/*******************************************************************************
* Copyright (c) 2000, 2008 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.wst.jsdt.core;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IProgressMonitor;
/**
* 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 javaScript 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>
*
* Provisional API: This class/interface is part of an interim API that is still under development and expected to
* change significantly before reaching stability. It is being made available at this early stage to solicit feedback
* from pioneering adopters on the understanding that any code that uses this API will almost certainly be broken
* (repeatedly) as the API evolves.
*/
public interface IBuffer {
/**
* 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 JavaScript 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.
*
* @param offset the zero-based starting offset
* @param length the number of characters to retrieve
* @return the given range of text in this buffer
*/
public String getText(int offset, int length);
/**
* 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 JavaScriptModelException 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 JavaScriptModelException;
/**
* 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);
}