// Copyright (c) 2009 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.debug.ui;
import org.chromium.debug.core.ChromiumDebugPlugin;
import org.chromium.debug.core.model.DebugElementImpl;
import org.chromium.debug.core.model.EvaluateContext;
import org.chromium.debug.core.model.Variable;
import org.chromium.sdk.JsEvaluateContext;
import org.chromium.sdk.JsVariable;
import org.eclipse.core.runtime.Status;
import org.eclipse.debug.core.DebugException;
import org.eclipse.debug.core.model.IDebugElement;
import org.eclipse.debug.core.model.IValue;
import org.eclipse.debug.core.model.IWatchExpressionDelegate;
import org.eclipse.debug.core.model.IWatchExpressionListener;
import org.eclipse.debug.core.model.IWatchExpressionResult;
/**
* Performs the Watch expression evaluation while debugging Chromium JavaScript.
*/
public class JsWatchExpressionDelegate implements IWatchExpressionDelegate {
private static final String[] EMPTY_STRINGS = new String[0];
private static final class GoodWatchExpressionResult implements IWatchExpressionResult {
private final Variable variable;
private final String expression;
private IValue value;
private DebugException exception;
private GoodWatchExpressionResult(Variable variable, String expression) {
this.variable = variable;
this.expression = expression;
}
public String[] getErrorMessages() {
return exception == null
? EMPTY_STRINGS
: new String[] { exception.getStatus().getMessage() };
}
public DebugException getException() {
getValue();
return exception;
}
public String getExpressionText() {
return expression;
}
public synchronized IValue getValue() {
if (value == null && exception == null) {
value = variable.getValue();
}
return value;
}
public boolean hasErrors() {
getValue();
return exception != null;
}
}
private static final class BadWatchExpressionResult implements IWatchExpressionResult {
private final DebugException exception;
private final String expressionText;
private BadWatchExpressionResult(DebugException exception, String expressionText) {
this.exception = exception;
this.expressionText = expressionText;
}
public String[] getErrorMessages() {
return new String[] { exception.getStatus().getMessage() };
}
public DebugException getException() {
return exception;
}
public String getExpressionText() {
return expressionText;
}
public IValue getValue() {
return null;
}
public boolean hasErrors() {
return true;
}
}
public void evaluateExpression(final String expression, final IDebugElement context,
final IWatchExpressionListener listener) {
final DebugElementImpl contextImpl = (DebugElementImpl) context;
if (!contextImpl.getDebugTarget().isSuspended()) {
// can only evaluate while suspended. Notify empty result.
listener.watchEvaluationFinished(new IWatchExpressionResult() {
public String[] getErrorMessages() {
return EMPTY_STRINGS;
}
public DebugException getException() {
return null;
}
public String getExpressionText() {
return expression;
}
public IValue getValue() {
return null;
}
public boolean hasErrors() {
return false;
}
});
return;
}
final EvaluateContext evaluateContext =
(EvaluateContext) contextImpl.getAdapter(EvaluateContext.class);
if (evaluateContext == null) {
listener.watchEvaluationFinished(new BadWatchExpressionResult(
new DebugException(new Status(Status.ERROR,
ChromiumDebugUIPlugin.PLUGIN_ID,"Bad debug context")), //$NON-NLS-1$
expression));
return;
}
evaluateContext.getJsEvaluateContext().evaluateAsync(
expression, null,
new JsEvaluateContext.EvaluateCallback() {
public void success(JsVariable variable) {
final Variable var = Variable.forRealValue(evaluateContext, variable, false, null);
listener.watchEvaluationFinished(new GoodWatchExpressionResult(var, expression));
}
public void failure(String message) {
listener.watchEvaluationFinished(new BadWatchExpressionResult(new DebugException(
createErrorStatus(message == null
? Messages.JsWatchExpressionDelegate_ErrorEvaluatingExpression
: message, null)), expression));
return;
}
},
null);
}
private static Status createErrorStatus(String message, Exception e) {
return new Status(Status.ERROR, ChromiumDebugPlugin.PLUGIN_ID, message, e);
}
}