Merge lp:~tintou/scratch/scratch-backup-changes into lp:~elementary-apps/scratch/scratch

[Corentin Noël]

The restoration point isn't kept in memory but in the backup file.
Don't check for file existence at focus but creates a FileMonitor to have every events on real-time.

With this the file loading process is much faster.

[xapantu (xapantu)]

Some in-line comments, maybe more to come.

Here is a crash, after using the "save as" button (maybe not related, I don't have a backtrace yet).

xapantu@ntu /t/s/build> src/scratch-text-editor
[INFO 02:22:03.881206] Application.vala:155: Scratch version: 2.2.1
[INFO 02:22:03.881260] Application.vala:157: Kernel version: 4.1.4-1-ARCH
[DEBUG 02:22:03.882757] Settings.vala:163: Loading settings from schema 'org.pantheon.scratch.saved-state'
[DEBUG 02:22:03.883261] Settings.vala:163: Loading settings from schema 'org.pantheon.scratch.settings'
[DEBUG 02:22:03.884352] Settings.vala:163: Loading settings from schema 'org.pantheon.scratch.services'
[DEBUG 02:22:03.959510] [Gtk] Connecting to session manager
[WARNING 02:22:03.965308] [Gtk] Attempting to add a widget with type GtkScrolledWindow to a GtkDialog, but as a GtkBin subclass a GtkDialog can only contain one widget at a time; it already contains a widget of type GtkBox
[WARNING 02:22:03.965550] [libpeas] Failed to enable unknown plugin loader 'gjs'
[DEBUG 02:22:03.991315] Settings.vala:163: Loading settings from schema 'org.pantheon.scratch.plugins.terminal'
[WARNING 02:22:04.011552] [libpeas] Failed to enable unknown plugin loader 'gjs'
[WARNING 02:22:04.045298] [GLib-GObject] The property GtkSettings:gtk-menu-images is deprecated and shouldn't be used anymore. It will be removed in a future version.
[FATAL 02:22:04.051353] [Gtk] gtk_header_bar_pack: assertion 'gtk_widget_get_parent (widget) == NULL' failed
[FATAL 02:22:04.157390] [Gtk] gtk_action_set_visible: assertion 'GTK_IS_ACTION (action)' failed
[DEBUG 02:22:04.157634] MainWindow.vala:673: open temporary file: Fichier texte à partir de 2015-09-24 01:28:31
[DEBUG 02:22:04.162284] sql-schema.vala:204: schema_version is 10
[INFO 02:22:04.206977] Document.vala:171: Opening "Nouveau document"
[DEBUG 02:22:04.312185] SplitView.vala:124: View added successfully
[WARNING 02:22:04.501706] [GLib-GObject] The property GtkCellRendererPixbuf:follow-state is deprecated and shouldn't be used anymore. It will be removed in a future version.
[DEBUG 02:22:04.502441] Settings.vala:163: Loading settings from schema 'org.pantheon.scratch.plugins.folder-manager'
[DEBUG 02:22:04.596172] sql-schema.vala:204: schema_version is 10
[INFO 02:22:04.606347] Document.vala:171: Opening "Nouveau document"
[WARNING 02:22:04.616528] DocumentView.vala:142: This Document was already opened! Not opening a duplicate!
[DEBUG 02:22:04.618693] sql-schema.vala:204: schema_version is 10
[INFO 02:22:04.625701] Document.vala:171: Opening "40_39.diff"
[FATAL 02:22:04.712490] [Gtk] gtk_text_view_get_editable: assertion 'GTK_IS_TEXT_VIEW (text_view)' failed
[FATAL 02:22:04.718433] [Gtk] gtk_text_view_get_editable: assertion 'GTK_IS_TEXT_VIEW (text_view)' failed
[FATAL 02:22:04.722147] [Gtk] gtk_text_view_get_editable: assertion 'GTK_IS_TEXT_VIEW (text_view)' failed
[FATAL 02:22:04.727046] [Gtk] gtk_text_view_get_editable: assertion 'GTK_IS_TEXT_VIEW (text_view)' failed
[FATAL 02:22:04.730144] [Gtk] gtk_text_view_get_editable: assertion 'GTK_IS_TEXT_VIEW (text_view)' failed
[FATAL 02:22:04.732916] [Gtk] gtk_text_view_get_editable: assertion 'GTK_IS_TEXT_VIEW (text_view)' failed
[FAT...

