// Copyright (C) 2010 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 com.google.gerrit.prettify.client;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.resources.client.TextResource;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.NamedFrame;
/**
* Creates a private JavaScript environment, typically inside an IFrame.
* <p>
* Instances must be created through {@code GWT.create(PrivateScopeImpl.class)}.
* A scope must remain attached to the primary document for its entire life.
* Behavior is undefined if a scope is detached and attached again later. It is
* best to attach the scope with {@code RootPanel.get().add(scope)} as soon as
* it has been created.
*/
public class PrivateScopeImpl extends Composite {
private static int scopeId;
protected final String scopeName;
public PrivateScopeImpl() {
scopeName = nextScopeName();
NamedFrame frame = new NamedFrame(scopeName);
frame.setUrl("javascript:''");
initWidget(frame);
setVisible(false);
}
public void compile(TextResource js) {
eval(js.getText());
}
public void eval(String js) {
nativeEval(getContext(), js);
}
public JavaScriptObject getContext() {
return nativeGetContext(scopeName);
}
private static String nextScopeName() {
return "_PrivateScope" + (++scopeId);
}
private static native void nativeEval(JavaScriptObject ctx, String js)
/*-{ ctx.eval(js); }-*/;
private static native JavaScriptObject nativeGetContext(String scopeName)
/*-{ return $wnd[scopeName]; }-*/;
}