fix deprecated and lint warnings

Author: tommyxchow

lib/models/irc.dart

@@ -146,7 +146,7 @@ class IRCMessage {
         span.add(
           TextSpan(
             text: '${DateFormat.Hm().format(parsedTime)} ',
-            style: style?.copyWith(color: style.color?.withOpacity(0.5)),
+            style: style?.copyWith(color: style.color?.withValues(alpha: 0.5)),
           ),
         );
       }
@@ -155,7 +155,7 @@ class IRCMessage {
         span.add(
           TextSpan(
             text: '${DateFormat('h:mm').format(parsedTime)} ',
-            style: style?.copyWith(color: style.color?.withOpacity(0.5)),
+            style: style?.copyWith(color: style.color?.withValues(alpha: 0.5)),
           ),
         );
       }

lib/screens/channel/channel.dart

@@ -126,7 +126,8 @@ class _VideoChatState extends State<VideoChat> {
             duration: const Duration(milliseconds: 200),
             child: Container(
               decoration: BoxDecoration(
-                color: Colors.black.withOpacity(settingsStore.overlayOpacity),
+                color: Colors.black
+                    .withValues(alpha: settingsStore.overlayOpacity),
               ),
               child: IgnorePointer(
                 ignoring: !_videoStore.overlayVisible,
@@ -234,8 +235,8 @@ class _VideoChatState extends State<VideoChat> {
                   : MediaQuery.of(context).size.width *
                       _chatStore.settings.chatWidth,
               color: _chatStore.settings.fullScreen
-                  ? Colors.black.withOpacity(
-                      _chatStore.settings.fullScreenChatOverlayOpacity,
+                  ? Colors.black.withValues(
+                      alpha: _chatStore.settings.fullScreenChatOverlayOpacity,
                     )
                   : Theme.of(context).scaffoldBackgroundColor,
               child: chat,

lib/screens/channel/chat/details/chat_modes.dart

@@ -11,7 +11,7 @@ class ChatModes extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final disabledColor =
-        Theme.of(context).colorScheme.onSurface.withOpacity(0.5);
+        Theme.of(context).colorScheme.onSurface.withValues(alpha: 0.5);
 
     return Row(
       mainAxisAlignment: MainAxisAlignment.spaceBetween,

lib/screens/channel/chat/widgets/chat_message.dart

@@ -30,7 +30,9 @@ class ChatMessage extends StatelessWidget {
 
     // Ignore if long-pressing own username.
     if (ircMessage.user == null ||
-        ircMessage.user == chatStore.auth.user.details?.login) return;
+        ircMessage.user == chatStore.auth.user.details?.login) {
+      return;
+    }
 
     showModalBottomSheet(
       isScrollControlled: true,
@@ -139,7 +141,8 @@ class ChatMessage extends StatelessWidget {
     final defaultTextStyle = DefaultTextStyle.of(context).style;
     final messageHeaderIconSize =
         defaultBadgeSize * chatStore.settings.badgeScale;
-    final messageHeaderTextColor = defaultTextStyle.color?.withOpacity(0.5);
+    final messageHeaderTextColor =
+        defaultTextStyle.color?.withValues(alpha: 0.5);
     const messageHeaderFontWeight = FontWeight.w600;
 
     return Observer(
@@ -433,7 +436,7 @@ class ChatMessage extends StatelessWidget {
             : Container(
                 padding: const EdgeInsets.only(left: 8, right: 12),
                 decoration: BoxDecoration(
-                  color: highlightColor.withOpacity(0.1),
+                  color: highlightColor.withValues(alpha: 0.1),
                   border: Border(
                     left: BorderSide(color: highlightColor, width: 4),
                   ),

lib/screens/channel/video/video_bar.dart

@@ -72,7 +72,7 @@ class VideoBar extends StatelessWidget {
                           Theme.of(context)
                               .colorScheme
                               .onSurface
-                              .withOpacity(0.8),
+                              .withValues(alpha: 0.8),
                       fontWeight: subtitleTextWeight,
                     ),
                   ),
@@ -102,7 +102,7 @@ class VideoBar extends StatelessWidget {
                               Theme.of(context)
                                   .colorScheme
                                   .onSurface
-                                  .withOpacity(0.8),
+                                  .withValues(alpha: 0.8),
                           fontWeight: subtitleTextWeight,
                         ),
                       ),

lib/screens/home/stream_list/stream_card.dart

@@ -151,7 +151,7 @@ class StreamCard extends StatelessWidget {
               overflow: TextOverflow.ellipsis,
               style: TextStyle(
                 fontSize: subFontSize,
-                color: fontColor?.withOpacity(0.8),
+                color: fontColor?.withValues(alpha: 0.8),
               ),
             ),
           ),
@@ -179,7 +179,7 @@ class StreamCard extends StatelessWidget {
                   overflow: TextOverflow.ellipsis,
                   style: TextStyle(
                     fontSize: subFontSize,
-                    color: fontColor?.withOpacity(0.8),
+                    color: fontColor?.withValues(alpha: 0.8),
                   ),
                 ),
               ),
@@ -190,7 +190,7 @@ class StreamCard extends StatelessWidget {
             '${NumberFormat().format(streamInfo.viewerCount)} viewers',
             style: TextStyle(
               fontSize: subFontSize,
-              color: fontColor?.withOpacity(0.8),
+              color: fontColor?.withValues(alpha: 0.8),
               fontFeatures: const [FontFeature.tabularFigures()],
             ),
           ),

lib/widgets/alert_message.dart

@@ -16,7 +16,7 @@ class AlertMessage extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final defaultColor =
-        Theme.of(context).colorScheme.onSurface.withOpacity(0.5);
+        Theme.of(context).colorScheme.onSurface.withValues(alpha: 0.5);
 
     return Row(
       mainAxisAlignment:

lib/widgets/loading_indicator.dart

@@ -19,7 +19,8 @@ class LoadingIndicator extends StatelessWidget {
         Text(
           subtitle!,
           style: TextStyle(
-            color: Theme.of(context).colorScheme.onSurface.withOpacity(0.5),
+            color:
+                Theme.of(context).colorScheme.onSurface.withValues(alpha: 0.5),
           ),
         ),
       ],