review: Needs Fixing

[lp:~tintou/scratch/scratch-backup-changes]

1559. By Corentin Noël on 2015-10-21

Don't save the file while restoring it.

[Corentin Noël (tintou)]

Lucas: I fixed most inline comment you did, but most of the code is just copy/paste from older functions so it's not the scope of this branch to change all the behavior and strings :)

[lp:~tintou/scratch/scratch-backup-changes]

1560. By Corentin Noël on 2015-10-21

Fix save as.
Fixed Outline plugin cmake.

[xapantu (xapantu)]

Ok, nice, I will check that as soon as possible!

On 21/10/2015 22:31, Corentin Noël wrote:
> Lucas: I fixed most inline comment you did, but most of the code is just copy/paste from older functions so it's not the scope of this branch to change all the behavior and strings :)
>

[Zisu Andrei (matzipan)]

How do I test this?

review: Needs Information

[Zisu Andrei (matzipan)]

From tintou:

I think you have to open a document, and delete it, and see if scratch shows the infobar without even focusing it. Also see if the file~ is created and removed as it should be.

Unmerged revisions

1560. By Corentin Noël on 2015-10-21

Fix save as.
Fixed Outline plugin cmake.

1559. By Corentin Noël on 2015-10-21

Don't save the file while restoring it.

1558. By Corentin Noël on 2015-09-16

Fixed reverting sensitivity not being per-document.

1557. By Corentin Noël on 2015-09-16

More efficient document loading and changes handling.

=== modified file 'plugins/outline/CMakeLists.txt'
--- plugins/outline/CMakeLists.txt	2015-03-19 14:49:48 +0000
+++ plugins/outline/CMakeLists.txt	2015-10-21 20:31:41 +0000
@@ -21,6 +21,11 @@
 set(VALA_SHORTVER "${maj_ver}.${min_ver}" CACHE INTERNAL "")
 
 
+pkg_check_modules (LIBVALA "libvala-${VALA_SHORTVER}")
+
+if (${LIBVALA_FOUND})
+link_directories(${LIBVALA_LIBRARY_DIRS})
+add_definitions(${LIBVALA_CFLAGS})
 
 vala_precompile(VALA_C ${PLUGIN_NAME}
     CtagsSymbolResolver.vala
@@ -49,15 +54,14 @@
 include (GResource)
 glib_compile_resources (GLIB_RESOURCES_OUTLINE SOURCE icons/outline.gresource.xml)
 
-pkg_check_modules(OUTLINE_DEPS libvala-${VALA_SHORTVER})
-link_directories(${OUTLINE_DEPS_LIBRARY_DRIS})
-add_definitions(${OUTLINE_DEPS_CFLAGS})
-
 add_library(${PLUGIN_NAME} MODULE ${VALA_C} ${GLIB_RESOURCES_OUTLINE})
 add_dependencies(${PLUGIN_NAME} ${LIBNAME} scratch)
-target_link_libraries(${PLUGIN_NAME} ${NORMAL_LIBRARIES} ${OUTLINE_DEPS_LIBRARIES})
+target_link_libraries(${PLUGIN_NAME} ${NORMAL_LIBRARIES} ${LIBVALA_LIBRARIES})
 
 install(TARGETS ${PLUGIN_NAME} DESTINATION ${PLUGINDIR}/${PLUGIN_NAME})
 install(FILES ${PLUGIN_NAME}.plugin DESTINATION ${PLUGINDIR}/${PLUGIN_NAME})
 
 message("-- Outline plugin will be compiled")
+else()
+message("-- Outline plugin will NOT be compiled")
+endif()

