org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/text/java/CompletionProposalLabelProvider.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2005 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.ui.text.java;

 import org.eclipse.jface.resource.ImageDescriptor;

 import org.eclipse.jface.text.Assert;

 import org.eclipse.jdt.core.CompletionContext;
 import org.eclipse.jdt.core.CompletionProposal;
 import org.eclipse.jdt.core.Flags;
 import org.eclipse.jdt.core.Signature;

 import org.eclipse.jdt.internal.corext.template.java.SignatureUtil;
 import org.eclipse.jdt.internal.corext.util.Messages;

 import org.eclipse.jdt.ui.JavaElementImageDescriptor;
 import org.eclipse.jdt.ui.JavaElementLabels;

 import org.eclipse.jdt.internal.ui.JavaPluginImages;
 import org.eclipse.jdt.internal.ui.viewsupport.JavaElementImageProvider;


 /**
  * Provides labels for java content assist proposals. The functionality is
  * similar to the one provided by {@link org.eclipse.jdt.ui.JavaElementLabels},
  * but based on signatures and {@link CompletionProposal}s.
  *
  * @see Signature
  * @since 3.1
  */
 public class CompletionProposalLabelProvider {

 	/**
 	 * The completion context.
 	 *
 	 * @since 3.2
 	 */
 	private CompletionContext fContext;

 	/**
 	 * Creates a new label provider.
 	 */
 	public CompletionProposalLabelProvider() {
 	}

 	/**
 	 * Creates and returns a parameter list of the given method proposal
 	 * suitable for display. The list does not include parentheses. The lower
 	 * bound of parameter types is returned.
 	 * <p>
 	 * Examples:
 	 * <pre>
 	 *   &quot;void method(int i, Strings)&quot; -&gt; &quot;int i, String s&quot;
 	 *   &quot;? extends Number method(java.lang.String s, ? super Number n)&quot; -&gt; &quot;String s, Number n&quot;
 	 * </pre>
 	 * </p>
 	 *
 	 * @param methodProposal the method proposal to create the parameter list
 	 *        for. Must be of kind {@link CompletionProposal#METHOD_REF}.
 	 * @return the list of comma-separated parameters suitable for display
 	 */
 	public String createParameterList(CompletionProposal methodProposal) {
 		Assert.isTrue(methodProposal.getKind() == CompletionProposal.METHOD_REF);
 		return appendUnboundedParameterList(new StringBuffer(), methodProposal).toString();
 	}

 	/**
 	 * Appends the parameter list to <code>buffer</code>. See
 	 * <code>createUnboundedParameterList</code> for details.
 	 *
 	 * @param buffer the buffer to append to
 	 * @param methodProposal the method proposal
 	 * @return the modified <code>buffer</code>
 	 */
 	private StringBuffer appendUnboundedParameterList(StringBuffer buffer, CompletionProposal methodProposal) {
 		// TODO remove once https://bugs.eclipse.org/bugs/show_bug.cgi?id=85293
 		// gets fixed.
 		char[] signature= SignatureUtil.fix83600(methodProposal.getSignature());
 		char[][] parameterNames= methodProposal.findParameterNames(null);
 		char[][] parameterTypes= Signature.getParameterTypes(signature);
 		for (int i= 0; i < parameterTypes.length; i++) {
 			parameterTypes[i]= createTypeDisplayName(SignatureUtil.getLowerBound(parameterTypes[i]));
 		}
 		return appendParameterSignature(buffer, parameterTypes, parameterNames);
 	}

 	/**
 	 * Returns the display string for a java type signature.
 	 *
 	 * @param typeSignature the type signature to create a display name for
 	 * @return the display name for <code>typeSignature</code>
 	 * @throws IllegalArgumentException if <code>typeSignature</code> is not a
 	 *         valid signature
 	 * @see Signature#toCharArray(char[])
 	 * @see Signature#getSimpleName(char[])
 	 */
 	private char[] createTypeDisplayName(char[] typeSignature) throws IllegalArgumentException {
 		char[] displayName= Signature.getSimpleName(Signature.toCharArray(typeSignature));

 		// XXX see https://bugs.eclipse.org/bugs/show_bug.cgi?id=84675
 		boolean useShortGenerics= false;
 		if (useShortGenerics) {
 			StringBuffer buf= new StringBuffer();
 			buf.append(displayName);
 			int pos;
 			do {
 				pos= buf.indexOf("? extends "); //$NON-NLS-1$
 				if (pos >= 0) {
 					buf.replace(pos, pos + 10, "+"); //$NON-NLS-1$
 				} else {
 					pos= buf.indexOf("? super "); //$NON-NLS-1$
 					if (pos >= 0)
 						buf.replace(pos, pos + 8, "-"); //$NON-NLS-1$
 				}
 			} while (pos >= 0);
 			return buf.toString().toCharArray();
 		}
 		return displayName;
 	}

 	/**
 	 * Creates a display string of a parameter list (without the parentheses)
 	 * for the given parameter types and names.
 	 *
 	 * @param parameterTypes the parameter types
 	 * @param parameterNames the parameter names
 	 * @return the display string of the parameter list defined by the passed
 	 *         arguments
 	 */
 	private final StringBuffer appendParameterSignature(StringBuffer buffer, char[][] parameterTypes, char[][] parameterNames) {
 		if (parameterTypes != null) {
 			for (int i = 0; i < parameterTypes.length; i++) {
 				if (i > 0) {
 					buffer.append(',');
 					buffer.append(' ');
 				}
 				buffer.append(parameterTypes[i]);
 				if (parameterNames != null && parameterNames[i] != null) {
 					buffer.append(' ');
 					buffer.append(parameterNames[i]);
 				}
 			}
 		}
 		return buffer;
 	}

