Add RTE keyboard navigation in editing

src/components/views/rooms/wysiwyg_composer/ComposerContext.ts

@@ -17,15 +17,18 @@ limitations under the License.
 import { createContext, useContext } from "react";
 
 import { SubSelection } from "./types";
+import EditorStateTransfer from "../../../../utils/EditorStateTransfer";
 
-export function getDefaultContextValue(): { selection: SubSelection } {
+export function getDefaultContextValue(defaultValue?: Partial<ComposerContextState>): { selection: SubSelection } {
     return {
         selection: { anchorNode: null, anchorOffset: 0, focusNode: null, focusOffset: 0, isForward: true },
+        ...defaultValue,
     };
 }
 
 export interface ComposerContextState {
     selection: SubSelection;
+    editorStateTransfer?: EditorStateTransfer;
 }
 
 export const ComposerContext = createContext<ComposerContextState>(getDefaultContextValue());

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

@@ -52,7 +52,7 @@ export default function EditWysiwygComposer({
     className,
     ...props
 }: EditWysiwygComposerProps): JSX.Element {
-    const defaultContextValue = useRef(getDefaultContextValue());
+    const defaultContextValue = useRef(getDefaultContextValue({ editorStateTransfer }));
     const initialContent = useInitialContent(editorStateTransfer);
     const isReady = !editorStateTransfer || initialContent !== undefined;
 

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

@@ -47,7 +47,7 @@ export const WysiwygComposer = memo(function WysiwygComposer({
     rightComponent,
     children,
 }: WysiwygComposerProps) {
-    const inputEventProcessor = useInputEventProcessor(onSend);
+    const inputEventProcessor = useInputEventProcessor(onSend, initialContent);
 
     const { ref, isWysiwygReady, content, actionStates, wysiwyg } = useWysiwyg({ initialContent, inputEventProcessor });
 

src/components/views/rooms/wysiwyg_composer/hooks/useInputEventProcessor.ts

@@ -14,40 +14,164 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { WysiwygEvent } from "@matrix-org/matrix-wysiwyg";
+import { Wysiwyg, WysiwygEvent } from "@matrix-org/matrix-wysiwyg";
 import { useCallback } from "react";
+import { MatrixClient } from "matrix-js-sdk/src/matrix";
 
 import { useSettingValue } from "../../../../../hooks/useSettings";
+import { getKeyBindingsManager } from "../../../../../KeyBindingsManager";
+import { KeyBindingAction } from "../../../../../accessibility/KeyboardShortcuts";
+import { findEditableEvent } from "../../../../../utils/EventUtils";
+import dis from "../../../../../dispatcher/dispatcher";
+import { Action } from "../../../../../dispatcher/actions";
+import { useRoomContext } from "../../../../../contexts/RoomContext";
+import { IRoomState } from "../../../../structures/RoomView";
+import { ComposerContextState, useComposerContext } from "../ComposerContext";
+import EditorStateTransfer from "../../../../../utils/EditorStateTransfer";
+import { useMatrixClientContext } from "../../../../../contexts/MatrixClientContext";
+import { isCaretAtEnd, isCaretAtStart } from "../utils/selection";
+import { getEventsFromEditorStateTransfer } from "../utils/event";
+import { endEditing } from "../utils/editing";
 
-function isEnterPressed(event: KeyboardEvent): boolean {
-    // Ugly but here we need to send the message only if Enter is pressed
-    // And we need to stop the event propagation on enter to avoid the composer to grow
-    return event.key === "Enter" && !event.shiftKey && !event.ctrlKey && !event.metaKey && !event.altKey;
-}
-
-export function useInputEventProcessor(onSend: () => void): (event: WysiwygEvent) => WysiwygEvent | null {
+export function useInputEventProcessor(
+    onSend: () => void,
+    initialContent?: string,
+): (event: WysiwygEvent, composer: Wysiwyg, editor: HTMLElement) => WysiwygEvent | null {
+    const roomContext = useRoomContext();
+    const composerContext = useComposerContext();
+    const mxClient = useMatrixClientContext();
     const isCtrlEnter = useSettingValue<boolean>("MessageComposerInput.ctrlEnterToSend");
+
     return useCallback(
-        (event: WysiwygEvent) => {
+        (event: WysiwygEvent, composer: Wysiwyg, editor: HTMLElement) => {
             if (event instanceof ClipboardEvent) {
                 return event;
             }
 
-            const isKeyboardEvent = event instanceof KeyboardEvent;
-            const isEnterPress = !isCtrlEnter && isKeyboardEvent && isEnterPressed(event);
-            const isInsertParagraph = !isCtrlEnter && !isKeyboardEvent && event.inputType === "insertParagraph";
-            // sendMessage is sent when cmd+enter is pressed
-            const isSendMessage = isCtrlEnter && !isKeyboardEvent && event.inputType === "sendMessage";
-
-            if (isEnterPress || isInsertParagraph || isSendMessage) {
+            const send = (): void => {
                 event.stopPropagation?.();
                 event.preventDefault?.();
                 onSend();
-                return null;
-            }
+            };
 
