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- /*
- * YUI Compressor
- * http://developer.yahoo.com/yui/compressor/
- * Author: Julien Lecomte - http://www.julienlecomte.net/
- * Author: Isaac Schlueter - http://foohack.com/
- * Author: Stoyan Stefanov - http://phpied.com/
- * Copyright (c) 2011 Yahoo! Inc. All rights reserved.
- * The copyrights embodied in the content of this file are licensed
- * by Yahoo! Inc. under the BSD (revised) open source license.
- */
- package com.yahoo.platform.yui.compressor;
- import java.io.IOException;
- import java.io.Reader;
- import java.io.Writer;
- import java.util.regex.Pattern;
- import java.util.regex.Matcher;
- import java.util.ArrayList;
- public class CssCompressor {
- private StringBuffer srcsb = new StringBuffer();
- public CssCompressor(Reader in) throws IOException {
- // Read the stream...
- int c;
- while ((c = in.read()) != -1) {
- srcsb.append((char) c);
- }
- }
- // Leave data urls alone to increase parse performance.
- protected String extractDataUrls(String css, ArrayList preservedTokens) {
- int maxIndex = css.length() - 1;
- int appendIndex = 0;
- StringBuffer sb = new StringBuffer();
- Pattern p = Pattern.compile("url\\(\\s*([\"']?)data\\:");
- Matcher m = p.matcher(css);
-
- /*
- * Since we need to account for non-base64 data urls, we need to handle
- * ' and ) being part of the data string. Hence switching to indexOf,
- * to determine whether or not we have matching string terminators and
- * handling sb appends directly, instead of using matcher.append* methods.
- */
- while (m.find()) {
- int startIndex = m.start() + 4; // "url(".length()
- String terminator = m.group(1); // ', " or empty (not quoted)
-
- if (terminator.length() == 0) {
- terminator = ")";
- }
- boolean foundTerminator = false;
- int endIndex = m.end() - 1;
- while(foundTerminator == false && endIndex+1 <= maxIndex) {
- endIndex = css.indexOf(terminator, endIndex+1);
- if ((endIndex > 0) && (css.charAt(endIndex-1) != '\\')) {
- foundTerminator = true;
- if (!")".equals(terminator)) {
- endIndex = css.indexOf(")", endIndex);
- }
- }
- }
- // Enough searching, start moving stuff over to the buffer
- sb.append(css.substring(appendIndex, m.start()));
- if (foundTerminator) {
- String token = css.substring(startIndex, endIndex);
- token = token.replaceAll("\\s+", "");
- preservedTokens.add(token);
- String preserver = "url(___YUICSSMIN_PRESERVED_TOKEN_" + (preservedTokens.size() - 1) + "___)";
- sb.append(preserver);
- appendIndex = endIndex + 1;
- } else {
- // No end terminator found, re-add the whole match. Should we throw/warn here?
- sb.append(css.substring(m.start(), m.end()));
- appendIndex = m.end();
- }
- }
- sb.append(css.substring(appendIndex));
- return sb.toString();
- }
- public void compress(Writer out, int linebreakpos)
- throws IOException {
- Pattern p;
- Matcher m;
- String css = srcsb.toString();
- int startIndex = 0;
- int endIndex = 0;
- int i = 0;
- int max = 0;
- ArrayList preservedTokens = new ArrayList(0);
- ArrayList comments = new ArrayList(0);
- String token;
- int totallen = css.length();
- String placeholder;
- css = this.extractDataUrls(css, preservedTokens);
- StringBuffer sb = new StringBuffer(css);
- // collect all comment blocks...
- while ((startIndex = sb.indexOf("/*", startIndex)) >= 0) {
- endIndex = sb.indexOf("*/", startIndex + 2);
- if (endIndex < 0) {
- endIndex = totallen;
- }
- token = sb.substring(startIndex + 2, endIndex);
- comments.add(token);
- sb.replace(startIndex + 2, endIndex, "___YUICSSMIN_PRESERVE_CANDIDATE_COMMENT_" + (comments.size() - 1) + "___");
- startIndex += 2;
- }
- css = sb.toString();
- // preserve strings so their content doesn't get accidentally minified
- sb = new StringBuffer();
- p = Pattern.compile("(\"([^\\\\\"]|\\\\.|\\\\)*\")|(\'([^\\\\\']|\\\\.|\\\\)*\')");
- m = p.matcher(css);
- while (m.find()) {
- token = m.group();
- char quote = token.charAt(0);
- token = token.substring(1, token.length() - 1);
- // maybe the string contains a comment-like substring?
