Add option to preserve "modification date" on file saving for UI

See https://github.com/Martchus/tageditor/issues/67

application/settings.cpp

@@ -128,6 +128,8 @@ void restore()
         v.tagPocessing.unsupportedFieldHandling = UnsupportedFieldHandling::Ignore;
     }
     v.tagPocessing.autoTagManagement = settings.value(QStringLiteral("autotagmanagement"), true).toBool();
+    v.tagPocessing.preserveModificationTime
+        = settings.value(QStringLiteral("preservemodificationtime"), v.tagPocessing.preserveModificationTime).toBool();
     settings.beginGroup(QStringLiteral("id3v1"));
     switch (settings.value(QStringLiteral("usage"), 0).toInt()) {
     case 1:
@@ -259,6 +261,7 @@ void save()
     settings.setValue(QStringLiteral("preferredencoding"), static_cast<int>(v.tagPocessing.preferredEncoding));
     settings.setValue(QStringLiteral("unsupportedfieldhandling"), static_cast<int>(v.tagPocessing.unsupportedFieldHandling));
     settings.setValue(QStringLiteral("autotagmanagement"), v.tagPocessing.autoTagManagement);
+    settings.setValue(QStringLiteral("preservemodificationtime"), v.tagPocessing.preserveModificationTime);
     settings.beginGroup(QStringLiteral("id3v1"));
     settings.setValue(QStringLiteral("usage"), static_cast<int>(v.tagPocessing.creationSettings.id3v1usage));
     settings.endGroup();

application/settings.h

@@ -79,6 +79,7 @@ struct TagProcessing {
     TagParser::TagTextEncoding preferredEncoding = TagParser::TagTextEncoding::Utf8;
     UnsupportedFieldHandling unsupportedFieldHandling = UnsupportedFieldHandling::Ignore;
     bool autoTagManagement = true;
+    bool preserveModificationTime = false;
     TagParser::TagCreationSettings creationSettings;
     FileLayout fileLayout;
 };

gui/settingsdialog.cpp

@@ -357,6 +357,7 @@ bool TagProcessingGeneralOptionPage::apply()
             settings.unsupportedFieldHandling = UnsupportedFieldHandling::Discard;
         }
         settings.autoTagManagement = ui()->autoTagManagementCheckBox->isChecked();
+        settings.preserveModificationTime = ui()->preserveModificationTimeCheckBox->isChecked();
     }
     return true;
 }
@@ -391,6 +392,7 @@ void TagProcessingGeneralOptionPage::reset()
             break;
         }
         ui()->autoTagManagementCheckBox->setChecked(settings.autoTagManagement);
+        ui()->preserveModificationTimeCheckBox->setChecked(settings.preserveModificationTime);
     }
 }
 

gui/tageditorwidget.cpp

@@ -53,6 +53,7 @@
 #include <QtConcurrent>
 
 #include <algorithm>
+#include <filesystem>
 #include <functional>
 #include <iostream>
 
@@ -1161,7 +1162,7 @@ bool TagEditorWidget::startSaving()
     m_fileInfo.setMaxPadding(fileLayoutSettings.maxPadding);
     m_fileInfo.setPreferredPadding(fileLayoutSettings.preferredPadding);
     m_fileInfo.setBackupDirectory(settings.editor.backupDirectory);
-    const auto startThread = [this] {
+    const auto startThread = [this, preserveModificationTime = settings.tagPocessing.preserveModificationTime] {
         // define functions to show the saving progress and to actually applying the changes
         auto showPercentage([this](AbortableProgressFeedback &progress) {
             if (m_abortClicked) {
@@ -1183,6 +1184,13 @@ bool TagEditorWidget::startSaving()
         auto ioError = QString();
         auto processingError = false, canceled = false;
         try {
+            auto modificationDateError = std::error_code();
+            auto modificationDate = std::filesystem::file_time_type();
+            auto modifiedFilePath = std::filesystem::path();
+            if (preserveModificationTime) {
+                modifiedFilePath = m_fileInfo.saveFilePath().empty() ? m_fileInfo.path() : m_fileInfo.saveFilePath();
+                modificationDate = std::filesystem::last_write_time(modifiedFilePath, modificationDateError);
+            }
             try {
                 m_fileInfo.applyChanges(m_diag, progress);
             } catch (const OperationAbortedException &) {
@@ -1194,8 +1202,18 @@ bool TagEditorWidget::startSaving()
                     ioError = tr("unknown error");
                 }
             }
+            if (preserveModificationTime) {
+                if (!modificationDateError) {
+                    std::filesystem::last_write_time(modifiedFilePath, modificationDate, modificationDateError);
+                }
+                if (modificationDateError) {
+                    m_diag.emplace_back(
+                        DiagLevel::Critical, "Unable to preserve modification time: " + modificationDateError.message(), "applying changes");
+                }
+            }
         } catch (const exception &e) {
-            m_diag.emplace_back(TagParser::DiagLevel::Critical, argsToString("Something completely unexpected happened: ", e.what()), "making");
+            m_diag.emplace_back(
+                TagParser::DiagLevel::Critical, argsToString("Something completely unexpected happened: ", e.what()), "applying changes");
             processingError = true;
         }
         QMetaObject::invokeMethod(

gui/tagprocessinggeneraloptionpage.ui

@@ -98,21 +98,45 @@
     </widget>
    </item>
    <item>
-    <widget class="QLabel" name="label">
-     <property name="text">
-      <string>&lt;span style=&quot;font-weight: bold;&quot;&gt;Automatic tag management&lt;/span&gt;
-&lt;br&gt;If enabled, appropriate tags will be created and removed according to the settings automatically when opening a file. Otherwise you have to do this manually (eg. adding an ID3 tag if none is present yet) and settings like ID3 usage have no effect.</string>
-     </property>
-     <property name="wordWrap">
-      <bool>true</bool>
+    <widget class="QGroupBox" name="timestampsGroupBox_2">
+     <property name="title">
+      <string>Automatic tag management</string>
      </property>
+     <layout class="QVBoxLayout" name="verticalLayout_5">
+      <item>
+       <widget class="QLabel" name="label">
+        <property name="text">
+         <string>If enabled, appropriate tags will be created and removed according to the settings automatically when opening a file. Otherwise you have to do this manually (eg. adding an ID3 tag if none is present yet) and settings like ID3 usage have no effect.</string>
+        </property>
+        <property name="wordWrap">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QCheckBox" name="autoTagManagementCheckBox">
+        <property name="text">
+         <string>Enable automatic tag management (default)</string>
+        </property>
+       </widget>
+      </item>
+     </layout>
     </widget>
    </item>
    <item>
-    <widget class="QCheckBox" name="autoTagManagementCheckBox">
-     <property name="text">
-      <string>Enable automatic tag management (default)</string>
+    <widget class="QGroupBox" name="timestampsGroupBox">
+     <property name="title">
+      <string>Timestamps</string>
      </property>
+     <layout class="QVBoxLayout" name="verticalLayout_4">
+      <item>
+       <widget class="QCheckBox" name="preserveModificationTimeCheckBox">
+        <property name="text">
+         <string>Preserve modification time</string>
+        </property>
+       </widget>
+      </item>
+     </layout>
     </widget>
    </item>
    <item>
@@ -133,7 +157,7 @@
  <resources/>
  <connections/>
  <buttongroups>
-  <buttongroup name="preferredTextEncodingButtonGroup"/>
   <buttongroup name="unsupportedButtonGroup"/>
+  <buttongroup name="preferredTextEncodingButtonGroup"/>
  </buttongroups>
 </ui>