/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* 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 android.util;
import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;
/**
* <p>Various utilities for debugging and logging.</p>
*/
public class DebugUtils {
/** @hide */ public DebugUtils() {}
/**
* <p>Filters objects against the <code>ANDROID_OBJECT_FILTER</code>
* environment variable. This environment variable can filter objects
* based on their class name and attribute values.</p>
*
* <p>Here is the syntax for <code>ANDROID_OBJECT_FILTER</code>:</p>
*
* <p><code>ClassName@attribute1=value1@attribute2=value2...</code></p>
*
* <p>Examples:</p>
* <ul>
* <li>Select TextView instances: <code>TextView</code></li>
* <li>Select TextView instances of text "Loading" and bottom offset of 22:
* <code>TextView@text=Loading.*@bottom=22</code></li>
* </ul>
*
* <p>The class name and the values are regular expressions.</p>
*
* <p>This class is useful for debugging and logging purpose:</p>
* <pre>
* if (DEBUG) {
* if (DebugUtils.isObjectSelected(childView) && LOGV_ENABLED) {
* Log.v(TAG, "Object " + childView + " logged!");
* }
* }
* </pre>
*
* <p><strong>NOTE</strong>: This method is very expensive as it relies
* heavily on regular expressions and reflection. Calls to this method
* should always be stripped out of the release binaries and avoided
* as much as possible in debug mode.</p>
*
* @param object any object to match against the ANDROID_OBJECT_FILTER
* environement variable
* @return true if object is selected by the ANDROID_OBJECT_FILTER
* environment variable, false otherwise
*/
public static boolean isObjectSelected(Object object) {
boolean match = false;
String s = System.getenv("ANDROID_OBJECT_FILTER");
if (s != null && s.length() > 0) {
String[] selectors = s.split("@");
// first selector == class name
if (object.getClass().getSimpleName().matches(selectors[0])) {
// check potential attributes
for (int i = 1; i < selectors.length; i++) {
String[] pair = selectors[i].split("=");
Class<?> klass = object.getClass();
try {
Method declaredMethod = null;
Class<?> parent = klass;
do {
declaredMethod = parent.getDeclaredMethod("get" +
pair[0].substring(0, 1).toUpperCase() +
pair[0].substring(1),
(Class[]) null);
} while ((parent = klass.getSuperclass()) != null &&
declaredMethod == null);
if (declaredMethod != null) {
Object value = declaredMethod
.invoke(object, (Object[])null);
match |= (value != null ?
value.toString() : "null").matches(pair[1]);
}
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
}
}
return match;
}
/** @hide */
public static void buildShortClassTag(Object cls, StringBuilder out) {
if (cls == null) {
out.append("null");
} else {
String simpleName = cls.getClass().getSimpleName();
if (simpleName == null || simpleName.isEmpty()) {
simpleName = cls.getClass().getName();
int end = simpleName.lastIndexOf('.');
if (end > 0) {
simpleName = simpleName.substring(end+1);
}
}
out.append(simpleName);
out.append('{');
out.append(Integer.toHexString(System.identityHashCode(cls)));
}
}
}