/*******************************************************************************
* 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.rubypeople.rdt.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 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 {
/**
* 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 Ruby 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 RubyModelException
* 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 RubyModelException;
/**
* 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);
}