=== modified file 'src/MainWindow.vala'
--- src/MainWindow.vala	2015-10-01 10:42:31 +0000
+++ src/MainWindow.vala	2015-10-21 20:31:41 +0000
@@ -322,7 +322,7 @@
             main_actions.get_action ("SaveFileAs").sensitive = val;
             main_actions.get_action ("Undo").sensitive = val;
             main_actions.get_action ("Redo").sensitive = val;
-            main_actions.get_action ("Revert").sensitive = val;
+            main_actions.get_action ("Revert").sensitive = val && main_actions.get_action ("Revert").sensitive;
             this.toolbar.share_app_menu.sensitive = val;
 
             // Zoom button

=== modified file 'src/Services/Document.vala'
--- src/Services/Document.vala	2015-09-16 01:11:55 +0000
+++ src/Services/Document.vala	2015-10-21 20:31:41 +0000
@@ -20,7 +20,6 @@
 ***/
 
 namespace Scratch.Services {
-
     public enum DocumentStates {
         NORMAL,
         READONLY
@@ -45,22 +44,38 @@
         public signal void doc_saved ();
         public signal void doc_closed ();
 
+        public bool can_revert = false;
+
         // Widgets
         public Scratch.Widgets.SourceView source_view;
         private Gtk.InfoBar info_bar;
 
         // Objects
         private Gtk.SourceFile source_file;
+        private FileMonitor file_monitor = null;
+        public File backup_file;
         public File file {
             get { return source_file.location; }
             set {
                 source_file.set_location (value);
-                file_changed ();
+                backup_file = File.new_for_path ("%s~".printf (value.get_path ()));
+                attribute_changed ();
+                if (file_monitor != null) {
+                    file_monitor.changed.disconnect (monitor_changed);
+                    file_monitor.cancel ();
+                }
+
+                try {
+                    file_monitor = value.monitor_file (FileMonitorFlags.WATCH_MOUNTS);
+                    file_monitor.changed.connect (monitor_changed);
+                } catch (Error e) {
+                    debug (e.message);
+                }
             }
         }
 
-        public string original_content;
         public bool saved = true;
+        private bool ignore_next = false;
         private bool error_shown = false;
         public bool is_file_temporary {
             get {
@@ -84,7 +99,7 @@
 
         // Mount state of the file
         private bool mounted = true;
-        private Mount mount;
+        private bool read_only = false;
 
         public Document (Gtk.ActionGroup actions, File? file = null) {
             this.main_actions = actions;
@@ -123,14 +138,15 @@
                                 Source.remove (timeout_saving);
                                 timeout_saving = 0;
                             }
+
                             timeout_saving = Timeout.add (1000, () => {
                                 save.begin ();
                                 timeout_saving = 0;
                                 return false;
                             });
-                        }
-                        else
+                        } else {
                             this.set_saved_status (false);
+                        }
                      });
                 });
             } else if (onchange_handler_id != 0) {
@@ -159,9 +175,7 @@
             // Focus in event for SourceView
             this.source_view.focus_in_event.connect (() => {
                 main_actions.get_action ("SaveFile").visible = !(settings.autosave);
-                check_file_status ();
                 check_undoable_actions ();
-
                 return false;
             });
 
@@ -197,9 +211,10 @@
                 return false;
             }
 
+            can_revert = false;
             source_view.buffer.set_modified (false);
-            original_content = source_view.buffer.text;
             loaded = true;
+            check_undoable_actions ();
 
             doc_opened ();
 
