/*
* ModeShape (http://www.modeshape.org)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.modeshape.common.text;
import org.modeshape.common.annotation.Immutable;
/**
* A class that represents the position of a particular character in terms of the lines and columns of a character sequence.
*/
@Immutable
public final class Position {
/**
* The position is used when there is no content.
*/
public static final Position EMPTY_CONTENT_POSITION = new Position(-1, 1, 0);
private final int line;
private final int column;
private final int indexInContent;
public Position( int indexInContent,
int line,
int column ) {
this.indexInContent = indexInContent < 0 ? -1 : indexInContent;
this.line = line;
this.column = column;
assert this.indexInContent >= -1;
assert this.line > 0;
assert this.column >= 0;
// make sure that negative index means an EMPTY_CONTENT_POSITION
assert this.indexInContent < 0 ? this.line == 1 && this.column == 0 : true;
}
/**
* Get the 0-based index of this position in the content character array.
*
* @return the index; never negative except for the first position in an empty content.
*/
public int getIndexInContent() {
return indexInContent;
}
/**
* Get the 1-based column number of the character.
*
* @return the column number; always positive
*/
public int getColumn() {
return column;
}
/**
* Get the 1-based line number of the character.
*
* @return the line number; always positive
*/
public int getLine() {
return line;
}
@Override
public int hashCode() {
return indexInContent;
}
@Override
public String toString() {
return "" + indexInContent + ':' + line + ':' + column;
}
/**
* Return a new position that is the addition of this position and that supplied.
*
* @param position the position to add to this object; may not be null
* @return the combined position
*/
public Position add( Position position ) {
if (this.getIndexInContent() < 0) {
return position.getIndexInContent() < 0 ? EMPTY_CONTENT_POSITION : position;
}
if (position.getIndexInContent() < 0) {
return this;
}
int index = this.getIndexInContent() + position.getIndexInContent();
int line = position.getLine() + this.getLine() - 1;
int column = this.getLine() == 1 ? this.getColumn() + position.getColumn() : this.getColumn();
return new Position(index, line, column);
}
}