org.eclipse.text/src/org/eclipse/jface/text/IDocument.java

/**********************************************************************
Copyright (c) 2000, 2002 IBM Corp. 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 implementation
**********************************************************************/

package org.eclipse.jface.text;


/**
 * An <code>IDocument</code> represents text providing support for 
 * <ul>
 * <li> text manipulation
 * <li> positions
 * <li> partitions
 * <li> line information
 * <li> search
 * <li> document change listeners
 * <li> document partition change listeners
 * </ul>
 *
 * A document allows to set its content and to manipulate it. For manipulation
 * a document provides the <code>replace</code> method which substitutes a given
 * string for a specified text range in the document. On each document change, all
 * registered document listeners are informed exactly once.
 *
 * Positions are stickers to the document's text that are updated when the
 * document is changed. Positions are updated by <code>IPositionUpdater</code>s. Position 
 * updaters are managed as a list. The list defines the sequence in which position 
 * updaters are invoked.This way, position updaters may rely on each other. 
 * Positions are grouped into categories.  A category is a ordered list of positions.
 * the document defines the order of position in a category based on the position's offset
 * based on the implementation of the method <code>computeIndexInCategory</code>.
 * Each document must support a default position category whose name is specified by this
 * interface.<p>
 *
 * A document can be considered consisting of a sequence of not overlapping partitions.
 * A partition is defined by its offset, its length, and its type. Partitions are 
 * updated on every document manipulation and ensured to be up-to-date when the document
 * listeners are informed. A document uses an <code>IDocumentPartitioner</code> to 
 * manage its partitions. A document may be unpartitioned which happens when there is no
 * partitioner. In this case, the document is considered as one singloe partition of a
 * default type. The default type is specified by this interface. If a document change
 * changes the document's partitioning all registered partitioning listeners are
 * informed exactly once.<p>
 *
 * An <code>IDocument</code> uses an <code>ILineTracker</code> to map line numbers and character 
 * positions onto each other based on the document's line delimiters. When moving text 
 * between documents using different line delimiters, the text must be converted to 
 * use the target document's line delimiters. <p>
 *
 * <code>IDocument</code> throws <code>BadLocationException</code> if the parameters of
 * queries or manipulation requests are not inside the bounds of the document. The purpose
 * of this style of exception handling is
 * <ul>
 * <li> prepare document for multi-thread access
 * <li> allow clients to implement backtracking recovery methods
 * <li> prevent clients from upfront contract checking when dealing with documents.
 * </ul>
 * Clients may implement this interface or use the default implementation provided
 * by <code>AbstractDocument</code> and <code>Document</code>.
 *
 * @see Position
 * @see IPositionUpdater
 * @see IDocumentPartitioner
 * @see ILineTracker
 * @see IDocumentListener
 * @see IDocumentPartitioningListener
 */
public interface IDocument {
	
	
	/**
	 * The identifier of the default position category.
	 */
	final static String DEFAULT_CATEGORY= "__dflt_position_category"; //$NON-NLS-1$
	
	/**
	 * The identifier of the default partition content type.
	 */
	final static String DEFAULT_CONTENT_TYPE= "__dftl_partition_content_type"; //$NON-NLS-1$
	
	
	
	
	/* --------------- text access and manipulation --------------------------- */
	
	/**
	 * Returns the character at the given document offset in this document.
	 *
	 * @param offset a document offset
	 * @return the character at the offset
	 * @exception BadLocationException if the offset is invalid in this document
	 */
	char getChar(int offset) throws BadLocationException;
	
	/**
	 * Returns the number of characters in this document.
	 *
	 * @return the number of characters in this document
	 */
	int getLength();
	
	/**
	 * Returns this document's complete text.
	 *
	 * @return the document's complete text
	 */
	String get();
	
	/**
	 * Returns this document's text for the specified range.
	 *
	 * @param offset the document offset
	 * @param length the length of the specified range
	 * @return the document's text for the specified range
	 * @exception BadLocationException if the range is invalid in this document
	 */
	String get(int offset, int length) throws BadLocationException;
	
	/**
	 * Replaces the content of the document with the given text.
	 * Sends a <code>DocumentEvent</code> to all registered <code>IDocumentListener</code>.
	 * This method is a convenience method for <code>
	 * replace(0, getLength(), text)</code>.
	 *
	 * @param text the new content of the document
	 *
	 * @see DocumentEvent
	 * @see IDocumentListener
	 */
	void set(String text);
		
	/**
	 * Subsitutes the given text for the specified document range.
	 * Sends a <code>DocumentEvent</code> to all registered <code>IDocumentListener</code>.
	 *
	 * @param offset the document offset
	 * @param length the length of the specified range
	 * @param text the substitution text
	 * @exception BadLocationException if the offset is invalid in this document
	 *
	 * @see DocumentEvent
	 * @see IDocumentListener
	 */
	void replace(int offset, int length, String text) throws BadLocationException;
		
