/*
* Copyright 2015 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 javaemul.internal;
/**
* A helper to print log messages to console.
* <p> Note that, this is not a public API and can change/disappear in any release.
*/
public class ConsoleLogger {
public static ConsoleLogger createIfSupported() {
return isSupported() ? new ConsoleLogger() : null;
}
private static native boolean isSupported() /*-{
return !!window.console;
}-*/;
public native void log(String level, String message) /*-{
console[level](message);
}-*/;
public void log(String level, Throwable t) {
log(level, t, "Exception: ", true);
}
private void log(String level, Throwable t, String label, boolean expanded) {
groupStart(label + t.toString(), expanded);
log(level, getBackingError(t, t.getBackingJsObject()));
Throwable cause = t.getCause();
if (cause != null) {
log(level, cause, "Caused by: ", false);
}
for (Throwable suppressed : t.getSuppressed()) {
log(level, suppressed, "Suppressed: ", false);
}
groupEnd();
}
private native void groupStart(String msg, boolean expanded) /*-{
// Not all browsers support grouping:
var groupStart = (!expanded && console.groupCollapsed) || console.group || console.log;
groupStart.call(console, msg);
}-*/;
private native void groupEnd() /*-{
var groupEnd = console.groupEnd || function(){};
groupEnd.call(console);
}-*/;
private native String getBackingError(Throwable t, Object backingError) /*-{
// Converts CollectorLegacy (IE8/IE9/Safari5) function stack to something readable.
function stringify(fnStack) {
if (!fnStack || fnStack.length == 0) {
return "";
}
return "\t" + fnStack.join("\n\t");
}
return backingError && (backingError.stack || stringify(t["fnStack"]));
}-*/;
}