Mercurial > projects > dwt2

comparison org.eclipse.core.commands/src/org/eclipse/core/commands/ParameterType.d @ 12:bc29606a740c

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Added dwt-addons in original directory structure of eclipse.org
author Frank Benoit <benoit@tionex.de>
date Sat, 14 Mar 2009 18:23:29 +0100
parents
children 6f068362a363
comparison
equal deleted inserted replaced
11:43904fec5dca 12:bc29606a740c
1 /*******************************************************************************
2 * Copyright (c) 2005, 2006 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 org.eclipse.core.commands.ParameterType;
14
15 import org.eclipse.core.commands.common.HandleObject;
16 import org.eclipse.core.commands.common.NotDefinedException;
17 import org.eclipse.core.internal.commands.util.Util;
18 import org.eclipse.core.commands.AbstractParameterValueConverter;
19 import org.eclipse.core.commands.IParameterTypeListener;
20 import org.eclipse.core.commands.ParameterTypeEvent;
21
22 import java.lang.all;
23 import tango.text.convert.Format;
24
25 /**
26 * <p>
27 * Provides information about the type of a command parameter. Clients can use a
28 * parameter type to check if an object matches the type of the parameter with
29 * {@link #isCompatible(Object)} and can get an
30 * {@link AbstractParameterValueConverter} to convert between objects matching
31 * the parameter type and strings that encode the object's identity.
32 * </p>
33 * <p>
34 * A command parameter is not required to declare a type. To determine if a
35 * given parameter has a type, check if an {@link IParameter} implements
36 * {@link ITypedParameter} and if so, use
37 * {@link ITypedParameter#getParameterType()} like this:
38 * </p>
39 *
40 * <pre>
41 * IParameter parameter = // ... get IParameter from Command
42 * if (parameter instanceof ITypedParameter) {
43 * ParameterType type = ((ITypedParameter)parameter).getParameterType();
44 * if (type !is null) {
45 * // this parameter has a ParameterType
46 * }
47 * }
48 * </pre>
49 *
50 * @see IParameter
51 * @see ITypedParameter#getParameterType()
52 * @since 3.2
53 */
54 public final class ParameterType : HandleObject, Comparable {
55
56 /**
57 * TODO: this was copied from
58 * org.eclipse.core.internal.expressions.Expressions is there a better place
59 * to reference this?
60 *
61 * @param element
62 * The element to test; may be <code>null</code>.
63 * @param type
64 * The type against which we are testing;may be <code>null</code>.
65 * @return <code>true</code> if the <code>element</code> is an instance
66 * of <code>type</code>; <code>false</code> otherwise.
67 */
68 private static final bool isInstanceOf(Object element,
69 String type) {
70 // null isn't an instanceof of anything.
71 if (element is null) {
72 return false;
73 }
74 return isSubtype(element.classinfo, type);
75 }
76
77 /**
78 * TODO: this was copied from
79 * org.eclipse.core.internal.expressions.Expressions is there a better place
80 * to reference this?
81 *
82 * @param clazz
83 * The class to match; may be <code>null</code>.
84 * @param type
85 * The type against which we are testing;may be <code>null</code>.
86 * @return <code>true</code> if the <code>element</code> is an instance
87 * of <code>type</code>; <code>false</code> otherwise.
88 */
89 private static final bool isSubtype(ClassInfo clazz, String type) {
90 if (clazz.name.equals(type)) {
91 return true;
92 }
93 ClassInfo superClass = clazz.base;
94 if (superClass !is null && isSubtype(superClass, type)) {
95 return true;
96 }
97 Interface[] interfaces = clazz.interfaces;
98 for (int i = 0; i < interfaces.length; i++) {
99 if (isSubtype(interfaces[i].classinfo, type)) {
100 return true;
101 }
102 }
103 return false;
104 }
105
106 /**
107 * An {@link AbstractParameterValueConverter} for converting parameter
108 * values between objects and strings. This may be <code>null</code>.
109 */
110 private /+transient+/ AbstractParameterValueConverter parameterTypeConverter;
111
112 /**
113 * A string specifying the object type of this parameter type. This will be
114 * <code>null</code> when the parameter type is undefined but never null
115 * when it is defined.
116 */
117 private /+transient+/ String type = null;
118
119 /**
120 * Constructs a new instance based on the given identifier. When a parameter
121 * type is first constructed, it is undefined. Parameter types should only
122 * be constructed by the {@link CommandManager} to ensure that the
123 * identifier remains unique.
124 *
125 * @param id
126 * The identifier for this type. This value must not be
127 * <code>null</code>, and must be unique amongst all parameter
128 * types.
129 */
130 this(String id) {
131 super(id);
132 }
133
134 /**
135 * Adds a listener to this parameter type that will be notified when its
136 * state changes.
137 *
138 * @param listener
139 * The listener to be added; must not be <code>null</code>.
