Add a progress indicator to voice message preview (#1956)

ElementX/Sources/Other/Progress/ProgressCursorModifier.swift

@@ -0,0 +1,42 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Compound
+import SwiftUI
+
+extension View {
+    func progressCursor<CursorView: View>(progress: CGFloat,
+                                          cursorView: @escaping () -> CursorView) -> some View {
+        modifier(ProgressCursorModifier(progress: progress,
+                                        cursorView: cursorView))
+    }
+}
+
+private struct ProgressCursorModifier<CursorView: View>: ViewModifier {
+    let progress: CGFloat
+    @ViewBuilder var cursorView: () -> CursorView
+    
+    func body(content: Content) -> some View {
+        GeometryReader { geometry in
+            content
+                .overlay(alignment: .leading) {
+                    cursorView()
+                        .offset(CGSize(width: progress * geometry.size.width, height: 0.0))
+                        .frame(height: geometry.size.height)
+                }
+        }
+    }
+}