Fixed dart lint issues.

Author: diegotori

lib/src/helpers/adaptive_controls.dart

@@ -23,8 +23,6 @@ class AdaptiveControls extends StatelessWidget {
           backgroundColor: Color.fromRGBO(41, 41, 41, 0.7),
           iconColor: Color.fromARGB(255, 200, 200, 200),
         );
-      default:
-        return const MaterialControls();
     }
   }
 }

lib/src/material/material_controls.dart

@@ -470,7 +470,7 @@ class _MaterialControlsState extends State<MaterialControls>
             text: '/ ${formatDuration(duration)}',
             style: TextStyle(
               fontSize: 14.0,
-              color: Colors.white.withOpacity(.75),
+              color: Colors.white.withValues(alpha: .75),
               fontWeight: FontWeight.normal,
             ),
           )
@@ -682,8 +682,9 @@ class _MaterialControlsState extends State<MaterialControls>
               playedColor: Theme.of(context).colorScheme.secondary,
               handleColor: Theme.of(context).colorScheme.secondary,
               bufferedColor:
-                  Theme.of(context).colorScheme.surface.withOpacity(0.5),
-              backgroundColor: Theme.of(context).disabledColor.withOpacity(.5),
+                  Theme.of(context).colorScheme.surface.withValues(alpha: 0.5),
+              backgroundColor:
+                  Theme.of(context).disabledColor.withValues(alpha: .5),
             ),
         draggableProgressBar: chewieController.draggableProgressBar,
       ),

lib/src/material/material_desktop_controls.dart

@@ -591,8 +591,9 @@ class _MaterialDesktopControlsState extends State<MaterialDesktopControls>
               playedColor: Theme.of(context).colorScheme.secondary,
               handleColor: Theme.of(context).colorScheme.secondary,
               bufferedColor:
-                  Theme.of(context).colorScheme.surface.withOpacity(0.5),
-              backgroundColor: Theme.of(context).disabledColor.withOpacity(.5),
+                  Theme.of(context).colorScheme.surface.withValues(alpha: 0.5),
+              backgroundColor:
+                  Theme.of(context).disabledColor.withValues(alpha: 0.5),
             ),
         draggableProgressBar: chewieController.draggableProgressBar,
       ),