 	/**
 	 * Creates a display label for the given method proposal. The display label
 	 * consists of:
 	 * <ul>
 	 *   <li>the method name</li>
 	 *   <li>the parameter list (see {@link #createParameterList(CompletionProposal)})</li>
 	 *   <li>the upper bound of the return type (see {@link SignatureUtil#getUpperBound(String)})</li>
 	 *   <li>the raw simple name of the declaring type</li>
 	 * </ul>
 	 * <p>
 	 * Examples:
 	 * For the <code>get(int)</code> method of a variable of type <code>List<? extends Number></code>, the following
 	 * display name is returned: <code>get(int index)  Number - List</code>.<br>
 	 * For the <code>add(E)</code> method of a variable of type <code>List<? super Number></code>, the following
 	 * display name is returned: <code>add(Number o)  void - List</code>.<br>
 	 * </p>
 	 *
 	 * @param methodProposal the method proposal to display
 	 * @return the display label for the given method proposal
 	 */
 	String createMethodProposalLabel(CompletionProposal methodProposal) {
 		StringBuffer nameBuffer= new StringBuffer();

 		// method name
 		nameBuffer.append(methodProposal.getName());

 		// parameters
 		nameBuffer.append('(');
 		appendUnboundedParameterList(nameBuffer, methodProposal);
 		nameBuffer.append(')');

 		// return type
 		if (!methodProposal.isConstructor()) {
 			// TODO remove SignatureUtil.fix83600 call when bugs are fixed
 			char[] returnType= createTypeDisplayName(SignatureUtil.getUpperBound(Signature.getReturnType(SignatureUtil.fix83600(methodProposal.getSignature()))));
 			nameBuffer.append("  "); //$NON-NLS-1$
 			nameBuffer.append(returnType);
 		}

 		// declaring type
 		nameBuffer.append(" - "); //$NON-NLS-1$
 		String declaringType= extractDeclaringTypeFQN(methodProposal);
 		declaringType= Signature.getSimpleName(declaringType);
 		nameBuffer.append(declaringType);

 		return nameBuffer.toString();
 	}

 	/**
 	 * Creates a display label for the given method proposal. The display label consists of:
 	 * <ul>
 	 * <li>the method name</li>
 	 * <li>the raw simple name of the declaring type</li>
 	 * </ul>
 	 * <p>
 	 * Examples: For the <code>get(int)</code> method of a variable of type
 	 * <code>List<? extends Number></code>, the following display name is returned <code>get(int) - List</code>.<br>
 	 * For the <code>add(E)</code> method of a variable of type <code>List</code>, the
 	 * following display name is returned:
 	 * <code>add(Object) - List</code>.<br>
 	 * </p>
 	 *
 	 * @param methodProposal the method proposal to display
 	 * @return the display label for the given method proposal
 	 * @since 3.2
 	 */
 	String createJavadocMethodProposalLabel(CompletionProposal methodProposal) {
 		StringBuffer nameBuffer= new StringBuffer();

 		// method name
 		nameBuffer.append(methodProposal.getCompletion());

 		// declaring type
 		nameBuffer.append(" - "); //$NON-NLS-1$
 		String declaringType= extractDeclaringTypeFQN(methodProposal);
 		declaringType= Signature.getSimpleName(declaringType);
 		nameBuffer.append(declaringType);

 		return nameBuffer.toString();
 	}

 	String createOverrideMethodProposalLabel(CompletionProposal methodProposal) {
 		StringBuffer nameBuffer= new StringBuffer();

 		// method name
 		nameBuffer.append(methodProposal.getName());

 		// parameters
 		nameBuffer.append('(');
 		appendUnboundedParameterList(nameBuffer, methodProposal);
 		nameBuffer.append(")  "); //$NON-NLS-1$

 		// return type
 		// TODO remove SignatureUtil.fix83600 call when bugs are fixed
 		char[] returnType= createTypeDisplayName(SignatureUtil.getUpperBound(Signature.getReturnType(SignatureUtil.fix83600(methodProposal.getSignature()))));
 		nameBuffer.append(returnType);

 		// declaring type
 		nameBuffer.append(" - "); //$NON-NLS-1$

 		String declaringType= extractDeclaringTypeFQN(methodProposal);
 		declaringType= Signature.getSimpleName(declaringType);
 		nameBuffer.append(Messages.format(JavaTextMessages.ResultCollector_overridingmethod, new String(declaringType)));

 		return nameBuffer.toString();
 	}

 	/**
 	 * Extracts the fully qualified name of the declaring type of a method
 	 * reference.
 	 *
 	 * @param methodProposal a proposed method
 	 * @return the qualified name of the declaring type
 	 */
 	private String extractDeclaringTypeFQN(CompletionProposal methodProposal) {
 		char[] declaringTypeSignature= methodProposal.getDeclarationSignature();
 		// special methods may not have a declaring type: methods defined on arrays etc.
 		// TODO remove when bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=84690 gets fixed
 		if (declaringTypeSignature == null)
 			return "java.lang.Object"; //$NON-NLS-1$
 		return SignatureUtil.stripSignatureToFQN(String.valueOf(declaringTypeSignature));
 	}

 	/**
 	 * Creates a display label for a given type proposal. The display label
 	 * consists of:
 	 * <ul>
 	 *   <li>the simple type name (erased when the context is in javadoc)</li>
 	 *   <li>the package name</li>
 	 * </ul>
 	 * <p>
 	 * Examples:
 	 * A proposal for the generic type <code>java.util.List&lt;E&gt;</code>, the display label
 	 * is: <code>List<E> - java.util</code>.
 	 * </p>
 	 *
 	 * @param typeProposal the method proposal to display
 	 * @return the display label for the given type proposal
 	 */
 	String createTypeProposalLabel(CompletionProposal typeProposal) {
 		char[] signature;
 		if (fContext != null && fContext.isInJavadoc())
 			signature= Signature.getTypeErasure(typeProposal.getSignature());
 		else
 			signature= typeProposal.getSignature();
 		char[] fullName= Signature.toCharArray(signature);
 		return createTypeProposalLabel(fullName);
 	}

