| /******************************************************************************* |
| * Copyright (c) 2000, 2004 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Common Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/cpl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jface.text; |
| |
| |
| /** |
| * Standard implementation of {@link org.eclipse.jface.text.ITextSelection}. |
| * <p> |
| * Makes advantage of the weak contract of correctness of its interface. If |
| * generated from a selection provider, it only remembers its offset and length |
| * and computes the remaining information on request. |
| */ |
| public class TextSelection implements ITextSelection { |
| |
| /** Internal empty text selection */ |
| private final static ITextSelection NULL= new TextSelection(); |
| |
| /** |
| * Returns a shared instance of an empty text selection. |
| * |
| * @return a shared instance of an empty text selection |
| */ |
| public static ITextSelection emptySelection() { |
| return NULL; |
| } |
| |
| /** Document which delivers the data of the selection */ |
| private IDocument fDocument; |
| /** Offset of the selection */ |
| private int fOffset; |
| /** Length of the selection */ |
| private int fLength; |
| |
| |
| /** |
| * Creates an empty text selection. |
| */ |
| private TextSelection() { |
| this(null, -1, -1); |
| } |
| |
| /** |
| * Creates a text selection for the given range. This |
| * selection object describes generically a text range and |
| * is intended to be an argument for the <code>setSelection</code> |
| * method of selection providers. |
| * |
| * @param offset the offset of the range |
| * @param length the length of the range |
| */ |
| public TextSelection(int offset, int length) { |
| this(null, offset, length); |
| } |
| |
| /** |
| * Creates a text selection for the given range of the given document. |
| * This selection object is created by selection providers in responds |
| * <code>getSelection</code>. |
| * |
| * @param document the document whose text range is selected in a viewer |
| * @param offset the offset of the selected range |
| * @param length the length of the selected range |
| */ |
| public TextSelection(IDocument document, int offset, int length) { |
| fDocument= document; |
| fOffset= offset; |
| fLength= length; |
| } |
| |
| /** |
| * |
| * Returns true if the offset and length are smaller than 0. |
| * A selection of length 0, is a valid text selection as it |
| * describes, e.g., the cursor position in a viewer. |
| * |
| * @return <code>true</code> if this selection is empty |
| * @see org.eclipse.jface.viewers.ISelection#isEmpty() |
| */ |
| public boolean isEmpty() { |
| return fOffset < 0 || fLength < 0; |
| } |
| |
| /* |
| * @see org.eclipse.jface.text.ITextSelection#getOffset() |
| */ |
| public int getOffset() { |
| return fOffset; |
| } |
| |
| /* |
| * @see org.eclipse.jface.text.ITextSelection#getLength() |
| */ |
| public int getLength() { |
| return fLength; |
| } |
| |
| /* |
| * @see org.eclipse.jface.text.ITextSelection#getStartLine() |
| */ |
| public int getStartLine() { |
| |
| try { |
| if (fDocument != null) |
| return fDocument.getLineOfOffset(fOffset); |
| } catch (BadLocationException x) { |
| } |
| |
| return -1; |
| } |
| |
| /* |
| * @see org.eclipse.jface.text.ITextSelection#getEndLine() |
| */ |
| public int getEndLine() { |
| try { |
| if (fDocument != null) { |
| int endOffset= fOffset + fLength; |
| if (fLength != 0) |
| endOffset--; |
| return fDocument.getLineOfOffset(endOffset); |
| } |
| } catch (BadLocationException x) { |
| } |
| |
| return -1; |
| } |
| |
| /* |
| * @see org.eclipse.jface.text.ITextSelection#getText() |
| */ |
| public String getText() { |
| try { |
| if (fDocument != null) |
| return fDocument.get(fOffset, fLength); |
| } catch (BadLocationException x) { |
| } |
| |
| return null; |
| } |
| |
| /* |
| * @see java.lang.Object#equals(Object) |
| */ |
| public boolean equals(Object obj) { |
| if (obj == this) |
| return true; |
| |
| if (obj == null || getClass() != obj.getClass()) |
| return false; |
| |
| TextSelection s= (TextSelection) obj; |
| boolean sameRange= (s.fOffset == fOffset && s.fLength == fLength); |
| if (sameRange) { |
| |
| if (s.fDocument == null && fDocument == null) |
| return true; |
| if (s.fDocument == null || fDocument == null) |
| return false; |
| |
| try { |
| String sContent= s.fDocument.get(fOffset, fLength); |
| String content= fDocument.get(fOffset, fLength); |
| return sContent.equals(content); |
| } catch (BadLocationException x) { |
| } |
| } |
| |
| return false; |
| } |
| |
| /* |
| * @see java.lang.Object#hashCode() |
| */ |
| public int hashCode() { |
| int low= fDocument != null ? fDocument.hashCode() : 0; |
| return (fOffset << 24) | (fLength << 16) | low; |
| } |
| } |
| |