/*******************************************************************************
* Copyright (c) 2004, 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.wst.jsdt.core;
import org.eclipse.wst.jsdt.core.compiler.IProblem;
/**
* Abstract base class for a completion requestor which is passed completion
* proposals as they are generated in response to a code assist request.
* <p>
* This class is intended to be subclassed by clients.
* </p>
* <p>
* The code assist engine normally invokes methods on completion
* requestor in the following sequence:
* <pre>
* requestor.beginReporting();
* requestor.acceptContext(context);
* requestor.accept(proposal_1);
* requestor.accept(proposal_2);
* ...
* requestor.endReporting();
* </pre>
* If, however, the engine is unable to offer completion proposals
* for whatever reason, <code>completionFailure</code> is called
* with a problem object describing why completions were unavailable.
* In this case, the sequence of calls is:
* <pre>
* requestor.beginReporting();
* requestor.acceptContext(context);
* requestor.completionFailure(problem);
* requestor.endReporting();
* </pre>
* In either case, the bracketing <code>beginReporting</code>
* <code>endReporting</code> calls are always made as well as
* <code>acceptContext</code> call.
* </p>
*
* @see ICodeAssist
*
* 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 abstract class CompletionRequestor {
/**
* The set of CompletionProposal kinds that this requestor
* ignores; <code>0</code> means the set is empty.
* 1 << completionProposalKind
*/
private int ignoreSet = 0;
private String[] favoriteReferences;
/**
* The set of CompletionProposal kinds that this requestor
* allows for required proposals; <code>0</code> means the set is empty.
* 1 << completionProposalKind
*/
private int requiredProposalAllowSet[] = null;
/**
* Creates a new completion requestor.
* The requestor is interested in all kinds of completion
* proposals; none will be ignored.
*/
public CompletionRequestor() {
// do nothing
}
/**
* Returns whether the given kind of completion proposal is ignored.
*
* @param completionProposalKind one of the kind constants declared
* on <code>CompletionProposal</code>
* @return <code>true</code> if the given kind of completion proposal
* is ignored by this requestor, and <code>false</code> if it is of
* interest
* @see #setIgnored(int, boolean)
* @see CompletionProposal#getKind()
*/
public boolean isIgnored(int completionProposalKind) {
if (completionProposalKind < CompletionProposal.FIRST_KIND
|| completionProposalKind > CompletionProposal.LAST_KIND) {
throw new IllegalArgumentException("Unknown kind of completion proposal: "+completionProposalKind); //$NON-NLS-1$
}
return 0 != (this.ignoreSet & (1 << completionProposalKind));
}
/**
* Sets whether the given kind of completion proposal is ignored.
*
* @param completionProposalKind one of the kind constants declared
* on <code>CompletionProposal</code>
* @param ignore <code>true</code> if the given kind of completion proposal
* is ignored by this requestor, and <code>false</code> if it is of
* interest
* @see #isIgnored(int)
* @see CompletionProposal#getKind()
*/
public void setIgnored(int completionProposalKind, boolean ignore) {
if (completionProposalKind < CompletionProposal.FIRST_KIND
|| completionProposalKind > CompletionProposal.LAST_KIND) {
throw new IllegalArgumentException("Unknown kind of completion proposal: "+completionProposalKind); //$NON-NLS-1$
}
if (ignore) {
this.ignoreSet |= (1 << completionProposalKind);
} else {
this.ignoreSet &= ~(1 << completionProposalKind);
}
}
/**
* Returns whether a proposal of a given kind with a required proposal
* of the given kind is allowed.
*
* @param proposalKind one of the kind constants declared
* @param requiredProposalKind one of the kind constants declared
* on <code>CompletionProposal</code>
* @return <code>true</code> if a proposal of a given kind with a required proposal
* of the given kind is allowed by this requestor, and <code>false</code>
* if it isn't of interest.
* <p>
* By default, all kinds of required proposals aren't allowed.
* </p>
* @see #setAllowsRequiredProposals(int, int, boolean)
* @see CompletionProposal#getKind()
* @see CompletionProposal#getRequiredProposals()
*
*/
public boolean isAllowingRequiredProposals(int proposalKind, int requiredProposalKind) {
if (proposalKind < CompletionProposal.FIRST_KIND
|| proposalKind > CompletionProposal.LAST_KIND) {
throw new IllegalArgumentException("Unknown kind of completion proposal: "+requiredProposalKind); //$NON-NLS-1$
}
if (requiredProposalKind < CompletionProposal.FIRST_KIND
|| requiredProposalKind > CompletionProposal.LAST_KIND) {
throw new IllegalArgumentException("Unknown required kind of completion proposal: "+requiredProposalKind); //$NON-NLS-1$
}
if (this.requiredProposalAllowSet == null) return false;
return 0 != (this.requiredProposalAllowSet[proposalKind] & (1 << requiredProposalKind));
}
/**
* Sets whether a proposal of a given kind with a required proposal
* of the given kind is allowed.