@@ -286,6 +301,7 @@
             save_cancellable = new GLib.Cancellable ();
             var source_file_saver = new Gtk.SourceFileSaver (source_view.buffer, source_file);
             try {
+                ignore_next = true;
                 yield source_file_saver.save_async (GLib.Priority.DEFAULT, save_cancellable, null);
             } catch (Error e) {
                 // We don't need to send an error message at cancellation (corresponding to error code 19)
@@ -299,9 +315,10 @@
             // Zeitgeist integration
             zg_log.save_insert (file.get_uri (), get_mime_type ());
 #endif
-
             doc_saved ();
+            can_revert = true;
             this.set_saved_status (true);
+            check_undoable_actions ();
 
             message ("File \"%s\" saved succesfully", get_basename ());
 
@@ -316,12 +333,18 @@
             bool is_current_file_temporary = this.is_file_temporary;
 
             if (filech.run () == Gtk.ResponseType.ACCEPT) {
-                this.file = File.new_for_uri (filech.get_file ().get_uri ());
+                var dest = File.new_for_uri (filech.get_file ().get_uri ());
+                try {
+                    file.copy (dest, GLib.FileCopyFlags.OVERWRITE);
+                } catch (Error e) {
+                    critical (e.message);
+                    return false;
+                }
+                file = dest;
                 // Update last visited path
                 Utils.last_path = Path.get_dirname (filech.get_file ().get_uri ());
                 filech.destroy ();
-            }
-            else {
+            } else {
                 filech.destroy ();
                 return false;
             }
@@ -338,7 +361,7 @@
             }
 
             // Delete backup file
-            delete_backup (current_file + "~");
+            delete_backup ();
 
             // Change syntax highlight
             this.source_view.change_syntax_highlight_from_file (this.file);
@@ -401,10 +424,11 @@
         
         // Get file name
         public string get_basename () {
-            if (is_file_temporary)
+            if (is_file_temporary) {
                 return _("New Document");
-            else
+            } else {
                 return file.get_basename ();
+            }
         }
 
         // Set InfoBars message
@@ -421,6 +445,7 @@
                 if (w != null)
                     w.destroy ();
             });
+
             ((Gtk.Box)info_bar.get_action_area ()).get_children ().foreach ((w) => {
                 if (w != null)
                     w.destroy ();
@@ -438,17 +463,21 @@
             var main = info_bar.get_content_area () as Gtk.Box;
             main.orientation = Gtk.Orientation.HORIZONTAL;
             main.pack_start (l, false, false, 0);
-            if (button1 != null)
+            if (button1 != null) {
                 info_bar.add_button (button1, 0);
-            if (button2 != null)
+            }
+
+            if (button2 != null) {
                 info_bar.add_button (button2, 1);
+            }
 
             // Response
             info_bar.response.connect ((id) => {
-                if (id == 0)
+                if (id == 0) {
                     callback1 ();
-                else if (id == 1)
+                } else if (id == 1) {
                     callback2 ();
+                }
             });
 
             // Show everything
@@ -476,7 +505,8 @@
 
         // Revert
         public void revert () {
-            this.source_view.set_text (original_content, false);
+            restore_backup ();
+            can_revert = false;
             check_undoable_actions ();
         }
 
@@ -493,26 +523,28 @@
         // Get language name
         public string get_language_name () {
             var lang = this.source_view.buffer.language;
-            if (lang != null)
+            if (lang != null) {
                 return lang.name;
-            else
+            } else {
                 return "";
+            }
         }
 
         // Get language id
         public string get_language_id () {
             var lang = this.source_view.buffer.language;
-            if (lang != null)
+            if (lang != null) {
                 return lang.id;
-            else
+            } else {
                 return "";
+            }
         }
 