 	String createJavadocTypeProposalLabel(CompletionProposal typeProposal) {
 		char[] fullName= Signature.toCharArray(typeProposal.getSignature());
 		return createJavadocTypeProposalLabel(fullName);
 	}

 	String createJavadocSimpleProposalLabel(CompletionProposal proposal) {
 		// TODO get rid of this
 		return createSimpleLabel(proposal);
 	}

 	String createTypeProposalLabel(char[] fullName) {
 		// only display innermost type name as type name, using any
 		// enclosing types as qualification
 		int qIndex= findSimpleNameStart(fullName);

 		StringBuffer buf= new StringBuffer();
 		buf.append(fullName, qIndex, fullName.length - qIndex);
 		if (qIndex > 0) {
 			buf.append(JavaElementLabels.CONCAT_STRING);
 			buf.append(fullName, 0, qIndex - 1);
 		}
 		return buf.toString();
 	}

 	String createJavadocTypeProposalLabel(char[] fullName) {
 		// only display innermost type name as type name, using any
 		// enclosing types as qualification
 		int qIndex= findSimpleNameStart(fullName);

 		StringBuffer buf= new StringBuffer("{@link "); //$NON-NLS-1$
 		buf.append(fullName, qIndex, fullName.length - qIndex);
 		buf.append('}');
 		if (qIndex > 0) {
 			buf.append(JavaElementLabels.CONCAT_STRING);
 			buf.append(fullName, 0, qIndex - 1);
 		}
 		return buf.toString();
 	}

 	private int findSimpleNameStart(char[] array) {
 		int lastDot= 0;
 		for (int i= 0, len= array.length; i < len; i++) {
 			char ch= array[i];
 			if (ch == '<') {
 				return lastDot;
 			} else if (ch == '.') {
 				lastDot= i + 1;
 			}
 		}
 		return lastDot;
 	}

 	String createSimpleLabelWithType(CompletionProposal proposal) {
 		StringBuffer buf= new StringBuffer();
 		buf.append(proposal.getCompletion());
 		char[] typeName= Signature.getSignatureSimpleName(proposal.getSignature());
 		if (typeName.length > 0) {
 			buf.append("    "); //$NON-NLS-1$
 			buf.append(typeName);
 		}
 		return buf.toString();
 	}

 	String createLabelWithTypeAndDeclaration(CompletionProposal proposal) {
 		StringBuffer buf= new StringBuffer();
 		buf.append(proposal.getCompletion());
 		char[] typeName= Signature.getSignatureSimpleName(proposal.getSignature());
 		if (typeName.length > 0) {
 			buf.append("    "); //$NON-NLS-1$
 			buf.append(typeName);
 		}
 		char[] declaration= proposal.getDeclarationSignature();
 		if (declaration != null) {
 			declaration= Signature.getSignatureSimpleName(declaration);
 			if (declaration.length > 0) {
 				buf.append(" - "); //$NON-NLS-1$
 				buf.append(declaration);
 			}
 		}

 		return buf.toString();
 	}

 	String createPackageProposalLabel(CompletionProposal proposal) {
 		Assert.isTrue(proposal.getKind() == CompletionProposal.PACKAGE_REF);
 		return String.valueOf(proposal.getDeclarationSignature());
 	}

 	String createSimpleLabel(CompletionProposal proposal) {
 		return String.valueOf(proposal.getCompletion());
 	}

 	String createAnonymousTypeLabel(CompletionProposal proposal) {
 		char[] declaringTypeSignature= proposal.getDeclarationSignature();

 		StringBuffer buffer= new StringBuffer();
 		buffer.append(Signature.getSignatureSimpleName(declaringTypeSignature));
 		buffer.append('(');
 		appendUnboundedParameterList(buffer, proposal);
 		buffer.append(')');
 		buffer.append("  "); //$NON-NLS-1$
 		buffer.append(JavaTextMessages.ResultCollector_anonymous_type);

 		return buffer.toString();
 	}

 	/**
 	 * Creates the display label for a given <code>CompletionProposal</code>.
 	 *
 	 * @param proposal the completion proposal to create the display label for
 	 * @return the display label for <code>proposal</code>
 	 */
 	public String createLabel(CompletionProposal proposal) {
 		switch (proposal.getKind()) {
 			case CompletionProposal.METHOD_NAME_REFERENCE:
 			case CompletionProposal.METHOD_REF:
 			case CompletionProposal.POTENTIAL_METHOD_DECLARATION:
 				if (fContext != null && fContext.isInJavadoc())
 					return createJavadocMethodProposalLabel(proposal);
 				return createMethodProposalLabel(proposal);
 			case CompletionProposal.METHOD_DECLARATION:
 				return createOverrideMethodProposalLabel(proposal);
 			case CompletionProposal.ANONYMOUS_CLASS_DECLARATION:
 				return createAnonymousTypeLabel(proposal);
 			case CompletionProposal.TYPE_REF:
 				return createTypeProposalLabel(proposal);
 			case CompletionProposal.JAVADOC_TYPE_REF:
 				return createJavadocTypeProposalLabel(proposal);
 			case CompletionProposal.JAVADOC_FIELD_REF:
 			case CompletionProposal.JAVADOC_VALUE_REF:
 			case CompletionProposal.JAVADOC_BLOCK_TAG:
 			case CompletionProposal.JAVADOC_INLINE_TAG:
 			case CompletionProposal.JAVADOC_PARAM_REF:
 				return createJavadocSimpleProposalLabel(proposal);
 			case CompletionProposal.JAVADOC_METHOD_REF:
 				return createJavadocMethodProposalLabel(proposal);
 			case CompletionProposal.PACKAGE_REF:
 				return createPackageProposalLabel(proposal);
 			case CompletionProposal.ANNOTATION_ATTRIBUTE_REF:
 			case CompletionProposal.FIELD_REF:
 				return createLabelWithTypeAndDeclaration(proposal);
 			case CompletionProposal.LOCAL_VARIABLE_REF:
 			case CompletionProposal.VARIABLE_DECLARATION:
 				return createSimpleLabelWithType(proposal);
 			case CompletionProposal.KEYWORD:
 			case CompletionProposal.LABEL_REF:
 				return createSimpleLabel(proposal);
 			default:
 				Assert.isTrue(false);
 				return null;
 		}
 	}

