feat: allow drag and drop to open text file

10 files changed, 474 insertions, 221 deletions

diff --git a/src/core/function/basic/ChannelObject.cpp b/src/core/function/basic/ChannelObject.cpp
index 39a5568b..27999f5e 100644
--- a/src/core/function/basic/ChannelObject.cpp
+++ b/src/core/function/basic/ChannelObject.cpp
@@ -28,8 +28,6 @@
 
 #include "ChannelObject.h"
 
-#include <iostream>
-
 namespace GpgFrontend {
 
 ChannelObject::ChannelObject() noexcept = default;
diff --git a/src/ui/main_window/MainWindow.cpp b/src/ui/main_window/MainWindow.cpp
index 8e5e1d03..597697f4 100644
--- a/src/ui/main_window/MainWindow.cpp
+++ b/src/ui/main_window/MainWindow.cpp
@@ -39,6 +39,7 @@
 #include "ui/struct/settings_object/KeyServerSO.h"
 #include "ui/widgets/KeyList.h"
 #include "ui/widgets/TextEdit.h"
+#include "ui/widgets/TextEditTabWidget.h"
 
 namespace GpgFrontend::UI {
 
@@ -97,7 +98,7 @@ void MainWindow::Init() noexcept {
             UISignalStation::GetInstance(),
             &UISignalStation::SignalKeyDatabaseRefresh);
 
-    connect(edit_->tab_widget_, &QTabWidget::currentChanged, this,
+    connect(edit_->tab_widget_, &TextEditTabWidget::currentChanged, this,
             &MainWindow::slot_disable_tab_actions);
     connect(UISignalStation::GetInstance(),
             &UISignalStation::SignalRefreshStatusBar, this,
diff --git a/src/ui/main_window/MainWindowSlotFunction.cpp b/src/ui/main_window/MainWindowSlotFunction.cpp
index cea105b7..9a8e57d0 100644
--- a/src/ui/main_window/MainWindowSlotFunction.cpp
+++ b/src/ui/main_window/MainWindowSlotFunction.cpp
@@ -276,23 +276,6 @@ void MainWindow::upload_key_to_server() {
 }
 
 void MainWindow::SlotOpenFile(const QString& path) {
-  QFileInfo const info(path);
-  if (!info.isFile() || !info.isReadable()) {
-    QMessageBox::critical(
-        this, tr("Error"),
-        tr("Cannot open this file. Please make sure that this "
-           "is a regular file and it's readable."));
-    return;
-  }
-
-  if (info.size() > static_cast<qint64>(1024 * 1024)) {
-    QMessageBox::critical(
-        this, tr("Error"),
-        tr("Cannot open this file. The file is TOO LARGE (>1MB) for "
-           "GpgFrontend Text Editor."));
-    return;
-  }
-
   edit_->SlotOpenFile(path);
 }
 
diff --git a/src/ui/widgets/InfoBoardWidget.cpp b/src/ui/widgets/InfoBoardWidget.cpp
index 21a6c08a..92b22452 100644
--- a/src/ui/widgets/InfoBoardWidget.cpp
+++ b/src/ui/widgets/InfoBoardWidget.cpp
@@ -32,6 +32,7 @@
 #include "core/model/SettingsObject.h"
 #include "ui/UISignalStation.h"
 #include "ui/struct/settings_object/AppearanceSO.h"
+#include "ui/widgets/TextEditTabWidget.h"
 #include "ui_InfoBoard.h"
 
 namespace GpgFrontend::UI {
@@ -103,7 +104,7 @@ void InfoBoardWidget::AssociateTextEdit(QTextEdit* edit) {
   connect(edit, &QTextEdit::textChanged, this, &InfoBoardWidget::SlotReset);
 }
 
-void InfoBoardWidget::AssociateTabWidget(QTabWidget* tab) {
+void InfoBoardWidget::AssociateTabWidget(TextEditTabWidget* tab) {
   m_text_page_ = nullptr;
   m_tab_widget_ = tab;
   connect(tab, &QTabWidget::tabBarClicked, this, &InfoBoardWidget::SlotReset);
diff --git a/src/ui/widgets/InfoBoardWidget.h b/src/ui/widgets/InfoBoardWidget.h
index b124cea2..1dfe7a52 100644
--- a/src/ui/widgets/InfoBoardWidget.h
+++ b/src/ui/widgets/InfoBoardWidget.h
@@ -46,6 +46,8 @@ typedef enum {
   INFO_ERROR_NEUTRAL = 3,
 } InfoBoardStatus;
 
