/*
* Copyright 2008 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.gwt.resources.css;
import com.google.gwt.dev.util.TextOutput;
import com.google.gwt.resources.css.ast.Context;
import com.google.gwt.resources.css.ast.CssDef;
import com.google.gwt.resources.css.ast.CssEval;
import com.google.gwt.resources.css.ast.CssExternalSelectors;
import com.google.gwt.resources.css.ast.CssIf;
import com.google.gwt.resources.css.ast.CssMediaRule;
import com.google.gwt.resources.css.ast.CssNoFlip;
import com.google.gwt.resources.css.ast.CssNode;
import com.google.gwt.resources.css.ast.CssPageRule;
import com.google.gwt.resources.css.ast.CssProperty;
import com.google.gwt.resources.css.ast.CssRule;
import com.google.gwt.resources.css.ast.CssSelector;
import com.google.gwt.resources.css.ast.CssSprite;
import com.google.gwt.resources.css.ast.CssSubstitution;
import com.google.gwt.resources.css.ast.CssUnknownAtRule;
import com.google.gwt.resources.css.ast.CssUrl;
import com.google.gwt.resources.css.ast.CssVisitor;
import java.util.ArrayList;
import java.util.List;
import java.util.SortedMap;
import java.util.TreeMap;
/**
* Generates a static CSS template string and provides information on where to
* inject dynamic expressions.
*/
public class CssGenerationVisitor extends CssVisitor {
private final TextOutput out;
private boolean needsOpenBrace;
private boolean needsComma;
private final boolean substituteDots;
private final SortedMap<Integer, List<CssSubstitution>> substitutionPositions = new TreeMap<Integer, List<CssSubstitution>>();
/**
* Constructor.
*
* @param out the output hondler
*/
public CssGenerationVisitor(TextOutput out) {
this(out, false);
}
/**
* Constructor for producing an abbreviated form of the template for use with
* {@link CssNode#toString()}.
*
* @param out the output handler
* @param substituteDots if <code>true</code> locations in the text output
* where expression substitutions would normally occur are replaced
* with a textual placeholder
*/
public CssGenerationVisitor(TextOutput out, boolean substituteDots) {
this.out = out;
this.substituteDots = substituteDots;
}
@Override
public void endVisit(CssIf x, Context ctx) {
// Match up an explanatory comment
out.indentOut();
out.printOpt("/* } */");
out.newlineOpt();
}
@Override
public void endVisit(CssMediaRule x, Context ctx) {
out.indentOut();
out.print("}");
out.newlineOpt();
}
@Override
public void endVisit(CssNoFlip x, Context ctx) {
out.printOpt("/*} @noflip */");
out.newlineOpt();
}
@Override
public void endVisit(CssPageRule x, Context ctx) {
out.indentOut();
out.print("}");
out.newlineOpt();
}
@Override
public void endVisit(CssRule x, Context ctx) {
if (!x.getProperties().isEmpty()) {
// Don't print empty rule blocks
closeBrace();
}
}
@Override
public void endVisit(CssUnknownAtRule x, Context ctx) {
out.printOpt("/* Unknown at-rule */\n");
out.print(x.getRule());
}
public SortedMap<Integer, List<CssSubstitution>> getSubstitutionPositions() {
return substitutionPositions;
}
@Override
public boolean visit(CssDef x, Context ctx) {
// These are not valid CSS
out.printOpt("/* CssDef */");
out.newlineOpt();
return false;
}
@Override
public boolean visit(CssEval x, Context ctx) {
// These are not valid CSS
out.printOpt("/* CssEval */");
out.newlineOpt();
return false;
}
@Override
public boolean visit(CssExternalSelectors x, Context ctx) {
// These are not valid CSS
out.printOpt("/* @external");
for (String className : x.getClasses()) {
out.printOpt(" ");
out.printOpt(className);
}
out.printOpt("; */");
out.newlineOpt();
return false;
}
@Override
public boolean visit(CssIf x, Context ctx) {
// Record where the contents of the if block should be inserted
StringBuilder expr = new StringBuilder("/* @if ");
if (x.getExpression() != null) {
expr.append(x.getExpression()).append(" ");
} else {
expr.append(x.getPropertyName()).append(" ");
for (String v : x.getPropertyValues()) {
expr.append(v).append(" ");
}
}
expr.append("{ */");
out.printOpt(expr.toString());
out.newlineOpt();
out.indentIn();
addSubstitition(x);
return false;
}
@Override
public boolean visit(CssMediaRule x, Context ctx) {
out.print("@MEDIA");
for (String m : x.getMedias()) {
out.print(" " + m);
}
spaceOpt();
out.print("{");
out.newlineOpt();
out.indentIn();
return true;
}
@Override
public boolean visit(CssNoFlip x, Context ctx) {
out.printOpt("/*@noflip { */");
out.newlineOpt();
return true;
}
@Override
public boolean visit(CssPageRule x, Context ctx) {
out.print("@page");
if (x.getPseudoPage() != null) {
out.print(" :");
out.print(x.getPseudoPage());
}
spaceOpt();
out.print("{");
out.newlineOpt();
out.indentIn();
return true;
}
@Override
public boolean visit(CssProperty x, Context ctx) {
if (needsOpenBrace) {
openBrace();
needsOpenBrace = false;
}
out.print(x.getName());
colon();
addSubstitition(x);
if (x.isImportant()) {
important();
}
semi();
return true;
}
@Override
public boolean visit(CssRule x, Context ctx) {
if (x.getProperties().isEmpty()) {
// Don't print empty rule blocks
return false;
}
needsOpenBrace = true;
needsComma = false;
return true;
}
@Override
public boolean visit(CssSelector x, Context ctx) {
if (needsComma) {
comma();
}
needsComma = true;
out.print(x.getSelector());
return true;
}
@Override
public boolean visit(CssSprite x, Context ctx) {
// These are not valid CSS
out.printOpt("/* CssSprite */");
out.newlineOpt();
addSubstitition(x);
return false;
}
@Override
public boolean visit(CssUrl x, Context ctx) {
// These are not valid CSS
out.printOpt("/* CssUrl */");
out.newlineOpt();
return false;
}
private <T extends CssNode & CssSubstitution> void addSubstitition(T node) {
if (substituteDots) {
out.printOpt(".....");
out.newlineOpt();
} else {
int position = out.toString().length();
if (substitutionPositions.containsKey(position)) {
substitutionPositions.get(position).add(node);
} else {
List<CssSubstitution> nodes = new ArrayList<CssSubstitution>();
nodes.add(node);
substitutionPositions.put(position, nodes);
}
}
}
private void closeBrace() {
out.indentOut();
out.print('}');
out.newlineOpt();
}
private void colon() {
spaceOpt();
out.print(':');
spaceOpt();
}
private void comma() {
out.print(',');
spaceOpt();
}
private void important() {
out.print(" !important");
}
private void openBrace() {
spaceOpt();
out.print('{');
out.newlineOpt();
out.indentIn();
}
private void semi() {
out.print(';');
out.newlineOpt();
}
private void spaceOpt() {
out.printOpt(' ');
}
}