user/src/com/google/gwt/logging/client/ConsoleLogHandler.java

/*
 * 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 java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogRecord;

/**
 * A Handler that prints logs to the window.console - this is used by things
 * like FirebugLite in IE, and Safari debug mode.
 * Note we are consciously using 'window' rather than '$wnd' to avoid issues
 * similar to http://code.google.com/p/fbug/issues/detail?id=2914
 */
public class ConsoleLogHandler extends Handler {

  public ConsoleLogHandler() {
    setFormatter(new TextLogFormatter(true));
    setLevel(Level.ALL);
  }
  
  @Override
  public void close() {
    // No action needed
  }

  @Override
  public void flush() {
    // No action needed
  }

  @Override
  public void publish(LogRecord record) {
    if (!isSupported() || !isLoggable(record)) {
      return;
    }
    String msg = getFormatter().format(record);
    log(msg);
  }

  private native boolean isSupported() /*-{
    return ((window.console != null) &&
            (window.console.firebug == null) && 
            (window.console.log != null) &&
            (typeof(window.console.log) == 'function'));
  }-*/;

  private native void log(String message) /*-{
    window.console.log(message);
  }-*/;

}