 	/**
 	 * Creates and returns a decorated image descriptor for a completion proposal.
 	 *
 	 * @param proposal the proposal for which to create an image descriptor
 	 * @return the created image descriptor, or <code>null</code> if no image is available
 	 */
 	public ImageDescriptor createImageDescriptor(CompletionProposal proposal) {
 		final int flags= proposal.getFlags();

 		ImageDescriptor descriptor;
 		switch (proposal.getKind()) {
 			case CompletionProposal.METHOD_DECLARATION:
 			case CompletionProposal.METHOD_NAME_REFERENCE:
 			case CompletionProposal.METHOD_REF:
 			case CompletionProposal.ANNOTATION_ATTRIBUTE_REF:
 			case CompletionProposal.POTENTIAL_METHOD_DECLARATION:
 				descriptor= JavaElementImageProvider.getMethodImageDescriptor(false, flags);
 				break;
 			case CompletionProposal.ANONYMOUS_CLASS_DECLARATION:
 			case CompletionProposal.TYPE_REF:
 				switch (Signature.getTypeSignatureKind(proposal.getSignature())) {
 					case Signature.CLASS_TYPE_SIGNATURE:
 						descriptor= JavaElementImageProvider.getTypeImageDescriptor(false, false, flags, false);
 						break;
 					case Signature.TYPE_VARIABLE_SIGNATURE:
 						descriptor= JavaPluginImages.DESC_OBJS_TYPEVARIABLE;
 						break;
 					default:
 						descriptor= null;
 				}
 				break;
 			case CompletionProposal.FIELD_REF:
 				descriptor= JavaElementImageProvider.getFieldImageDescriptor(false, flags);
 				break;
 			case CompletionProposal.LOCAL_VARIABLE_REF:
 			case CompletionProposal.VARIABLE_DECLARATION:
 				descriptor= JavaPluginImages.DESC_OBJS_LOCAL_VARIABLE;
 				break;
 			case CompletionProposal.PACKAGE_REF:
 				descriptor= JavaPluginImages.DESC_OBJS_PACKAGE;
 				break;
 			case CompletionProposal.KEYWORD:
 			case CompletionProposal.LABEL_REF:
 				descriptor= null;
 				break;
 			case CompletionProposal.JAVADOC_METHOD_REF:
 			case CompletionProposal.JAVADOC_TYPE_REF:
 			case CompletionProposal.JAVADOC_FIELD_REF:
 			case CompletionProposal.JAVADOC_VALUE_REF:
 			case CompletionProposal.JAVADOC_BLOCK_TAG:
 			case CompletionProposal.JAVADOC_INLINE_TAG:
 			case CompletionProposal.JAVADOC_PARAM_REF:
 				descriptor = JavaPluginImages.DESC_OBJS_JAVADOCTAG;
 				break;
 			default:
 				descriptor= null;
 				Assert.isTrue(false);
 		}

 		if (descriptor == null)
 			return null;
 		return decorateImageDescriptor(descriptor, proposal);
 	}

 	ImageDescriptor createMethodImageDescriptor(CompletionProposal proposal) {
 		final int flags= proposal.getFlags();
 		return decorateImageDescriptor(JavaElementImageProvider.getMethodImageDescriptor(false, flags), proposal);
 	}

 	ImageDescriptor createTypeImageDescriptor(CompletionProposal proposal) {
 		final int flags= proposal.getFlags();
 		boolean isInterfaceOrAnnotation= Flags.isInterface(flags) || Flags.isAnnotation(flags);
 		return decorateImageDescriptor(JavaElementImageProvider.getTypeImageDescriptor(true /* in order to get all visibility decorations */, isInterfaceOrAnnotation, flags, false), proposal);
 	}

 	ImageDescriptor createFieldImageDescriptor(CompletionProposal proposal) {
 		final int flags= proposal.getFlags();
 		return decorateImageDescriptor(JavaElementImageProvider.getFieldImageDescriptor(false, flags), proposal);
 	}

 	ImageDescriptor createLocalImageDescriptor(CompletionProposal proposal) {
 		return decorateImageDescriptor(JavaPluginImages.DESC_OBJS_LOCAL_VARIABLE, proposal);
 	}

 	ImageDescriptor createPackageImageDescriptor(CompletionProposal proposal) {
 		return decorateImageDescriptor(JavaPluginImages.DESC_OBJS_PACKAGE, proposal);
 	}

 	/**
 	 * Returns a version of <code>descriptor</code> decorated according to
 	 * the passed <code>modifier</code> flags.
 	 *
 	 * @param descriptor the image descriptor to decorate
 	 * @param proposal the proposal
 	 * @return an image descriptor for a method proposal
 	 * @see Flags
 	 */
 	private ImageDescriptor decorateImageDescriptor(ImageDescriptor descriptor, CompletionProposal proposal) {
 		int adornments= 0;
 		int flags= proposal.getFlags();
 		int kind= proposal.getKind();

 		if (Flags.isDeprecated(flags))
 			adornments |= JavaElementImageDescriptor.DEPRECATED;

 		if (kind == CompletionProposal.FIELD_REF || kind == CompletionProposal.METHOD_DECLARATION || kind == CompletionProposal.METHOD_DECLARATION || kind == CompletionProposal.METHOD_NAME_REFERENCE || kind == CompletionProposal.METHOD_REF)
 			if (Flags.isStatic(flags))
 				adornments |= JavaElementImageDescriptor.STATIC;

 		if (kind == CompletionProposal.METHOD_DECLARATION || kind == CompletionProposal.METHOD_DECLARATION || kind == CompletionProposal.METHOD_NAME_REFERENCE || kind == CompletionProposal.METHOD_REF)
 			if (Flags.isSynchronized(flags))
 				adornments |= JavaElementImageDescriptor.SYNCHRONIZED;

 		if (kind == CompletionProposal.TYPE_REF && Flags.isAbstract(flags) && !Flags.isInterface(flags))
 			adornments |= JavaElementImageDescriptor.ABSTRACT;

 		return new JavaElementImageDescriptor(descriptor, adornments, JavaElementImageProvider.SMALL_SIZE);
 	}

