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comparison dwtx/jface/text/templates/TemplateCompletionProcessor.d @ 129:eb30df5ca28b

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Added JFace Text sources
author Frank Benoit <benoit@tionex.de>
date Sat, 23 Aug 2008 19:10:48 +0200
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children c4fb132a086c
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128:8df1d4193877 129:eb30df5ca28b
1 /*******************************************************************************
2 * Copyright (c) 2000, 2005 IBM Corporation and others.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Eclipse Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html
7 *
8 * Contributors:
9 * IBM Corporation - initial API and implementation
10 * Port to the D programming language:
11 * Frank Benoit <benoit@tionex.de>
12 *******************************************************************************/
13 module dwtx.jface.text.templates.TemplateCompletionProcessor;
14
15 import dwt.dwthelper.utils;
16
17 import java.util.ArrayList;
18 import java.util.Collections;
19 import java.util.Comparator;
20 import java.util.List;
21
22 import dwt.graphics.Image;
23 import dwtx.jface.text.BadLocationException;
24 import dwtx.jface.text.IDocument;
25 import dwtx.jface.text.IRegion;
26 import dwtx.jface.text.ITextSelection;
27 import dwtx.jface.text.ITextViewer;
28 import dwtx.jface.text.Region;
29 import dwtx.jface.text.contentassist.ICompletionProposal;
30 import dwtx.jface.text.contentassist.IContentAssistProcessor;
31 import dwtx.jface.text.contentassist.IContextInformation;
32 import dwtx.jface.text.contentassist.IContextInformationValidator;
33
34
35 /**
36 * A completion processor that computes template proposals. Subclasses need to
37 * provide implementations for {@link #getTemplates(String)},
38 * {@link #getContextType(ITextViewer, IRegion)} and {@link #getImage(Template)}.
39 *
40 * @since 3.0
41 */
42 public abstract class TemplateCompletionProcessor : IContentAssistProcessor {
43
44 private static final class ProposalComparator : Comparator {
45 public int compare(Object o1, Object o2) {
46 return ((TemplateProposal) o2).getRelevance() - ((TemplateProposal) o1).getRelevance();
47 }
48 }
49
50 private static final Comparator fgProposalComparator= new ProposalComparator();
51
52 /*
53 * @see dwtx.jface.text.contentassist.IContentAssistProcessor#computeCompletionProposals(dwtx.jface.text.ITextViewer,
54 * int)
55 */
56 public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) {
57
58 ITextSelection selection= (ITextSelection) viewer.getSelectionProvider().getSelection();
59
60 // adjust offset to end of normalized selection
61 if (selection.getOffset() is offset)
62 offset= selection.getOffset() + selection.getLength();
63
64 String prefix= extractPrefix(viewer, offset);
65 Region region= new Region(offset - prefix.length(), prefix.length());
66 TemplateContext context= createContext(viewer, region);
67 if (context is null)
68 return new ICompletionProposal[0];
69
70 context.setVariable("selection", selection.getText()); // name of the selection variables {line, word}_selection //$NON-NLS-1$
71
72 Template[] templates= getTemplates(context.getContextType().getId());
73
74 List matches= new ArrayList();
75 for (int i= 0; i < templates.length; i++) {
76 Template template= templates[i];
77 try {
78 context.getContextType().validate(template.getPattern());
79 } catch (TemplateException e) {
80 continue;
81 }
82 if (template.matches(prefix, context.getContextType().getId()))
83 matches.add(createProposal(template, context, (IRegion) region, getRelevance(template, prefix)));
84 }
85
86 Collections.sort(matches, fgProposalComparator);
87
88 return (ICompletionProposal[]) matches.toArray(new ICompletionProposal[matches.size()]);
89 }
90
91 /**
92 * Creates a new proposal.
93 * <p>
94 * Forwards to {@link #createProposal(Template, TemplateContext, IRegion, int)}.
95 * Do neither call nor override.
96 * </p>
97 *
98 * @param template the template to be applied by the proposal
99 * @param context the context for the proposal
100 * @param region the region the proposal applies to
101 * @param relevance the relevance of the proposal
102 * @return a new <code>ICompletionProposal</code> for
103 * <code>template</code>
104 * @deprecated use the version specifying <code>IRegion</code> as third parameter
105 * @since 3.1
106 */
107 protected ICompletionProposal createProposal(Template template, TemplateContext context, Region region, int relevance) {
108 return createProposal(template, context, (IRegion) region, relevance);
109 }
110
111 /**
112 * Creates a new proposal.
113 * <p>
114 * The default implementation returns an instance of
115 * {@link TemplateProposal}. Subclasses may replace this method to provide
116 * their own implementations.
