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
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Eclipse Public License, Version 1.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.eclipse.org/org/documents/epl-v10.php
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.ide.eclipse.adt.internal.editors.layout.gre;
import com.android.ide.common.api.IViewRule;
import com.android.ide.eclipse.adt.AdtPlugin;
import com.android.ide.eclipse.adt.internal.sdk.ProjectState;
import com.android.ide.eclipse.adt.internal.sdk.Sdk;
import com.android.sdklib.internal.project.ProjectProperties;
import com.android.utils.Pair;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.QualifiedName;
import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.List;
/**
* The {@link RuleLoader} is responsible for loading (and unloading)
* {@link IViewRule} classes. There is typically one {@link RuleLoader}
* per project.
*/
public class RuleLoader {
/**
* Qualified name for the per-project non-persistent property storing the
* {@link RuleLoader} for this project
*/
private final static QualifiedName RULE_LOADER = new QualifiedName(AdtPlugin.PLUGIN_ID,
"ruleloader"); //$NON-NLS-1$
private final IProject mProject;
private ClassLoader mUserClassLoader;
private List<Pair<File, Long>> mUserJarTimeStamps;
private long mLastCheckTimeStamp;
/**
* Flag set when we've attempted to initialize the {@link #mUserClassLoader}
* already
*/
private boolean mUserClassLoaderInited;
/**
* Returns the {@link RuleLoader} for the given project
*
* @param project the project the loader is associated with
* @return an {@RuleLoader} for the given project,
* never null
*/
public static RuleLoader get(IProject project) {
RuleLoader loader = null;
try {
loader = (RuleLoader) project.getSessionProperty(RULE_LOADER);
} catch (CoreException e) {
// Not a problem; we will just create a new one
}
if (loader == null) {
loader = new RuleLoader(project);
try {
project.setSessionProperty(RULE_LOADER, loader);
} catch (CoreException e) {
AdtPlugin.log(e, "Can't store RuleLoader");
}
}
return loader;
}
/** Do not call; use the {@link #get} factory method instead. */
private RuleLoader(IProject project) {
mProject = project;
}
/**
* Find out whether the given project has 3rd party ViewRules, and if so
* return a ClassLoader which can locate them. If not, return null.
* @param project The project to load user rules from
* @return A class loader which can user view rules, or otherwise null
*/
private ClassLoader computeUserClassLoader(IProject project) {
// Default place to locate layout rules. The user may also add to this
// path by defining a config property specifying
// additional .jar files to search via a the layoutrules.jars property.
ProjectState state = Sdk.getProjectState(project);
ProjectProperties projectProperties = state.getProperties();
// Ensure we have the latest & greatest version of the properties.
// This allows users to reopen editors in a running Eclipse instance
// to get updated view rule jars
projectProperties.reload();
String path = projectProperties.getProperty(
ProjectProperties.PROPERTY_RULES_PATH);
if (path != null && path.length() > 0) {
mUserJarTimeStamps = new ArrayList<Pair<File, Long>>();
mLastCheckTimeStamp = System.currentTimeMillis();
List<URL> urls = new ArrayList<URL>();
String[] pathElements = path.split(File.pathSeparator);
for (String pathElement : pathElements) {
pathElement = pathElement.trim(); // Avoid problems with trailing whitespace etc
File pathFile = new File(pathElement);
if (!pathFile.isAbsolute()) {
pathFile = new File(project.getLocation().toFile(), pathElement);
}
// Directories and jar files are okay. Do we need to
// validate the files here as .jar files?
if (pathFile.isFile() || pathFile.isDirectory()) {
URL url;
try {
url = pathFile.toURI().toURL();
urls.add(url);
mUserJarTimeStamps.add(Pair.of(pathFile, pathFile.lastModified()));
} catch (MalformedURLException e) {
AdtPlugin.log(IStatus.WARNING,
"Invalid URL: %1$s", //$NON-NLS-1$
e.toString());
}
}
}
if (urls.size() > 0) {
return new URLClassLoader(urls.toArray(new URL[urls.size()]),
RulesEngine.class.getClassLoader());
}
}
return null;
}
/**
* Return the class loader to use for custom views, or null if no custom
* view rules are registered for the project. Note that this class loader
* can change over time (if the jar files are updated), so callers should be
* prepared to unload previous instances.
*
* @return a class loader to use for custom view rules, or null
*/
public ClassLoader getClassLoader() {
if (mUserClassLoader == null) {
// Only attempt to load rule paths once.
// TODO: Check the timestamp on the project.properties file so we can dynamically
// pick up cases where the user edits the path
if (!mUserClassLoaderInited) {
mUserClassLoaderInited = true;
mUserClassLoader = computeUserClassLoader(mProject);
}
} else {
// Check the timestamp on the jar files in the custom view path to see if we
// need to reload the classes (but only do this at most every 3 seconds)
if (mUserJarTimeStamps != null) {
long time = System.currentTimeMillis();
if (time - mLastCheckTimeStamp > 3000) {
mLastCheckTimeStamp = time;
for (Pair<File, Long> pair : mUserJarTimeStamps) {
File file = pair.getFirst();
Long prevModified = pair.getSecond();
long modified = file.lastModified();
if (prevModified.longValue() != modified) {
mUserClassLoaderInited = true;
mUserJarTimeStamps = null;
mUserClassLoader = computeUserClassLoader(mProject);
}
}
}
}
}
return mUserClassLoader;
}
}
|
