package com.termux.terminal;
import java.util.Arrays;
/**
* A row in a terminal, composed of a fixed number of cells.
* <p>
* The text in the row is stored in a char[] array, {@link #mText}, for quick access during rendering.
*/
public final class TerminalRow {
private static final float SPARE_CAPACITY_FACTOR = 1.5f;
/** The number of columns in this terminal row. */
private final int mColumns;
/** The text filling this terminal row. */
public char[] mText;
/** The number of java char:s used in {@link #mText}. */
private short mSpaceUsed;
/** If this row has been line wrapped due to text output at the end of line. */
boolean mLineWrap;
/** The style bits of each cell in the row. See {@link TextStyle}. */
final long[] mStyle;
/** Construct a blank row (containing only whitespace, ' ') with a specified style. */
public TerminalRow(int columns, long style) {
mColumns = columns;
mText = new char[(int) (SPARE_CAPACITY_FACTOR * columns)];
mStyle = new long[columns];
clear(style);
}
/** NOTE: The sourceX2 is exclusive. */
public void copyInterval(TerminalRow line, int sourceX1, int sourceX2, int destinationX) {
final int x1 = line.findStartOfColumn(sourceX1);
final int x2 = line.findStartOfColumn(sourceX2);
boolean startingFromSecondHalfOfWideChar = (sourceX1 > 0 && line.wideDisplayCharacterStartingAt(sourceX1 - 1));
final char[] sourceChars = (this == line) ? Arrays.copyOf(line.mText, line.mText.length) : line.mText;
int latestNonCombiningWidth = 0;
for (int i = x1; i < x2; i++) {
char sourceChar = sourceChars[i];
int codePoint = Character.isHighSurrogate(sourceChar) ? Character.toCodePoint(sourceChar, sourceChars[++i]) : sourceChar;
if (startingFromSecondHalfOfWideChar) {
// Just treat copying second half of wide char as copying whitespace.
codePoint = ' ';
startingFromSecondHalfOfWideChar = false;
}
int w = WcWidth.width(codePoint);
if (w > 0) {
destinationX += latestNonCombiningWidth;
sourceX1 += latestNonCombiningWidth;
latestNonCombiningWidth = w;
}
setChar(destinationX, codePoint, line.getStyle(sourceX1));
}
}
public int getSpaceUsed() {
return mSpaceUsed;
}
/** Note that the column may end of second half of wide character. */
public int findStartOfColumn(int column) {
if (column == mColumns) return getSpaceUsed();
int currentColumn = 0;
int currentCharIndex = 0;
while (true) { // 0<2 1 < 2
int newCharIndex = currentCharIndex;
char c = mText[newCharIndex++]; // cci=1, cci=2
boolean isHigh = Character.isHighSurrogate(c);
int codePoint = isHigh ? Character.toCodePoint(c, mText[newCharIndex++]) : c;
int wcwidth = WcWidth.width(codePoint); // 1, 2
if (wcwidth > 0) {
currentColumn += wcwidth;
if (currentColumn == column) {
while (newCharIndex < mSpaceUsed) {
// Skip combining chars.
if (Character.isHighSurrogate(mText[newCharIndex])) {
if (WcWidth.width(Character.toCodePoint(mText[newCharIndex], mText[newCharIndex + 1])) <= 0) {
newCharIndex += 2;
} else {
break;
}
} else if (WcWidth.width(mText[newCharIndex]) <= 0) {
newCharIndex++;
} else {
break;
}
}
return newCharIndex;
} else if (currentColumn > column) {
// Wide column going past end.
return currentCharIndex;
}
}
currentCharIndex = newCharIndex;
}
}
private boolean wideDisplayCharacterStartingAt(int column) {
for (int currentCharIndex = 0, currentColumn = 0; currentCharIndex < mSpaceUsed; ) {
char c = mText[currentCharIndex++];
int codePoint = Character.isHighSurrogate(c) ? Character.toCodePoint(c, mText[currentCharIndex++]) : c;
int wcwidth = WcWidth.width(codePoint);
if (wcwidth > 0) {
if (currentColumn == column && wcwidth == 2) return true;
currentColumn += wcwidth;
if (currentColumn > column) return false;
}
}
return false;
}
public void clear(long style) {
Arrays.fill(mText, ' ');
Arrays.fill(mStyle, style);
mSpaceUsed = (short) mColumns;
}
// https://github.com/steven676/Android-Terminal-Emulator/commit/9a47042620bec87617f0b4f5d50568535668fe26
public void setChar(int columnToSet, int codePoint, long style) {
mStyle[columnToSet] = style;
final int newCodePointDisplayWidth = WcWidth.width(codePoint);
final boolean newIsCombining = newCodePointDisplayWidth <= 0;
boolean wasExtraColForWideChar = (columnToSet > 0) && wideDisplayCharacterStartingAt(columnToSet - 1);
if (newIsCombining) {
// When standing at second half of wide character and inserting combining:
if (wasExtraColForWideChar) columnToSet--;
} else {
// Check if we are overwriting the second half of a wide character starting at the previous column:
if (wasExtraColForWideChar) setChar(columnToSet - 1, ' ', style);
// Check if we are overwriting the first half of a wide character starting at the next column:
boolean overwritingWideCharInNextColumn = newCodePointDisplayWidth == 2 && wideDisplayCharacterStartingAt(columnToSet + 1);
if (overwritingWideCharInNextColumn) setChar(columnToSet + 1, ' ', style);
}
char[] text = mText;
final int oldStartOfColumnIndex = findStartOfColumn(columnToSet);
final int oldCodePointDisplayWidth = WcWidth.width(text, oldStartOfColumnIndex);
// Get the number of elements in the mText array this column uses now
int oldCharactersUsedForColumn;
if (columnToSet + oldCodePointDisplayWidth < mColumns) {
oldCharactersUsedForColumn = findStartOfColumn(columnToSet + oldCodePointDisplayWidth) - oldStartOfColumnIndex;
} else {
// Last character.
