/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.editor.content.paragraph;
import com.google.gwt.dom.client.BRElement;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Node;
import org.waveprotocol.wave.client.common.util.DomHelper;
import org.waveprotocol.wave.client.editor.content.ContentElement;
import org.waveprotocol.wave.client.editor.impl.NodeManager;
import org.waveprotocol.wave.model.document.util.FilteredView.Skip;
/**
* Shared {@link ParagraphHelper} code for browsers using <br/> elements
* as spacers. Note that the exact behaviour of the spacers once added
* is determined by further deferred binding of this class for Safari vs.
* Firefox.
*
*/
public class ParagraphHelperBr extends ParagraphHelper {
private static final String BR_REF = NodeManager.getNextMarkerName("br");
/**
* @param n Node to test, or null
* @return true if n is a spacer <br/>, WHETHER OR NOT we created it
* or the browser's native editor created it
*/
protected boolean isSpacer(Node n) {
if (n == null) {
return false;
}
if (DomHelper.isTextNode(n)) {
return false;
}
Element e = n.cast();
return e.getTagName().toLowerCase().equals("br") && !NodeManager.hasBackReference(e);
}
@Override
public Node getEndingNodelet(Element paragraph) {
Node maybeSpacer = paragraph.getLastChild();
return isSpacer(maybeSpacer) ? maybeSpacer : null;
}
/**
* {@inheritDoc}
*/
@Override
public void onEmpty(Element paragraph) {
appendSpacer(paragraph);
}
/**
* Appends a spacer <br sp='t'/> element to paragraph
* Each paragraph owns a spacer which gets reused, so it
* is safe to call this method multiple times.
*
* @param paragraph
*/
protected void appendSpacer(Element paragraph) {
Element spacer = getSpacer(paragraph);
paragraph.appendChild(spacer);
}
/**
* Get the spacer for the given paragraph.
* Lazily creates & registers one if not present.
* If there's one that the browser created, registers it as our own.
* If the browser put a different one in to the one that we were already
* using, replace ours with the browser's.
* @param paragraph
* @return The spacer
*/
protected BRElement getSpacer(Element paragraph) {
Node last = paragraph.getLastChild();
BRElement spacer = paragraph.getPropertyJSO(BR_REF).cast();
if (spacer == null) {
// Register our spacer, using one the browser put in if present
spacer = isSpacer(last) ? last.<BRElement>cast() : Document.get().createBRElement();
setupSpacer(paragraph, spacer);
} else if (isSpacer(last) && last != spacer) {
// The browser put a different one in by itself, so let's use that one
if (spacer.hasParentElement()) {
spacer.removeFromParent();
}
spacer = last.<BRElement>cast();
setupSpacer(paragraph, spacer);
}
return spacer;
}
/**
* Setup the given br element as the paragraph's spacer
* @param paragraph
* @param spacer
*/
private void setupSpacer(Element paragraph, BRElement spacer) {
NodeManager.setTransparency(spacer, Skip.DEEP);
paragraph.setPropertyJSO(BR_REF, spacer);
}
/**
* {@inheritDoc}
*/
@Override
public void assertHealthy(ContentElement paragraph) {
//TODO(danilatos): Bring this check back. Something doesn't look right about it atm,
//need to think about it.
// if (paragraph.getImplNodelet().getChildCount() == 0) {
// Element nodelet = paragraph.getImplNodelet();
// Assert.assertTrue(
// "Empty Paragraph must have <br/> spacer",
// isSpacer(nodelet.getFirstChild()));
// Assert.assertTrue(
// "Empty Paragraph must have only <br/> spacer",
// nodelet.getChildCount() == 1);
// }
super.assertHealthy(paragraph);
}
}