/*******************************************************************************
* Copyright (c) 2000, 2011 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.templates;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.eclipse.core.runtime.Assert;
import org.eclipse.text.edits.MalformedTreeException;
import org.eclipse.text.edits.MultiTextEdit;
import org.eclipse.text.edits.RangeMarker;
import org.eclipse.text.edits.ReplaceEdit;
import org.eclipse.text.edits.TextEdit;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.IDocument;
/**
* A context type defines a context within which templates are resolved. It
* stores a number of <code>TemplateVariableResolver</code>s. A
* <code>TemplateBuffer</code> can be resolved in a
* <code>TemplateContext</code> using the
* {@link #resolve(TemplateBuffer, TemplateContext)} method.
* <p>
* Clients may extend this class.
* </p>
*
* @since 3.0
*/
public class TemplateContextType {
/** The id of the context type. */
private /* final */ String fId= null;
/** Variable resolvers used by this content type. */
private final Map/*<String, TemplateVariableResolver>*/ fResolvers= new HashMap();
/** The name of the context type. */
private String fName= null;
/**
* Creates a context type with an identifier. The identifier must be unique,
* a qualified name is suggested. The id is also used as name.
*
* @param id the unique identifier of the context type
*/
public TemplateContextType(String id) {
this(id, id);
}
/**
* Creates a context type with an identifier. The identifier must be unique, a qualified name is suggested.
*
* @param id the unique identifier of the context type
* @param name the name of the context type
*/
public TemplateContextType(String id, String name) {
Assert.isNotNull(id);
Assert.isNotNull(name);
fId= id;
fName= name;
}
/**
* Returns the id of the context type.
*
* @return the id of the receiver
*/
public String getId() {
return fId;
}
/**
* Returns the name of the context type.
*
* @return the name of the context type
*/
public String getName() {
return fName;
}
/**
* Creates a context type with a <code>null</code> identifier.
* <p>
* This is a framework-only constructor that exists only so that context
* types can be contributed via an extension point and that should not be
* called in client code except for subclass constructors; use
* {@link #TemplateContextType(String)} instead.
* </p>
*/
public TemplateContextType() {
}
/**
* Sets the id of this context.
* <p>
* This is a framework-only method that exists solely so that context types
* can be contributed via an extension point and that should not be called
* in client code; use {@link #TemplateContextType(String)} instead.
* </p>
*
* @param id the identifier of this context
* @throws RuntimeException an unspecified exception if the id has already
* been set on this context type
*/
public final void setId(String id) throws RuntimeException {
Assert.isNotNull(id);
Assert.isTrue(fId == null); // may only be called once when the context is instantiated
fId= id;
}
/**
* Sets the name of the context type.
*
* <p>
* This is a framework-only method that exists solely so that context types
* can be contributed via an extension point and that should not be called
* in client code; use {@link #TemplateContextType(String, String)} instead.
* </p>
*
* @param name the name of the context type
*/
public final void setName(String name) {
Assert.isTrue(fName == null); // only initialized by extension code
fName= name;
}
/**
* Adds a variable resolver to the context type. If there already is a resolver
* for the same type, the previous one gets replaced by <code>resolver</code>.
*
* @param resolver the resolver to be added under its name
*/
public void addResolver(TemplateVariableResolver resolver) {
Assert.isNotNull(resolver);
fResolvers.put(resolver.getType(), resolver);
}
/**
* Removes a template variable from the context type.
*
* @param resolver the variable to be removed
*/
public void removeResolver(TemplateVariableResolver resolver) {
Assert.isNotNull(resolver);
fResolvers.remove(resolver.getType());
}
/**
* Removes all template variables from the context type.
*/
public void removeAllResolvers() {
fResolvers.clear();
}
/**
* Returns an iterator for the variables known to the context type.
*
* @return an iterator over the variables in this context type (element type: {@link TemplateVariableResolver})
*/
public Iterator resolvers() {
return Collections.unmodifiableMap(fResolvers).values().iterator();
}
/**
* Returns the resolver for the given type.
