--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwtx/jface/text/templates/TemplateCompletionProcessor.d	Sat Aug 23 19:10:48 2008 +0200
@@ -0,0 +1,254 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 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
+ * Port to the D programming language:
+ *     Frank Benoit <benoit@tionex.de>
+ *******************************************************************************/
+module dwtx.jface.text.templates.TemplateCompletionProcessor;
+
+import dwt.dwthelper.utils;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+import dwt.graphics.Image;
+import dwtx.jface.text.BadLocationException;
+import dwtx.jface.text.IDocument;
+import dwtx.jface.text.IRegion;
+import dwtx.jface.text.ITextSelection;
+import dwtx.jface.text.ITextViewer;
+import dwtx.jface.text.Region;
+import dwtx.jface.text.contentassist.ICompletionProposal;
+import dwtx.jface.text.contentassist.IContentAssistProcessor;
+import dwtx.jface.text.contentassist.IContextInformation;
+import dwtx.jface.text.contentassist.IContextInformationValidator;
+
+
+/**
+ * A completion processor that computes template proposals. Subclasses need to
+ * provide implementations for {@link #getTemplates(String)},
+ * {@link #getContextType(ITextViewer, IRegion)} and {@link #getImage(Template)}.
+ *
+ * @since 3.0
+ */
+public abstract class TemplateCompletionProcessor : IContentAssistProcessor {
+
+    private static final class ProposalComparator : Comparator {
+        public int compare(Object o1, Object o2) {
+            return ((TemplateProposal) o2).getRelevance() - ((TemplateProposal) o1).getRelevance();
+        }
+    }
+
+    private static final Comparator fgProposalComparator= new ProposalComparator();
+
+    /*
+     * @see dwtx.jface.text.contentassist.IContentAssistProcessor#computeCompletionProposals(dwtx.jface.text.ITextViewer,
+     *      int)
+     */
+    public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) {
+
+        ITextSelection selection= (ITextSelection) viewer.getSelectionProvider().getSelection();
+
+        // adjust offset to end of normalized selection
+        if (selection.getOffset() is offset)
+            offset= selection.getOffset() + selection.getLength();
+
+        String prefix= extractPrefix(viewer, offset);
+        Region region= new Region(offset - prefix.length(), prefix.length());
+        TemplateContext context= createContext(viewer, region);
+        if (context is null)
+            return new ICompletionProposal[0];
+
+        context.setVariable("selection", selection.getText()); // name of the selection variables {line, word}_selection //$NON-NLS-1$
+
+        Template[] templates= getTemplates(context.getContextType().getId());
+
+        List matches= new ArrayList();
+        for (int i= 0; i < templates.length; i++) {
+            Template template= templates[i];
+            try {
+                context.getContextType().validate(template.getPattern());
+            } catch (TemplateException e) {
+                continue;
+            }
+            if (template.matches(prefix, context.getContextType().getId()))
+                matches.add(createProposal(template, context, (IRegion) region, getRelevance(template, prefix)));
+        }
+
+        Collections.sort(matches, fgProposalComparator);
+
+        return (ICompletionProposal[]) matches.toArray(new ICompletionProposal[matches.size()]);
+    }
+
+    /**
+     * Creates a new proposal.
+     * <p>
+     * Forwards to {@link #createProposal(Template, TemplateContext, IRegion, int)}.
+     * Do neither call nor override.
+     * </p>
+     *
+     * @param template the template to be applied by the proposal
+     * @param context the context for the proposal
+     * @param region the region the proposal applies to
+     * @param relevance the relevance of the proposal
+     * @return a new <code>ICompletionProposal</code> for
+     *         <code>template</code>
+     * @deprecated use the version specifying <code>IRegion</code> as third parameter
+     * @since 3.1
+     */
+    protected ICompletionProposal createProposal(Template template, TemplateContext context, Region region, int relevance) {
+        return createProposal(template, context, (IRegion) region, relevance);
+    }
+
+    /**
+     * Creates a new proposal.
+     * <p>
+     * The default implementation returns an instance of
+     * {@link TemplateProposal}. Subclasses may replace this method to provide
+     * their own implementations.
+     * </p>
+     *
+     * @param template the template to be applied by the proposal
+     * @param context the context for the proposal
+     * @param region the region the proposal applies to
+     * @param relevance the relevance of the proposal
+     * @return a new <code>ICompletionProposal</code> for
+     *         <code>template</code>
+     */
+    protected ICompletionProposal createProposal(Template template, TemplateContext context, IRegion region, int relevance) {
+        return new TemplateProposal(template, context, region, getImage(template), relevance);
+    }
+
+    /**
+     * Returns the templates valid for the context type specified by <code>contextTypeId</code>.