 	/**
 	 * Sets the completion context.
 	 *
 	 * @param context the completion context
 	 * @since 3.2
 	 */
 	void setContext(CompletionContext context) {
 		fContext= context;
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2005 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.ui.text.java;

	import org.eclipse.jface.resource.ImageDescriptor;

	import org.eclipse.jface.text.Assert;

	import org.eclipse.jdt.core.CompletionContext;
	import org.eclipse.jdt.core.CompletionProposal;
	import org.eclipse.jdt.core.Flags;
	import org.eclipse.jdt.core.Signature;

	import org.eclipse.jdt.internal.corext.template.java.SignatureUtil;
	import org.eclipse.jdt.internal.corext.util.Messages;

	import org.eclipse.jdt.ui.JavaElementImageDescriptor;
	import org.eclipse.jdt.ui.JavaElementLabels;

	import org.eclipse.jdt.internal.ui.JavaPluginImages;
	import org.eclipse.jdt.internal.ui.viewsupport.JavaElementImageProvider;


	/**
	* Provides labels for java content assist proposals. The functionality is
	* similar to the one provided by {@link org.eclipse.jdt.ui.JavaElementLabels},
	* but based on signatures and {@link CompletionProposal}s.
	*
	* @see Signature
	* @since 3.1
	*/
	public class CompletionProposalLabelProvider {

	/**
	* The completion context.
	*
	* @since 3.2
	*/
	private CompletionContext fContext;

	/**
	* Creates a new label provider.
	*/
	public CompletionProposalLabelProvider() {
	}

	/**
	* Creates and returns a parameter list of the given method proposal
	* suitable for display. The list does not include parentheses. The lower
	* bound of parameter types is returned.
	* <p>
	* Examples:
	* <pre>
	* "void method(int i, Strings)" -> "int i, String s"
	* "? extends Number method(java.lang.String s, ? super Number n)" -> "String s, Number n"
	* </pre>
	* </p>
	*
	* @param methodProposal the method proposal to create the parameter list
	* for. Must be of kind {@link CompletionProposal#METHOD_REF}.
	* @return the list of comma-separated parameters suitable for display
	*/
	public String createParameterList(CompletionProposal methodProposal) {
	Assert.isTrue(methodProposal.getKind() == CompletionProposal.METHOD_REF);
	return appendUnboundedParameterList(new StringBuffer(), methodProposal).toString();
	}

	/**
	* Appends the parameter list to <code>buffer</code>. See
	* <code>createUnboundedParameterList</code> for details.
	*
	* @param buffer the buffer to append to
	* @param methodProposal the method proposal
	* @return the modified <code>buffer</code>
	*/
	private StringBuffer appendUnboundedParameterList(StringBuffer buffer, CompletionProposal methodProposal) {
	// TODO remove once https://bugs.eclipse.org/bugs/show_bug.cgi?id=85293
	// gets fixed.
	char[] signature= SignatureUtil.fix83600(methodProposal.getSignature());
	char[][] parameterNames= methodProposal.findParameterNames(null);
	char[][] parameterTypes= Signature.getParameterTypes(signature);
	for (int i= 0; i < parameterTypes.length; i++) {
	parameterTypes[i]= createTypeDisplayName(SignatureUtil.getLowerBound(parameterTypes[i]));
	}
	return appendParameterSignature(buffer, parameterTypes, parameterNames);
	}

	/**
	* Returns the display string for a java type signature.
	*
	* @param typeSignature the type signature to create a display name for
	* @return the display name for <code>typeSignature</code>
	* @throws IllegalArgumentException if <code>typeSignature</code> is not a
	* valid signature
	* @see Signature#toCharArray(char[])
	* @see Signature#getSimpleName(char[])
	*/
	private char[] createTypeDisplayName(char[] typeSignature) throws IllegalArgumentException {
	char[] displayName= Signature.getSimpleName(Signature.toCharArray(typeSignature));

	// XXX see https://bugs.eclipse.org/bugs/show_bug.cgi?id=84675
	boolean useShortGenerics= false;
	if (useShortGenerics) {
	StringBuffer buf= new StringBuffer();
	buf.append(displayName);
	int pos;
	do {
	pos= buf.indexOf("? extends "); //$NON-NLS-1$
	if (pos >= 0) {
	buf.replace(pos, pos + 10, "+"); //$NON-NLS-1$
	} else {
	pos= buf.indexOf("? super "); //$NON-NLS-1$
	if (pos >= 0)
	buf.replace(pos, pos + 8, "-"); //$NON-NLS-1$
	}
	} while (pos >= 0);
	return buf.toString().toCharArray();
	}
	return displayName;
	}

	/**
	* Creates a display string of a parameter list (without the parentheses)
	* for the given parameter types and names.
	*
	* @param parameterTypes the parameter types
	* @param parameterNames the parameter names
	* @return the display string of the parameter list defined by the passed
	* arguments
	*/
	private final StringBuffer appendParameterSignature(StringBuffer buffer, char[][] parameterTypes, char[][] parameterNames) {
	if (parameterTypes != null) {
	for (int i = 0; i < parameterTypes.length; i++) {
	if (i > 0) {
	buffer.append(',');
	buffer.append(' ');
	}
	buffer.append(parameterTypes[i]);
	if (parameterNames != null && parameterNames[i] != null) {
	buffer.append(' ');
	buffer.append(parameterNames[i]);
	}
	}
	}
	return buffer;
	}

