/*******************************************************************************
* Copyright (c) 2000, 2010 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.core;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.text.edits.TextEdit;
import org.eclipse.text.edits.UndoEdit;
/**
* A buffer contains the text contents of a resource. It is not language-specific. The contents may
* be in the process of being edited, differing from the actual contents of the underlying resource.
* A buffer has an owner, which is an <code>IOpenable</code>. If a buffer does not have an
* underlying resource, saving the buffer has no effect. Buffers can be read-only.
* <p>
* Note that java model operations that manipulate an <code>IBuffer</code> (for example,
* <code>IType.createMethod(...)</code>) ensures that the same line delimiter (either
* <code>"\n"</code> or <code>"\r"</code> or <code>"\r\n"</code>) is used across the whole buffer.
* Thus these operations may change the line delimiter(s) included in the string to be append, or
* replaced. However implementers of this interface should be aware that other clients of
* <code>IBuffer</code> might not do such transformations beforehand.
* <p>
* This interface may be implemented by clients.
* </p>
*/
public interface IBuffer {
/**
* Implementors of {@link IBuffer} can additionally implement
* {@link IBuffer.ITextEditCapability}. This adds the capability to apply text edits to the
* buffer and will be used by {@link ICompilationUnit#applyTextEdit(TextEdit, IProgressMonitor)}
* .
*
* <p>
* This interface may be implemented by clients.
* </p>
*
* @since 3.4
*/
public interface ITextEditCapability {
/**
* Applies a text edit to this underlying buffer.
*
* @param edit the edit to apply
* @param monitor the progress monitor to use or <code>null</code> if no progress should be
* reported
* @return the undo edit
* @throws JavaModelException if this edit can not be applied to the buffer. Reasons
* include:
* <ul>
* <li>The provided edit can not be applied as there is a problem with the text
* edit locations ({@link IJavaModelStatusConstants#BAD_TEXT_EDIT_LOCATION})}.</li>
* </ul>
*/
public UndoEdit applyTextEdit(TextEdit edit, IProgressMonitor monitor) throws JavaModelException;
}
/**
* Adds the given listener for changes to this buffer. Has no effect if an identical listener is
* already registered or if the buffer is closed.
*
* @param listener the listener of buffer changes
*/
public void addBufferChangedListener(IBufferChangedListener listener);
/**
* Appends the given character array to the contents of the buffer. This buffer will now have
* unsaved changes. Any client can append to the contents of the buffer, not just the owner of
* the buffer. Reports a buffer changed event.
* <p>
* Has no effect if this buffer is read-only or if the buffer is closed.
*
* @param text the given character array to append to contents of the buffer
*/
public void append(char[] text);
/**
* Appends the given string to the contents of the buffer. This buffer will now have unsaved
* changes. Any client can append to the contents of the buffer, not just the owner of the
* buffer. Reports a buffer changed event.
* <p>
* Has no effect if this buffer is read-only or if the buffer is closed.
*
* @param text the <code>String</code> to append to the contents of the buffer
*/
public void append(String text);
/**
* Closes the buffer. Any unsaved changes are lost. Reports a buffer changed event with a 0
* offset and a 0 length. When this event is fired, the buffer should already be closed.
* <p>
* Further operations on the buffer are not allowed, except for close. If an attempt is made to
* close an already closed buffer, the second attempt has no effect.
*/
public void close();
/**
* Returns the character at the given position in this buffer.
* <p>
* The returned value is undefined if the buffer is closed.
*
* @param position a zero-based source offset in this buffer
* @return the character at the given position in this buffer
*/
public char getChar(int position);
/**
* Returns the contents of this buffer as a character array, or <code>null</code> if the buffer
* has not been initialized.
* <p>
* Callers should make no assumption about whether the returned character array is or is not the
* genuine article or a copy. In other words, if the client wishes to change this array, they
* should make a copy. Likewise, if the client wishes to hang on to the array in its current
* state, they should make a copy.
* </p>
* <p>
* The returned value is undefined if the buffer is closed.
*
* @return the characters contained in this buffer
*/
public char[] getCharacters();
/**
* Returns the contents of this buffer as a <code>String</code>. Like all strings, the result is
* an immutable value object., It can also answer <code>null</code> if the buffer has not been
* initialized.
* <p>
* The returned value is undefined if the buffer is closed.
*
* @return the contents of this buffer as a <code>String</code>
*/
public String getContents();
/**
* Returns number of characters stored in this buffer.
* <p>
* The returned value is undefined if the buffer is closed.
*
* @return the number of characters in this buffer
*/
public int getLength();
/**
* Returns the Java openable element owning of this buffer.
*
* @return the openable element owning this buffer
*/
public IOpenable getOwner();
/**
* Returns the given range of text in this buffer.
* <p>
* The returned value is undefined if the buffer is closed.
