| /******************************************************************************* |
| * Copyright (c) 2006, 2008 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jface.internal.text.revisions; |
| |
| import org.eclipse.jface.text.source.ILineRange; |
| |
| /** |
| * A variable {@link org.eclipse.jface.text.source.ILineRange} with the following invariant: |
| * <ul> |
| * <li>{@link #start() start} >= 0 |
| * <li>{@link #length() length} > 0, i.e. a range cannot be empty |
| * </ul> |
| * <p> |
| * Attempts to create or modify a <code>Range</code> such that this invariant would be violated |
| * result in a {@link LineIndexOutOfBoundsException} being |
| * thrown. |
| * </p> |
| * |
| * @since 3.2 |
| */ |
| public final class Range implements ILineRange, Cloneable { |
| /** |
| * Creates a new range with the same start and length as the passed line range. |
| * |
| * @param range the range to copy |
| * @return a <code>Range</code> with the same start and length as <code>range</code> |
| * @throws LineIndexOutOfBoundsException if the passed {@link ILineRange} does not adhere to the |
| * contract of {@link Range} |
| */ |
| public static Range copy(ILineRange range) throws LineIndexOutOfBoundsException { |
| return createRelative(range.getStartLine(), range.getNumberOfLines()); |
| } |
| |
| /** |
| * Creates a new range equal to the passed line range. |
| * |
| * @param range the range to copy |
| * @return a <code>Range</code> equal to <code>range</code> |
| */ |
| public static Range copy(Range range) { |
| return createRelative(range.start(), range.length()); |
| } |
| |
| /** |
| * Creates a new range with the given start offset and length. |
| * |
| * @param start the first line of the new range, must be >= 0 |
| * @param length the number of lines included in the new range, must be > 0 |
| * @return a <code>Range</code> with the given start and length |
| * @throws LineIndexOutOfBoundsException if the parameters violate the invariant of |
| * {@link Range} |
| */ |
| public static Range createRelative(int start, int length) throws LineIndexOutOfBoundsException { |
| return new Range(start, length); |
| } |
| |
| /** |
| * Creates a new range with the given start and end offsets. |
| * |
| * @param start the first line of the new range, must be >= 0 |
| * @param end the first line not in the range any more (exclusive), must be > <code>start</code> |
| * @return a <code>Range</code> with the given start and end offsets |
| * @throws LineIndexOutOfBoundsException if the parameters violate the invariant of |
| * {@link Range} |
| */ |
| public static Range createAbsolute(int start, int end) { |
| return new Range(start, end - start); |
| } |
| |
| private int fStart; |
| private int fLength; |
| |
| /* |
| * Private constructor. |
| */ |
| private Range(int start, int length) { |
| moveTo(start); |
| setLength(length); |
| } |
| |
| @Override |
| public int getStartLine() { |
| return start(); |
| } |
| |
| @Override |
| public int getNumberOfLines() { |
| return length(); |
| } |
| |
| /** |
| * Returns the first line contained in this range. Short equivalent of {@link #getStartLine()}. |
| * |
| * @return the first line contained in this range |
| */ |
| public int start() { |
| return fStart; |
| } |
| |
| /** |
| * Returns the number of lines contained in this range. Short equivalent of {@link #getNumberOfLines()}. |
| * |
| * @return the number of lines contained in this range |
| */ |
| public int length() { |
| return fLength; |
| } |
| |
| /** |
| * Returns the first line after this range. Equivalent to {@linkplain #start() start} + {@linkplain #length() length}. |
| * |
| * @return the first line after this range |
| */ |
| public int end() { |
| return start() + length(); |
| } |
| |
| /** |
| * Moves the receiver to <code>start</code>, keeping {@link #length()} constant. |
| * |
| * @param start the new start, must be >= 0 |
| * @throws LineIndexOutOfBoundsException if <code>start</code> < 0 |
| */ |
| public void moveTo(int start) throws LineIndexOutOfBoundsException { |
| if (!(start >= 0)) |
| throw new LineIndexOutOfBoundsException("Cannot set a negative start: " + start); //$NON-NLS-1$ |
| fStart= start; |
| } |
| |
| /** |
| * Moves this range such that the {@link #end()} is at <code>end</code>, keeping |
| * {@link #length()} constant. |
| * |
| * @param end the new end |
| * @throws LineIndexOutOfBoundsException if <code>end</code> <= {@link #start()} |
