/**
* 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 org.waveprotocol.wave.client.uibuilder;
import org.waveprotocol.wave.client.common.safehtml.SafeHtmlBuilder;
/**
* Helper methods for UI builders.
*
*/
public final class BuilderHelper {
public static final String KIND_ATTRIBUTE = "kind";
public interface Component {
/**
* @param baseId
* @return the dom id to use for the given component.
*/
String getDomId(String baseId);
}
// No instances - this is a container of static helpers.
private BuilderHelper() {
}
/** @return a non-null equivalent of a nullable ui. */
public static UiBuilder nonNull(UiBuilder ui) {
return ui != null ? ui : UiBuilder.EMPTY;
}
/** @return a non-null equivalent of a nullable ui. */
public static HtmlClosure nonNull(HtmlClosure ui) {
return ui != null ? ui : HtmlClosureCollection.EMPTY;
}
/** @return a builder composed of a sequence of builders. */
public static HtmlClosure compose(final UiBuilder... uis) {
return new HtmlClosure() {
@Override
public void outputHtml(SafeHtmlBuilder out) {
for (UiBuilder ui : uis) {
nonNull(ui).outputHtml(out);
}
}
};
}
}