Copy css for edition

res/css/_components.pcss

@@ -299,8 +299,9 @@
 @import "./views/rooms/_TopUnreadMessagesBar.pcss";
 @import "./views/rooms/_VoiceRecordComposerTile.pcss";
 @import "./views/rooms/_WhoIsTypingTile.pcss";
-@import "./views/rooms/wysiwyg_composer/_FormattingButtons.pcss";
-@import "./views/rooms/wysiwyg_composer/_WysiwygComposer.pcss";
+@import "./views/rooms/wysiwyg_composer/components/_FormattingButtons.pcss";
+@import "./views/rooms/wysiwyg_composer/_SendWysiwygComposer.pcss";
+@import "./views/rooms/wysiwyg_composer/_EditWysiwygComposer.pcss";
 @import "./views/settings/_AvatarSetting.pcss";
 @import "./views/settings/_CrossSigningPanel.pcss";
 @import "./views/settings/_CryptographyPanel.pcss";

res/css/views/rooms/wysiwyg_composer/_EditWysiwygComposer.pcss

@@ -0,0 +1,53 @@
+/*
+Copyright 2019 New Vector Ltd
+Copyright 2019 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_EditWysiwygComposer {
+    --EditWysiwygComposer-padding-inline: 3px;
+
+    display: flex;
+    flex-direction: column;
+    max-width: 100%; /* disable overflow */
+    width: auto;
+    gap: 5px;
+    padding: 3px var(--EditWysiwygComposer-padding-inline);
+
+    .mx_WysiwygComposer_container {
+        border-radius: 4px;
+        border: solid 1px $primary-hairline-color;
+        background-color: $background;
+        max-height: 200px;
+        padding: 3px 6px;
+
+        &:focus {
+            border-color: rgba($accent, 0.5); /* Only ever used here */
+        }
+    }
+
+    .mx_EditWysiwygComposer_buttons {
+        display: flex;
+        flex-flow: row wrap-reverse; /* display "Save" over "Cancel" */
+        justify-content: flex-end;
+        gap: 5px;
+        margin-inline-start: auto;
+
+        .mx_AccessibleButton {
+            flex: 1;
+            box-sizing: border-box;
+            min-width: 100px; /* magic number to align the edge of the button with the input area */
+        }
+    }
+}

res/css/views/rooms/wysiwyg_composer/_SendWysiwygComposer.pcss

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-.mx_WysiwygComposer {
+.mx_SendWysiwygComposer {
     flex: 1;
     display: flex;
     flex-direction: column;

src/components/views/rooms/wysiwyg_composer/EditWysiwygComposer.tsx

@@ -47,6 +47,7 @@ export function EditWysiwygComposer({ editorStateTransfer, ...props }: EditWysiw
     const { editMessage, endEditing, onChange, isSaveDisabled } = useEditing(initialContent, editorStateTransfer);
 
     return isReady && <WysiwygComposer
+        className="mx_EditWysiwygComposer"
         initialContent={initialContent}
         onChange={onChange}
         onSend={editMessage}

src/components/views/rooms/wysiwyg_composer/SendWysiwygComposer.tsx

@@ -39,7 +39,7 @@ const Content = forwardRef<HTMLElement, ContentProps>(
 
 export function SendWysiwygComposer(props: SendWysiwygComposerProps) {
     return (
-        <WysiwygComposer {...props}>{ (ref, wysiwyg) => (
+        <WysiwygComposer className="mx_SendWysiwygComposer" {...props}>{ (ref, wysiwyg) => (
             <Content disabled={props.disabled} ref={ref} formattingFunctions={wysiwyg} />
         ) }
         </WysiwygComposer>);

src/components/views/rooms/wysiwyg_composer/components/WysiwygComposer.tsx

@@ -26,6 +26,7 @@ interface WysiwygComposerProps {
     onChange?: (content: string) => void;
     onSend: () => void;
     initialContent?: string;
+    className?: string;
     children?: (
         ref: MutableRefObject<HTMLDivElement | null>,
         wysiwyg: FormattingFunctions,
@@ -33,7 +34,7 @@ interface WysiwygComposerProps {
 }
 
 export const WysiwygComposer = memo(function WysiwygComposer(
-    { disabled = false, onChange, onSend, initialContent, children }: WysiwygComposerProps,
+    { disabled = false, onChange, onSend, initialContent, className, children }: WysiwygComposerProps,
 ) {
     const inputEventProcessor = useInputEventProcessor(onSend);
 
@@ -47,7 +48,7 @@ export const WysiwygComposer = memo(function WysiwygComposer(
     }, [onChange, content, disabled]);
 
     return (
-        <div className="mx_WysiwygComposer">
+        <div className={className}>
             <FormattingButtons composer={wysiwyg} formattingStates={formattingStates} />
             <Editor ref={ref} disabled={!isWysiwygReady || disabled} />
             { children?.(ref, wysiwyg) }