         // Duplicate selected text
         public void duplicate_selection () {
             this.source_view.duplicate_selection ();
         }
-        
+
         // Show an error dialog which says "Hey, I cannot read that file!"
         private void show_error_dialog () {
             if (this.error_shown)
@@ -528,139 +560,76 @@
             dialog.destroy ();
             this.close ();
         }
-        
-        // Check if the file was deleted/changed by an external source
-        public void check_file_status () {
-            // If the file does not exist anymore
-            if (!exists ()) {
-                if (mounted == false) {
-                    string message = _("The location containing the file \"%s\" was unmounted. Do you want to save somewhere else?").printf ("<b>%s</b>".printf (get_basename ()));
-
-                    set_message (Gtk.MessageType.WARNING, message, _("Save As…"), () => {
-                        this.save_as.begin ();
-                        hide_info_bar ();
-                    });
-                } else {
-                    string message = _("File \"%s\" was deleted. Do you want to save it anyway?").printf ("<b>%s</b>".printf (get_basename ()));
-
-                    set_message (Gtk.MessageType.WARNING, message, _("Save"), () => {
-                        this.save.begin ();
-                        hide_info_bar ();
-                    });
-                }
-                main_actions.get_action ("SaveFile").sensitive = false;
-                this.source_view.editable = false;
-                return;
-            }
-            // If the file can't be written
-            if (!can_write ()) {
-                string message = _("You cannot save changes on file \"%s\". Do you want to save the changes to this file in a different location?").printf ("<b>%s</b>".printf (get_basename ()));
-
-                set_message (Gtk.MessageType.WARNING, message, _("Save changes elsewhere"), () => {
-                    this.save_as.begin ();
-                    hide_info_bar ();
-                });
-                main_actions.get_action ("SaveFile").sensitive = false;
-                this.source_view.editable = !settings.autosave;
-            }
-            else {
-                main_actions.get_action ("SaveFile").sensitive = true;
-                this.source_view.editable = true;
-            }
-            // Detect external changes
-            if (loaded) {
-                var new_buffer = new Gtk.SourceBuffer (null);
-                var source_file_loader = new Gtk.SourceFileLoader (new_buffer, source_file);
-                source_file_loader.load_async.begin (GLib.Priority.DEFAULT, null, null, (obj, res) => {
-                    try {
-                        source_file_loader.load_async.end (res);
-                    } catch (Error e) {
-                        critical (e.message);
-                        show_error_dialog ();
-                        return;
-                    }
-
-                    if (source_view.buffer.text == new_buffer.text)
-                        return;
-
-                    if (!source_view.buffer.get_modified ()) {
-                        if (settings.autosave) {
-                            source_view.set_text (new_buffer.text, false);
-                        } else {
-                            string message =  _("File \"%s\" was modified by an external application. Do you want to load it again or continue your editing?").printf ("<b>%s</b>".printf (get_basename ()));
-                            set_message (Gtk.MessageType.WARNING, message, _("Load"), () => {
-                                this.source_view.set_text (new_buffer.text, false);
-                                hide_info_bar ();
-                            }, _("Continue"), () => {
-                                hide_info_bar ();
-                            });
-                        }
-                    }
-                });
-            }
-        }
 
         // Set Undo/Redo action sensitive property
         public void check_undoable_actions () {
             main_actions.get_action ("Undo").sensitive = this.source_view.buffer.can_undo;
             main_actions.get_action ("Redo").sensitive = this.source_view.buffer.can_redo;
-            main_actions.get_action ("Revert").sensitive = (original_content != source_view.buffer.text);
+            main_actions.get_action ("Revert").sensitive = can_revert;
         }
 
         // Set saved status
         public void set_saved_status (bool val) {
             this.saved = val;
-
             string unsaved_identifier = "* ";
-
             if (!val) {
-                if (!(unsaved_identifier in this.label))
+                if (!(unsaved_identifier in this.label)) {
                     this.label = unsaved_identifier + this.label;
-            }
-            else
+                }
+            } else {
                 this.label = this.label.replace (unsaved_identifier, "");
+            }
         }
 