+class TextEditTabWidget;
+
 /**
  * @brief Class for handling the verify label shown at bottom of a textedit-page
  */
@@ -72,7 +74,7 @@ class InfoBoardWidget : public QWidget {
    *
    * @param tab
    */
-  void AssociateTabWidget(QTabWidget* tab);
+  void AssociateTabWidget(TextEditTabWidget* tab);
 
   /**
    * @brief
diff --git a/src/ui/widgets/PlainTextEditorPage.cpp b/src/ui/widgets/PlainTextEditorPage.cpp
index 6e92b5b6..bd1c9837 100644
--- a/src/ui/widgets/PlainTextEditorPage.cpp
+++ b/src/ui/widgets/PlainTextEditorPage.cpp
@@ -54,6 +54,9 @@ PlainTextEditorPage::PlainTextEditorPage(QString file_path, QWidget *parent)
   this->ui_->characterLabel->setText(tr("0 character"));
   this->ui_->lfLabel->setHidden(true);
   this->ui_->encodingLabel->setText("Unicode");
+  this->ui_->textPage->setAcceptDrops(false);
+
+  setAcceptDrops(false);
 
   connect(ui_->textPage, &QPlainTextEdit::textChanged, this, [=]() {
     // if file is loading
diff --git a/src/ui/widgets/TextEdit.cpp b/src/ui/widgets/TextEdit.cpp
index 4d83cff3..a742d49d 100644
--- a/src/ui/widgets/TextEdit.cpp
+++ b/src/ui/widgets/TextEdit.cpp
@@ -26,22 +26,23 @@
  *
  */
 
-#include "ui/widgets/TextEdit.h"
+#include "TextEdit.h"
 
 #include <QtPrintSupport>
+#include <cstddef>
 #include <tuple>
+#include <utility>
 #include <vector>
 
 #include "core/GpgModel.h"
-#include "core/function/GlobalSettingStation.h"
-#include "core/model/CacheObject.h"
 #include "ui/UISignalStation.h"
+#include "ui/widgets/HelpPage.h"
+#include "ui/widgets/TextEditTabWidget.h"
 
 namespace GpgFrontend::UI {
 
 TextEdit::TextEdit(QWidget* parent) : QWidget(parent) {
-  count_page_ = 0;
-  tab_widget_ = new QTabWidget(this);
+  tab_widget_ = new TextEditTabWidget(this);
   tab_widget_->setMovable(true);
   tab_widget_->setTabsClosable(true);
   tab_widget_->setDocumentMode(true);
@@ -58,46 +59,13 @@ TextEdit::TextEdit(QWidget* parent) : QWidget(parent) {
   setAcceptDrops(false);
 }
 
-void TextEdit::SlotNewTab() {
-  QString header = tr("untitled") + QString::number(++count_page_) + ".txt";
-
-  auto* page = new PlainTextEditorPage();
-  auto index = tab_widget_->addTab(page, header);
-  tab_widget_->setTabIcon(index, QIcon(":/icons/file.png"));
-  tab_widget_->setCurrentIndex(tab_widget_->count() - 1);
-  page->GetTextPage()->setFocus();
-  connect(page->GetTextPage()->document(), &QTextDocument::modificationChanged,
-          this, &TextEdit::SlotShowModified);
-  connect(page->GetTextPage()->document(), &QTextDocument::contentsChanged,
-          this, &TextEdit::slot_save_status_to_cache_for_revovery);
-}
+void TextEdit::SlotNewTab() { tab_widget_->SlotNewTab(); }
 
 void TextEdit::SlotNewTabWithContent(QString title, const QString& content) {
-  QString header = tr("untitled") + QString::number(++count_page_) + ".txt";
-  if (!title.isEmpty()) {
-    // modify title
-    if (!title.isEmpty() && title[0] == '*') {
-      title.remove(0, 1);
-    }
-    // set title
-    header = title;
-  }
-
-  auto* page = new PlainTextEditorPage();
-  auto index = tab_widget_->addTab(page, header);
-  tab_widget_->setTabIcon(index, QIcon(":/icons/file.png"));
-  tab_widget_->setCurrentIndex(tab_widget_->count() - 1);
-  page->GetTextPage()->setFocus();
-  connect(page->GetTextPage()->document(), &QTextDocument::modificationChanged,
-          this, &TextEdit::SlotShowModified);
-  connect(page->GetTextPage()->document(), &QTextDocument::contentsChanged,
-          this, &TextEdit::slot_save_status_to_cache_for_revovery);
-
-  // set content with modified status
-  page->GetTextPage()->document()->setPlainText(content);
+  tab_widget_->SlotNewTabWithContent(std::move(title), content);
 }
 