- // one, maybe more? put'em back then
- if (token.indexOf("___YUICSSMIN_PRESERVE_CANDIDATE_COMMENT_") >= 0) {
- for (i = 0, max = comments.size(); i < max; i += 1) {
- token = token.replace("___YUICSSMIN_PRESERVE_CANDIDATE_COMMENT_" + i + "___", comments.get(i).toString());
- }
- }
- // minify alpha opacity in filter strings
- token = token.replaceAll("(?i)progid:DXImageTransform.Microsoft.Alpha\\(Opacity=", "alpha(opacity=");
- preservedTokens.add(token);
- String preserver = quote + "___YUICSSMIN_PRESERVED_TOKEN_" + (preservedTokens.size() - 1) + "___" + quote;
- m.appendReplacement(sb, preserver);
- }
- m.appendTail(sb);
- css = sb.toString();
- // strings are safe, now wrestle the comments
- for (i = 0, max = comments.size(); i < max; i += 1) {
- token = comments.get(i).toString();
- placeholder = "___YUICSSMIN_PRESERVE_CANDIDATE_COMMENT_" + i + "___";
- // ! in the first position of the comment means preserve
- // so push to the preserved tokens while stripping the !
- if (token.startsWith("!")) {
- preservedTokens.add(token);
- css = css.replace(placeholder, "___YUICSSMIN_PRESERVED_TOKEN_" + (preservedTokens.size() - 1) + "___");
- continue;
- }
- // \ in the last position looks like hack for Mac/IE5
- // shorten that to /*\*/ and the next one to /**/
- if (token.endsWith("\\")) {
- preservedTokens.add("\\");
- css = css.replace(placeholder, "___YUICSSMIN_PRESERVED_TOKEN_" + (preservedTokens.size() - 1) + "___");
- i = i + 1; // attn: advancing the loop
- preservedTokens.add("");
- css = css.replace("___YUICSSMIN_PRESERVE_CANDIDATE_COMMENT_" + i + "___", "___YUICSSMIN_PRESERVED_TOKEN_" + (preservedTokens.size() - 1) + "___");
- continue;
- }
- // keep empty comments after child selectors (IE7 hack)
- // e.g. html >/**/ body
- if (token.length() == 0) {
- startIndex = css.indexOf(placeholder);
- if (startIndex > 2) {
- if (css.charAt(startIndex - 3) == '>') {
- preservedTokens.add("");
- css = css.replace(placeholder, "___YUICSSMIN_PRESERVED_TOKEN_" + (preservedTokens.size() - 1) + "___");
- }
- }
- }
- // in all other cases kill the comment
- css = css.replace("/*" + placeholder + "*/", "");
- }
- // Normalize all whitespace strings to single spaces. Easier to work with that way.
- css = css.replaceAll("\\s+", " ");
- // Remove the spaces before the things that should not have spaces before them.
- // But, be careful not to turn "p :link {...}" into "p:link{...}"
- // Swap out any pseudo-class colons with the token, and then swap back.
- sb = new StringBuffer();
- p = Pattern.compile("(^|\\})(([^\\{:])+:)+([^\\{]*\\{)");
- m = p.matcher(css);
- while (m.find()) {
- String s = m.group();
- s = s.replaceAll(":", "___YUICSSMIN_PSEUDOCLASSCOLON___");
- s = s.replaceAll( "\\\\", "\\\\\\\\" ).replaceAll( "\\$", "\\\\\\$" );
- m.appendReplacement(sb, s);
- }
- m.appendTail(sb);
- css = sb.toString();
- // Remove spaces before the things that should not have spaces before them.
- css = css.replaceAll("\\s+([!{};:>+\\(\\)\\],])", "$1");
- // bring back the colon
- css = css.replaceAll("___YUICSSMIN_PSEUDOCLASSCOLON___", ":");
- // retain space for special IE6 cases
- css = css.replaceAll(":first\\-(line|letter)(\\{|,)", ":first-$1 $2");
- // no space after the end of a preserved comment
- css = css.replaceAll("\\*/ ", "*/");
- // If there is a @charset, then only allow one, and push to the top of the file.
- css = css.replaceAll("^(.*)(@charset \"[^\"]*\";)", "$2$1");
- css = css.replaceAll("^(\\s*@charset [^;]+;\\s*)+", "$1");
- // Put the space back in some cases, to support stuff like
- // @media screen and (-webkit-min-device-pixel-ratio:0){
- css = css.replaceAll("\\band\\(", "and (");
- // Remove the spaces after the things that should not have spaces after them.
- css = css.replaceAll("([!{}:;>+\\(\\[,])\\s+", "$1");
- // remove unnecessary semicolons
- css = css.replaceAll(";+}", "}");
- // Replace 0(px,em,%) with 0.
- css = css.replaceAll("([\\s:])(0)(px|em|%|in|cm|mm|pc|pt|ex)", "$1$2");
- // Replace 0 0 0 0; with 0.
