Fix markdown preview persistence and enable external links in attachment editor

Co-authored-by: droidmonkey <[email protected]>

Author: Copilot

src/gui/entry/attachments/TextAttachmentsPreviewWidget.cpp

@@ -48,6 +48,7 @@ namespace
 TextAttachmentsPreviewWidget::TextAttachmentsPreviewWidget(QWidget* parent)
     : QWidget(parent)
     , m_ui(new Ui::TextAttachmentsPreviewWidget())
+    , m_userManuallySelectedType(false)
 {
     m_ui->setupUi(this);
 
@@ -63,6 +64,8 @@ void TextAttachmentsPreviewWidget::openAttachment(attachments::Attachment attach
     }
 
     m_attachment = std::move(attachments);
+    // Reset manual selection flag when opening a new attachment
+    m_userManuallySelectedType = false;
 
     updateUi();
 }
@@ -88,10 +91,13 @@ void TextAttachmentsPreviewWidget::initTypeCombobox()
     filterProxyMode->sort(0, Qt::SortOrder::DescendingOrder);
     m_ui->typeComboBox->setModel(filterProxyMode);
 
-    connect(m_ui->typeComboBox,
-            QOverload<int>::of(&QComboBox::currentIndexChanged),
-            this,
-            &TextAttachmentsPreviewWidget::onTypeChanged);
+    connect(m_ui->typeComboBox, QOverload<int>::of(&QComboBox::currentIndexChanged), this, [this](int index) {
+        m_userManuallySelectedType = true;
+        onTypeChanged(index);
+    });
+
+    // Configure text browser to open external links
+    m_ui->previewTextBrowser->setOpenExternalLinks(true);
 
     m_ui->typeComboBox->setCurrentIndex(m_ui->typeComboBox->findData(PlainText));
 
@@ -100,11 +106,17 @@ void TextAttachmentsPreviewWidget::initTypeCombobox()
 
 void TextAttachmentsPreviewWidget::updateUi()
 {
-    if (!m_attachment.name.isEmpty()) {
+    // Only auto-select format based on file extension if user hasn't manually chosen one
+    if (!m_userManuallySelectedType && !m_attachment.name.isEmpty()) {
         const auto mimeType = Tools::getMimeType(QFileInfo(m_attachment.name));
 
         auto index = m_ui->typeComboBox->findData(ConvertToPreviewTextType(mimeType));
-        m_ui->typeComboBox->setCurrentIndex(index);
+        if (index >= 0) {
+            // Temporarily block signals to avoid triggering manual selection flag
+            m_ui->typeComboBox->blockSignals(true);
+            m_ui->typeComboBox->setCurrentIndex(index);
+            m_ui->typeComboBox->blockSignals(false);
+        }
     }
 
     onTypeChanged(m_ui->typeComboBox->currentIndex());

src/gui/entry/attachments/TextAttachmentsPreviewWidget.h

@@ -58,4 +58,5 @@ private slots:
     QScopedPointer<Ui::TextAttachmentsPreviewWidget> m_ui;
 
     attachments::Attachment m_attachment;
+    bool m_userManuallySelectedType;
 };