StaticText/EnrichedString: Styling support (#9187)

* StaticText/EnrichedString: Styling support

* Fix tooltip fg/bgcolor

* Fix default color for substr(), add unittests

1 files changed, 55 insertions, 16 deletions

diff --git a/src/util/enriched_string.cpp b/src/util/enriched_string.cpp
index 642188a52..d5f8aa661 100644
--- a/src/util/enriched_string.cpp
+++ b/src/util/enriched_string.cpp
@@ -45,15 +45,27 @@ EnrichedString::EnrichedString(const wchar_t *str, const SColor &color)
 	addAtEnd(translate_string(std::wstring(str)), color);
 }
 
+void EnrichedString::clear()
+{
+	m_string.clear();
+	m_colors.clear();
+	m_has_background = false;
+	m_default_length = 0;
+	m_default_color = irr::video::SColor(255, 255, 255, 255);
+}
+
 void EnrichedString::operator=(const wchar_t *str)
 {
 	clear();
-	addAtEnd(translate_string(std::wstring(str)), SColor(255, 255, 255, 255));
+	addAtEnd(translate_string(std::wstring(str)), m_default_color);
 }
 
 void EnrichedString::addAtEnd(const std::wstring &s, const SColor &initial_color)
 {
 	SColor color(initial_color);
+	bool use_default = (m_default_length == m_string.size() &&
+		color == m_default_color);
+
 	size_t i = 0;
 	while (i < s.length()) {
 		if (s[i] != L'\x1b') {
@@ -90,6 +102,12 @@ void EnrichedString::addAtEnd(const std::wstring &s, const SColor &initial_color
 				continue;
 			}
 			parseColorString(wide_to_utf8(parts[1]), color, true);
+
+			// No longer use default color after first escape
+			if (use_default) {
+				m_default_length = m_string.size();
+				use_default = false;
+			}
 		} else if (parts[0] == L"b") {
 			if (parts.size() < 2) {
 				continue;
@@ -98,6 +116,10 @@ void EnrichedString::addAtEnd(const std::wstring &s, const SColor &initial_color
 			m_has_background = true;
 		}
 	}
+
+	// Update if no escape character was found
+	if (use_default)
+		m_default_length = m_string.size();
 }
 
 void EnrichedString::addChar(const EnrichedString &source, size_t i)
@@ -110,7 +132,7 @@ void EnrichedString::addCharNoColor(wchar_t c)
 {
 	m_string += c;
 	if (m_colors.empty()) {
-		m_colors.emplace_back(255, 255, 255, 255);
+		m_colors.emplace_back(m_default_color);
 	} else {
 		m_colors.push_back(m_colors[m_colors.size() - 1]);
 	}
@@ -118,35 +140,40 @@ void EnrichedString::addCharNoColor(wchar_t c)
 
 EnrichedString EnrichedString::operator+(const EnrichedString &other) const
 {
-	std::vector<SColor> result;
-	result.insert(result.end(), m_colors.begin(), m_colors.end());
-	result.insert(result.end(), other.m_colors.begin(), other.m_colors.end());
-	return EnrichedString(m_string + other.m_string, result);
+	EnrichedString result = *this;
+	result += other;
+	return result;
 }
 
 void EnrichedString::operator+=(const EnrichedString &other)
 {
+	bool update_default_color = m_default_length == m_string.size();
+
 	m_string += other.m_string;
 	m_colors.insert(m_colors.end(), other.m_colors.begin(), other.m_colors.end());
+
+	if (update_default_color) {
+		m_default_length += other.m_default_length;
+		updateDefaultColor();
+	}
 }
 
 EnrichedString EnrichedString::substr(size_t pos, size_t len) const
 {
-	if (pos == m_string.length()) {
+	if (pos >= m_string.length())
 		return EnrichedString();
-	}
-	if (len == std::string::npos || pos + len > m_string.length()) {
-		return EnrichedString(
-			m_string.substr(pos, std::string::npos),
-			std::vector<SColor>(m_colors.begin() + pos, m_colors.end())
-		);
-	}
 
-	return EnrichedString(
+	if (len == std::string::npos || pos + len > m_string.length())
+		len = m_string.length() - pos;
+
+	EnrichedString str(
 		m_string.substr(pos, len),
 		std::vector<SColor>(m_colors.begin() + pos, m_colors.begin() + pos + len)
 	);
-
+	if (pos < m_default_length)
+		str.m_default_length = m_default_length - pos;
+	str.setDefaultColor(m_default_color);
+	return str;
 }
 
 const wchar_t *EnrichedString::c_str() const
@@ -163,3 +190,15 @@ const std::wstring &EnrichedString::getString() const
 {
 	return m_string;
 }
+
+void EnrichedString::setDefaultColor(const irr::video::SColor &color)
+{
+	m_default_color = color;
+	updateDefaultColor();
+}
+
+void EnrichedString::updateDefaultColor()
+{
+	for (size_t i = 0; i < m_default_length; ++i)
+		m_colors[i] = m_default_color;
+}