-void TextEdit::slotNewHelpTab(const QString& title, const QString& path) const {
+void TextEdit::SlotNewHelpTab(const QString& title, const QString& path) const {
   auto* page = new HelpPage(path);
   tab_widget_->addTab(page, title);
   tab_widget_->setCurrentIndex(tab_widget_->count() - 1);
@@ -119,31 +87,42 @@ void TextEdit::SlotNewFileTab() {
 }
 
 void TextEdit::SlotOpenFile(const QString& path) {
-  QFile file(path);
-  auto result = file.open(QIODevice::ReadOnly | QIODevice::Text);
-  if (result) {
-    auto* page = new PlainTextEditorPage(path);
-    connect(page->GetTextPage()->document(),
-            &QTextDocument::modificationChanged, this,
-            &TextEdit::SlotShowModified);
-    // connect to cache recovery fucntion
-    connect(page->GetTextPage()->document(), &QTextDocument::contentsChanged,
-            this, &TextEdit::slot_save_status_to_cache_for_revovery);
+  QFileInfo const info(path);
+  if (!info.isFile() || !info.isReadable()) {
+    QMessageBox::critical(
+        this, tr("Error"),
+        tr("Cannot open this file. Please make sure that this "
+           "is a regular file and it's readable."));
+    return;
+  }
 
-    QApplication::setOverrideCursor(Qt::WaitCursor);
-    auto index = tab_widget_->addTab(page, stripped_name(path));
-    tab_widget_->setTabIcon(index, QIcon(":/icons/file.png"));
-    tab_widget_->setCurrentIndex(tab_widget_->count() - 1);
-    QApplication::restoreOverrideCursor();
-    page->GetTextPage()->setFocus();
-    page->ReadFile();
-  } else {
+  if (info.size() > static_cast<qint64>(1024 * 1024)) {
+    QMessageBox::critical(
+        this, tr("Error"),
+        tr("Cannot open this file. The file is TOO LARGE (>1MB) for "
+           "GpgFrontend Text Editor."));
+    return;
+  }
+
+  QFile file(path);
+  if (!file.open(QIODevice::ReadOnly)) {
     QMessageBox::warning(
-        this, tr("Warning"),
-        tr("Cannot read file %1:\n%2.").arg(path).arg(file.errorString()));
+        this, tr("File Open Error"),
+        tr("The file \"%1\" could not be opened.").arg(info.fileName()));
+    return;
   }
 
+  QByteArray file_data = file.read(1024);
   file.close();
+
+  if (file_data.contains('\0')) {
+    QMessageBox::warning(this, tr("Binary File Detected"),
+                         tr("The file \"%1\" appears to be a binary file "
+                            "and will not be opened.")
+                             .arg(info.fileName()));
+    return;
+  }
+  tab_widget_->SlotOpenFile(path);
 }
 
 void TextEdit::SlotOpen() {
@@ -168,19 +147,17 @@ void TextEdit::SlotSave() {
     // docname.remove(0,2);
     SlotSaveAs();
   } else {
-    save_file(file_name);
+    saveFile(file_name);
   }
 }
 
-bool TextEdit::save_file(const QString& fileName) {
-  if (fileName.isEmpty()) {
-    return false;
-  }
+auto TextEdit::saveFile(const QString& file_name) -> bool {
+  if (file_name.isEmpty()) return false;
 
   PlainTextEditorPage* page = SlotCurPageTextEdit();
   if (page == nullptr) return false;
 
-  QFile file(fileName);
+  QFile file(file_name);
   if (file.open(QIODevice::WriteOnly | QIODevice::Text)) {
     QTextStream output_stream(&file);
     QApplication::setOverrideCursor(Qt::WaitCursor);
@@ -191,8 +168,8 @@ bool TextEdit::save_file(const QString& fileName) {
     document->setModified(false);
 
     int cur_index = tab_widget_->currentIndex();
-    tab_widget_->setTabText(cur_index, stripped_name(fileName));
-    page->SetFilePath(fileName);
+    tab_widget_->setTabText(cur_index, stripped_name(file_name));
+    page->SetFilePath(file_name);
     page->NotifyFileSaved();
 
     file.close();
@@ -200,7 +177,7 @@ bool TextEdit::save_file(const QString& fileName) {
   }
   QMessageBox::warning(
       this, tr("Warning"),
-      tr("Cannot read file %1:\n%2.").arg(fileName).arg(file.errorString()));
+      tr("Cannot read file %1:\n%2.").arg(file_name).arg(file.errorString()));
   return false;
 }
 
