/*******************************************************************************
* Copyright (c) 2000, 2007 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.jface.text.contentassist;
import org.eclipse.jface.text.ITextViewer;
/**
* An <code>IContentAssistant</code> provides support on interactive content completion.
* The content assistant is a {@link org.eclipse.jface.text.ITextViewer} add-on. Its
* purpose is to propose, display, and insert completions of the content
* of the text viewer's document at the viewer's cursor position. In addition
* to handle completions, a content assistant can also be requested to provide
* context information. Context information is shown in a tool tip like popup.
* As it is not always possible to determine the exact context at a given
* document offset, a content assistant displays the possible contexts and requests
* the user to choose the one whose information should be displayed.
* <p>
* A content assistant has a list of {@link org.eclipse.jface.text.contentassist.IContentAssistProcessor}
* objects each of which is registered for a particular document content
* type. The content assistant uses the processors to react on the request
* of completing documents or presenting context information.
* </p>
* <p>
* In order to provide backward compatibility for clients of <code>IContentAssistant</code>, extension
* interfaces are used to provide a means of evolution. The following extension interfaces exist:
* <ul>
* <li>{@link org.eclipse.jface.text.contentassist.IContentAssistantExtension} since version 3.0 introducing
* the following functions:
* <ul>
* <li>handle documents with multiple partitions</li>
* <li>insertion of common completion prefixes</li>
* </ul>
* </li>
* <li>{@link org.eclipse.jface.text.contentassist.IContentAssistantExtension2} since version 3.2 introducing
* the following functions:
* <ul>
* <li>repeated invocation (cycling) mode</li>
* <li>completion listeners</li>
* <li>a local status line for the completion popup</li>
* <li>control over the behavior when no proposals are available</li>
* </ul>
* </li>
* <li>{@link org.eclipse.jface.text.contentassist.IContentAssistantExtension3} since version 3.2 introducing
* the following function:
* <ul>
* <li>a key-sequence to listen for in repeated invocation mode</li>
* </ul>
* </li>
* <li>{@link org.eclipse.jface.text.contentassist.IContentAssistantExtension4} since version 3.4 introducing
* the following function:
* <ul>
* <li>allows to get a handler for the given command identifier</li>
* </ul>
* </li>
* </ul>
* </p>
* <p>
* The interface can be implemented by clients. By default, clients use
* {@link org.eclipse.jface.text.contentassist.ContentAssistant} as the standard
* implementer of this interface.
* </p>
*
* @see org.eclipse.jface.text.ITextViewer
* @see org.eclipse.jface.text.contentassist.IContentAssistProcessor
*/
public interface IContentAssistant {
//------ proposal popup orientation styles ------------
/** The context info list will overlay the list of completion proposals. */
public final static int PROPOSAL_OVERLAY= 10;
/** The completion proposal list will be removed before the context info list will be shown. */
public final static int PROPOSAL_REMOVE= 11;
/** The context info list will be presented without hiding or overlapping the completion proposal list. */
public final static int PROPOSAL_STACKED= 12;
//------ context info box orientation styles ----------
/** Context info will be shown above the location it has been requested for without hiding the location. */
public final static int CONTEXT_INFO_ABOVE= 20;
/** Context info will be shown below the location it has been requested for without hiding the location. */
public final static int CONTEXT_INFO_BELOW= 21;
/**
* Installs content assist support on the given text viewer.
*
* @param textViewer the text viewer on which content assist will work
*/
void install(ITextViewer textViewer);
/**
* Uninstalls content assist support from the text viewer it has
* previously be installed on.
*/
void uninstall();
/**
* Shows all possible completions of the content at the viewer's cursor position.
*
* @return an optional error message if no proposals can be computed
*/
String showPossibleCompletions();
/**
* Shows context information for the content at the viewer's cursor position.
*
* @return an optional error message if no context information can be computed
*/
String showContextInformation();
/**
* Returns the content assist processor to be used for the given content type.
*
* @param contentType the type of the content for which this
* content assistant is to be requested
* @return an instance content assist processor or
* <code>null</code> if none exists for the specified content type
*/
IContentAssistProcessor getContentAssistProcessor(String contentType);
}