* </p>
*
* @param offset the zero-based starting offset
* @param length the number of characters to retrieve
* @return the given range of text in this buffer
* @exception IndexOutOfBoundsException when buffer is out of synch
*/
public String getText(int offset, int length) throws IndexOutOfBoundsException;
/**
* Returns the underlying resource for which this buffer was opened, or <code>null</code> if
* this buffer was not opened on a resource.
*
* @return the underlying resource for this buffer, or <code>null</code> if none.
*/
public IResource getUnderlyingResource();
/**
* Returns whether this buffer has been modified since it was opened or since it was last saved.
* If a buffer does not have an underlying resource, this method always returns
* <code>true</code>.
* <p>
* NOTE: when a buffer does not have unsaved changes, the model may decide to close it to claim
* some memory back. If the associated element needs to be reopened later on, its buffer factory
* will be requested to create a new buffer.
* </p>
*
* @return a <code>boolean</code> indicating presence of unsaved changes (in the absence of any
* underlying resource, it will always return <code>true</code>).
*/
public boolean hasUnsavedChanges();
/**
* Returns whether this buffer has been closed.
*
* @return a <code>boolean</code> indicating whether this buffer is closed.
*/
public boolean isClosed();
/**
* Returns whether this buffer is read-only.
*
* @return a <code>boolean</code> indicating whether this buffer is read-only
*/
public boolean isReadOnly();
/**
* Removes the given listener from this buffer. Has no affect if an identical listener is not
* registered or if the buffer is closed.
*
* @param listener the listener
*/
public void removeBufferChangedListener(IBufferChangedListener listener);
/**
* Replaces the given range of characters in this buffer with the given text.
* <code>position</code> and <code>position + length</code> must be in the range [0,
* getLength()]. <code>length</code> must not be negative.
* <p>
* Has no effect if this buffer is read-only or if the buffer is closed.
*
* @param position the zero-based starting position of the affected text range in this buffer
* @param length the length of the affected text range in this buffer
* @param text the replacing text as a character array
*/
public void replace(int position, int length, char[] text);
/**
* Replaces the given range of characters in this buffer with the given text.
* <code>position</code> and <code>position + length</code> must be in the range [0,
* getLength()]. <code>length</code> must not be negative.
* <p>
* Has no effect if this buffer is read-only or if the buffer is closed.
*
* @param position the zero-based starting position of the affected text range in this buffer
* @param length the length of the affected text range in this buffer
* @param text the replacing text as a <code>String</code>
*/
public void replace(int position, int length, String text);
/**
* Saves the contents of this buffer to its underlying resource. If successful, this buffer will
* have no unsaved changes. The buffer is left open. Saving a buffer with no unsaved changes has
* no effect - the underlying resource is not changed. If the buffer does not have an underlying
* resource or is read-only, this has no effect.
* <p>
* The <code>force</code> parameter controls how this method deals with cases where the
* workbench is not completely in sync with the local file system. If <code>false</code> is
* specified, this method will only attempt to overwrite a corresponding file in the local file
* system provided it is in sync with the workbench. This option ensures there is no unintended
* data loss; it is the recommended setting. However, if <code>true</code> is specified, an
* attempt will be made to write a corresponding file in the local file system, overwriting any
* existing one if need be. In either case, if this method succeeds, the resource will be marked
* as being local (even if it wasn't before).
* <p>
* Has no effect if this buffer is read-only or if the buffer is closed.
*
* @param progress the progress monitor to notify
* @param force a <code> boolean </code> flag indicating how to deal with resource
* inconsistencies.
*
* @exception JavaModelException if an error occurs writing the buffer to the underlying
* resource
*
* @see org.eclipse.core.resources.IFile#setContents(java.io.InputStream, boolean, boolean,
* org.eclipse.core.runtime.IProgressMonitor)
*/
public void save(IProgressMonitor progress, boolean force) throws JavaModelException;
/**
* Sets the contents of this buffer to the given character array. This buffer will now have
* unsaved changes. Any client can set the contents of the buffer, not just the owner of the
* buffer. Reports a buffer changed event.
* <p>
* Equivalent to <code>replace(0,getLength(),contents)</code>.
* </p>
* <p>
* Has no effect if this buffer is read-only or if the buffer is closed.
*
* @param contents the new contents of this buffer as a character array
*/
public void setContents(char[] contents);
/**
* Sets the contents of this buffer to the given <code>String</code>. This buffer will now have
* unsaved changes. Any client can set the contents of the buffer, not just the owner of the
* buffer. Reports a buffer changed event.
* <p>
* Equivalent to <code>replace(0,getLength(),contents)</code>.
* </p>
* <p>
* Has no effect if this buffer is read-only or if the buffer is closed.
*
* @param contents the new contents of this buffer as a <code>String</code>
*/
public void setContents(String contents);
}