/*
* 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.base.Preconditions;
import com.google.common.css.compiler.ast.ChunkAware;
import com.google.common.css.compiler.ast.CssCompilerPass;
import com.google.common.css.compiler.ast.CssDefinitionNode;
import com.google.common.css.compiler.ast.CssFontFaceNode;
import com.google.common.css.compiler.ast.CssFunctionNode;
import com.google.common.css.compiler.ast.CssKeyframesNode;
import com.google.common.css.compiler.ast.CssMediaRuleNode;
import com.google.common.css.compiler.ast.CssNode;
import com.google.common.css.compiler.ast.CssSelectorNode;
import com.google.common.css.compiler.ast.CssTree;
import com.google.common.css.compiler.ast.DefaultTreeVisitor;
import java.util.Map;
/**
* Pass which marks which {@link ChunkAware} nodes belong to which chunk.
*
* @param <T> type of chunk id objects set on {@link ChunkAware} nodes
*
* @author dgajda@google.com (Damian Gajda)
*/
public class MapChunkAwareNodesToChunk<T> extends DefaultTreeVisitor
implements CssCompilerPass {
private final CssTree tree;
private final Map<String, T> fileToChunk;
public MapChunkAwareNodesToChunk(
CssTree tree, Map<String, T> fileToChunk) {
this.tree = tree;
this.fileToChunk = fileToChunk;
}
@Override
public boolean enterDefinition(CssDefinitionNode definition) {
definition.setChunk(getChunk(definition));
return true;
}
/**
* Marks the selector with an appropriate chunk.
*/
@Override
public boolean enterSelector(CssSelectorNode selector) {
selector.setChunk(getChunk(selector));
return true;
}
@Override
public boolean enterFunctionNode(CssFunctionNode function) {
function.setChunk(getChunk(function));
return true;
}
@Override
public boolean enterMediaRule(CssMediaRuleNode media) {
media.setChunk(getChunk(media));
return true;
}
@Override
public boolean enterKeyframesRule(CssKeyframesNode keyframes) {
keyframes.setChunk(getChunk(keyframes));
return true;
}
@Override
public boolean enterFontFace(CssFontFaceNode fontFaceNode) {
fontFaceNode.setChunk(getChunk(fontFaceNode));
return true;
}
/**
* Determine the chunk for the given node.
*
* @param node A css node that is chunk aware.
*/
private <N extends CssNode & ChunkAware> T getChunk(N node) {
@SuppressWarnings("unchecked")
T chunk = (T) node.getChunk();
if (chunk == null) {
chunk = getChunk(node, fileToChunk);
}
return chunk;
}
@Override
public void runPass() {
tree.getVisitController().startVisit(this);
}
/**
* Finds the chunk of a node, by looking up the filename of its
* source code location in the given map from filenames to
* chunks. Assumes that the map is complete, such that it always
* contains the filename of any valid source code location.
*
* @param node the node to find the chunk for
* @param fileToChunk a map from filenames to chunks
* @return the chunk of the node according to the map
*/
static <T> T getChunk(CssNode node, Map<String, T> fileToChunk) {
String file = node.getSourceCodeLocation().getSourceCode().getFileName();
T chunk = fileToChunk.get(file);
Preconditions.checkNotNull(chunk, "File '%s' does not have chunk mapping",
file);
return chunk;
}
}