	/**
	 * Registers the document listener with the document. After registration
	 * the IDocumentListener is informed about each change of this document.
	 * If the listener is already registered nothing happens.<p>
	 * An <code>IDocumentListener</code> may call back to this method
	 * when being inside a document notification. 
	 *
	 * @param listener the listener to be registered
	 */
	void addDocumentListener(IDocumentListener listener);
	
	/**
	 * Removes the listener from the document's list of document listeners.
	 * If the listener is not registered with the document nothing happens.<p>
	 * An <code>IDocumentListener</code> may call back to this method
	 * when being inside a document notification. 
	 *
	 * @param listener the listener to be removed
	 */
	void removeDocumentListener(IDocumentListener listener);
	
	/**
	 * Adds the given document listener as one which is notified before
	 * those document listeners added with <code>addDocumentListener</code>
	 * are notified. If the given listener is also registered using
	 * <code>addDocumentListener</code> it will be notified twice.
	 * If the listener is already registered nothing happens.<p>
	 * 
	 * This method is not for public use, it may only be called by
	 * implementers of <code>IDocumentAdapter</code> and only if those 
	 * implementers need to implement <code>IDocumentListener</code>.
	 * 
	 * @param documentAdapter the listener to be added as prenotified document listener
	 */
	void addPrenotifiedDocumentListener(IDocumentListener documentAdapter);
	
	/**
	 * Removes the given document listener from the document's list of
	 * prenotified document listeners. If the listener is not registered
	 * with the document nothing happens. <p>
	 * 
	 * This method is not for public use, it may only be called by
	 * implementers of <code>IDocumentAdapter</code> and only if those 
	 * implementers need to implement <code>IDocumentListener</code>.
	 * 
	 * @param documentAdapter the listener to be removed
	 * 
	 * @see #addPrenotifiedDocumentListener(IDocumentListener)
	 */
	void removePrenotifiedDocumentListener(IDocumentListener documentAdapter);
	
	
	
	/* -------------------------- positions ----------------------------------- */
	
	/**
	 * Adds a new position category to the document. If the position category
	 * already exists nothing happens.
	 *
	 * @param category the category to be added
	 */
	void addPositionCategory(String category);
	
	/**
	 * Deletes the position category from the document. All positions
	 * in this category are thus deleted as well.
	 *
	 * @param category the category to be removed
	 * @exception BadPositionCategoryException if category is undefined in this document
	 */
	void removePositionCategory(String category) throws BadPositionCategoryException;
	
	/**
	 * Returns all position categories of this document. This
	 * includes the default position category.
	 *
	 * @return the document's position categories
	 */
	String[] getPositionCategories();
	
	/**
	 * Checks the presence of the specified position category.
	 *
	 * @param category the category to check
	 * @return <code>true</code> if category is defined
	 */
	boolean containsPositionCategory(String category);
	
	/**
	 * Adds the position to the document's default position category.
	 * This is a convenience method for <code>addPosition(DEFAULT_CATEGORY, position)</code>.
	 *
	 * @param position the position to be added
	 * @exception BadLocationException if position describes an invalid range in this document
	 */
	void addPosition(Position position) throws BadLocationException;
	
	/**
	 * Removes the given position from the document's default position category.
	 * This is a convenience method for <code>removePosition(DEFAULT_CATEGORY, position)</code>.
	 *
	 * @param position the position to be removed
	 */
	void removePosition(Position position);
	
	/**
	 * Adds the position to the specified position category of the document.
	 * A position that has been added to a position category is updated on each
	 * change applied to the document. Positions may be added multiple times.
	 * The order of the category is maintained.
	 *
	 * @param category the category to which to add
	 * @param position the position to be added
	 * @exception BadLocationException if position describes an invalid range in this document
	 * @exception BadPositionCategoryException if the category is undefined in this document
	 */
	void addPosition(String category, Position position) throws BadLocationException, BadPositionCategoryException;
	
	/**
	 * Removes the given position from the specified position category. 
	 * If the position is not part of the specified category nothing happens.
	 * If the position has been added multiple times, only the first occurence is deleted.
	 *
	 * @param category the category from which to delete
	 * @param position the position to be deleted
	 * @exception BadPositionCategoryException if category is undefined in this document
	 */
	void removePosition(String category, Position position) throws BadPositionCategoryException;
	
