compose: Support redesigned button feedback

This disables the splash effect for all the compose buttons and the
send button, and implements a rounded rectangular background that
appears on hover/pressed.

Different from the style that all the compose buttons share, this
feedback also applies to the send button, and will apply to more buttons
in the app.  In the future we should migrate more buttons to use this
style, so it doesn't belong to a shared base class.

See also:
  https://www.figma.com/design/1JTNtYo9memgW7vV6d0ygq/Zulip-Mobile?node-id=3707-41711&node-type=frame&t=sSYomsJzGCt34D8N-0

Fixes: #915

Signed-off-by: Zixuan James Li <[email protected]>

Author: PIG208

lib/widgets/compose_box.dart

@@ -1002,7 +1002,8 @@ class _SendButtonState extends State<_SendButton> {
         icon: Icon(ZulipIcons.send,
           // We set [Icon.color] instead of [IconButton.color] because the
           // latter implicitly uses colors derived from it to override the
-          // ambient [ButtonStyle.overlayColor].
+          // ambient [ButtonStyle.overlayColor], where we set the color for
+          // the highlight state to match the Figma design.
           color: iconColor),
         onPressed: _send));
   }
@@ -1047,6 +1048,7 @@ class _ComposeBoxLayout extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final themeData = Theme.of(context);
+    final designVariables = DesignVariables.of(context);
 
     final inputThemeData = themeData.copyWith(
       inputDecorationTheme: const InputDecorationTheme(
@@ -1055,6 +1057,18 @@ class _ComposeBoxLayout extends StatelessWidget {
         contentPadding: EdgeInsets.zero,
         border: InputBorder.none));
 
+    // TODO(#417): Disable splash effects for all buttons globally.
+    final iconButtonThemeData = IconButtonThemeData(
+      style: IconButton.styleFrom(
+        splashFactory: NoSplash.splashFactory,
+        // TODO(#417): The Figma design specifies a different icon color on
+        //   pressed, but `IconButton` currently does not have support for
+        //   that.  See also:
+        //     https://www.figma.com/design/1JTNtYo9memgW7vV6d0ygq/Zulip-Mobile?node-id=3707-41711&node-type=frame&t=sSYomsJzGCt34D8N-0
+        highlightColor: designVariables.editorButtonPressedBg,
+        shape: const RoundedRectangleBorder(
+          borderRadius: BorderRadius.all(Radius.circular(4)))));
+
     final composeButtons = [
       _AttachFileButton(contentController: contentController, contentFocusNode: contentFocusNode),
       _AttachMediaButton(contentController: contentController, contentFocusNode: contentFocusNode),
@@ -1073,12 +1087,14 @@ class _ComposeBoxLayout extends StatelessWidget {
             ]))),
         SizedBox(
           height: _composeButtonSize,
-          child: Row(
-            mainAxisAlignment: MainAxisAlignment.spaceBetween,
-            children: [
-              Row(children: composeButtons),
-              sendButton,
-            ])),
+          child: IconButtonTheme(
+            data: iconButtonThemeData,
+            child: Row(
+              mainAxisAlignment: MainAxisAlignment.spaceBetween,
+              children: [
+                Row(children: composeButtons),
+                sendButton,
+              ]))),
       ]));
   }
 }

lib/widgets/theme.dart

@@ -122,6 +122,7 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
       contextMenuCancelText: const Color(0xff222222),
       contextMenuItemBg: const Color(0xff6159e1),
       contextMenuItemText: const Color(0xff381da7),
+      editorButtonPressedBg: Colors.black.withValues(alpha: 0.06),
       foreground: const Color(0xff000000),
       icon: const Color(0xff6159e1),
       labelCounterUnread: const Color(0xff222222),
@@ -161,6 +162,7 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
       contextMenuCancelText: const Color(0xffffffff).withValues(alpha: 0.75),
       contextMenuItemBg: const Color(0xff7977fe),
       contextMenuItemText: const Color(0xff9398fd),
+      editorButtonPressedBg: Colors.white.withValues(alpha: 0.06),
       foreground: const Color(0xffffffff),
       icon: const Color(0xff7977fe),
       labelCounterUnread: const Color(0xffffffff).withValues(alpha: 0.7),
@@ -207,6 +209,7 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
     required this.contextMenuCancelText,
     required this.contextMenuItemBg,
     required this.contextMenuItemText,
+    required this.editorButtonPressedBg,
     required this.foreground,
     required this.icon,
     required this.labelCounterUnread,
@@ -254,6 +257,7 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
   final Color contextMenuCancelText;
   final Color contextMenuItemBg;
   final Color contextMenuItemText;
+  final Color editorButtonPressedBg;
   final Color foreground;
   final Color icon;
   final Color labelCounterUnread;
@@ -296,6 +300,7 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
     Color? contextMenuCancelText,
     Color? contextMenuItemBg,
     Color? contextMenuItemText,
+    Color? editorButtonPressedBg,
     Color? foreground,
     Color? icon,
     Color? labelCounterUnread,
@@ -333,6 +338,7 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
       contextMenuCancelText: contextMenuCancelText ?? this.contextMenuCancelText,
       contextMenuItemBg: contextMenuItemBg ?? this.contextMenuItemBg,
       contextMenuItemText: contextMenuItemText ?? this.contextMenuItemBg,
+      editorButtonPressedBg: editorButtonPressedBg ?? this.editorButtonPressedBg,
       foreground: foreground ?? this.foreground,
       icon: icon ?? this.icon,
       labelCounterUnread: labelCounterUnread ?? this.labelCounterUnread,
@@ -377,6 +383,7 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
       contextMenuCancelText: Color.lerp(contextMenuCancelText, other.contextMenuCancelText, t)!,
       contextMenuItemBg: Color.lerp(contextMenuItemBg, other.contextMenuItemBg, t)!,
       contextMenuItemText: Color.lerp(contextMenuItemText, other.contextMenuItemBg, t)!,
+      editorButtonPressedBg: Color.lerp(editorButtonPressedBg, other.editorButtonPressedBg, t)!,
       foreground: Color.lerp(foreground, other.foreground, t)!,
       icon: Color.lerp(icon, other.icon, t)!,
       labelCounterUnread: Color.lerp(labelCounterUnread, other.labelCounterUnread, t)!,