/*
* 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.dev.jjs.impl;
import com.google.gwt.core.ext.linker.StatementRanges;
import com.google.gwt.core.ext.linker.impl.StandardStatementRanges;
import java.util.ArrayList;
/**
* Base class for transforming program text.
*/
public abstract class JsAbstractTextTransformer {
protected String js;
protected StatementRanges statementRanges;
public JsAbstractTextTransformer(String js, StatementRanges statementRanges) {
this.js = js;
this.statementRanges = statementRanges;
}
public JsAbstractTextTransformer(JsAbstractTextTransformer xformer) {
this.js = xformer.getJs();
this.statementRanges = xformer.getStatementRanges();
}
public abstract void exec();
public String getJs() {
return js;
}
public StatementRanges getStatementRanges() {
return statementRanges;
}
protected void addStatement(String code, StringBuilder newJs,
ArrayList<Integer> starts, ArrayList<Integer> ends) {
beginStatement(newJs, starts);
newJs.append(code);
endStatement(newJs, ends);
}
protected void beginStatement(StringBuilder newJs,
ArrayList<Integer> starts) {
starts.add(newJs.length());
}
/**
* Called if any operations need to be performed before all statements have
* been processed.
*/
protected void beginStatements(StringBuilder newJs, ArrayList<Integer> starts,
ArrayList<Integer> ends) {
}
protected void endStatement(StringBuilder newJs, ArrayList<Integer> ends) {
ends.add(newJs.length());
}
/**
* Called if any operations need to be performed after all statements have
* been processed.
*/
protected void endStatements(StringBuilder newJs, ArrayList<Integer> starts,
ArrayList<Integer> ends) {
}
protected String getJsForRange(int stmtIndex) {
return js.substring(statementRanges.start(stmtIndex),
statementRanges.end(stmtIndex));
}
/**
* Dump functions and fragments back into a new JS string, and calculate a new
* StatementRanges object.
*/
protected void recomputeJsAndStatementRanges(int[] stmtIndices) {
StringBuilder newJs = new StringBuilder();
ArrayList<Integer> starts = new ArrayList<Integer>();
ArrayList<Integer> ends = new ArrayList<Integer>();
beginStatements(newJs, starts, ends);
for (int i = 0; i < stmtIndices.length; i++) {
String code = getJsForRange(stmtIndices[i]);
addStatement(code, newJs, starts, ends);
}
endStatements(newJs, starts, ends);
assert
starts.size() == ends.size() :
"Size mismatch between start and" + " end statement ranges.";
assert starts.get(0) == 0 && ends.get(ends.size() - 1) ==
newJs.length() :
"statement ranges don't cover entire JS output string.";
StandardStatementRanges newRanges = new StandardStatementRanges(starts,
ends);
js = newJs.toString();
statementRanges = newRanges;
}
}