Improve file loading robustness and drag-and-drop handling

- Add error handling for UTF-8 decoding to gracefully handle invalid bytes
- Refactor DnD target handling with explicit target list and proper context completion
- Remove completed TODO item for file open event emission
- Clean up memory by deleting file contents after decoding

src/core/widgets/code/mixins/source_view_dnd_mixin.py

@@ -3,7 +3,10 @@
 # Lib imports
 import gi
 gi.require_version('Gtk', '3.0')
+#gi.require_version('Gdk', '3.0')
 from gi.repository import Gtk
+#from gi.repository import Gdk
+
 
 # Application imports
 
@@ -12,25 +15,41 @@ from gi.repository import Gtk
 class SourceViewDnDMixin:
 
     def _set_up_dnd(self):
-        PLAIN_TEXT_TARGET_TYPE = 70
-        URI_TARGET_TYPE        = 80
-        text_target = Gtk.TargetEntry.new('text/plain', Gtk.TargetFlags(0), PLAIN_TEXT_TARGET_TYPE)
-        uri_target  = Gtk.TargetEntry.new('text/uri-list', Gtk.TargetFlags(0), URI_TARGET_TYPE)
-        targets     = [ text_target, uri_target ]
+        URI_TARGET_TYPE        = 10
+        PLAIN_TEXT_TARGET_TYPE = 50
+
+        uri_target  = Gtk.TargetEntry.new(
+            'text/uri-list', Gtk.TargetFlags(0), URI_TARGET_TYPE
+        )
+        text_target = Gtk.TargetEntry.new(
+            'text/plain', Gtk.TargetFlags(0), PLAIN_TEXT_TARGET_TYPE
+        )
+        targets     = Gtk.TargetList.new([ uri_target, text_target ])
 
         self.drag_dest_set_target_list(targets)
 
-    def _on_drag_data_received(self, widget, drag_context, x, y, data, info, time):
-        if info == 70: return
+    def _on_drag_data_received(
+        self, widget, drag_context, x, y, data, info, time
+    ):
+        target = data.get_target().name()
 
-        if info == 80:
+        if (info == 10) or (target == "text/uri-list"):
             uris = data.get_uris()
-
             if not uris:
                 uris = data.get_text().split("\n")
 
             self._on_uri_data_received(uris)
 
+            drag_context.finish(True, False, time)
+
+            return
+        elif (info == 50) or (target == "text/plain"):
+            ...
+        else:
+            logger.info(f"DnD Dropped File Type: {target}")
+
+        drag_context.finish(False, False, time)
+
     def _on_uri_data_received(self, uris: list[str]):
             uris = self.command.filter_out_loaded_files(uris)
             if not uris: return

src/core/widgets/code/source_file.py

@@ -169,7 +169,12 @@ class SourceFile(GtkSource.File):
         loaded, contents, etag_out = gfile.load_contents()
         if not loaded: raise Exception("File couldn't be loaded...'")
 
-        text         = contents.decode("UTF-8")
+        # Note:
+        # "strict" (default) -> raises an error on invalid bytes
+        # "ignore"           -> skips invalid bytes entirely
+        # "replace"          -> replaces invalid bytes with <20>
+        # "backslashreplace" -> uses escape sequences like \xFF
+        text         = contents.decode("UTF-8", errors = "replace")
         info         = gfile.query_info('standard::content-type', Gio.FileQueryInfoFlags.NONE, None)
         content_type = info.get_content_type()
         self.ftype   = Gio.content_type_get_mime_type(content_type) \
@@ -177,6 +182,7 @@ class SourceFile(GtkSource.File):
                         .replace("text/", "") \
                         .replace("x-", "")
 
+        del contents
         self.set_path(gfile)
         logger.debug(f"File content type: {self.ftype}")
         self._load_data(text)