	/**
	 * Returns all positions of the given position category.
	 * The positions are ordered according to the category's order.
	 * Manipulating this list does not affect the document, but manipulating the
	 * position does affect the document.
	 *
	 * @param category the category
	 * @return the list of all positions
	 * @exception BadPositionCategoryException if category is undefined in this document
	 */
	Position[] getPositions(String category) throws BadPositionCategoryException;
	
	/**
	 * Determines whether a position described by the parameters is managed by this document.
	 *
	 * @param category the category to check
	 * @param offset the offset of the position to find
	 * @param length the length of the position to find
	 * @return <code>true</code> if position is found
	 */
	boolean containsPosition(String category, int offset, int length);
		
	/**
	 * Computes the index at which a <code>Position</code> with the
	 * specified offset would be inserted into the given category. As the
	 * ordering inside a category only depends on the offset, the index must be
	 * choosen to be the first of all positions with the same offset.
	 *
	 * @param category the category in which would be added
	 * @param offset the position offset to be considered
	 * @return the index into the category
	 * @exception BadLocationException if offset is invalid in this document
	 * @exception BadPositionCategoryException if category is undefined in this document
	 */
	int computeIndexInCategory(String category, int offset) throws BadLocationException, BadPositionCategoryException;
		
	/**
	 * Appends a new position updater to the document's list of position updaters.
	 * Position updaters may be added multiple times.<p>
	 * An <code>IPositionUpdater</code> may call back to this method
	 * when being inside a document notification. 
	 *
	 * @param updater the updater to be added
	 */
	void addPositionUpdater(IPositionUpdater updater);
	
	/**
	 * Removes the position updater from the document's list of position updaters.
	 * If the position updater has multiple occurences only the first occurence is
	 * removed. If the position updater is not registered with this document, nothing
	 * happens.<p>
	 * An <code>IPositionUpdater</code> may call back to this method
	 * when being inside a document notification. 
	 *
	 * @param updater the updater to be removed
	 */
	void removePositionUpdater(IPositionUpdater updater);
	
	/**
	 * Inserts the position updater at the specified index in the document's 
	 * list of position updaters. Positions updaters may be inserted multiple times.<p>
	 * An <code>IPositionUpdater</code> may call back to this method
	 * when being inside a document notification. 
	 *
	 * @param updater the updater to be inserted
	 * @param index the index in the document's updater list
	 */
	void insertPositionUpdater(IPositionUpdater updater, int index);
	
	/**
	 * Returns the list of position updaters attached to the document.
	 *
	 * @return the list of position updaters
	 */
	IPositionUpdater[] getPositionUpdaters();
	
	
	
	
	/* -------------------------- partitions ---------------------------------- */
	
	/**
	 * Returns the set of legal content types of document partitions.
	 * This set can be empty. The set can contain more content types than 
	 * contained by the result of <code>getPartitioning(0, getLength())</code>.
	 *
	 * @return the set of legal content types
	 */
	String[] getLegalContentTypes();
	
	/**
	 * Returns the type of the document partition containing the given offset.
	 * This is a convenience method for <code>getPartition(offset).getType()</code>.
	 *
	 * @param offset the document offset
	 * @return the partition type
	 * @exception BadLocationException if offset is invalid in this document
	 */
	String getContentType(int offset) throws BadLocationException;
	
	/**
	 * Returns the document partition in which the position is located.
	 *
	 * @param offset the document offset
	 * @return a specification of the partition
	 * @exception BadLocationException if offset is invalid in this document
	 */
	ITypedRegion getPartition(int offset) throws BadLocationException;
	
	/**
	 * Computes the partitioning of the given document range using the 
	 * document's partitioner.
	 *
	 * @param offset the document offset at which the range starts
	 * @param length the length of the document range
	 * @return a specification of the range's partitioning
	 * @exception BadLocationException if the range is invalid in this document
	 */
	ITypedRegion[] computePartitioning(int offset, int length) throws BadLocationException;
	
	/**
	 * Registers the document partitioning listener with the document. After registration
	 * the document partitioning listener is informed about each partition change
	 * cause by a document manipulation or by changing the document's partitioner. 
	 * If a document partitioning listener is also
	 * a document listener, the following notification sequence is guaranteed if a
	 * document manipulation changes the document partitioning:
	 * <ul>
	 * <li>listener.documentAboutToBeChanged(DocumentEvent);
	 * <li>listener.documentPartitioningChanged();
	 * <li>listener.documentChanged(DocumentEvent);
	 * </ul>
	 * If the listener is already registered nothing happens.<p>
	 * An <code>IDocumentPartitioningListener</code> may call back to this method
	 * when being inside a document notification. 
	 *
	 * @param listener the listener to be added
	 */
	void addDocumentPartitioningListener(IDocumentPartitioningListener listener);
	
