From: Carl Hetherington <cth@carlh.net>
Date: Sat, 25 Feb 2023 22:38:47 +0000 (+0100)
Subject: Add word_wrap().
X-Git-Tag: v2.16.45~7
X-Git-Url: https://git.carlh.net/gitweb/?p=dcpomatic.git;a=commitdiff_plain;h=61614dcb37ce1bc3cf3fc2915ccac741cfef68e5

Add word_wrap().
---

diff --git a/src/lib/util.cc b/src/lib/util.cc
index 6ed66c40f..20a965781 100644
--- 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;
+}
+
diff --git a/src/lib/util.h b/src/lib/util.h
index d53fc06e0..4c8a2b1b7 100644
--- a/src/lib/util.h
+++ b/src/lib/util.h
@@ -95,5 +95,6 @@ extern boost::filesystem::path default_font_file ();
 extern void start_of_thread (std::string name);
 extern std::string error_details(boost::system::error_code ec);
 extern bool contains_assetmap(boost::filesystem::path dir);
+extern std::string word_wrap(std::string input, int columns);
 
 #endif
diff --git a/test/util_test.cc b/test/util_test.cc
index 872e6f885..49d0b3bc2 100644
--- a/test/util_test.cc
+++ b/test/util_test.cc
@@ -147,3 +147,11 @@ BOOST_AUTO_TEST_CASE (copy_in_bits_test)
 		check_file ("build/test/random.dat", "build/test/random.dat2");
 	}
 }
+
+
+BOOST_AUTO_TEST_CASE(word_wrap_test)
+{
+	BOOST_CHECK_EQUAL(word_wrap("hello world", 8), "hello \nworld\n");
+	BOOST_CHECK(word_wrap("hello this is a longer bit of text and it should be word-wrapped", 31) == string{"hello this is a longer bit of \ntext and it should be word-\nwrapped\n"});
+	BOOST_CHECK_EQUAL(word_wrap("hellocan'twrapthissadly", 5), "hello\ncan't\nwrapt\nhissa\ndly\n");
+}