com.google.gwt.uibinder.attributeparsers.LengthAttributeParser Maven / Gradle / Ivy
/*
* 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.gwt.uibinder.attributeparsers;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.uibinder.rebind.MortalLogger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Parses a CSS length value (e.g., "2em", "50%"), returning a comma-separated
* (double, Unit) pair.
*/
public class LengthAttributeParser implements AttributeParser {
static final String UNIT = Unit.class.getCanonicalName();
// This regular expression matches CSS length patterns of the form
// (value)(unit), where the two may be separated by whitespace. Either part
// can be a {class.method} expression.
private static final Pattern pattern = Pattern.compile("((?:\\{[\\w\\.]+\\})|[\\+\\-]?[\\d\\.]+)\\s*(\\{?[\\w\\.\\%]*\\}?)?");
private final MortalLogger logger;
private final DoubleAttributeParser doubleParser;
private final EnumAttributeParser enumParser;
LengthAttributeParser(DoubleAttributeParser doubleParser,
EnumAttributeParser enumParser, MortalLogger logger) {
this.doubleParser = doubleParser;
this.enumParser = enumParser;
this.logger = logger;
}
public String parse(String lengthStr) throws UnableToCompleteException {
Matcher matcher = pattern.matcher(lengthStr);
if (!matcher.matches()) {
logger.die("Unable to parse %s as length", lengthStr);
}
String valueStr = matcher.group(1);
String value = doubleParser.parse(valueStr);
String unit = null;
String unitStr = matcher.group(2);
if (unitStr.length() > 0) {
if (!unitStr.startsWith("{")) {
// For non-refs, convert % => PCT, px => PX, etc.
if ("%".equals(unitStr)) {
unitStr = "PCT";
}
unitStr = unitStr.toUpperCase();
}
// Now let the default enum parser handle it.
unit = enumParser.parse(unitStr);
} else {
// Use PX by default.
unit = UNIT + ".PX";
}
return value + ", " + unit;
}
}