- css = css.replaceAll(":0 0 0 0(;|})", ":0$1");
- css = css.replaceAll(":0 0 0(;|})", ":0$1");
- css = css.replaceAll(":0 0(;|})", ":0$1");
- // Replace background-position:0; with background-position:0 0;
- // same for transform-origin
- sb = new StringBuffer();
- p = Pattern.compile("(?i)(background-position|transform-origin|webkit-transform-origin|moz-transform-origin|o-transform-origin|ms-transform-origin):0(;|})");
- m = p.matcher(css);
- while (m.find()) {
- m.appendReplacement(sb, m.group(1).toLowerCase() + ":0 0" + m.group(2));
- }
- m.appendTail(sb);
- css = sb.toString();
- // Replace 0.6 to .6, but only when preceded by : or a white-space
- css = css.replaceAll("(:|\\s)0+\\.(\\d+)", "$1.$2");
- // Shorten colors from rgb(51,102,153) to #336699
- // This makes it more likely that it'll get further compressed in the next step.
- p = Pattern.compile("rgb\\s*\\(\\s*([0-9,\\s]+)\\s*\\)");
- m = p.matcher(css);
- sb = new StringBuffer();
- while (m.find()) {
- String[] rgbcolors = m.group(1).split(",");
- StringBuffer hexcolor = new StringBuffer("#");
- for (i = 0; i < rgbcolors.length; i++) {
- int val = Integer.parseInt(rgbcolors[i]);
- if (val < 16) {
- hexcolor.append("0");
- }
- hexcolor.append(Integer.toHexString(val));
- }
- m.appendReplacement(sb, hexcolor.toString());
- }
- m.appendTail(sb);
- css = sb.toString();
- // Shorten colors from #AABBCC to #ABC. Note that we want to make sure
- // the color is not preceded by either ", " or =. Indeed, the property
- // filter: chroma(color="#FFFFFF");
- // would become
- // filter: chroma(color="#FFF");
- // which makes the filter break in IE.
- // We also want to make sure we're only compressing #AABBCC patterns inside { }, not id selectors ( #FAABAC {} )
- // We also want to avoid compressing invalid values (e.g. #AABBCCD to #ABCD)
- p = Pattern.compile("(\\=\\s*?[\"']?)?" + "#([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])" + "(:?\\}|[^0-9a-fA-F{][^{]*?\\})");
- m = p.matcher(css);
- sb = new StringBuffer();
- int index = 0;
- while (m.find(index)) {
- sb.append(css.substring(index, m.start()));
- boolean isFilter = (m.group(1) != null && !"".equals(m.group(1)));
- if (isFilter) {
- // Restore, as is. Compression will break filters
- sb.append(m.group(1) + "#" + m.group(2) + m.group(3) + m.group(4) + m.group(5) + m.group(6) + m.group(7));
- } else {
- if( m.group(2).equalsIgnoreCase(m.group(3)) &&
- m.group(4).equalsIgnoreCase(m.group(5)) &&
- m.group(6).equalsIgnoreCase(m.group(7))) {
- // #AABBCC pattern
- sb.append("#" + (m.group(3) + m.group(5) + m.group(7)).toLowerCase());
- } else {
- // Non-compressible color, restore, but lower case.
- sb.append("#" + (m.group(2) + m.group(3) + m.group(4) + m.group(5) + m.group(6) + m.group(7)).toLowerCase());
- }
- }
- index = m.end(7);
- }
- sb.append(css.substring(index));
- css = sb.toString();
- // border: none -> border:0
- sb = new StringBuffer();
- p = Pattern.compile("(?i)(border|border-top|border-right|border-bottom|border-right|outline|background):none(;|})");
- m = p.matcher(css);
- while (m.find()) {
- m.appendReplacement(sb, m.group(1).toLowerCase() + ":0" + m.group(2));
- }
- m.appendTail(sb);
- css = sb.toString();
- // shorter opacity IE filter
- css = css.replaceAll("(?i)progid:DXImageTransform.Microsoft.Alpha\\(Opacity=", "alpha(opacity=");
- // Remove empty rules.
- css = css.replaceAll("[^\\}\\{/;]+\\{\\}", "");
- // TODO: Should this be after we re-insert tokens. These could alter the break points. However then
- // we'd need to make sure we don't break in the middle of a string etc.
- if (linebreakpos >= 0) {
- // Some source control tools don't like it when files containing lines longer
- // than, say 8000 characters, are checked in. The linebreak option is used in
- // that case to split long lines after a specific column.
- i = 0;
- int linestartpos = 0;
- sb = new StringBuffer(css);
- while (i < sb.length()) {
- char c = sb.charAt(i++);
- if (c == '}' && i - linestartpos > linebreakpos) {
- sb.insert(i, '\n');
- linestartpos = i;
- }
- }
- css = sb.toString();
- }
- // Replace multiple semi-colons in a row by a single one
- // See SF bug #1980989
- css = css.replaceAll(";;+", ";");
- // restore preserved comments and strings
- for(i = 0, max = preservedTokens.size(); i < max; i++) {
- css = css.replace("___YUICSSMIN_PRESERVED_TOKEN_" + i + "___", preservedTokens.get(i).toString());
- }
- // Trim the final string (for any leading or trailing white spaces)
- css = css.trim();
- // Write the output...
- out.write(css);
- }
- }
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