	/**
	 * Removes the listener from this document's list of document partitioning
	 * listeners. If the listener is not registered with the document nothing
	 * happens.<p>
	 * An <code>IDocumentPartitioningListener</code> may call back to this method
	 * when being inside a document notification. 
	 *
	 * @param listener the listener to be removed
	 */
	void removeDocumentPartitioningListener(IDocumentPartitioningListener listener);
	
	/**
	 * Sets this document's partitioner. The caller of this method is responsible for
	 * disconnecting the document's old partitioner from the document and to
	 * connect the new partitioner to the document. Informs all document partitioning
	 * listeners about this change.
	 *
	 * @param the document's new partitioner
	 *
	 * @see IDocumentPartitioningListener
	 */
	void setDocumentPartitioner(IDocumentPartitioner partitioner);	
	
	/**
	 * Returns this document's partitioner.
	 *
	 * @return this document's partitioner
	 */
	IDocumentPartitioner getDocumentPartitioner();
	
	
	
	/* ---------------------- line information -------------------------------- */
	
	/**
	 * Returns the length of the given line including the line's delimiter.
	 *
	 * @param line the line of interest
	 * @return the length of the line
	 * @exception BadLocationException if the line number is invalid in this document
	 */
	int getLineLength(int line) throws BadLocationException;
	
	/**
	 * Returns the number of the line at which the character of the specified position is located. 
	 * The first line has the line number 0. A new line starts directly after a line
	 * delimiter. <code>(pos == document length)</code> is a valid argument also there is no
	 * corresponding character.
	 *
	 * @param offset the document offset
	 * @return the number of the line
	 * @exception BadLocationException if the offset is invalid in this document
	 */
	int getLineOfOffset(int offset) throws BadLocationException;
	
	/**
	 * Determines the offset of the first character of the given line.
	 *
	 * @param line the line of interest
	 * @return the document offset
	 * @exception BadLocationException if the line number is invalid in this document
	 */
	int getLineOffset(int line) throws BadLocationException;
	
	/**
	 * Returns a description of the specified line. The line is described by its
	 * offset and its length excluding the line's delimiter.
	 *
	 * @param line the line of interest
	 * @return a line description
	 * @exception BadLocationException if the line number is invalid in this document
	 */
	IRegion getLineInformation(int line) throws BadLocationException;
	
	/**
	 * Returns a description of the line at the given offset.
	 * The description contains the offset and the length of the line
	 * excluding the line's delimiter.
	 *
	 * @param offset the offset whose line should be described
	 * @return a region describing the line
	 * @exception BadLocationException if offset is invalid in this document
	 */
	IRegion getLineInformationOfOffset(int offset) throws BadLocationException;
	
	/**
	 * Returns the number of lines in this document
	 *
	 * @return the number of lines in this document
	 */
	int getNumberOfLines();
	
	/**
	 * Returns the number of lines which are occupied by a given text range.
	 *
	 * @param offset the offset of the specified text range
	 * @param length the length of the specified text range
	 * @return the number of lines occupied by the specified range
	 * @exception BadLocationException if specified range is invalid in this tracker
	 */
	int getNumberOfLines(int offset, int length) throws BadLocationException;
	
	/**
	 * Computes the number of lines in the given text. For a given
	 * implementer of this interface this method returns the same
	 * result as <code>set(text); getNumberOfLines()</code>.
	 * 
	 * @param text the text whose number of lines should be computed
	 * @return the number of lines in the given text
	 */
	int computeNumberOfLines(String text);
	
	
	/* ------------------ line delimiter conversion --------------------------- */
	
	/**
	 * Returns the document's legal line delimiters.
	 *
	 * @return the document's legal line delimiters
	 */
	String[] getLegalLineDelimiters();
	
	/**
	 * Returns the line delimiter of that line.
	 *
	 * @param line the line of interest
	 * @return the line delimiter of that line
	 * @exception BadLocationException if the line number is invalid in this document
	 */
	String getLineDelimiter(int line) throws BadLocationException;
		
	
	
	/* ---------------------------- search ------------------------------------ */
	
	/**
	 * Returns the offset of a given search string in the document based on a set of search criteria.
	 *
	 * @param startOffset document offset at which search starts
	 * @param findString the string to find
	 * @param forwardSearch the search direction
	 * @param caseSensitive indicates whether lower and upper case should be distinguished
	 * @param wholeWord indicates whether the findString should be limited by white spaces as 
	 * 		defined by Character.isWhiteSpace
	 * @return the offset of the first occurence of findString based on the parameters
	 * @exception BadLocationException if startOffset is an invalid document offset
	 */
	int search(int startOffset, String findString, boolean forwardSearch, boolean caseSensitive, boolean wholeWord) throws BadLocationException;
}