oldCharactersUsedForColumn = mSpaceUsed - oldStartOfColumnIndex;
}
// Find how many chars this column will need
int newCharactersUsedForColumn = Character.charCount(codePoint);
if (newIsCombining) {
// Combining characters are added to the contents of the column instead of overwriting them, so that they
// modify the existing contents.
// FIXME: Put a limit of combining characters.
// FIXME: Unassigned characters also get width=0.
newCharactersUsedForColumn += oldCharactersUsedForColumn;
}
int oldNextColumnIndex = oldStartOfColumnIndex + oldCharactersUsedForColumn;
int newNextColumnIndex = oldStartOfColumnIndex + newCharactersUsedForColumn;
final int javaCharDifference = newCharactersUsedForColumn - oldCharactersUsedForColumn;
if (javaCharDifference > 0) {
// Shift the rest of the line right.
int oldCharactersAfterColumn = mSpaceUsed - oldNextColumnIndex;
if (mSpaceUsed + javaCharDifference > text.length) {
// We need to grow the array
char[] newText = new char[text.length + mColumns];
System.arraycopy(text, 0, newText, 0, oldStartOfColumnIndex + oldCharactersUsedForColumn);
System.arraycopy(text, oldNextColumnIndex, newText, newNextColumnIndex, oldCharactersAfterColumn);
mText = text = newText;
} else {
System.arraycopy(text, oldNextColumnIndex, text, newNextColumnIndex, oldCharactersAfterColumn);
}
} else if (javaCharDifference < 0) {
// Shift the rest of the line left.
System.arraycopy(text, oldNextColumnIndex, text, newNextColumnIndex, mSpaceUsed - oldNextColumnIndex);
}
mSpaceUsed += javaCharDifference;
// Store char. A combining character is stored at the end of the existing contents so that it modifies them:
//noinspection ResultOfMethodCallIgnored - since we already now how many java chars is used.
Character.toChars(codePoint, text, oldStartOfColumnIndex + (newIsCombining ? oldCharactersUsedForColumn : 0));
if (oldCodePointDisplayWidth == 2 && newCodePointDisplayWidth == 1) {
// Replace second half of wide char with a space. Which mean that we actually add a ' ' java character.
if (mSpaceUsed + 1 > text.length) {
char[] newText = new char[text.length + mColumns];
System.arraycopy(text, 0, newText, 0, newNextColumnIndex);
System.arraycopy(text, newNextColumnIndex, newText, newNextColumnIndex + 1, mSpaceUsed - newNextColumnIndex);
mText = text = newText;
} else {
System.arraycopy(text, newNextColumnIndex, text, newNextColumnIndex + 1, mSpaceUsed - newNextColumnIndex);
}
text[newNextColumnIndex] = ' ';
++mSpaceUsed;
} else if (oldCodePointDisplayWidth == 1 && newCodePointDisplayWidth == 2) {
if (columnToSet == mColumns - 1) {
throw new IllegalArgumentException("Cannot put wide character in last column");
} else if (columnToSet == mColumns - 2) {
// Truncate the line to the second part of this wide char:
mSpaceUsed = (short) newNextColumnIndex;
} else {
// Overwrite the contents of the next column, which mean we actually remove java characters. Due to the
// check at the beginning of this method we know that we are not overwriting a wide char.
int newNextNextColumnIndex = newNextColumnIndex + (Character.isHighSurrogate(mText[newNextColumnIndex]) ? 2 : 1);
int nextLen = newNextNextColumnIndex - newNextColumnIndex;
// Shift the array leftwards.
System.arraycopy(text, newNextNextColumnIndex, text, newNextColumnIndex, mSpaceUsed - newNextNextColumnIndex);
mSpaceUsed -= nextLen;
}
}
}
boolean isBlank() {
for (int charIndex = 0, charLen = getSpaceUsed(); charIndex < charLen; charIndex++)
if (mText[charIndex] != ' ') return false;
return true;
}
public final long getStyle(int column) {
return mStyle[column];
}
}