	/**
	* Creates a display label for the given method proposal. The display label
	* consists of:
	* <ul>
	* <li>the method name</li>
	* <li>the parameter list (see {@link #createParameterList(CompletionProposal)})</li>
	* <li>the upper bound of the return type (see {@link SignatureUtil#getUpperBound(String)})</li>
	* <li>the raw simple name of the declaring type</li>
	* </ul>
	* <p>
	* Examples:
	* For the <code>get(int)</code> method of a variable of type <code>List<? extends Number></code>, the following
	* display name is returned: <code>get(int index) Number - List</code>.<br>
	* For the <code>add(E)</code> method of a variable of type <code>List<? super Number></code>, the following
	* display name is returned: <code>add(Number o) void - List</code>.<br>
	* </p>
	*
	* @param methodProposal the method proposal to display
	* @return the display label for the given method proposal
	*/
	String createMethodProposalLabel(CompletionProposal methodProposal) {
	StringBuffer nameBuffer= new StringBuffer();

	// method name
	nameBuffer.append(methodProposal.getName());

	// parameters
	nameBuffer.append('(');
	appendUnboundedParameterList(nameBuffer, methodProposal);
	nameBuffer.append(')');

	// return type
	if (!methodProposal.isConstructor()) {
	// TODO remove SignatureUtil.fix83600 call when bugs are fixed
	char[] returnType= createTypeDisplayName(SignatureUtil.getUpperBound(Signature.getReturnType(SignatureUtil.fix83600(methodProposal.getSignature()))));
	nameBuffer.append(" "); //$NON-NLS-1$
	nameBuffer.append(returnType);
	}

	// declaring type
	nameBuffer.append(" - "); //$NON-NLS-1$
	String declaringType= extractDeclaringTypeFQN(methodProposal);
	declaringType= Signature.getSimpleName(declaringType);
	nameBuffer.append(declaringType);

	return nameBuffer.toString();
	}

	/**
	* Creates a display label for the given method proposal. The display label consists of:
	* <ul>
	* <li>the method name</li>
	* <li>the raw simple name of the declaring type</li>
	* </ul>
	* <p>
	* Examples: For the <code>get(int)</code> method of a variable of type
	* <code>List<? extends Number></code>, the following display name is returned <code>get(int) - List</code>.<br>
	* For the <code>add(E)</code> method of a variable of type <code>List</code>, the
	* following display name is returned:
	* <code>add(Object) - List</code>.<br>
	* </p>
	*
	* @param methodProposal the method proposal to display
	* @return the display label for the given method proposal
	* @since 3.2
	*/
	String createJavadocMethodProposalLabel(CompletionProposal methodProposal) {
	StringBuffer nameBuffer= new StringBuffer();

	// method name
	nameBuffer.append(methodProposal.getCompletion());

	// declaring type
	nameBuffer.append(" - "); //$NON-NLS-1$
	String declaringType= extractDeclaringTypeFQN(methodProposal);
	declaringType= Signature.getSimpleName(declaringType);
	nameBuffer.append(declaringType);

	return nameBuffer.toString();
	}

	String createOverrideMethodProposalLabel(CompletionProposal methodProposal) {
	StringBuffer nameBuffer= new StringBuffer();

	// method name
	nameBuffer.append(methodProposal.getName());

	// parameters
	nameBuffer.append('(');
	appendUnboundedParameterList(nameBuffer, methodProposal);
	nameBuffer.append(") "); //$NON-NLS-1$

	// return type
	// TODO remove SignatureUtil.fix83600 call when bugs are fixed
	char[] returnType= createTypeDisplayName(SignatureUtil.getUpperBound(Signature.getReturnType(SignatureUtil.fix83600(methodProposal.getSignature()))));
	nameBuffer.append(returnType);

	// declaring type
	nameBuffer.append(" - "); //$NON-NLS-1$

	String declaringType= extractDeclaringTypeFQN(methodProposal);
	declaringType= Signature.getSimpleName(declaringType);
	nameBuffer.append(Messages.format(JavaTextMessages.ResultCollector_overridingmethod, new String(declaringType)));

	return nameBuffer.toString();
	}

	/**
	* Extracts the fully qualified name of the declaring type of a method
	* reference.
	*
	* @param methodProposal a proposed method
	* @return the qualified name of the declaring type
	*/
	private String extractDeclaringTypeFQN(CompletionProposal methodProposal) {
	char[] declaringTypeSignature= methodProposal.getDeclarationSignature();
	// special methods may not have a declaring type: methods defined on arrays etc.
	// TODO remove when bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=84690 gets fixed
	if (declaringTypeSignature == null)
	return "java.lang.Object"; //$NON-NLS-1$
	return SignatureUtil.stripSignatureToFQN(String.valueOf(declaringTypeSignature));
	}

	/**
	* Creates a display label for a given type proposal. The display label
	* consists of:
	* <ul>
	* <li>the simple type name (erased when the context is in javadoc)</li>
	* <li>the package name</li>
	* </ul>
	* <p>
	* Examples:
	* A proposal for the generic type <code>java.util.List<E></code>, the display label
	* is: <code>List<E> - java.util</code>.
	* </p>
	*
	* @param typeProposal the method proposal to display
	* @return the display label for the given type proposal
	*/
	String createTypeProposalLabel(CompletionProposal typeProposal) {
	char[] signature;
	if (fContext != null && fContext.isInJavadoc())
	signature= Signature.getTypeErasure(typeProposal.getSignature());
	else
	signature= typeProposal.getSignature();
	char[] fullName= Signature.toCharArray(signature);
	return createTypeProposalLabel(fullName);
	}

	String createJavadocTypeProposalLabel(CompletionProposal typeProposal) {
	char[] fullName= Signature.toCharArray(typeProposal.getSignature());
	return createJavadocTypeProposalLabel(fullName);
	}