@@ -217,7 +194,7 @@ auto TextEdit::SlotSaveAs() -> bool {
     path = tab_widget_->tabText(tab_widget_->currentIndex()).remove(0, 2);
   }
 
-  return save_file(QFileDialog::getSaveFileName(this, tr("Save file"), path));
+  return saveFile(QFileDialog::getSaveFileName(this, tr("Save file"), path));
 }
 
 void TextEdit::SlotCloseTab() {
@@ -294,7 +271,7 @@ auto TextEdit::maybe_save_current_tab(bool askToSave) -> bool {
         // docname.remove(0,2);
         return SlotSaveAs();
       }
-      return save_file(file_path);
+      return saveFile(file_path);
     }
     return result == QMessageBox::Discard;
   }
@@ -354,32 +331,25 @@ auto TextEdit::MaybeSaveAnyTab() -> bool {
   return false;
 }
 
-PlainTextEditorPage* TextEdit::CurTextPage() const {
-  return qobject_cast<PlainTextEditorPage*>(tab_widget_->currentWidget());
-}
-
 void TextEdit::SlotAppendText2CurTextPage(const QString& text) {
   if (CurTextPage() == nullptr) SlotNewTab();
   CurTextPage()->GetTextPage()->appendPlainText(text);
 }
 
-FilePage* TextEdit::CurFilePage() const {
-  auto* cur_file_page = qobject_cast<FilePage*>(tab_widget_->currentWidget());
-  if (cur_file_page != nullptr) {
-    return cur_file_page;
-  }
-  return nullptr;
+auto TextEdit::CurTextPage() const -> PlainTextEditorPage* {
+  return tab_widget_->CurTextPage();
 }
 
-int TextEdit::TabCount() const { return tab_widget_->count(); }
-
-PlainTextEditorPage* TextEdit::SlotCurPageTextEdit() const {
-  auto* cur_page =
-      qobject_cast<PlainTextEditorPage*>(tab_widget_->currentWidget());
-  return cur_page;
+auto TextEdit::SlotCurPageTextEdit() const -> PlainTextEditorPage* {
+  return tab_widget_->SlotCurPageTextEdit();
 }
+auto TextEdit::CurFilePage() const -> FilePage* {
+  return tab_widget_->CurFilePage();
+}
+
+auto TextEdit::TabCount() const -> int { return tab_widget_->count(); }
 
-FilePage* TextEdit::SlotCurPageFileTreeView() const {
+auto TextEdit::SlotCurPageFileTreeView() const -> FilePage* {
   auto* cur_page = qobject_cast<FilePage*>(tab_widget_->currentWidget());
   return cur_page;
 }
@@ -432,7 +402,7 @@ void TextEdit::LoadFile(const QString& fileName) {
   // statusBar()->showMessage(tr("File loaded"), 2000);
 }
 
-QString TextEdit::stripped_name(const QString& full_file_name) {
+auto TextEdit::stripped_name(const QString& full_file_name) -> QString {
   return QFileInfo(full_file_name).fileName();
 }
 
@@ -476,7 +446,7 @@ void TextEdit::SlotShowModified(bool changed) const {
   // if doc is modified now, add leading * to title,
   // otherwise remove the leading * from the title
   if (CurTextPage()->GetTextPage()->document()->isModified()) {
-    tab_widget_->setTabText(index, title.prepend("* "));
+    tab_widget_->setTabText(index, title.trimmed().prepend("* "));
   } else {
     tab_widget_->setTabText(index, title.remove(0, 2));
   }
@@ -602,56 +572,4 @@ void TextEdit::slot_file_page_path_changed(const QString& path) const {
   emit UISignalStation::GetInstance()
       -> SignalMainWindowlUpdateBasicalOperaMenu(0);
 }
-
-void TextEdit::slot_save_status_to_cache_for_revovery() {
-  if (this->text_page_data_modified_count_++ % 8 != 0) return;
-
-  auto settings =
-      GpgFrontend::GlobalSettingStation::GetInstance().GetSettings();
-
-  bool restore_text_editor_page =
-      settings.value("basic/restore_text_editor_page", false).toBool();
-  if (!restore_text_editor_page) {
-    FLOG_D("restore_text_editor_page is false, ignoring...");
-    return;
-  }
-
-  int tab_count = tab_widget_->count();
-  std::vector<std::tuple<int, QString, QString>> unsaved_pages;
-
-  for (int i = 0; i < tab_count; i++) {
-    auto* target_page =
-        qobject_cast<PlainTextEditorPage*>(tab_widget_->widget(i));
-
-    // if this page is no textedit, there should be nothing to save
-    if (target_page == nullptr) {
-      continue;
-    }
-
-    auto* document = target_page->GetTextPage()->document();
-    auto tab_title = tab_widget_->tabText(i);
-    if (!target_page->ReadDone() || !target_page->isEnabled() ||
-        !document->isModified()) {
-      continue;
-    }
-
-    unsaved_pages.emplace_back(i, tab_title, document->toRawText());
-  }
-
-  CacheObject cache("editor_unsaved_pages");
-  QJsonArray unsaved_page_array;
-  for (const auto& page : unsaved_pages) {
-    const auto [index, title, content] = page;
-
-    QJsonObject page_json;
-    page_json["index"] = index;
-    page_json["title"] = title;
-    page_json["content"] = content;
-
-    unsaved_page_array.push_back(page_json);
-  }
-
-  cache.setArray(unsaved_page_array);
-}
-
 }  // namespace GpgFrontend::UI
diff --git a/src/ui/widgets/TextEdit.h b/src/ui/widgets/TextEdit.h
index 50939d0e..4b893a3a 100644
--- a/src/ui/widgets/TextEdit.h
+++ b/src/ui/widgets/TextEdit.h
@@ -30,20 +30,19 @@
 
