fix, set scrollbar thickness to 12

Signed-off-by: dignow <linlong1265@gmail.com>

flutter/lib/common.dart

@@ -265,6 +265,14 @@ class MyTheme {
       ? EdgeInsets.only(left: dialogPadding)
       : EdgeInsets.only(left: dialogPadding / 3);
 
+  static ScrollbarThemeData scrollbarTheme = ScrollbarThemeData(
+    thickness: MaterialStateProperty.all(kScrollbarThickness),
+  );
+
+  static ScrollbarThemeData scrollbarThemeDark = scrollbarTheme.copyWith(
+    thumbColor: MaterialStateProperty.all(Colors.grey[500]),
+  );
+
   static ThemeData lightTheme = ThemeData(
     brightness: Brightness.light,
     hoverColor: Color.fromARGB(255, 224, 224, 224),
@@ -280,6 +288,7 @@ class MyTheme {
         ),
       ),
     ),
+    scrollbarTheme: scrollbarTheme,
     inputDecorationTheme: isDesktop
         ? InputDecorationTheme(
             fillColor: grayBg,
@@ -364,6 +373,7 @@ class MyTheme {
         ),
       ),
     ),
+    scrollbarTheme: scrollbarThemeDark,
     inputDecorationTheme: isDesktop
         ? InputDecorationTheme(
             fillColor: Color(0xFF24252B),
@@ -390,9 +400,6 @@ class MyTheme {
     tabBarTheme: const TabBarTheme(
       labelColor: Colors.white70,
     ),
-    scrollbarTheme: ScrollbarThemeData(
-      thumbColor: MaterialStateProperty.all(Colors.grey[500]),
-    ),
     tooltipTheme: tooltipTheme(),
     splashColor: isDesktop ? Colors.transparent : null,
     highlightColor: isDesktop ? Colors.transparent : null,

flutter/lib/consts.dart

@@ -13,6 +13,8 @@ const String kPeerPlatformLinux = "Linux";
 const String kPeerPlatformMacOS = "Mac OS";
 const String kPeerPlatformAndroid = "Android";
 
+const double kScrollbarThickness = 12.0;
+
 /// [kAppTypeMain] used by 'Desktop Main Page' , 'Mobile (Client and Server)', "Install Page"
 const String kAppTypeMain = "main";
 

flutter/lib/desktop/pages/remote_page.dart

@@ -694,6 +694,7 @@ class _ImagePaintState extends State<ImagePaint> {
         enableCustomMouseWheelScrolling: cursorOverImage.isFalse,
         customMouseWheelScrollConfig: scrollConfig,
         child: RawScrollbar(
+          thickness: kScrollbarThickness,
           thumbColor: Colors.grey,
           controller: _horizontal,
           thumbVisibility: false,
@@ -711,6 +712,7 @@ class _ImagePaintState extends State<ImagePaint> {
         enableCustomMouseWheelScrolling: cursorOverImage.isFalse,
         customMouseWheelScrollConfig: scrollConfig,
         child: RawScrollbar(
+          thickness: kScrollbarThickness,
           thumbColor: Colors.grey,
           controller: _vertical,
           thumbVisibility: false,