Update Send button bg color (#5170)

* Update Send button bg color

Change the gradient bg to accent/rest.

* Tidy-up ComposerToolbar to match iOS 18 Figma.

Also simplifies the tests a bit.

* Add a .glassEffect to Compound's SendButton.

* Add a border to TimelineReplyView.

Also use the same sizes in both the message bubbles and the composer.

* Change icon size and container in message bubbles

- Container size = 36x36px
- Icon size = 24x24px

* Update icon of reply contents to be 24x24

* Update the VoiceMessageButton to match the designs.

* Adopt Liquid Glass in the ComposerToolbar.

* Generate and fix snapshots.

---------

Co-authored-by: Doug <douglase@element.io>

compound-ios/Sources/Compound/Buttons/SendButton.swift

@@ -8,40 +8,62 @@
 import SwiftUI
 
 /// The button component for sending messages and media.
+///
+/// The button's size is 44pt x 44pt on iOS 26 and later, and 36pt x 36pt on iOS 18 and earlier.
 public struct SendButton: View {
     @Environment(\.isEnabled) private var isEnabled
     @Environment(\.colorScheme) private var colorScheme
     
+    public enum Mode { case send, edit }
+    /// Whether the button is for sending a new message or editing an existing one.
+    private let mode: Mode
     /// The action to perform when the user triggers the button.
     private let action: () -> Void
     
+    private var icon: KeyPath<CompoundIcons, Image> {
+        switch mode {
+        case .send: \.sendSolid
+        case .edit: \.check
+        }
+    }
+    
     private var iconColor: Color {
         guard isEnabled else { return .compound.iconQuaternary }
         return colorScheme == .light ? .compound.iconOnSolidPrimary : .compound.iconPrimary
     }
     
-    private var gradient: Gradient {
-        isEnabled ? .compound.action : .init(colors: [.clear])
+    private var backgroundColor: Color {
+        isEnabled ? .compound.bgAccentRest : .clear
     }
     
     /// Creates a send button that performs the provided action.
-    public init(action: @escaping () -> Void) {
+    public init(mode: Mode = .send, action: @escaping () -> Void) {
+        self.mode = mode
         self.action = action
     }
     
     public var body: some View {
         Button(action: action) {
-            CompoundIcon(\.sendSolid, size: .medium, relativeTo: .compound.headingLG)
-                .foregroundStyle(iconColor)
-                .scaledPadding(6, relativeTo: .compound.headingLG)
-                .background { buttonShape }
+            label
                 .compositingGroup()
         }
     }
     
-    var buttonShape: some View {
-        Circle()
-            .fill(LinearGradient(gradient: gradient, startPoint: .top, endPoint: .bottom))
+    @ViewBuilder
+    public var label: some View {
+        if #available(iOS 26, *), isEnabled, !ProcessInfo.processInfo.isRunningTests {
+            baseIcon
+                .glassEffect(.regular.tint(backgroundColor).interactive(), in: .circle)
+        } else {
+            baseIcon
+                .background(backgroundColor, in: .circle)
+        }
+    }
+    
+    var baseIcon: some View {
+        CompoundIcon(icon, size: .medium, relativeTo: .compound.headingLG)
+            .foregroundStyle(iconColor)
+            .scaledPadding(Compound.supportsGlass ? 10 : 6, relativeTo: .compound.headingLG)
     }
 }
 
@@ -66,6 +88,8 @@ public struct SendButton_Previews: PreviewProvider, TestablePreview {
             SendButton { }
                 .disabled(true)
             SendButton { }
+            
+            SendButton(mode: .edit) { }
         }
     }
 }

compound-ios/Sources/Compound/Extensions/ProcessInfo.swift

@@ -0,0 +1,14 @@
+//
+// Copyright 2026 Element Creations Ltd.
+//
+// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+// Please see LICENSE files in the repository root for full details.
+//
+
+import Foundation
+
+extension ProcessInfo {
+    var isRunningTests: Bool {
+        environment["XCTestBundlePath"] != nil
+    }
+}

compound-ios/Sources/Compound/Extensions/SupportsGlass.swift

@@ -0,0 +1,16 @@
+//
+// Copyright 2026 Element Creations Ltd.
+//
+// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+// Please see LICENSE files in the repository root for full details.
+//
+
+import SwiftUI
+
+public var supportsGlass: Bool {
+    if #available(iOS 26, *) {
+        true
+    } else {
+        false
+    }
+}

compound-ios/Tests/CompoundTests/__Snapshots__/PreviewTests/sendButton.iPad-en-US-0.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:acfb01682b484e788e3fd8f883977baaf488cc7cea84da845fbe0bab8185733d
-size 79822
+oid sha256:9dbba8e66eeb5c78a165952f3dcf2773708178f4d6e4a4a527e69b81b950ceb2
+size 76551

compound-ios/Tests/CompoundTests/__Snapshots__/PreviewTests/sendButton.iPhone-en-US-0.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:8857d2a0cc92634cf7f55390e9fd5a3b23bc496ebc25c2bd4fb660bb191c04d1
-size 39502
+oid sha256:5f972698dc7c7d720205c3ce53426a43b28a638778c1d238341c84fc85542f69
+size 35696