 #include "ui/dialog/QuitDialog.h"
 #include "ui/widgets/FilePage.h"
-#include "ui/widgets/HelpPage.h"
 #include "ui/widgets/PlainTextEditorPage.h"
 
 namespace GpgFrontend::UI {
-/**
- * @brief TextEdit class
- */
+
+class TextEditTabWidget;
+
 class TextEdit : public QWidget {
   Q_OBJECT
  public:
   /**
    * @brief
    */
-  TextEdit(QWidget* parent);
+  explicit TextEdit(QWidget* parent);
 
   /**
    * @details Load the content of file into the current textpage
@@ -60,36 +59,37 @@ class TextEdit : public QWidget {
    * @return \li false, if the close event should be aborted.
    *         \li true, otherwise
    */
-  bool MaybeSaveAnyTab();
+  auto MaybeSaveAnyTab() -> bool;
 
   /**
    * @brief
    *
    * @return int
    */
-  [[nodiscard]] int TabCount() const;
+  [[nodiscard]] auto TabCount() const -> int;
 
   /**
    * @details textpage of the currently activated tab
    * @return \li reference to QTextEdit if tab has one
    *         \li 0 otherwise (e.g. if helppage)
    */
-  [[nodiscard]] PlainTextEditorPage* CurTextPage() const;
+  [[nodiscard]] auto CurTextPage() const -> PlainTextEditorPage*;
 
   /**
    * @brief
    *
    * @return FilePage*
    */
-  [[nodiscard]] FilePage* CurFilePage() const;
+  [[nodiscard]] auto CurFilePage() const -> FilePage*;
 
   /**
    * @details  List of currently unsaved tabs.
    * @returns QHash<int, QString> Hash of tab indexes and title of unsaved tabs.
    */
-  [[nodiscard]] QHash<int, QString> UnsavedDocuments() const;
+  [[nodiscard]] auto UnsavedDocuments() const -> QHash<int, QString>;
 
-  QTabWidget* tab_widget_; /** Widget containing the tabs of the editor */
+  TextEditTabWidget*
+      tab_widget_; /** Widget containing the tabs of the editor */
 
  public slots:
 
@@ -97,13 +97,13 @@ class TextEdit : public QWidget {
    * @details Return pointer to the currently activated text edit tab page.
    *
    */
-  PlainTextEditorPage* SlotCurPageTextEdit() const;
+  [[nodiscard]] auto SlotCurPageTextEdit() const -> PlainTextEditorPage*;
 
   /**
    * @details Return pointer to the currently activated file tree view tab page.
    *
    */
-  FilePage* SlotCurPageFileTreeView() const;
+  [[nodiscard]] auto SlotCurPageFileTreeView() const -> FilePage*;
 
   /**
    * @details Insert a ">" at the beginning of every line of current textedit.
@@ -128,7 +128,7 @@ class TextEdit : public QWidget {
    *
    * @return Return the return value of the savefile method
    */
-  bool SlotSaveAs();
+  auto SlotSaveAs() -> bool;
 
   /**
    * @details Show an OpenFileDoalog and open the file in a new tab.
@@ -166,7 +166,7 @@ class TextEdit : public QWidget {
    * @param title title for the tab
    * @param path  path for html file to show
    */
-  void slotNewHelpTab(const QString& title, const QString& path) const;
+  void SlotNewHelpTab(const QString& title, const QString& path) const;
 
