Add word_wrap().

[dcpomatic.git] / src / lib / util.cc

diff --git a/src/lib/util.cc b/src/lib/util.cc
index 6ed66c40f27d14f3cc0dfd6c556b4a6f3c5b0d60..20a96578144109bd613cbf2a98f6f5cb6df0ff18 100644 (file)
--- a/src/lib/util.cc
+++ b/src/lib/util.cc
@@ -47,6 +47,7 @@
 #include "ratio.h"
 #include "rect.h"
 #include "render_text.h"
+#include "scope_guard.h"
 #include "string_text.h"
 #include "text_decoder.h"
 #include "util.h"
@@ -73,6 +74,7 @@ LIBDCP_ENABLE_WARNINGS
 #include <unicode/utypes.h>
 #include <unicode/unistr.h>
 #include <unicode/translit.h>
+#include <unicode/brkiter.h>
 #include <boost/algorithm/string.hpp>
 #include <boost/range/algorithm/replace_if.hpp>
 #include <boost/thread.hpp>
@@ -1079,3 +1081,38 @@ contains_assetmap(boost::filesystem::path dir)
        return boost::filesystem::is_regular_file(dir / "ASSETMAP") || boost::filesystem::is_regular_file(dir / "ASSETMAP.xml");
 }
 
+
+string
+word_wrap(string input, int columns)
+{
+       icu::Locale locale;
+       UErrorCode status = U_ZERO_ERROR;
+       auto iter = icu::BreakIterator::createLineInstance(locale, status);
+       ScopeGuard sg = [iter]() { delete iter; };
+       if (U_FAILURE(status)) {
+               return input;
+       }
+
+       auto input_icu = icu::UnicodeString::fromUTF8(icu::StringPiece(input));
+       iter->setText(input_icu);
+
+       int position = 0;
+       string output;
+       while (position < input_icu.length()) {
+               int end_of_line = iter->preceding(position + columns + 1);
+               icu::UnicodeString line;
+               if (end_of_line <= position) {
+                       /* There's no good line-break position; just break in the middle of a word */
+                       line = input_icu.tempSubString(position, columns);
+                       position += columns;
+               } else {
+                       line = input_icu.tempSubString(position, end_of_line - position);
+                       position = end_of_line;
+               }
+               line.toUTF8String(output);
+               output += "\n";
+       }
+
+       return output;
+}
+