1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
|
package org.eclipse.mylyn.commons.core;
/*******************************************************************************
* Copyright (c) 2011 Tasktop Technologies.
* 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:
* Tasktop Technologies - initial API and implementation
*******************************************************************************/
import java.util.ArrayList;
import java.util.List;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.MultiStatus;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Status;
import org.eclipse.osgi.util.NLS;
/**
* @author Steffen Pingel
* @since 3.7
*/
public class ExtensionPointReader<T> {
private final String extensionId;
private final String elementId;
private final Class<T> clazz;
private String classAttributeId;
private final String pluginId;
private final List<T> items;
public ExtensionPointReader(String pluginId, String extensionId, String elementId, Class<T> clazz) {
Assert.isNotNull(pluginId);
Assert.isNotNull(extensionId);
Assert.isNotNull(elementId);
Assert.isNotNull(clazz);
this.pluginId = pluginId;
this.extensionId = extensionId;
this.elementId = elementId;
this.clazz = clazz;
this.classAttributeId = "class"; //$NON-NLS-1$
this.items = new ArrayList<T>();
}
public final String getPluginId() {
return pluginId;
}
public final String getElementId() {
return elementId;
}
public final void setClassAttributeId(String classAttributeId) {
this.classAttributeId = classAttributeId;
}
public final String getClassAttributeId() {
return classAttributeId;
}
public IStatus read() {
items.clear();
IExtensionRegistry registry = Platform.getExtensionRegistry();
if (registry == null) {
return Status.CANCEL_STATUS;
}
MultiStatus result = new MultiStatus(pluginId, 0, NLS.bind(
"Extensions for {0}/{1} failed to load", pluginId, elementId), null); //$NON-NLS-1$
IExtensionPoint extensionPoint = registry.getExtensionPoint(pluginId + "." + extensionId); //$NON-NLS-1$
if (extensionPoint != null) {
IExtension[] extensions = extensionPoint.getExtensions();
for (IExtension extension : extensions) {
IConfigurationElement[] elements = extension.getConfigurationElements();
for (IConfigurationElement element : elements) {
if (element.getName().equals(elementId)) {
T item = readElement(element, result);
if (item != null) {
items.add(item);
}
}
}
}
}
handleResult(result);
return result;
}
protected void handleResult(IStatus result) {
if (!result.isOK()) {
StatusHandler.log(result);
}
}
public T getItem() {
return (items.isEmpty()) ? null : items.get(0);
}
public List<T> getItems() {
return new ArrayList<T>(items);
}
protected T readElement(IConfigurationElement element, MultiStatus result) {
try {
Object object = element.createExecutableExtension(getClassAttributeId());
if (clazz.isInstance(object)) {
return clazz.cast(object);
} else {
result.add(new Status(IStatus.ERROR, pluginId, NLS.bind(
"Class ''{0}'' does not extend expected class for extension contributed by {1}", //$NON-NLS-1$
object.getClass().getCanonicalName(), getPluginId())));
}
} catch (Throwable e) {
result.add(new Status(IStatus.ERROR, pluginId, NLS.bind(
"Failed to load for extension contributed by {0}", getPluginId()), e)); //$NON-NLS-1$
}
return null;
}
}
|