	String createJavadocSimpleProposalLabel(CompletionProposal proposal) {
	// TODO get rid of this
	return createSimpleLabel(proposal);
	}

	String createTypeProposalLabel(char[] fullName) {
	// only display innermost type name as type name, using any
	// enclosing types as qualification
	int qIndex= findSimpleNameStart(fullName);

	StringBuffer buf= new StringBuffer();
	buf.append(fullName, qIndex, fullName.length - qIndex);
	if (qIndex > 0) {
	buf.append(JavaElementLabels.CONCAT_STRING);
	buf.append(fullName, 0, qIndex - 1);
	}
	return buf.toString();
	}

	String createJavadocTypeProposalLabel(char[] fullName) {
	// only display innermost type name as type name, using any
	// enclosing types as qualification
	int qIndex= findSimpleNameStart(fullName);

	StringBuffer buf= new StringBuffer("{@link "); //$NON-NLS-1$
	buf.append(fullName, qIndex, fullName.length - qIndex);
	buf.append('}');
	if (qIndex > 0) {
	buf.append(JavaElementLabels.CONCAT_STRING);
	buf.append(fullName, 0, qIndex - 1);
	}
	return buf.toString();
	}

	private int findSimpleNameStart(char[] array) {
	int lastDot= 0;
	for (int i= 0, len= array.length; i < len; i++) {
	char ch= array[i];
	if (ch == '<') {
	return lastDot;
	} else if (ch == '.') {
	lastDot= i + 1;
	}
	}
	return lastDot;
	}

	String createSimpleLabelWithType(CompletionProposal proposal) {
	StringBuffer buf= new StringBuffer();
	buf.append(proposal.getCompletion());
	char[] typeName= Signature.getSignatureSimpleName(proposal.getSignature());
	if (typeName.length > 0) {
	buf.append(" "); //$NON-NLS-1$
	buf.append(typeName);
	}
	return buf.toString();
	}

	String createLabelWithTypeAndDeclaration(CompletionProposal proposal) {
	StringBuffer buf= new StringBuffer();
	buf.append(proposal.getCompletion());
	char[] typeName= Signature.getSignatureSimpleName(proposal.getSignature());
	if (typeName.length > 0) {
	buf.append(" "); //$NON-NLS-1$
	buf.append(typeName);
	}
	char[] declaration= proposal.getDeclarationSignature();
	if (declaration != null) {
	declaration= Signature.getSignatureSimpleName(declaration);
	if (declaration.length > 0) {
	buf.append(" - "); //$NON-NLS-1$
	buf.append(declaration);
	}
	}

	return buf.toString();
	}

	String createPackageProposalLabel(CompletionProposal proposal) {
	Assert.isTrue(proposal.getKind() == CompletionProposal.PACKAGE_REF);
	return String.valueOf(proposal.getDeclarationSignature());
	}

	String createSimpleLabel(CompletionProposal proposal) {
	return String.valueOf(proposal.getCompletion());
	}

	String createAnonymousTypeLabel(CompletionProposal proposal) {
	char[] declaringTypeSignature= proposal.getDeclarationSignature();

	StringBuffer buffer= new StringBuffer();
	buffer.append(Signature.getSignatureSimpleName(declaringTypeSignature));
	buffer.append('(');
	appendUnboundedParameterList(buffer, proposal);
	buffer.append(')');
	buffer.append(" "); //$NON-NLS-1$
	buffer.append(JavaTextMessages.ResultCollector_anonymous_type);

	return buffer.toString();
	}

	/**
	* Creates the display label for a given <code>CompletionProposal</code>.
	*
	* @param proposal the completion proposal to create the display label for
	* @return the display label for <code>proposal</code>
	*/
	public String createLabel(CompletionProposal proposal) {
	switch (proposal.getKind()) {
	case CompletionProposal.METHOD_NAME_REFERENCE:
	case CompletionProposal.METHOD_REF:
	case CompletionProposal.POTENTIAL_METHOD_DECLARATION:
	if (fContext != null && fContext.isInJavadoc())
	return createJavadocMethodProposalLabel(proposal);
	return createMethodProposalLabel(proposal);
	case CompletionProposal.METHOD_DECLARATION:
	return createOverrideMethodProposalLabel(proposal);
	case CompletionProposal.ANONYMOUS_CLASS_DECLARATION:
	return createAnonymousTypeLabel(proposal);
	case CompletionProposal.TYPE_REF:
	return createTypeProposalLabel(proposal);
	case CompletionProposal.JAVADOC_TYPE_REF:
	return createJavadocTypeProposalLabel(proposal);
	case CompletionProposal.JAVADOC_FIELD_REF:
	case CompletionProposal.JAVADOC_VALUE_REF:
	case CompletionProposal.JAVADOC_BLOCK_TAG:
	case CompletionProposal.JAVADOC_INLINE_TAG:
	case CompletionProposal.JAVADOC_PARAM_REF:
	return createJavadocSimpleProposalLabel(proposal);
	case CompletionProposal.JAVADOC_METHOD_REF:
	return createJavadocMethodProposalLabel(proposal);
	case CompletionProposal.PACKAGE_REF:
	return createPackageProposalLabel(proposal);
	case CompletionProposal.ANNOTATION_ATTRIBUTE_REF:
	case CompletionProposal.FIELD_REF:
	return createLabelWithTypeAndDeclaration(proposal);
	case CompletionProposal.LOCAL_VARIABLE_REF:
	case CompletionProposal.VARIABLE_DECLARATION:
	return createSimpleLabelWithType(proposal);
	case CompletionProposal.KEYWORD:
	case CompletionProposal.LABEL_REF:
	return createSimpleLabel(proposal);
	default:
	Assert.isTrue(false);
	return null;
	}
	}

	/**
	* Creates and returns a decorated image descriptor for a completion proposal.
	*
	* @param proposal the proposal for which to create an image descriptor
	* @return the created image descriptor, or <code>null</code> if no image is available
	*/
	public ImageDescriptor createImageDescriptor(CompletionProposal proposal) {
	final int flags= proposal.getFlags();

