public File createDiff(File out, String dest) {
File result = out;
try {
String[] a = DiffPrint.slurp(original);
String[] b = DiffPrint.slurp(revised);
Diff d = new Diff(a, b);
Diff.change script = d.diff_2(false);
if (script == null) {
JOptionPane.showMessageDialog(null, "Error: No differences");
result = null;
} else {
DiffPrint.Base p = new DiffPrint.UnifiedPrint(a, b);
FileWriter fw = new FileWriter(result);
p.setOutput(fw);
p.print_header(".orig" + dest, dest);
p.print_script(script);
p.close();
doubleCheckChunkHeaders(result);
}
} catch (Exception e) {
result = null;
}
return result;
}
private void doubleCheckChunkHeaders(File out) {
try {
String[] patch = DiffPrint.slurp(out);
int currHeader = -1;
int before = 0;
int after = 0;
int offset = 0;
ChunkHeader curr = null;
for (int i = 0; i < patch.length; i++) {
if (patch[i].startsWith("@@")) {
if (currHeader != -1 && curr != null) { // finish
curr.setBeforeRange(before);
curr.setAfterRange(after);
patch[currHeader] = curr.toString();
}
currHeader = i;
curr = new ChunkHeader(patch[i]);
offset += (after - before);
curr.setOffset(offset);
before = 0;
after = 0;
} else if (patch[i].startsWith("+")) {
after++;
} else if (patch[i].startsWith("-")) {
before++;
} else if (patch[i].startsWith(" ")) {
before++;
after++;
}
}
if (currHeader != -1 && curr != null) { // last header
curr.setBeforeRange(before);
curr.setAfterRange(after);
patch[currHeader] = curr.toString();
}
writeToFile(out, patch);
} catch (Exception e) {
}
}