#3427 highlighting: improved encrypted text highlighting

Signed-off-by: Patrizio Bekerle <[email protected]>

Author: pbek

CHANGELOG.md

@@ -16,6 +16,9 @@
   - Fixed Evernote import code block handling to preserve leading indentation and code fences
     - Code blocks imported from Evernote now maintain their original formatting
     - Fixed an issue where PHP and other code blocks would lose their indentation or code fence markers
+- **Improved encrypted text highlighting** in the note editor (for [#3427](https://github.com/pbek/QOwnNotes/issues/3427))
+  - Encrypted text blocks are now visually distinguished with smaller font size for better readability
+  - Encrypted text blocks now skip markdown highlighting, spell checking, and link detection to improve performance
 
 ## 26.1.3
 

src/entities/note.cpp

@@ -3409,6 +3409,14 @@ QString Note::parseEncryptedNoteText(const QString &noteText) {
     return match.hasMatch() ? match.captured(1) : QLatin1String("");
 }
 
+bool Note::isEncryptedTextBegin(const QString &text) {
+    return text == NOTE_TEXT_ENCRYPTION_PRE_STRING;
+}
+
+bool Note::isEncryptedTextEnd(const QString &text) {
+    return text == NOTE_TEXT_ENCRYPTION_POST_STRING;
+}
+
 /**
  * Returns encrypted note text if it is encrypted
  */

src/entities/note.h

@@ -405,6 +405,8 @@ class Note {
     [[nodiscard]] QString getDecryptedNoteText(const QString &encryptedNoteText) const;
 
     static QString parseEncryptedNoteText(const QString &noteText);
+    static bool isEncryptedTextBegin(const QString &text);
+    static bool isEncryptedTextEnd(const QString &text);
 
     QString getNextcloudFileLink() const;
 

src/helpers/qownnotesmarkdownhighlighter.cpp

@@ -27,6 +27,8 @@
 #include "mainwindow.h"
 #include "qownspellchecker.h"
 
+constexpr qreal ENCRYPTED_TEXT_FONT_SCALE = 1.5;
+
 QOwnNotesMarkdownHighlighter::QOwnNotesMarkdownHighlighter(QTextDocument *parent,
                                                            HighlightingOptions highlightingOptions)
     : MarkdownHighlighter(parent, highlightingOptions) {
@@ -41,6 +43,9 @@ void QOwnNotesMarkdownHighlighter::updateCurrentNote(Note *note) {
     if (note != nullptr) {
         _currentNote = note;
     }
+
+    _hasEncrypted = _currentNote ? _currentNote->hasEncryptedNoteText() : false;
+    _highlightEncrypted = false;  // Reset state when note changes
 }
 
 /**
@@ -57,22 +62,44 @@ void QOwnNotesMarkdownHighlighter::highlightBlock(const QString &text) {
     setCurrentBlockState(HighlighterState::NoState);
     currentBlock().setUserState(HighlighterState::NoState);
 
-    // do the Markdown highlighting before the spellcheck highlighting
-    // if we do it afterward, it overwrites the spellcheck highlighting
-    MarkdownHighlighter::highlightMarkdown(text);
-    if (text.contains(QLatin1String("note://")) ||
-        text.contains(QChar('.') + _defaultNoteFileExt)) {
-        highlightBrokenNotesLink(text);
+    // Only check for encryption markers if the note has encrypted content
+    if (_hasEncrypted) {
+        if (Note::isEncryptedTextBegin(text)) {
+            _highlightEncrypted = true;
+        }
     }
 
-    // skip spell checking empty blocks and blocks with just "spaces"
-    // the rest of the highlighting needs to be done e.g. for code blocks with
-    // empty lines
-    if (!text.isEmpty() && QOwnSpellChecker::instance()->isActive()) {
-        highlightSpellChecking(text);
+    if (_highlightEncrypted) {
+        auto format = _formats[MaskedSyntax];
+        // Reduce the font size for encrypted text
+        format.setFontPointSize(format.fontPointSize() / ENCRYPTED_TEXT_FONT_SCALE);
+        setFormat(0, text.length(), format);
+    } else {
+        // do the Markdown highlighting before the spellcheck highlighting
+        // if we do it afterward, it overwrites the spellcheck highlighting
+        highlightMarkdown(text);
     }
 
-    highlightScriptingRules(ScriptingService::instance()->getHighlightingRules(), text);
+    if (!_highlightEncrypted) {
+        if (text.contains(QLatin1String("note://")) ||
+            text.contains(QChar('.') + _defaultNoteFileExt)) {
+            highlightBrokenNotesLink(text);
+        }
+
+        // skip spell checking empty blocks and blocks with just "spaces"
+        // the rest of the highlighting needs to be done e.g. for code blocks with
+        // empty lines
+        if (!text.isEmpty() && QOwnSpellChecker::instance()->isActive()) {
+            highlightSpellChecking(text);
+        }
+
+        highlightScriptingRules(ScriptingService::instance()->getHighlightingRules(), text);
+    }
+
+    // Only check for encryption end marker if we're highlighting encrypted text
+    if (_hasEncrypted && _highlightEncrypted && Note::isEncryptedTextEnd(text)) {
+        _highlightEncrypted = false;
+    }
 
     _highlightingFinished = true;
 }

src/helpers/qownnotesmarkdownhighlighter.h

@@ -64,6 +64,8 @@ class QOwnNotesMarkdownHighlighter : public MarkdownHighlighter {
 
    private:
     Note *_currentNote = nullptr;
+    bool _hasEncrypted = false;
+    bool _highlightEncrypted = false;
 
     QString _defaultNoteFileExt;
     QRegularExpression _regexTagStyleLink;