140 */
141 public final void addListener(IParameterTypeListener listener) {
142 addListenerObject(cast(Object)listener);
143 }
144
145 /**
146 * Compares this parameter type with another object by comparing each of the
147 * non-transient attributes.
148 *
149 * @param object
150 * The object with which to compare; must be an instance of
151 * {@link ParameterType}.
152 * @return A negative integer, zero or a positive integer, if the object is
153 * greater than, equal to or less than this parameter type.
154 */
155 public final int compareTo(Object object) {
156 ParameterType castedObject = cast(ParameterType) object;
157 int compareTo = Util.compare(defined, castedObject.defined);
158 if (compareTo is 0) {
159 compareTo = Util.compare(id, castedObject.id);
160 }
161 return compareTo;
162 }
163
164 /**
165 * <p>
166 * Defines this parameter type, setting the defined property to
167 * <code>true</code>.
168 * </p>
169 * <p>
170 * Notification is sent to all listeners that something has changed.
171 * </p>
172 *
173 * @param type
174 * a string identifying the Java object type for this parameter
175 * type; <code>null</code> is interpreted as
176 * <code>"java.lang.Object"</code>
177 * @param parameterTypeConverter
178 * an {@link AbstractParameterValueConverter} to perform
179 * string/object conversions for parameter values; may be
180 * <code>null</code>
181 */
182 public final void define(String type,
183 AbstractParameterValueConverter parameterTypeConverter) {
184
185 bool definedChanged = !this.defined;
186 this.defined = true;
187
188 this.type = (type is null) ? Object.classinfo.name : type;
189 this.parameterTypeConverter = parameterTypeConverter;
190
191 fireParameterTypeChanged(new ParameterTypeEvent(this, definedChanged));
192 }
193
194 /**
195 * Notifies all listeners that this parameter type has changed. This sends
196 * the given event to all of the listeners, if any.
197 *
198 * @param event
199 * The event to send to the listeners; must not be
200 * <code>null</code>.
201 */
202 private final void fireParameterTypeChanged(ParameterTypeEvent event) {
203 if (event is null) {
204 throw new NullPointerException(
205 "Cannot send a null event to listeners."); //$NON-NLS-1$
206 }
207
208 if (!isListenerAttached()) {
209 return;
210 }
211
212 Object[] listeners = getListeners();
213 for (int i = 0; i < listeners.length; i++) {
214 IParameterTypeListener listener = cast(IParameterTypeListener) listeners[i];
215 listener.parameterTypeChanged(event);
216 }
217 }
218
219 /**
220 * Returns the value converter associated with this parameter, if any.
221 *
222 * @return The parameter value converter, or <code>null</code> if there is
223 * no value converter for this parameter.
224 * @throws NotDefinedException
225 * if the parameter type is not currently defined
226 */
227 public final AbstractParameterValueConverter getValueConverter() {
228 if (!isDefined()) {
229 throw new NotDefinedException(
230 "Cannot use getValueConverter() with an undefined ParameterType"); //$NON-NLS-1$
231 }
232
233 return parameterTypeConverter;
234 }
235
236 /**
237 * Returns whether the provided value is compatible with this parameter
238 * type. An object is compatible with a parameter type if the object is an
239 * instance of the class defined as the parameter's type class.
240 *
241 * @param value
242 * an object to check for compatibility with this parameter type;
243 * may be <code>null</code>.
244 * @return <code>true</code> if the value is compatible with this type,
245 * <code>false</code> otherwise
246 * @throws NotDefinedException
247 * if the parameter type is not currently defined
248 */
249 public bool isCompatible(Object value) {
250 if (!isDefined()) {
251 throw new NotDefinedException(
252 "Cannot use isCompatible() with an undefined ParameterType"); //$NON-NLS-1$
253 }
254 return isInstanceOf(value, type);
255 }
256
257 /**
258 * Unregisters listener for changes to properties of this parameter type.
259 *
260 * @param listener
261 * the instance to unregister. Must not be <code>null</code>.
262 * If an attempt is made to unregister an instance which is not
263 * already registered with this instance, no operation is
264 * performed.
265 */
266 public final void removeListener(IParameterTypeListener listener) {
267 removeListenerObject(cast(Object)listener);
268 }
269
270 /**
271 * The string representation of this parameter type. For debugging purposes
272 * only. This string should not be shown to an end user.
273 *
274 * @return The string representation; never <code>null</code>.
275 */
276 public override final String toString() {
277 if (string is null) {
278 string = Format( "ParameterType({},{})", id, defined );
279 }
280 return string;
281 }
282
283 /**
284 * Makes this parameter type become undefined. Notification is sent to all
285 * listeners.
286 */
287 public override final void undefine() {
288 string = null;
289
290 final bool definedChanged = defined;
291 defined = false;
292
293 type = null;
294 parameterTypeConverter = null;
295
296 fireParameterTypeChanged(new ParameterTypeEvent(this, definedChanged));
297 }
298
299 }