com.google.gwt.i18n.rebind.StringGenerator Maven / Gradle / Ivy
/*
* Copyright 2010 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.i18n.rebind;
/**
* Helper class to produce string expressions consisting of literals and
* computed values.
*/
public class StringGenerator {
/**
* Output string buffer.
*/
private StringBuffer buf;
/**
* True if we are in the middle of a string literal.
*/
private boolean inString;
/**
* True if the method's return type is SafeHtml (and SafeHtmlBuilder is to
* be used to generate the expression); otherwise a String expression is
* generated.
*/
private final boolean returnsSafeHtml;
/**
* Initialize the StringGenerator with an output buffer.
*
* @param buf output buffer
* @param returnsSafeHtml if true, an expression of type {@link SafeHtml} is
* being generated, otherwise a {@link String}-valued expression is
* generated
*/
public StringGenerator(StringBuffer buf, boolean returnsSafeHtml) {
this.buf = buf;
inString = false;
this.returnsSafeHtml = returnsSafeHtml;
if (returnsSafeHtml) {
buf.append("new " + MessagesMethodCreator.SAFE_HTML_BUILDER_FQCN + "()");
} else {
buf.append("new java.lang.StringBuffer()");
}
}
/**
* Append an expression to this string expression.
*
* @param expression to add
* @param isSafeHtmlTyped true if the expression is known to be of type
* {@link SafeHtml}; only relevant if this generator has been
* initialized to generate a {@link SafeHtml}-valued expression
* @param isPrimititiveTyped true if the expression is of a primitive type;
* only relevant if this generator has been initialized to generate
* a {@link SafeHtml}-valued expression
* @param needsConversionToString true if the expression is not known to be
* of type String and needs to be converted
*/
public void appendExpression(String expression, boolean isSafeHtmlTyped,
boolean isPrimititiveTyped, boolean needsConversionToString) {
if (inString) {
buf.append("\")");
inString = false;
}
/*
* SafeHtmlBuilder has append() methods for primitive types as well as for
* SafeHtml-valued expressions. For all other expression types, use
* appendEscaped(). In addition, if the expression is not known to be of
* type String, covert to String.
*/
if (returnsSafeHtml && !isSafeHtmlTyped && !isPrimititiveTyped) {
buf.append(".appendEscaped(");
if (needsConversionToString) {
buf.append("String.valueOf(");
}
} else {
buf.append(".append(");
}
buf.append(expression);
buf.append(")");
if (returnsSafeHtml && !isSafeHtmlTyped && !isPrimititiveTyped
&& needsConversionToString) {
buf.append(")");
}
}
/**
* Append part of a string literal.
*
* @param str part of string literal
*/
public void appendStringLiteral(String str) {
if (!inString) {
if (returnsSafeHtml) {
buf.append(".appendHtmlConstant(\"");
} else {
buf.append(".append(\"");
}
inString = true;
}
buf.append(str);
}
/**
* Append an expression to this string expression.
*
* @param expression to add, which the caller asserts is String-valued
*/
public void appendStringValuedExpression(String expression) {
appendExpression(expression, false, false, false);
}
/**
* Complete the string, closing an open quote and handling empty strings.
*/
public void completeString() {
if (inString) {
buf.append("\")");
}
if (returnsSafeHtml) {
buf.append(".toSafeHtml()");
} else {
buf.append(".toString()");
}
}
}