldLines = this.display.oldLines;
int newScrollRegion = display.rows - 1 - lines.size();
// Update the scroll region if needed.
// Note that settings the scroll region usually moves the cursor, so we need to get ready for that.
if (newScrollRegion < scrollRegion) {
// We need to scroll up to grow the status bar
terminal.puts(Capability.save_cursor);
for (int i = newScrollRegion; i < scrollRegion; i++) {
terminal.puts(Capability.cursor_down);
}
terminal.puts(Capability.change_scroll_region, 0, newScrollRegion);
terminal.puts(Capability.restore_cursor);
for (int i = newScrollRegion; i < scrollRegion; i++) {
terminal.puts(Capability.cursor_up);
}
scrollRegion = newScrollRegion;
} else if (newScrollRegion > scrollRegion) {
terminal.puts(Capability.save_cursor);
terminal.puts(Capability.change_scroll_region, 0, newScrollRegion);
terminal.puts(Capability.restore_cursor);
scrollRegion = newScrollRegion;
}
// if the display has more lines, we need to add empty ones to make sure they will be erased
List toDraw = new ArrayList<>(lines);
int nbToDraw = toDraw.size();
int nbOldLines = oldLines.size();
if (nbOldLines > nbToDraw) {
terminal.puts(Capability.save_cursor);
terminal.puts(Capability.cursor_address, display.rows - nbOldLines, 0);
for (int i = 0; i < nbOldLines - nbToDraw; i++) {
terminal.puts(Capability.clr_eol);
if (i < nbOldLines - nbToDraw - 1) {
terminal.puts(Capability.cursor_down);
}
oldLines.remove(0);
}
terminal.puts(Capability.restore_cursor);
}
// update display
display.update(lines, -1, flush);
}
private AttributedString getBorderString(int columns) {
if (borderString == null || borderString.length() != columns) {
char borderChar = '─';
AttributedStringBuilder bb = new AttributedStringBuilder();
for (int i = 0; i < columns; i++) {
bb.append(borderChar);
}
borderString = bb.toAttributedString();
}
return borderString;
}
/**
* The {@code suspend} method is used when a full-screen.
* If the status was not already suspended, the lines
* used by the status are cleared during this call.
*/
public void suspend() {
if (!suspended) {
suspended = true;
}
}
/**
* The {@code restore()} call is the opposite of {@code suspend()} and
* will make the status bar be updated again.
* If the status was suspended, the lines
* used by the status will be drawn during this call.
*/
public void restore() {
if (suspended) {
suspended = false;
update(this.lines);
}
}
public int size() {
return size(this.lines);
}
private int size(List lines) {
int l = lines.size();
return l > 0 ? l + border : 0;
}
@Override
public String toString() {
return "Status[" + "supported=" + supported + ']';
}
static class MovingCursorDisplay extends Display {
protected int firstLine;
public MovingCursorDisplay(Terminal terminal) {
super(terminal, false);
}
@Override
public void update(List newLines, int targetCursorPos, boolean flush) {
cursorPos = -1;
firstLine = rows - newLines.size();
super.update(newLines, targetCursorPos, flush);
if (cursorPos != -1) {
terminal.puts(Capability.restore_cursor);
}
}
@Override
protected void moveVisualCursorTo(int targetPos, List newLines) {
initCursor();
super.moveVisualCursorTo(targetPos, newLines);
}
@Override
protected int moveVisualCursorTo(int i1) {
initCursor();
return super.moveVisualCursorTo(i1);
}
void initCursor() {
if (cursorPos == -1) {
terminal.puts(Capability.save_cursor);
terminal.puts(Capability.cursor_address, firstLine, 0);
cursorPos = 0;
}
}
}
}
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