   /**
    * New File Tab to do file operation
@@ -197,46 +197,6 @@ class TextEdit : public QWidget {
    */
   void SlotSwitchTabDown() const;
 
- private:
-  uint text_page_data_modified_count_ = 0;  ///<
-
-  /**
-   * @details return just a filename stripped of a whole path
-   *
-   * @param a filename path
-   * @return QString containing the filename
-   */
-  static QString stripped_name(const QString& full_file_name);
-
-  /**
-   * @brief
-   *
-   * @param askToSave
-   */
-  bool maybe_save_current_tab(bool askToSave);
-
-  int count_page_;  ///< int containing the number of added tabs
-
- private slots:
-
-  void slot_file_page_path_changed(const QString& path) const;
-
-  /**
-   * @details Remove the tab with given index
-   *
-   * @param index Tab-number to remove
-   */
-  void slot_remove_tab(int index);
-
-  /**
-   * @brief
-   *
-   * @param index
-   */
-  void slot_save_status_to_cache_for_revovery();
-
- public slots:
-
   /**
    * @details Cut selected text in current text page.
    */
@@ -295,7 +255,34 @@ class TextEdit : public QWidget {
    *
    * @param fileName
    */
-  bool save_file(const QString& fileName);
+  auto saveFile(const QString& file_name) -> bool;
+
+ private:
+  /**
+   * @details return just a filename stripped of a whole path
+   *
+   * @param a filename path
+   * @return QString containing the filename
+   */
+  static auto stripped_name(const QString& full_file_name) -> QString;
+
+  /**
+   * @brief
+   *
+   * @param askToSave
+   */
+  auto maybe_save_current_tab(bool askToSave) -> bool;
+
+ private slots:
+
+  void slot_file_page_path_changed(const QString& path) const;
+
+  /**
+   * @details Remove the tab with given index
+   *
+   * @param index Tab-number to remove
+   */
+  void slot_remove_tab(int index);
 };
 