         // Backup functions
         private void create_backup () {
-            if (!can_write ())
+            if (read_only) {
                 return;
-
-            var backup = File.new_for_path (this.file.get_path () + "~");
-
-            if (!backup.query_exists ()) {
+            }
+
+            if (!backup_file.query_exists ()) {
                 try {
-                    file.copy (backup, FileCopyFlags.NONE);
+                    file.copy (backup_file, FileCopyFlags.NONE);
                 } catch (Error e) {
                     warning ("Cannot create backup copy for file \"%s\": %s", get_basename (), e.message);
                 }
             }
         }
 
-        private void delete_backup (string? backup_path = null) {
-
-            string backup_file  = "";
-
-            if (backup_path == null)
-                backup_file = file.get_path () + "~";
-            else
-                backup_file = backup_path;
-
-            debug ("Backup file deleting: %s", backup_file);
-            
-            var backup = File.new_for_path (backup_file);
-            if (backup == null || !backup.query_exists ()) {
-                debug ("Backup file doesn't exists: %s", backup.get_path ());
+        private void delete_backup () {
+            debug ("Backup file deleting: %s", backup_file.get_path ());
+            if (backup_file == null || !backup_file.query_exists ()) {
+                debug ("Backup file doesn't exists: %s", backup_file.get_path ());
                 return;
             }
+
             try {
-                backup.delete ();
-                debug ("Backup file deleted: %s", backup_file);
+                backup_file.delete ();
+                debug ("Backup file deleted: %s", backup_file.get_path ());
             } catch (Error e) {
                 warning ("Cannot delete backup for file \"%s\": %s", get_basename (), e.message);
             }
         }
 
+        private void restore_backup () {
+            var backup_source = new Gtk.SourceFile ();
+            backup_source.set_location (backup_file);
+            var new_buffer = new Gtk.SourceBuffer (null);
+            var source_file_loader = new Gtk.SourceFileLoader (new_buffer, backup_source);
+            loaded = false;
+            source_file_loader.load_async.begin (GLib.Priority.DEFAULT, null, null, (obj, res) => {
+                try {
+                    source_file_loader.load_async.end (res);
+                    source_view.buffer.text = new_buffer.text;
+                    loaded = true;
+                } catch (Error e) {
+                    critical (e.message);
+                    show_error_dialog ();
+                    return;
+                }
+            });
+        }
+
         private bool delete_temporary_file (bool force = false) {
             if (!is_file_temporary || (get_text ().length > 0 && !force))
                 return false;
@@ -674,46 +643,114 @@
         }
 
         // Return true if the file is writable
-        public bool can_write () {
-            FileInfo info;
-
-            bool writable = false;
-
-            try {
-                info = this.file.query_info (FileAttribute.ACCESS_CAN_WRITE, FileQueryInfoFlags.NONE, null);
-                writable = info.get_attribute_boolean (FileAttribute.ACCESS_CAN_WRITE);
-                return writable;
-            } catch (Error e) {
-                warning ("query_info failed, but filename appears to be correct, allowing as new file");
-                writable = true;
-                return writable;
-            }
-        }
 
         // Return true if the file exists
         public bool exists () {
             return this.file.query_exists ();
         }
 