	ImageDescriptor descriptor;
	switch (proposal.getKind()) {
	case CompletionProposal.METHOD_DECLARATION:
	case CompletionProposal.METHOD_NAME_REFERENCE:
	case CompletionProposal.METHOD_REF:
	case CompletionProposal.ANNOTATION_ATTRIBUTE_REF:
	case CompletionProposal.POTENTIAL_METHOD_DECLARATION:
	descriptor= JavaElementImageProvider.getMethodImageDescriptor(false, flags);
	break;
	case CompletionProposal.ANONYMOUS_CLASS_DECLARATION:
	case CompletionProposal.TYPE_REF:
	switch (Signature.getTypeSignatureKind(proposal.getSignature())) {
	case Signature.CLASS_TYPE_SIGNATURE:
	descriptor= JavaElementImageProvider.getTypeImageDescriptor(false, false, flags, false);
	break;
	case Signature.TYPE_VARIABLE_SIGNATURE:
	descriptor= JavaPluginImages.DESC_OBJS_TYPEVARIABLE;
	break;
	default:
	descriptor= null;
	}
	break;
	case CompletionProposal.FIELD_REF:
	descriptor= JavaElementImageProvider.getFieldImageDescriptor(false, flags);
	break;
	case CompletionProposal.LOCAL_VARIABLE_REF:
	case CompletionProposal.VARIABLE_DECLARATION:
	descriptor= JavaPluginImages.DESC_OBJS_LOCAL_VARIABLE;
	break;
	case CompletionProposal.PACKAGE_REF:
	descriptor= JavaPluginImages.DESC_OBJS_PACKAGE;
	break;
	case CompletionProposal.KEYWORD:
	case CompletionProposal.LABEL_REF:
	descriptor= null;
	break;
	case CompletionProposal.JAVADOC_METHOD_REF:
	case CompletionProposal.JAVADOC_TYPE_REF:
	case CompletionProposal.JAVADOC_FIELD_REF:
	case CompletionProposal.JAVADOC_VALUE_REF:
	case CompletionProposal.JAVADOC_BLOCK_TAG:
	case CompletionProposal.JAVADOC_INLINE_TAG:
	case CompletionProposal.JAVADOC_PARAM_REF:
	descriptor = JavaPluginImages.DESC_OBJS_JAVADOCTAG;
	break;
	default:
	descriptor= null;
	Assert.isTrue(false);
	}

	if (descriptor == null)
	return null;
	return decorateImageDescriptor(descriptor, proposal);
	}

	ImageDescriptor createMethodImageDescriptor(CompletionProposal proposal) {
	final int flags= proposal.getFlags();
	return decorateImageDescriptor(JavaElementImageProvider.getMethodImageDescriptor(false, flags), proposal);
	}

	ImageDescriptor createTypeImageDescriptor(CompletionProposal proposal) {
	final int flags= proposal.getFlags();
	boolean isInterfaceOrAnnotation= Flags.isInterface(flags) \|\| Flags.isAnnotation(flags);
	return decorateImageDescriptor(JavaElementImageProvider.getTypeImageDescriptor(true /* in order to get all visibility decorations */, isInterfaceOrAnnotation, flags, false), proposal);
	}

	ImageDescriptor createFieldImageDescriptor(CompletionProposal proposal) {
	final int flags= proposal.getFlags();
	return decorateImageDescriptor(JavaElementImageProvider.getFieldImageDescriptor(false, flags), proposal);
	}

	ImageDescriptor createLocalImageDescriptor(CompletionProposal proposal) {
	return decorateImageDescriptor(JavaPluginImages.DESC_OBJS_LOCAL_VARIABLE, proposal);
	}

	ImageDescriptor createPackageImageDescriptor(CompletionProposal proposal) {
	return decorateImageDescriptor(JavaPluginImages.DESC_OBJS_PACKAGE, proposal);
	}

	/**
	* Returns a version of <code>descriptor</code> decorated according to
	* the passed <code>modifier</code> flags.
	*
	* @param descriptor the image descriptor to decorate
	* @param proposal the proposal
	* @return an image descriptor for a method proposal
	* @see Flags
	*/
	private ImageDescriptor decorateImageDescriptor(ImageDescriptor descriptor, CompletionProposal proposal) {
	int adornments= 0;
	int flags= proposal.getFlags();
	int kind= proposal.getKind();

	if (Flags.isDeprecated(flags))
	adornments \|= JavaElementImageDescriptor.DEPRECATED;

	if (kind == CompletionProposal.FIELD_REF \|\| kind == CompletionProposal.METHOD_DECLARATION \|\| kind == CompletionProposal.METHOD_DECLARATION \|\| kind == CompletionProposal.METHOD_NAME_REFERENCE \|\| kind == CompletionProposal.METHOD_REF)
	if (Flags.isStatic(flags))
	adornments \|= JavaElementImageDescriptor.STATIC;

	if (kind == CompletionProposal.METHOD_DECLARATION \|\| kind == CompletionProposal.METHOD_DECLARATION \|\| kind == CompletionProposal.METHOD_NAME_REFERENCE \|\| kind == CompletionProposal.METHOD_REF)
	if (Flags.isSynchronized(flags))
	adornments \|= JavaElementImageDescriptor.SYNCHRONIZED;

	if (kind == CompletionProposal.TYPE_REF && Flags.isAbstract(flags) && !Flags.isInterface(flags))
	adornments \|= JavaElementImageDescriptor.ABSTRACT;

	return new JavaElementImageDescriptor(descriptor, adornments, JavaElementImageProvider.SMALL_SIZE);
	}

	/**
	* Sets the completion context.
	*
	* @param context the completion context
	* @since 3.2
	*/
	void setContext(CompletionContext context) {
	fContext= context;
	}

	}