Show a stop button to stop the recording

res/css/_components.scss

@@ -111,8 +111,8 @@
 @import "./views/elements/_AddressSelector.scss";
 @import "./views/elements/_AddressTile.scss";
 @import "./views/elements/_DesktopBuildsNotice.scss";
-@import "./views/elements/_DirectorySearchBox.scss";
 @import "./views/elements/_DesktopCapturerSourcePicker.scss";
+@import "./views/elements/_DirectorySearchBox.scss";
 @import "./views/elements/_Dropdown.scss";
 @import "./views/elements/_EditableItemList.scss";
 @import "./views/elements/_ErrorBoundary.scss";
@@ -211,13 +211,13 @@
 @import "./views/rooms/_SendMessageComposer.scss";
 @import "./views/rooms/_Stickers.scss";
 @import "./views/rooms/_TopUnreadMessagesBar.scss";
+@import "./views/rooms/_VoiceRecordComposerTile.scss";
 @import "./views/rooms/_WhoIsTypingTile.scss";
 @import "./views/settings/_AvatarSetting.scss";
 @import "./views/settings/_CrossSigningPanel.scss";
 @import "./views/settings/_DevicesPanel.scss";
 @import "./views/settings/_E2eAdvancedPanel.scss";
 @import "./views/settings/_EmailAddresses.scss";
-@import "./views/settings/_SpellCheckLanguages.scss";
 @import "./views/settings/_IntegrationManager.scss";
 @import "./views/settings/_Notifications.scss";
 @import "./views/settings/_PhoneNumbers.scss";
@@ -225,6 +225,7 @@
 @import "./views/settings/_SecureBackupPanel.scss";
 @import "./views/settings/_SetIdServer.scss";
 @import "./views/settings/_SetIntegrationManager.scss";
+@import "./views/settings/_SpellCheckLanguages.scss";
 @import "./views/settings/_UpdateCheckButton.scss";
 @import "./views/settings/tabs/_SettingsTab.scss";
 @import "./views/settings/tabs/room/_GeneralRoomSettingsTab.scss";

res/css/views/rooms/_VoiceRecordComposerTile.scss

@@ -0,0 +1,36 @@
+/*
+Copyright 2021 The Matrix.org Foundation C.I.C.
+
+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.
+*/
+
+.mx_VoiceRecordComposerTile_stop {
+    // 28px plus a 2px border makes this a 32px square (as intended)
+    width: 28px;
+    height: 28px;
+    border: 2px solid $voice-record-stop-border-color;
+    border-radius: 32px;
+    margin-right: 16px; // between us and the send button
+    position: relative;
+
+    &::after {
+        content: '';
+        width: 14px;
+        height: 14px;
+        position: absolute;
+        top: 6px;
+        left: 6px;
+        border-radius: 2px;
+        background-color: $voice-record-stop-symbol-color;
+    }
+}

res/themes/legacy-light/css/_legacy-light.scss

@@ -189,6 +189,9 @@ $roomsublist-skeleton-ui-bg: linear-gradient(180deg, #ffffff 0%, #ffffff00 100%)
 $groupFilterPanel-divider-color: $roomlist-header-color;
 $space-button-outline-color: #E3E8F0;
 
+$voice-record-stop-border-color: #E3E8F0;
+$voice-record-stop-symbol-color: $warning-color;
+
 $roomtile-preview-color: #9e9e9e;
 $roomtile-default-badge-bg-color: #61708b;
 $roomtile-selected-bg-color: #fff;

res/themes/light/css/_light.scss

@@ -180,6 +180,9 @@ $roomsublist-skeleton-ui-bg: linear-gradient(180deg, #ffffff 0%, #ffffff00 100%)
 $groupFilterPanel-divider-color: $roomlist-header-color;
 $space-button-outline-color: #E3E8F0;
 
+$voice-record-stop-border-color: #E3E8F0;
+$voice-record-stop-symbol-color: $warning-color;
+
 $roomtile-preview-color: $secondary-fg-color;
 $roomtile-default-badge-bg-color: #61708b;
 $roomtile-selected-bg-color: #FFF;