-        private void file_changed () {
-            if (mount != null) {
-                mount.unmounted.disconnect (unmounted_cb);
-                mount = null;
-            }
-
-            try {
-                mount = file.find_enclosing_mount ();
-                mount.unmounted.connect (unmounted_cb);
-            } catch (Error e) {
-                debug ("Could not find mount location");
-                return;
-            }
-            mounted = true;
-        }
-
-        private void unmounted_cb () {
-            warning ("Folder containing the file was unmounted");
+        private void monitor_changed (File file, File? other_file, FileMonitorEvent event_type) {
+            switch (event_type) {
+                case FileMonitorEvent.CHANGED:
+                    attribute_changed ();
+                    break;
+                case FileMonitorEvent.DELETED:
+                    deleted ();
+                    break;
+                case FileMonitorEvent.CREATED:
+                    if (ignore_next == false) {
+                        changed_external ();
+                    }
+
+                    ignore_next = false;
+                    break;
+                case FileMonitorEvent.UNMOUNTED:
+                    unmounted ();
+                    break;
+                case FileMonitorEvent.ATTRIBUTE_CHANGED:
+                    attribute_changed ();
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        private void changed_external () {
+            var new_buffer = new Gtk.SourceBuffer (null);
+            var source_file_loader = new Gtk.SourceFileLoader (new_buffer, source_file);
+            source_file_loader.load_async.begin (GLib.Priority.DEFAULT, null, null, (obj, res) => {
+                try {
+                    source_file_loader.load_async.end (res);
+                } catch (Error e) {
+                    critical (e.message);
+                    show_error_dialog ();
+                    return;
+                }
+
+                if (source_view.buffer.text == new_buffer.text)
+                    return;
+
+                if (!source_view.buffer.get_modified ()) {
+                    if (settings.autosave) {
+                        source_view.set_text (new_buffer.text, false);
+                        attribute_changed ();
+                    } else {
+                        string message =  _("File \"%s\" was modified by an external application. Do you want to load it again or continue your editing?").printf ("<b>%s</b>".printf (get_basename ()));
+                        set_message (Gtk.MessageType.WARNING, message, _("Load"), () => {
+                            this.source_view.set_text (new_buffer.text, false);
+                            attribute_changed ();
+                            hide_info_bar ();
+                        }, _("Continue"), () => {
+                            hide_info_bar ();
+                        });
+                    }
+                }
+            });
+        }
+
+        private void deleted () {
+            string message = _("File \"%s\" was deleted. Do you want recreate it?").printf ("<b>%s</b>".printf (get_basename ()));
+
+            set_message (Gtk.MessageType.WARNING, message, _("Save"), () => {
+                this.save.begin ();
+                hide_info_bar ();
+            });
+        }
+
+        private void unmounted () {
             mounted = false;
+            main_actions.get_action ("SaveFile").sensitive = false;
+            source_view.editable = false;
+            string message = _("The location containing the file \"%s\" was unmounted. Do you want to save somewhere else?").printf ("<b>%s</b>".printf (get_basename ()));
+
+            set_message (Gtk.MessageType.WARNING, message, _("Save As…"), () => {
+                this.save_as.begin ();
+                hide_info_bar ();
+            });
+        }
+
+        public void attribute_changed () {
+            FileInfo info;
+            try {
+                info = file.query_info (FileAttribute.ACCESS_CAN_WRITE, FileQueryInfoFlags.NONE, null);
+                read_only = !info.get_attribute_boolean (FileAttribute.ACCESS_CAN_WRITE);
+                if (read_only) {
+                    string message = _("You cannot save changes on file \"%s\". Do you want to save the changes to this file in a different location?").printf ("<b>%s</b>".printf (get_basename ()));
+
+                    set_message (Gtk.MessageType.WARNING, message, _("Save changes elsewhere"), () => {
+                        this.save_as.begin ();
+                        hide_info_bar ();
+                    });
+                    main_actions.get_action ("SaveFile").sensitive = false;
+                    this.source_view.editable = !settings.autosave;
+                } else {
+                    main_actions.get_action ("SaveFile").sensitive = true;
+                    this.source_view.editable = true;
+                }
+            } catch (Error e) {
+                warning ("query_info failed, but filename appears to be correct, allowing as new file");
+                read_only = false;
+            }
         }
     }
 }

=== modified file 'src/Services/FileHandler.vala'
--- src/Services/FileHandler.vala	2015-03-19 21:34:20 +0000
+++ src/Services/FileHandler.vala	2015-10-21 20:31:41 +0000
@@ -130,4 +130,4 @@
 
     }
 
-}
\ No newline at end of file
+}