feat: implement mouse event emulator for Qt WebEngineView to enhance hover effects

src/webdrop_bridge/ui/main_window.py

@@ -534,8 +534,8 @@ class MainWindow(QMainWindow):
     def _install_bridge_script(self) -> None:
         """Install the drag bridge JavaScript via QWebEngineScript.
 
-        Uses DocumentCreation injection point to ensure script runs as early as possible,
-        before any page scripts that might interfere with drag events.
+        Uses Deferred injection point to ensure script runs after the DOM is ready,
+        allowing proper event listener registration without race conditions.
 
         Embeds qwebchannel.js inline to avoid CSP issues with qrc:// URLs.
         Injects configuration that bridge script uses for dynamic URL pattern matching.
@@ -544,7 +544,9 @@ class MainWindow(QMainWindow):
 
         script = QWebEngineScript()
         script.setName("webdrop-bridge")
-        script.setInjectionPoint(QWebEngineScript.InjectionPoint.DocumentCreation)
+        # Use Deferred instead of DocumentCreation to allow DOM to be ready first
+        # This prevents race conditions with JavaScript event listeners
+        script.setInjectionPoint(QWebEngineScript.InjectionPoint.Deferred)
         script.setWorldId(QWebEngineScript.ScriptWorldId.MainWorld)
         script.setRunsOnSubFrames(False)
 
@@ -633,18 +635,47 @@ class MainWindow(QMainWindow):
             else:
                 logger.debug("Download interceptor not found (optional)")
 
-            # Combine: qwebchannel.js + config + bridge script + download interceptor
+            # Load mouse event emulator for hover effect support
+            mouse_emulator_search_paths = []
+            mouse_emulator_search_paths.append(Path(__file__).parent / "mouse_event_emulator.js")
+            if hasattr(sys, "_MEIPASS"):
+                mouse_emulator_search_paths.append(
+                    Path(sys._MEIPASS) / "webdrop_bridge" / "ui" / "mouse_event_emulator.js"  # type: ignore
+                )
+            mouse_emulator_search_paths.append(
+                exe_dir / "webdrop_bridge" / "ui" / "mouse_event_emulator.js"
+            )
+
+            mouse_emulator_code = ""
+            for path in mouse_emulator_search_paths:
+                if path.exists():
+                    try:
+                        with open(path, "r", encoding="utf-8") as f:
+                            mouse_emulator_code = f.read()
+                        logger.debug(f"Loaded mouse event emulator from {path}")
+                        break
+                    except (OSError, IOError) as e:
+                        logger.warning(f"Mouse event emulator exists but failed to load: {e}")
+            if not mouse_emulator_code:
+                logger.debug("Mouse event emulator not found (optional)")
+
+            # Combine: qwebchannel.js + config + bridge script + download interceptor + mouse emulator
             combined_code = qwebchannel_code + "\n\n" + config_code + "\n\n" + bridge_code
 
             if download_interceptor_code:
                 combined_code += "\n\n" + download_interceptor_code
 
+            # Add mouse event emulator last to ensure it runs after all other scripts
+            if mouse_emulator_code:
+                combined_code += "\n\n" + mouse_emulator_code
+
             logger.debug(
                 f"Combined script size: {len(combined_code)} chars "
                 f"(qwebchannel: {len(qwebchannel_code)}, "
                 f"config: {len(config_code)}, "
                 f"bridge: {len(bridge_code)}, "
-                f"interceptor: {len(download_interceptor_code)})"
+                f"interceptor: {len(download_interceptor_code)}, "
+                f"mouse_emulator: {len(mouse_emulator_code)})"
             )
             logger.debug(f"URL mappings in config: {len(self.config.url_mappings)}")
             for i, mapping in enumerate(self.config.url_mappings):