+     *
+     * @param contextTypeId the context type id
+     * @return the templates valid for this context type id
+     */
+    protected abstract Template[] getTemplates(String contextTypeId);
+
+    /**
+     * Creates a concrete template context for the given region in the document. This involves finding out which
+     * context type is valid at the given location, and then creating a context of this type. The default implementation
+     * returns a <code>DocumentTemplateContext</code> for the context type at the given location.
+     *
+     * @param viewer the viewer for which the context is created
+     * @param region the region into <code>document</code> for which the context is created
+     * @return a template context that can handle template insertion at the given location, or <code>null</code>
+     */
+    protected TemplateContext createContext(ITextViewer viewer, IRegion region) {
+        TemplateContextType contextType= getContextType(viewer, region);
+        if (contextType !is null) {
+            IDocument document= viewer.getDocument();
+            return new DocumentTemplateContext(contextType, document, region.getOffset(), region.getLength());
+        }
+        return null;
+    }
+
+    /**
+     * Returns the context type that can handle template insertion at the given region
+     * in the viewer's document.
+     *
+     * @param viewer the text viewer
+     * @param region the region into the document displayed by viewer
+     * @return the context type that can handle template expansion for the given location, or <code>null</code> if none exists
+     */
+    protected abstract TemplateContextType getContextType(ITextViewer viewer, IRegion region);
+
+    /**
+     * Returns the relevance of a template given a prefix. The default
+     * implementation returns a number greater than zero if the template name
+     * starts with the prefix, and zero otherwise.
+     *
+     * @param template the template to compute the relevance for
+     * @param prefix the prefix after which content assist was requested
+     * @return the relevance of <code>template</code>
+     * @see #extractPrefix(ITextViewer, int)
+     */
+    protected int getRelevance(Template template, String prefix) {
+        if (template.getName().startsWith(prefix))
+            return 90;
+        return 0;
+    }
+
+    /**
+     * Heuristically extracts the prefix used for determining template relevance
+     * from the viewer's document. The default implementation returns the String from
+     * offset backwards that forms a java identifier.
+     *
+     * @param viewer the viewer
+     * @param offset offset into document
+     * @return the prefix to consider
+     * @see #getRelevance(Template, String)
+     */
+    protected String extractPrefix(ITextViewer viewer, int offset) {
+        int i= offset;
+        IDocument document= viewer.getDocument();
+        if (i > document.getLength())
+            return ""; //$NON-NLS-1$
+
+        try {
+            while (i > 0) {
+                char ch= document.getChar(i - 1);
+                if (!Character.isJavaIdentifierPart(ch))
+                    break;
+                i--;
+            }
+
+            return document.get(i, offset - i);
+        } catch (BadLocationException e) {
+            return ""; //$NON-NLS-1$
+        }
+    }
+
+    /**
+     * Returns the image to be used for the proposal for <code>template</code>.
+     *
+     * @param template the template for which an image should be returned
+     * @return the image for <code>template</code>
+     */
+    protected abstract Image getImage(Template template);
+
+    /*
+     * @see dwtx.jface.text.contentassist.IContentAssistProcessor#computeContextInformation(dwtx.jface.text.ITextViewer, int)
+     */
+    public IContextInformation[] computeContextInformation(ITextViewer viewer, int documentOffset) {
+        return null;
+    }
+
+    /*
+     * @see dwtx.jface.text.contentassist.IContentAssistProcessor#getCompletionProposalAutoActivationCharacters()
+     */
+    public char[] getCompletionProposalAutoActivationCharacters() {
+        return null;
+    }
+
+    /*
+     * @see dwtx.jface.text.contentassist.IContentAssistProcessor#getContextInformationAutoActivationCharacters()
+     */
+    public char[] getContextInformationAutoActivationCharacters() {
+        return null;
+    }
+
+    /*
+     * @see dwtx.jface.text.contentassist.IContentAssistProcessor#getErrorMessage()
+     */
+    public String getErrorMessage() {
+        return null;
+    }
+
+    /*
+     * @see dwtx.jface.text.contentassist.IContentAssistProcessor#getContextInformationValidator()
+     */
+    public IContextInformationValidator getContextInformationValidator() {
+        return null;
+    }
+}