Redo portions of file editor to use more signals/slots rather than casting. * file-editor-tab.cc, file-editor-tab.h (file_editor_tab::~file_editor_tab): Add. Delete lexer to prevent memory leak. Delete _edit_area to prevent memory leak. (file_editor_tab::conditional_close): Add. Simple slot that uses QWidget pointer as unique ID, not for function call. (file_editor_tab::file_name_query): Add. Simple slot that signals file name to whomever is connected. (file_editor_tab::find, file_editor_tab : public QWidget): Removed use of exec() and keep a pointer to the find_dialog as a member. Toggle hide()/show() via a connected slot to toggle visibility as desired. * file-editor.cc, file-editor.h, file-editor-tab.cc file-editor-tab.h (file_editor : public file_editor_interface, file_editor_tab : public QWidget, file_editor_tab::file_editor_tab, file_editor_tab::closeEvent, file_editor_tab::load_file, file_editor_tab::new_file, file_editor_tab::run_file): Remove _file_editor pointer member from file_editor_tab and rid file_editor::get_main_window from file_editor. There should be no need for such information about higher-level hierarchy inside lower-level objects. (file_editor::request_open_file, file_editor_tab::open_file): Move QFileDialog to file_editor::request_open_file and delete file_editor_tab::open_file since most of the remaining functionality is in file_editor_tab::load_file. (file_editor::active_editor_tab): Deleted. (file_editor::fetab_change_request, file_editor_tab::change_editor_state): Added to initiate a request for the editor tab to change focus. (file_editor_tab::editor_state_changed): Added arguments to pass the copy status and the directory path so that editor doesn't have to call functions for such information. (file_editor::handle_editor_state_changed): Add copying directory of the file_editor_tab to the current editing directory. (file_editor::check_conflict_save, file_editor_tab::editor_check_conflict_save, file_editor_tab::save_file_as, file_editor_tab::handle_save_file_as_answer): Moved a portion of the save-file-as dialog mechanism to the file_editor where all file names can be obtained to check for conflict with already open files. The new signal indicates to the editor that a name check be done, and in turn the editor signals the tab to save the file. * main-window.cc, file-editor.cc, file-editor.h, file-editor-interface.h (file_editor::terminal, file_editor : public file_editor_interface, file_editor_interface : public QDockWidget): Since file_editor_tab no longer looks up to main_window, remove _main_window and _terminal from file_editor and file_editor_interface, as well as file_editor::terminal. * file-editor-tab.cc (file_editor_tab::file_has_changed): Make the dialog boxes non-modal and use slots to handle user answers. (file_editor_tab::closeEvent): Remove portion that accesses upper hierarchy member functions, can find better approaches. (file_editor_tab::file_editor_tab): Make there no parent for QsciScintilla so that window modality can be set to individual editor. * file-editor-tab.cc, file-editor.cc (file_editor_tab::load_file): Use show() member rather than exec() and set modality to window so that rest of application may function. Return a QString with message rather than a boolean. * file-editor-tab.cc, (file_editor_tab::file_has_changed): Remove static variable alreadyAsking. Multiple file_editor_tabs are using this code so do not want to block recognition of multiple file having changed on disk (bug #37406). Instead, simply stop tracking via the file watcher. (file_editor_tab::save_file, file_editor_tab::save_file_as, file_editor_tab::handle_save_file_as_answer, file_editor_tab::handle_save_file_as_answer_close): Added a remove_on_success variable. Changed the QFileDialog to WindowModal and created slots to handle file selected signal and finished signal. Signal/slot connects vary based upon remove_on_success setting. (file_editor_tab::check_file_modified): Changed the QFileDialog to NonModal and attach some slots. Editor tab can't be parent in case deleted, so use read-only state of the editor area. * file-editor-tab.h (file_editor_tab : public QWidget): New signals for file_editor for tab and file name management. (file_editor_tab::get_file_name): Delete. * file-editor.h (file_editor : public file_editor_interface): Make QStringList sessionFileNames a member of file_editor so that it can retain data between file_editor_tab signals. Also can be used for checking precense of filenames and prevent opening multiple copies (bug #36869) Added signals for file editor tabs--settings_changed, fetab_close_request, and query_file_name. Three new slots for tab and file name management. * file-editor-interface.h, file-editor.h (file_editor_interface::add_file_editor_tab, file_editor::add_file_editor_tab): Made the text name for the tab an input variable. * file-editor.cc (file_editor::~file_editor): Replace dynamic_cast with simple signal querying all file editor tabs for file names which end up in savedSessionTabs. (file_editor::handle_file_name_changed): Dynamic cast not necessary since QObject and QWidget are compatible. (file_editor::handle_tab_close_request): Replace dynamic_cast with signal to request file_editor_tab with associated tabID tag should close. (file_editor::handle_tab_remove_request): Rename of handle_tab_close_request. Instead of dynamic cast, loop through pointers comparing QWidget* to QObject*, if same tag remove tab via index and also delete which fixes a memory leak. (file_editor::handle_add_filename_to_list): Simple slot that uses append() of the list member functions. (file_editor::notice_settings): Rather than dynamic cast, emit signal for the file_editor_tabs. (file_editor::add_file_editor_tab): New variety of connections for improved flow. (file_editor::request_open_file): Given error messages are made WindowModal, the tab shouldn't be delete if file open is not successful. The file_editor_tab takes care of that. (file_editor::request_open_file): Added check and message box for the requested file already open in editor. For the non-interactive overloaded version, open a message dialog box to tell the user file not found, e.g., could not find file in the settings when launched. (file_editor::request_open_file): Inquire file names and update list before checking for existence of files. Supply empty title to editor tab then have file_editor_tab update name. * file-editor-tab.h, file-editor-tab.cc, file-editor.cc (file_editor_tab::run_file): New signal process_octave_code. (file_editor::add_file_editor_tab): Connect signal process_octave_code to file_editor's parent's slot handle_command_double_clicked.

