/*
* Copyright 2010 Google Inc.
*
* 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 com.google.gwt.logging.client;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.HasWidgets;
import com.google.gwt.user.client.ui.Label;
import java.util.logging.Formatter;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogRecord;
/**
* A handler which can log to any widget which extends the HasWidgets interface.
* This allows users to log to anywhere they would like in their UI - see the
* LogConfiguration class for an example. Note that the widget passed in must
* handle multiple calls to widget.add(widget) gracefully.
*/
public class HasWidgetsLogHandler extends Handler {
private HasWidgets widgetContainer;
public HasWidgetsLogHandler(HasWidgets container) {
this.widgetContainer = container;
setFormatter(new HtmlLogFormatter());
setLevel(Level.ALL);
}
public void clear() {
widgetContainer.clear();
}
@Override
public void close() {
// Do nothing
}
@Override
public void flush() {
// Do nothing
}
@Override
public void publish(LogRecord record) {
if (!isLoggable(record)) {
return;
}
Formatter formatter = getFormatter();
String msg = formatter.format(record);
// We want to make sure that unescaped messages are not output as HTML to
// the window and the HtmlLogFormatter ensures this. If you want to write a
// new formatter, subclass HtmlLogFormatter and override the getHtmlPrefix
// and getHtmlSuffix methods.
if (formatter instanceof HtmlLogFormatter) {
widgetContainer.add(new HTML(msg));
} else {
widgetContainer.add(new Label(msg));
}
}
}