*
* @param type the type for which a resolver is needed
* @return a resolver for the given type, or <code>null</code> if none is registered
*/
protected TemplateVariableResolver getResolver(String type) {
return (TemplateVariableResolver) fResolvers.get(type);
}
/**
* Validates a pattern, a <code>TemplateException</code> is thrown if
* validation fails.
*
* @param pattern the template pattern to validate
* @throws TemplateException if the pattern is invalid
*/
public void validate(String pattern) throws TemplateException {
TemplateTranslator translator= new TemplateTranslator();
TemplateBuffer buffer= translator.translate(pattern);
validateVariables(buffer.getVariables());
}
/**
* Validates the variables in this context type. If a variable is not valid,
* e.g. if its type is not known in this context type, a
* <code>TemplateException</code> is thrown.
* <p>
* The default implementation does nothing.
* </p>
*
* @param variables the variables to validate
* @throws TemplateException if one of the variables is not valid in this
* context type
*/
protected void validateVariables(TemplateVariable[] variables) throws TemplateException {
}
/**
* Resolves the variables in <code>buffer</code> within <code>context</code>
* and edits the template buffer to reflect the resolved variables.
*
* @param buffer the template buffer
* @param context the template context
* @throws MalformedTreeException if the positions in the buffer overlap
* @throws BadLocationException if the buffer cannot be successfully modified
*/
public void resolve(TemplateBuffer buffer, TemplateContext context) throws MalformedTreeException, BadLocationException {
Assert.isNotNull(context);
TemplateVariable[] variables= buffer.getVariables();
List positions= variablesToPositions(variables);
List edits= new ArrayList(5);
// iterate over all variables and try to resolve them
for (int i= 0; i != variables.length; i++) {
TemplateVariable variable= variables[i];
if (!variable.isResolved())
resolve(variable, context);
String value= variable.getDefaultValue();
int[] offsets= variable.getOffsets();
// update buffer to reflect new value
for (int k= 0; k != offsets.length; k++)
edits.add(new ReplaceEdit(offsets[k], variable.getInitialLength(), value));
}
IDocument document= new Document(buffer.getString());
MultiTextEdit edit= new MultiTextEdit(0, document.getLength());
edit.addChildren((TextEdit[]) positions.toArray(new TextEdit[positions.size()]));
edit.addChildren((TextEdit[]) edits.toArray(new TextEdit[edits.size()]));
edit.apply(document, TextEdit.UPDATE_REGIONS);
positionsToVariables(positions, variables);
buffer.setContent(document.get(), variables);
}
/**
* Resolves a single variable in a context. Resolving is delegated to the registered resolver.
*
* @param variable the variable to resolve
* @param context the context in which to resolve the variable
* @since 3.3
*/
public void resolve(TemplateVariable variable, TemplateContext context) {
String type= variable.getType();
TemplateVariableResolver resolver= (TemplateVariableResolver) fResolvers.get(type);
if (resolver == null)
resolver= new TemplateVariableResolver(type, ""); //$NON-NLS-1$
resolver.resolve(variable, context);
}
private static List variablesToPositions(TemplateVariable[] variables) {
List positions= new ArrayList(5);
for (int i= 0; i != variables.length; i++) {
int[] offsets= variables[i].getOffsets();
for (int j= 0; j != offsets.length; j++)
positions.add(new RangeMarker(offsets[j], 0));
}
return positions;
}
private static void positionsToVariables(List positions, TemplateVariable[] variables) {
Iterator iterator= positions.iterator();
for (int i= 0; i != variables.length; i++) {
TemplateVariable variable= variables[i];
int[] offsets= new int[variable.getOffsets().length];
for (int j= 0; j != offsets.length; j++)
offsets[j]= ((TextEdit) iterator.next()).getOffset();
variable.setOffsets(offsets);
}
}
}