--- a/libgui/src/m-editor/file-editor-tab.h
+++ b/libgui/src/m-editor/file-editor-tab.h
@@ -28,61 +28,88 @@
 #include <QCloseEvent>
 #include <QFileSystemWatcher>
 
+#include "find-dialog.h"
+
 class file_editor;
 class file_editor_tab : public QWidget
 {
   Q_OBJECT
   public:
-  file_editor_tab (file_editor *fileEditor);
-  bool copy_available ();
+  file_editor_tab (QString directory = "");
+  ~file_editor_tab ();
 
 public slots:
   void update_window_title(bool modified);
   void handle_copy_available(bool enableCopy);
   void handle_margin_clicked (int line, int margin, Qt::KeyboardModifiers state);
-  void comment_selected_text ();
-  void uncomment_selected_text ();
-  void find ();
-  void remove_bookmark ();
-  void toggle_bookmark ();
-  void next_bookmark ();
-  void previous_bookmark ();
-  void remove_all_breakpoints ();
-  void toggle_breakpoint ();
-  void next_breakpoint ();
-  void previous_breakpoint ();
-  void cut ();
-  void copy ();
-  void paste ();
-  void undo ();
-  void redo ();
+
+  /** Tells the editor tab to react on changed settings. */
+  void notice_settings ();
+  /** Will initiate close if associated with the identifier tag. */
+  void conditional_close (const QWidget* ID);
+  /** Change to a different editor tab by identifier tag. */
+  void change_editor_state (const QWidget* ID);
+  /** Simply transmit file name. */
+  void file_name_query (const QWidget* ID);
+
+  void undo (const QWidget* ID);
+  void redo (const QWidget* ID);
+  void copy (const QWidget* ID);
+  void cut (const QWidget* ID);
+  void paste (const QWidget* ID);
+  void save_file (const QWidget* ID);
+  void save_file (const QWidget* ID, const QString& fileName, bool remove_on_success);
+  void save_file_as (const QWidget* ID);
+  void run_file (const QWidget* ID);
+  void toggle_bookmark (const QWidget* ID);
+  void next_bookmark (const QWidget* ID);
+  void previous_bookmark (const QWidget* ID);
+  void remove_bookmark (const QWidget* ID);
+
+  void toggle_breakpoint (const QWidget* ID);
+  void next_breakpoint (const QWidget* ID);
+  void previous_breakpoint (const QWidget* ID);
+  void remove_all_breakpoints (const QWidget* ID);
+
+  void comment_selected_text (const QWidget* ID);
+  void uncomment_selected_text (const QWidget* ID);
+  void find (const QWidget* ID);
+
   void set_debugger_position (int line);
 
   void set_modified (bool modified = true);
 
-  bool open_file (const QString& dir = QString ());
-  bool load_file (const QString& fileName, bool silent = false);
+  QString load_file (const QString& fileName);
   void new_file ();
-  bool save_file ();
-  bool save_file (const QString& saveFileName);
-  bool save_file_as();
-  void run_file ();
 
   void file_has_changed (const QString& fileName);
-  QString get_file_name () const {return _file_name;}
-
-  /** Tells the editor tab to react on changed settings. */
-  void notice_settings ();
 
 signals:
   void file_name_changed (const QString& fileName);
-  void editor_state_changed ();
-  void close_request ();
+  void editor_state_changed (bool copy_available, const QString& fileName);
+  void tab_remove_request ();
+  void add_filename_to_list (const QString& fileName);
+  void editor_check_conflict_save (const QString& saveFileName, bool remove_on_success);
+  void process_octave_code (const QString& command);
 
 protected:
   void closeEvent (QCloseEvent *event);
   void set_file_name (const QString& fileName);
 
+private slots:
+  /** When user closes message box for reload question. */
+  void handle_file_reload_answer (int decision);
+  /** When user closes message box for resave question. */
+  void handle_file_resave_answer (int decision);
+  /** When user closes message box for modified question. */
+  void handle_file_modified_answer (int decision);
+  /** When user closes find_dialog box. */
+  void handle_find_dialog_finished (int decision);
+  /** When user closes QFileDialog box. */
+  void handle_save_file_as_answer (const QString& fileName);
+  void handle_save_file_as_answer_close (const QString& fileName);
+  void handle_save_file_as_answer_cancel ();
+
 private:
 
   struct bp_info
@@ -96,6 +123,10 @@
     int line;
   };
 
+  void save_file (const QString& saveFileName, bool remove_on_success = false);
+  void save_file_as (bool remove_on_success = false);
+  void message_duplicate_file_name (const QString& fileName);
+
   void update_lexer ();
   void request_add_breakpoint (int line);
   void request_remove_breakpoint (int line);
@@ -108,7 +139,6 @@
   void remove_breakpoint_callback (const bp_info& info);
   void remove_all_breakpoints_callback (const bp_info& info);
 
-  file_editor *         _file_editor;
   QsciScintilla *       _edit_area;
 
   QString               _file_name;
@@ -118,6 +148,10 @@
   bool                  _copy_available;
 
   QFileSystemWatcher    _file_system_watcher;
+
+  find_dialog *         _find_dialog;
+  bool                  _find_dialog_is_visible;
+  QRect                 _find_dialog_geometry;
 };
 
 #endif // FILEEDITORTAB_H