 }  // namespace GpgFrontend::UI
diff --git a/src/ui/widgets/TextEditTabWidget.cpp b/src/ui/widgets/TextEditTabWidget.cpp
new file mode 100644
index 00000000..c782e868
--- /dev/null
+++ b/src/ui/widgets/TextEditTabWidget.cpp
@@ -0,0 +1,242 @@
+/**
+ * Copyright (C) 2021-2024 Saturneric <[email protected]>
+ *
+ * This file is part of GpgFrontend.
+ *
+ * GpgFrontend is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GpgFrontend is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GpgFrontend. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The initial version of the source code is inherited from
+ * the gpg4usb project, which is under GPL-3.0-or-later.
+ *
+ * All the source code of GpgFrontend was modified and released by
+ * Saturneric <[email protected]> starting on May 12, 2021.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ */
+
+#include "TextEditTabWidget.h"
+
+#include "core/function/GlobalSettingStation.h"
+#include "core/model/CacheObject.h"
+#include "ui/widgets/PlainTextEditorPage.h"
+#include "widgets/FilePage.h"
+
+namespace GpgFrontend::UI {
+
+TextEditTabWidget::TextEditTabWidget(QWidget* parent) : QTabWidget(parent) {
+  setAcceptDrops(true);
+}
+
+void TextEditTabWidget::dragEnterEvent(QDragEnterEvent* event) {
+  event->acceptProposedAction();
+}
+
+void TextEditTabWidget::dropEvent(QDropEvent* event) {
+  if (!event->mimeData()->hasUrls()) return;
+
+  auto urls = event->mimeData()->urls();
+
+  for (const auto& url : urls) {
+    QString local_file = url.toLocalFile();
+
+    QFileInfo file_info(local_file);
+    if (file_info.size() > static_cast<qint64>(1024 * 1024)) {
+      QMessageBox::warning(
+          this, tr("File Too Large"),
+          tr("The file \"%1\" is larger than 1MB and will not be opened.")
+              .arg(file_info.fileName()));
+      continue;
+    }
+
+    QFile file(local_file);
+    if (!file.open(QIODevice::ReadOnly)) {
+      QMessageBox::warning(
+          this, tr("File Open Error"),
+          tr("The file \"%1\" could not be opened.").arg(file_info.fileName()));
+      continue;
+    }
+    QByteArray file_data = file.read(1024);
+    file.close();
+
+    if (file_data.contains('\0')) {
+      QMessageBox::warning(this, tr("Binary File Detected"),
+                           tr("The file \"%1\" appears to be a binary file "
+                              "and will not be opened.")
+                               .arg(file_info.fileName()));
+      continue;
+    }
+
+    SlotOpenFile(local_file);
+  }
+
+  event->acceptProposedAction();
+}
+
+void TextEditTabWidget::SlotOpenFile(const QString& path) {
+  QFile file(path);
+  auto result = file.open(QIODevice::ReadOnly | QIODevice::Text);
+  if (result) {
+    auto* page = new PlainTextEditorPage(path);
+    connect(page->GetTextPage()->document(),
+            &QTextDocument::modificationChanged, this,
+            &TextEditTabWidget::SlotShowModified);
+    // connect to cache recovery fucntion
+    connect(page->GetTextPage()->document(), &QTextDocument::contentsChanged,
+            this, &TextEditTabWidget::slot_save_status_to_cache_for_recovery);
+
+    QApplication::setOverrideCursor(Qt::WaitCursor);
+    auto index = this->addTab(page, stripped_name(path));
+    this->setTabIcon(index, QIcon(":/icons/file.png"));
+    this->setCurrentIndex(this->count() - 1);
+    QApplication::restoreOverrideCursor();
+    page->GetTextPage()->setFocus();
+    page->ReadFile();
+  } else {
+    QMessageBox::warning(
+        this, tr("Warning"),
+        tr("Cannot read file %1:\n%2.").arg(path).arg(file.errorString()));
+  }
+
+  file.close();
+}
+void TextEditTabWidget::SlotShowModified(bool changed) {
+  // get current tab
+  int index = this->currentIndex();
+  QString title = this->tabText(index);
+
+  // if changed
+  if (!changed) {
+    this->setTabText(index, title.remove(0, 2));
+    return;
+  }
+
+  // if doc is modified now, add leading * to title,
+  // otherwise remove the leading * from the title
+  if (CurTextPage()->GetTextPage()->document()->isModified()) {
+    this->setTabText(index, title.trimmed().prepend("* "));
+  } else {
+    this->setTabText(index, title.remove(0, 2));
+  }
+}
+auto TextEditTabWidget::CurTextPage() const -> PlainTextEditorPage* {
+  return qobject_cast<PlainTextEditorPage*>(this->currentWidget());
+}
+
+auto TextEditTabWidget::SlotCurPageTextEdit() -> PlainTextEditorPage* {
+  auto* cur_page = qobject_cast<PlainTextEditorPage*>(this->currentWidget());
+  return cur_page;
+}
+
+auto TextEditTabWidget::CurFilePage() const -> FilePage* {
+  auto* cur_file_page = qobject_cast<FilePage*>(this->currentWidget());
+  if (cur_file_page != nullptr) {
+    return cur_file_page;
+  }
+  return nullptr;
+}
+
+auto TextEditTabWidget::stripped_name(const QString& full_file_name)
+    -> QString {
+  return QFileInfo(full_file_name).fileName();
+}
+
+void TextEditTabWidget::slot_save_status_to_cache_for_recovery() {
+  if (this->text_page_data_modified_count_++ % 8 != 0) return;
+
+  auto settings = GlobalSettingStation::GetInstance().GetSettings();
+
+  bool restore_text_editor_page =
+      settings.value("basic/restore_text_editor_page", false).toBool();
+  if (!restore_text_editor_page) {
