From 3c41c286c7804cd0a50ae9cdf8a22825a946db38 Mon Sep 17 00:00:00 2001
From: Stenzek <stenzek@gmail.com>
Date: Fri, 22 Sep 2023 20:52:35 +1000
Subject: [PATCH] StringUtil: Add Ellipsise

---
 common/StringUtil.cpp                    | 46 +++++++++++++++++++++++-
 common/StringUtil.h                      |  4 +++
 tests/ctest/common/string_util_tests.cpp | 29 +++++++++++++++
 3 files changed, 78 insertions(+), 1 deletion(-)

diff --git a/common/StringUtil.cpp b/common/StringUtil.cpp
index ad9cfc1e25..5afdab8a5b 100644
--- a/common/StringUtil.cpp
+++ b/common/StringUtil.cpp
@@ -1,5 +1,5 @@
 /*  PCSX2 - PS2 Emulator for PCs
- *  Copyright (C) 2002-2021  PCSX2 Dev Team
+ *  Copyright (C) 2002-2023  PCSX2 Dev Team
  *
  *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
  *  of the GNU Lesser General Public License as published by the Free Software Found-
@@ -14,7 +14,10 @@
  */
 
 #include "PrecompiledHeader.h"
+
+#include "Assertions.h"
 #include "StringUtil.h"
+
 #include <cctype>
 #include <codecvt>
 #include <cstdio>
@@ -452,6 +455,47 @@ namespace StringUtil
 		return DecodeUTF8(str.data() + offset, str.length() - offset, ch);
 	}
 
+	std::string Ellipsise(const std::string_view& str, u32 max_length, const char* ellipsis /*= "..."*/)
+	{
+		std::string ret;
+		ret.reserve(max_length);
+
+		const u32 str_length = static_cast<u32>(str.length());
+		const u32 ellipsis_len = static_cast<u32>(std::strlen(ellipsis));
+		pxAssert(ellipsis_len > 0 && ellipsis_len <= max_length);
+
+		if (str_length > max_length)
+		{
+			const u32 copy_size = std::min(str_length, max_length - ellipsis_len);
+			if (copy_size > 0)
+				ret.append(str.data(), copy_size);
+			if (copy_size != str_length)
+				ret.append(ellipsis);
+		}
+		else
+		{
+			ret.append(str);
+		}
+
+		return ret;
+	}
+
+	void EllipsiseInPlace(std::string& str, u32 max_length, const char* ellipsis /*= "..."*/)
+	{
+		const u32 str_length = static_cast<u32>(str.length());
+		const u32 ellipsis_len = static_cast<u32>(std::strlen(ellipsis));
+		pxAssert(ellipsis_len > 0 && ellipsis_len <= max_length);
+
+		if (str_length > max_length)
+		{
+			const u32 keep_size = std::min(static_cast<u32>(str.length()), max_length - ellipsis_len);
+			if (keep_size != str_length)
+				str.erase(keep_size);
+
+			str.append(ellipsis);
+		}
+	}
+
 #ifdef _WIN32
 	std::wstring UTF8StringToWideString(const std::string_view& str)
 	{
diff --git a/common/StringUtil.h b/common/StringUtil.h
index 1b1138cd2d..48f0a77e3a 100644
--- a/common/StringUtil.h
+++ b/common/StringUtil.h
@@ -283,6 +283,10 @@ namespace StringUtil
 	size_t DecodeUTF8(const std::string_view& str, size_t offset, char32_t* ch);
 	size_t DecodeUTF8(const std::string& str, size_t offset, char32_t* ch);
 
+	// Replaces the end of a string with ellipsis if it exceeds the specified length.
+	std::string Ellipsise(const std::string_view& str, u32 max_length, const char* ellipsis = "...");
+	void EllipsiseInPlace(std::string& str, u32 max_length, const char* ellipsis = "...");
+
 	/// Strided memcpy/memcmp.
 	static inline void StrideMemCpy(void* dst, std::size_t dst_stride, const void* src, std::size_t src_stride,
 		std::size_t copy_size, std::size_t count)
diff --git a/tests/ctest/common/string_util_tests.cpp b/tests/ctest/common/string_util_tests.cpp
index 6bc40a535f..bcb6486c2c 100644
--- a/tests/ctest/common/string_util_tests.cpp
+++ b/tests/ctest/common/string_util_tests.cpp
@@ -113,3 +113,32 @@ TEST(StringUtil, FromCharsIsLocaleIndependent)
 }
 
 #endif
+
+TEST(StringUtil, Ellipsise)
+{
+	ASSERT_EQ(StringUtil::Ellipsise("HelloWorld", 6, "..."), "Hel...");
+	ASSERT_EQ(StringUtil::Ellipsise("HelloWorld", 7, ".."), "Hello..");
+	ASSERT_EQ(StringUtil::Ellipsise("HelloWorld", 20, ".."), "HelloWorld");
+	ASSERT_EQ(StringUtil::Ellipsise("", 20, "..."), "");
+	ASSERT_EQ(StringUtil::Ellipsise("Hello", 10, "..."), "Hello");
+}
+
+TEST(StringUtil, EllipsiseInPlace)
+{
+	std::string s;
+	s = "HelloWorld";
+	StringUtil::EllipsiseInPlace(s, 6, "...");
+	ASSERT_EQ(s, "Hel...");
+	s = "HelloWorld";
+	StringUtil::EllipsiseInPlace(s, 7, "..");
+	ASSERT_EQ(s, "Hello..");
+	s = "HelloWorld";
+	StringUtil::EllipsiseInPlace(s, 20, "..");
+	ASSERT_EQ(s, "HelloWorld");
+	s = "";
+	StringUtil::EllipsiseInPlace(s, 20, "...");
+	ASSERT_EQ(s, "");
+	s = "Hello";
+	StringUtil::EllipsiseInPlace(s, 10, "...");
+	ASSERT_EQ(s, "Hello");
+}