/*
* Copyright 2009 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 com.google.common.css.compiler.passes;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.css.compiler.ast.CssCommentNode;
import com.google.common.css.compiler.ast.CssCompilerPass;
import com.google.common.css.compiler.ast.CssConditionalBlockNode;
import com.google.common.css.compiler.ast.CssConditionalRuleNode;
import com.google.common.css.compiler.ast.CssDeclarationBlockNode;
import com.google.common.css.compiler.ast.CssDeclarationNode;
import com.google.common.css.compiler.ast.CssMediaRuleNode;
import com.google.common.css.compiler.ast.CssNode;
import com.google.common.css.compiler.ast.CssRefinerNode;
import com.google.common.css.compiler.ast.CssRulesetNode;
import com.google.common.css.compiler.ast.CssSelectorListNode;
import com.google.common.css.compiler.ast.CssSelectorNode;
import com.google.common.css.compiler.ast.DefaultTreeVisitor;
import com.google.common.css.compiler.ast.ErrorManager;
import com.google.common.css.compiler.ast.GssError;
import com.google.common.css.compiler.ast.VisitController;
import java.util.logging.Logger;
/**
* Compiler pass that traverses the tree and marks as non flippable the nodes
* that should not be BiDi flipped.
*
* @author oana@google.com (Oana Florescu)
*/
public class MarkNonFlippableNodes extends DefaultTreeVisitor
implements CssCompilerPass {
@VisibleForTesting
static final String INVALID_NOFLIP_ERROR_MESSAGE =
"@noflip must be moved outside of selector sequence since it applies " +
"to entire block.";
private final VisitController visitController;
private final ErrorManager errorManager;
private static final Logger logger = Logger.getLogger(
MarkNonFlippableNodes.class.getName());
/**
* String that matches the comment marking a rule that should not be
* flipped.
* TODO(oana): Expand this annotation and make it more flexible.
*/
private static final String NOFLIP = "/* @noflip */";
public MarkNonFlippableNodes(VisitController visitController,
ErrorManager errorManager) {
this.visitController = visitController;
this.errorManager = errorManager;
}
/**
* Returns whether the NOFLIP comment has been found among the comments of the
* node.
*/
private boolean hasNoFlip(CssNode node) {
for (CssCommentNode comment : node.getComments()) {
if (comment.getValue().equals(NOFLIP)) {
return true;
}
}
return false;
}
/**
* Returns whether the node's parent is a ruleset where the first selector is
* marked @noflip.
*/
private boolean firstParentSelectorHasNoFlip(CssDeclarationBlockNode node) {
CssNode parentNode = node.getParent();
if (parentNode instanceof CssRulesetNode) {
CssRulesetNode rulesetNode = (CssRulesetNode) parentNode;
CssSelectorListNode selectors = rulesetNode.getSelectors();
if (selectors.numChildren() == 0) {
return false;
}
if (!selectors.getChildAt(0).getShouldBeFlipped()) {
return true;
}
}
return false;
}
@Override
public boolean enterMediaRule(CssMediaRuleNode node) {
if (hasNoFlip(node)) {
node.setShouldBeFlipped(false);
}
return true;
}
@Override
public boolean enterSelector(CssSelectorNode node) {
if (hasNoFlip(node)) {
node.setShouldBeFlipped(false);
}
return true;
}
@Override
public void leaveSelector(CssSelectorNode node) {
for (CssRefinerNode refiner : node.getRefiners().getChildren()) {
if (hasNoFlip(refiner)) {
node.setShouldBeFlipped(false);
return;
}
}
}
@Override
public boolean enterRuleset(CssRulesetNode node) {
// A ruleset can be inside a media rule or inside the root so we need to
// check both its parent and its grandparent.
// TODO(oana): Add enter and leave methods for the blocks inside a media or
// conditional rule to avoid calling the grandparent here.
boolean noFlip = hasNoFlip(node) || !node.getParent().getShouldBeFlipped()
|| !node.getParent().getParent().getShouldBeFlipped();
if (noFlip) {
node.setShouldBeFlipped(false);
}
return true;
}
@Override
public void leaveRuleset(CssRulesetNode node) {
boolean firstSelector = true;
CssSelectorListNode selectors = node.getSelectors();
for (CssSelectorNode sel : selectors.childIterable()) {
if (!sel.getShouldBeFlipped()) {
if (!firstSelector) {
// Make sure no non-first selectors are marked @noflip.
errorManager.report(new GssError(INVALID_NOFLIP_ERROR_MESSAGE,
node.getSourceCodeLocation()));
} else {
node.setShouldBeFlipped(false);
selectors.setShouldBeFlipped(false);
}
return;
}
firstSelector = false;
}
}
@Override
public boolean enterConditionalBlock(CssConditionalBlockNode node) {
if (hasNoFlip(node) || !node.getParent().getShouldBeFlipped()
|| !node.getParent().getParent().getShouldBeFlipped()) {
node.setShouldBeFlipped(false);
}
return true;
}
@Override
public boolean enterConditionalRule(CssConditionalRuleNode node) {
if (hasNoFlip(node) || !node.getParent().getShouldBeFlipped()) {
node.setShouldBeFlipped(false);
}
return true;
}
@Override
public boolean enterDeclarationBlock(CssDeclarationBlockNode node) {
if (hasNoFlip(node) || !node.getParent().getShouldBeFlipped()
|| firstParentSelectorHasNoFlip(node)) {
node.setShouldBeFlipped(false);
}
return true;
}
@Override
public boolean enterDeclaration(CssDeclarationNode node) {
if (hasNoFlip(node) || !node.getParent().getShouldBeFlipped()) {
node.setShouldBeFlipped(false);
}
return true;
}
@Override
public void runPass() {
visitController.startVisit(this);
}
}