ui: Fixed annotation hovering slow in code snippet view due to style calculation from setting stylesheets

src/lib_gui/qt/element/QtCodeFile.cpp

@@ -1,6 +1,7 @@
 #include "QtCodeFile.h"
 
 #include <QVBoxLayout>
+#include <QStyle>
 
 #include "MessageChangeFileView.h"
 
@@ -363,23 +364,15 @@ void QtCodeFile::updateSnippets()
 	int maxDigits = 1;
 	for (QtCodeSnippet* snippet : m_snippets)
 	{
-		if (snippet != m_snippets.front() && snippet->styleSheet().size())
-		{
-			snippet->setStyleSheet("");
-		}
-
 		maxDigits = qMax(maxDigits, snippet->lineNumberDigits());
 	}
 
 	for (QtCodeSnippet* snippet : m_snippets)
 	{
+		snippet->setProperty("first", snippet == m_snippets.front());
+		snippet->style()->polish(snippet); // recomputes style to make property take effect
 		snippet->updateLineNumberAreaWidthForDigits(maxDigits);
 	}
-
-	if (!m_snippets.front()->styleSheet().size())
-	{
-		m_snippets.front()->setStyleSheet("#code_snippet { border: none; }");
-	}
 }
 
 void QtCodeFile::updateTitleBar()

src/lib_gui/qt/element/QtCodeFileList.cpp

@@ -236,19 +236,10 @@ void QtCodeFileList::updateFiles()
 {
 	for (QtCodeFile* file : m_files)
 	{
-		if (file != m_files.back())
-		{
-			file->setStyleSheet("#code_file { border: none; }");
-		}
-
+		file->setProperty("last", file == m_files.back());
 		file->updateContent();
 	}
 
-	if (m_files.size())
-	{
-		m_files.back()->setStyleSheet("");
-	}
-
 	// Perform delayed so all widgets are already visible
 	QTimer::singleShot(100, this, &QtCodeFileList::updateSnippetTitleAndScrollBarSlot);
 }