*
* Currently only a subset of kinds support required proposals. To see what combinations
* are supported you must look at {@link CompletionProposal#getRequiredProposals()}
* documentation.
*
* @param proposalKind one of the kind constants declared
* @param requiredProposalKind one of the kind constants declared
* on <code>CompletionProposal</code>
* @param allow <code>true</code> if a proposal of a given kind with a required proposal
* of the given kind is allowed by this requestor, and <code>false</code>
* if it isn't of interest
* @see #isAllowingRequiredProposals(int, int)
* @see CompletionProposal#getKind()
* @see CompletionProposal#getRequiredProposals()
*
*/
public void setAllowsRequiredProposals(int proposalKind, int requiredProposalKind, boolean allow) {
if (proposalKind < CompletionProposal.FIRST_KIND
|| proposalKind > CompletionProposal.LAST_KIND) {
throw new IllegalArgumentException("Unknown kind of completion proposal: "+requiredProposalKind); //$NON-NLS-1$
}
if (requiredProposalKind < CompletionProposal.FIRST_KIND
|| requiredProposalKind > CompletionProposal.LAST_KIND) {
throw new IllegalArgumentException("Unknown required kind of completion proposal: "+requiredProposalKind); //$NON-NLS-1$
}
if (this.requiredProposalAllowSet == null) {
this.requiredProposalAllowSet = new int[CompletionProposal.LAST_KIND + 1];
}
if (allow) {
this.requiredProposalAllowSet[proposalKind] |= (1 << requiredProposalKind);
} else {
this.requiredProposalAllowSet[proposalKind] &= ~(1 << requiredProposalKind);
}
}
/**
* Returns the favorite references which are used to compute some completion proposals.
* <p>
* Currently only on demand type references (<code>"java.util.Arrays.*"</code>),
* references to a static method or a static field are used to compute completion proposals.
* Other kind of reference could be used in the future.
* </p>
* <p><b>Note: This Method only applies to ECMAScript 4 which is not yet supported</b></p>
*
* @return favorite imports
*
*/
public String[] getFavoriteReferences() {
return this.favoriteReferences;
}
/**
* Set the favorite references which will be used to compute some completion proposals.
* A favorite reference is a qualified reference as it can be seen in an import statement.<br>
*
* <p><b>Note: This Method only applies to ECMAScript 4 which is not yet supported</b></p>
*
* @param favoriteImports
*
* @see #getFavoriteReferences()
*
*/
public void setFavoriteReferences(String[] favoriteImports) {
this.favoriteReferences = favoriteImports;
}
/**
* Pro forma notification sent before reporting a batch of
* completion proposals.
* <p>
* The default implementation of this method does nothing.
* Clients may override.
* </p>
*/
public void beginReporting() {
// do nothing
}
/**
* Pro forma notification sent after reporting a batch of
* completion proposals.
* <p>
* The default implementation of this method does nothing.
* Clients may override.
* </p>
*/
public void endReporting() {
// do nothing
}
/**
* Notification of failure to produce any completions.
* The problem object explains what prevented completing.
* <p>
* The default implementation of this method does nothing.
* Clients may override to receive this kind of notice.
* </p>
*
* @param problem the problem object
*/
public void completionFailure(IProblem problem) {
// default behavior is to ignore
}
/**
* Proposes a completion. Has no effect if the kind of proposal
* is being ignored by this requestor. Callers should consider
* checking {@link #isIgnored(int)} before avoid creating proposal
* objects that would only be ignored.
* <p>
* Similarly, implementers should check
* {@link #isIgnored(int) isIgnored(proposal.getKind())}
* and ignore proposals that have been declared as uninteresting.
* The proposal object passed is only valid for the duration of
* completion operation.
*
* @param proposal the completion proposal
* @exception IllegalArgumentException if the proposal is null
*/
public abstract void accept(CompletionProposal proposal);
/**
* Propose the context in which the completion occurs.
* <p>
* This method is called one and only one time before any call to
* {@link #accept(CompletionProposal)}.
* The default implementation of this method does nothing.
* Clients may override.
* </p>
* @param context the completion context
*
*/
public void acceptContext(CompletionContext context) {
// do nothing
}
}