| */ |
| public void moveEndTo(int end) throws LineIndexOutOfBoundsException { |
| moveTo(end - length()); |
| } |
| |
| /** |
| * Moves the range by <code>delta</code> lines, keeping {@link #length()} constant. The |
| * resulting start line must be >= 0. |
| * |
| * @param delta the number of lines to shift the range |
| * @throws LineIndexOutOfBoundsException if <code>-delta</code> > {@link #start()} |
| */ |
| public void moveBy(int delta) throws LineIndexOutOfBoundsException { |
| moveTo(start() + delta); |
| } |
| |
| /** |
| * Moves the start offset to <code>start</code>, keeping {@link #end()} constant. |
| * |
| * @param start the new start, must be >= 0 and < {@link #end()} |
| * @throws LineIndexOutOfBoundsException if <code>start</code> < 0 or >= {@link #end()} |
| */ |
| public void setStart(int start) throws LineIndexOutOfBoundsException { |
| int end= end(); |
| if (!(start >= 0 && start < end)) |
| throw new LineIndexOutOfBoundsException("Cannot set a negative start: " + start); //$NON-NLS-1$ |
| moveTo(start); |
| setEnd(end); |
| } |
| |
| /** |
| * Sets the end of this range, keeping {@link #start()} constant. |
| * |
| * @param end the new end, must be > {@link #start()} |
| * @throws LineIndexOutOfBoundsException if <code>end</code> <= {@link #start()} |
| */ |
| public void setEnd(int end) throws LineIndexOutOfBoundsException { |
| setLength(end - start()); |
| } |
| |
| /** |
| * Sets the length of this range, keeping {@link #start()} constant. |
| * |
| * @param length the new length, must be > 0 |
| * @throws LineIndexOutOfBoundsException if <code>length</code> <= 0 |
| */ |
| public void setLength(int length) throws LineIndexOutOfBoundsException { |
| if (!(length > 0)) |
| throw new LineIndexOutOfBoundsException("Cannot set length <= 0: " + length); //$NON-NLS-1$ |
| fLength= length; |
| } |
| |
| /** |
| * Sets the length of this range, keeping {@link #end()} constant. |
| * |
| * @param length the new length, must be > 0 and <= {@link #end()} |
| * @throws LineIndexOutOfBoundsException if <code>length</code> <= 0 |
| */ |
| public void setLengthAndMove(int length) throws LineIndexOutOfBoundsException { |
| setStart(end() - length); |
| } |
| |
| /** |
| * Resizes the range by <code>delta</code> lines, keeping {@link #start()} constant. |
| * |
| * @param delta the number of lines to resize the range |
| * @throws LineIndexOutOfBoundsException if <code>-delta</code> >= {@link #length()} |
| */ |
| public void resizeBy(int delta) throws LineIndexOutOfBoundsException { |
| setLength(length() + delta); |
| } |
| |
| /** |
| * Resizes the range by <code>delta</code> lines by moving the start offset, {@link #end()} remains unchanged. |
| * |
| * @param delta the number of lines to resize the range |
| * @throws LineIndexOutOfBoundsException if <code>-delta</code> >= {@link #length()} |
| */ |
| public void resizeAndMoveBy(int delta) throws LineIndexOutOfBoundsException { |
| setStart(start() + delta); |
| } |
| |
| /** |
| * Splits a range off the end of the receiver. The receiver is shortened to only include |
| * <code>remaining</code> lines after the split. |
| * |
| * @param remaining the number of lines to remain in the receiver, must be in [1, {@link #length() length}) |
| * @return the split off range |
| * @throws LineIndexOutOfBoundsException if <code>remaining</code>>= {@link #length()} or <code>remaining</code><= 0 |
| */ |
| public Range split(int remaining) throws LineIndexOutOfBoundsException { |
| if (!(remaining < length())) // assert before modification |
| throw new LineIndexOutOfBoundsException("Remaining must be less than length: " + length()); //$NON-NLS-1$ |
| |
| int splitLength= length() - remaining; |
| setLength(remaining); |
| return new Range(end(), splitLength); |
| } |
| |
| /** |
| * Returns <code>true</code> if the passed range has the same offset and length as the receiver. |
| * |
| * @param range another line range to compare the receiver to |
| * @return <code>true</code> if <code>range</code> has the same offset and length as the receiver |
| */ |
| public boolean equalRange(ILineRange range) { |
| if (range == this) |
| return true; |
| if (range == null) |
| return false; |
| return range.getStartLine() == start() && range.getNumberOfLines() == length(); |
| } |
| |
| @Override |
| public Object clone() { |
| return Range.copy(this); |
| } |
| } |