+    FLOG_D("restore_text_editor_page is false, ignoring...");
+    return;
+  }
+
+  int tab_count = this->count();
+  std::vector<std::tuple<int, QString, QString>> unsaved_pages;
+
+  for (int i = 0; i < tab_count; i++) {
+    auto* target_page = qobject_cast<PlainTextEditorPage*>(this->widget(i));
+
+    // if this page is no textedit, there should be nothing to save
+    if (target_page == nullptr) {
+      continue;
+    }
+
+    auto* document = target_page->GetTextPage()->document();
+    auto tab_title = this->tabText(i);
+    if (!target_page->ReadDone() || !target_page->isEnabled() ||
+        !document->isModified()) {
+      continue;
+    }
+
+    unsaved_pages.emplace_back(i, tab_title, document->toRawText());
+  }
+
+  CacheObject cache("editor_unsaved_pages");
+  QJsonArray unsaved_page_array;
+  for (const auto& page : unsaved_pages) {
+    const auto [index, title, content] = page;
+
+    QJsonObject page_json;
+    page_json["index"] = index;
+    page_json["title"] = title;
+    page_json["content"] = content;
+
+    unsaved_page_array.push_back(page_json);
+  }
+
+  cache.setArray(unsaved_page_array);
+}
+
+void TextEditTabWidget::SlotNewTab() {
+  QString header = tr("untitled") + QString::number(++count_page_) + ".txt";
+
+  auto* page = new PlainTextEditorPage();
+  auto index = this->addTab(page, header);
+  this->setTabIcon(index, QIcon(":/icons/file.png"));
+  this->setCurrentIndex(this->count() - 1);
+  page->GetTextPage()->setFocus();
+  connect(page->GetTextPage()->document(), &QTextDocument::modificationChanged,
+          this, &TextEditTabWidget::SlotShowModified);
+  connect(page->GetTextPage()->document(), &QTextDocument::contentsChanged,
+          this, &TextEditTabWidget::slot_save_status_to_cache_for_recovery);
+}
+void TextEditTabWidget::SlotNewTabWithContent(QString title,
+                                              const QString& content) {
+  QString header = tr("untitled") + QString::number(++count_page_) + ".txt";
+  if (!title.isEmpty()) {
+    // modify title
+    if (!title.isEmpty() && title[0] == '*') {
+      title.remove(0, 1);
+    }
+    // set title
+    header = title;
+  }
+
+  auto* page = new PlainTextEditorPage();
+  auto index = this->addTab(page, header);
+  this->setTabIcon(index, QIcon(":/icons/file.png"));
+  this->setCurrentIndex(this->count() - 1);
+  page->GetTextPage()->setFocus();
+  connect(page->GetTextPage()->document(), &QTextDocument::modificationChanged,
+          this, &TextEditTabWidget::SlotShowModified);
+  connect(page->GetTextPage()->document(), &QTextDocument::contentsChanged,
+          this, &TextEditTabWidget::slot_save_status_to_cache_for_recovery);
+
+  // set content with modified status
+  page->GetTextPage()->document()->setPlainText(content);
+}
+}  // namespace GpgFrontend::UI
diff --git a/src/ui/widgets/TextEditTabWidget.h b/src/ui/widgets/TextEditTabWidget.h
new file mode 100644
index 00000000..7c83a721
--- /dev/null
+++ b/src/ui/widgets/TextEditTabWidget.h
@@ -0,0 +1,118 @@
+/**
+ * Copyright (C) 2021-2024 Saturneric <[email protected]>
+ *
+ * This file is part of GpgFrontend.
+ *
+ * GpgFrontend is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GpgFrontend is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GpgFrontend. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The initial version of the source code is inherited from
+ * the gpg4usb project, which is under GPL-3.0-or-later.
+ *
+ * All the source code of GpgFrontend was modified and released by
+ * Saturneric <[email protected]> starting on May 12, 2021.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ */
+
+#pragma once
+
+#include "widgets/FilePage.h"
+namespace GpgFrontend::UI {
+
+class PlainTextEditorPage;
+
+class TextEditTabWidget : public QTabWidget {
+  Q_OBJECT
+ public:
+  explicit TextEditTabWidget(QWidget* parent = nullptr);
+
+ public slots:
+
+  /**
+   * @brief
+   *
+   */
+  void SlotNewTab();
+
+  /**
+   * @brief
+   *
+   * @param title
+   * @param content
+   */
+  void SlotNewTabWithContent(QString title, const QString& content);
+
+  /**
+   * @details Adds a new tab with opening file by path
+   */
+  void SlotOpenFile(const QString& path);
+
+  /**
+   * @details put a * in front of current tabs title, if current textedit is
+   * modified
+   */
+  void SlotShowModified(bool);
+
+  /**
+   * @brief
+   *
+   * @return PlainTextEditorPage*
+   */
+  [[nodiscard]] auto CurTextPage() const -> PlainTextEditorPage*;
+
+  /**
+   * @brief
+   *
+   * @return PlainTextEditorPage*
+   */
+  auto SlotCurPageTextEdit() -> PlainTextEditorPage*;
+
+  /**
+   * @brief
+   *
+   * @return FilePage*
+   */
+  [[nodiscard]] auto CurFilePage() const -> FilePage*;
+
+ protected:
+  /**
+   * @brief
+   *
+   * @param event
+   */
+  void dragEnterEvent(QDragEnterEvent* event) override;
+
+  /**
+   * @brief
+   *
+   * @param event
+   */
+  void dropEvent(QDropEvent* event) override;
+
+ private slots:
+  /**
+   * @brief
+   *
+   */
+  void slot_save_status_to_cache_for_recovery();
+
+ private:
+  int count_page_ = 0;
+  int text_page_data_modified_count_ = 0;
+
+  static auto stripped_name(const QString& full_file_name) -> QString;
+};
+
+}  // namespace GpgFrontend::UI
\ No newline at end of file