117 * </p>
118 *
119 * @param template the template to be applied by the proposal
120 * @param context the context for the proposal
121 * @param region the region the proposal applies to
122 * @param relevance the relevance of the proposal
123 * @return a new <code>ICompletionProposal</code> for
124 * <code>template</code>
125 */
126 protected ICompletionProposal createProposal(Template template, TemplateContext context, IRegion region, int relevance) {
127 return new TemplateProposal(template, context, region, getImage(template), relevance);
128 }
129
130 /**
131 * Returns the templates valid for the context type specified by <code>contextTypeId</code>.
132 *
133 * @param contextTypeId the context type id
134 * @return the templates valid for this context type id
135 */
136 protected abstract Template[] getTemplates(String contextTypeId);
137
138 /**
139 * Creates a concrete template context for the given region in the document. This involves finding out which
140 * context type is valid at the given location, and then creating a context of this type. The default implementation
141 * returns a <code>DocumentTemplateContext</code> for the context type at the given location.
142 *
143 * @param viewer the viewer for which the context is created
144 * @param region the region into <code>document</code> for which the context is created
145 * @return a template context that can handle template insertion at the given location, or <code>null</code>
146 */
147 protected TemplateContext createContext(ITextViewer viewer, IRegion region) {
148 TemplateContextType contextType= getContextType(viewer, region);
149 if (contextType !is null) {
150 IDocument document= viewer.getDocument();
151 return new DocumentTemplateContext(contextType, document, region.getOffset(), region.getLength());
152 }
153 return null;
154 }
155
156 /**
157 * Returns the context type that can handle template insertion at the given region
158 * in the viewer's document.
159 *
160 * @param viewer the text viewer
161 * @param region the region into the document displayed by viewer
162 * @return the context type that can handle template expansion for the given location, or <code>null</code> if none exists
163 */
164 protected abstract TemplateContextType getContextType(ITextViewer viewer, IRegion region);
165
166 /**
167 * Returns the relevance of a template given a prefix. The default
168 * implementation returns a number greater than zero if the template name
169 * starts with the prefix, and zero otherwise.
170 *
171 * @param template the template to compute the relevance for
172 * @param prefix the prefix after which content assist was requested
173 * @return the relevance of <code>template</code>
174 * @see #extractPrefix(ITextViewer, int)
175 */
176 protected int getRelevance(Template template, String prefix) {
177 if (template.getName().startsWith(prefix))
178 return 90;
179 return 0;
180 }
181
182 /**
183 * Heuristically extracts the prefix used for determining template relevance
184 * from the viewer's document. The default implementation returns the String from
185 * offset backwards that forms a java identifier.
186 *
187 * @param viewer the viewer
188 * @param offset offset into document
189 * @return the prefix to consider
190 * @see #getRelevance(Template, String)
191 */
192 protected String extractPrefix(ITextViewer viewer, int offset) {
193 int i= offset;
194 IDocument document= viewer.getDocument();
195 if (i > document.getLength())
196 return ""; //$NON-NLS-1$
197
198 try {
199 while (i > 0) {
200 char ch= document.getChar(i - 1);
201 if (!Character.isJavaIdentifierPart(ch))
202 break;
203 i--;
204 }
205
206 return document.get(i, offset - i);
207 } catch (BadLocationException e) {
208 return ""; //$NON-NLS-1$
209 }
210 }
211
212 /**
213 * Returns the image to be used for the proposal for <code>template</code>.
214 *
215 * @param template the template for which an image should be returned
216 * @return the image for <code>template</code>
217 */
218 protected abstract Image getImage(Template template);
219
220 /*
221 * @see dwtx.jface.text.contentassist.IContentAssistProcessor#computeContextInformation(dwtx.jface.text.ITextViewer, int)
222 */
223 public IContextInformation[] computeContextInformation(ITextViewer viewer, int documentOffset) {
224 return null;
225 }
226
227 /*
228 * @see dwtx.jface.text.contentassist.IContentAssistProcessor#getCompletionProposalAutoActivationCharacters()
229 */
230 public char[] getCompletionProposalAutoActivationCharacters() {
231 return null;
232 }
233
234 /*
235 * @see dwtx.jface.text.contentassist.IContentAssistProcessor#getContextInformationAutoActivationCharacters()
236 */
237 public char[] getContextInformationAutoActivationCharacters() {
238 return null;
239 }
240
241 /*
242 * @see dwtx.jface.text.contentassist.IContentAssistProcessor#getErrorMessage()
243 */
244 public String getErrorMessage() {
245 return null;
246 }
247
248 /*
249 * @see dwtx.jface.text.contentassist.IContentAssistProcessor#getContextInformationValidator()
250 */
251 public IContextInformationValidator getContextInformationValidator() {
252 return null;
253 }
254 }