-            return event;
+            const isKeyboardEvent = event instanceof KeyboardEvent;
+            if (isKeyboardEvent) {
+                return handleKeyboardEvent(
+                    event,
+                    send,
+                    initialContent,
+                    composer,
+                    editor,
+                    roomContext,
+                    composerContext,
+                    mxClient,
+                );
+            } else {
+                return handleInputEvent(event, send, isCtrlEnter);
+            }
         },
-        [isCtrlEnter, onSend],
+        [isCtrlEnter, onSend, initialContent, roomContext, composerContext, mxClient],
     );
 }
+
+type Send = () => void;
+
+function handleKeyboardEvent(
+    event: KeyboardEvent,
+    send: Send,
+    initialContent: string | undefined,
+    composer: Wysiwyg,
+    editor: HTMLElement,
+    roomContext: IRoomState,
+    composerContext: ComposerContextState,
+    mxClient: MatrixClient,
+): KeyboardEvent | null {
+    const { editorStateTransfer } = composerContext;
+    const isEditorModified = initialContent !== composer.content();
+    const action = getKeyBindingsManager().getMessageComposerAction(event);
+
+    switch (action) {
+        case KeyBindingAction.SendMessage:
+            send();
+            return null;
+        case KeyBindingAction.EditPrevMessage: {
+            // If not in edition
+            // Or if the caret is not at the beginning of the editor
+            // Or the editor is modified
+            if (!editorStateTransfer || !isCaretAtStart(editor) || isEditorModified) {
+                break;
+            }
+
+            dispatchEditEvent(event, false, editorStateTransfer, roomContext, mxClient);
+            return null;
+        }
+        case KeyBindingAction.EditNextMessage: {
+            // If not in edition
+            // Or if the caret is not at the end of the editor
+            // Or the editor is modified
+            if (!editorStateTransfer || !isCaretAtEnd(editor) || isEditorModified) {
+                break;
+            }
+
+            const isDispatched = dispatchEditEvent(event, true, editorStateTransfer, roomContext, mxClient);
+            if (!isDispatched) {
+                endEditing(roomContext);
+                event.preventDefault();
+                event.stopPropagation();
+            }
+
+            break;
+        }
+    }
+
+    return event;
+}
+
+function dispatchEditEvent(
+    event: KeyboardEvent,
+    isForward: boolean,
+    editorStateTransfer: EditorStateTransfer,
+    roomContext: IRoomState,
+    mxClient: MatrixClient,
+): boolean {
+    const foundEvents = getEventsFromEditorStateTransfer(editorStateTransfer, roomContext, mxClient);
+    if (!foundEvents) {
+        return false;
+    }
+
+    const newEvent = findEditableEvent({
+        events: foundEvents,
+        isForward,
+        fromEventId: editorStateTransfer.getEvent().getId(),
+    });
+    if (newEvent) {
+        dis.dispatch({
+            action: Action.EditEvent,
+            event: newEvent,
+            timelineRenderingType: roomContext.timelineRenderingType,
+        });
+        event.stopPropagation();
+        event.preventDefault();
+        return true;
+    }
+    return false;
+}
+
+type InputEvent = Exclude<WysiwygEvent, KeyboardEvent | ClipboardEvent>;
+
+function handleInputEvent(event: InputEvent, send: Send, isCtrlEnter: boolean): InputEvent | null {
+    switch (event.inputType) {
+        case "insertParagraph":
+            if (!isCtrlEnter) {
+                send();
+            }
+            return null;
+        case "sendMessage":
+            if (isCtrlEnter) {
+                send();
+            }
+            return null;
+    }
+
+    return event;
+}

src/components/views/rooms/wysiwyg_composer/hooks/usePlainTextListeners.ts

@@ -77,6 +77,7 @@ export function usePlainTextListeners(
     const onKeyDown = useCallback(
         (event: KeyboardEvent<HTMLDivElement>) => {
             if (event.key === Key.ENTER) {
+                // TODO use getKeyBindingsManager().getMessageComposerAction(event) like in useInputEventProcessor
                 const sendModifierIsPressed = IS_MAC ? event.metaKey : event.ctrlKey;
 
                 // if enter should send, send if the user is not pushing shift

src/components/views/rooms/wysiwyg_composer/utils/event.ts

@@ -0,0 +1,46 @@
+/*
+Copyright 2023 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.
+*/
+
+import { MatrixClient, MatrixEvent } from "matrix-js-sdk/src/matrix";
+
+import EditorStateTransfer from "../../../../../utils/EditorStateTransfer";
+import { IRoomState } from "../../../../structures/RoomView";
+
+// From EditMessageComposer private get events(): MatrixEvent[]
+export function getEventsFromEditorStateTransfer(
+    editorStateTransfer: EditorStateTransfer,
+    roomContext: IRoomState,
+    mxClient: MatrixClient,
+): MatrixEvent[] | undefined {
+    const liveTimelineEvents = roomContext.liveTimeline?.getEvents();
+    if (!liveTimelineEvents) {
+        return;
+    }
+
+    const roomId = editorStateTransfer.getEvent().getRoomId();
+    if (!roomId) {
+        return;
+    }
+
+    const room = mxClient.getRoom(roomId);
+    if (!room) {
+        return;
+    }
+
+    const pendingEvents = room.getPendingEvents();
+    const isInThread = Boolean(editorStateTransfer.getEvent().getThread());
+    return liveTimelineEvents.concat(isInThread ? [] : pendingEvents);
+}

src/components/views/rooms/wysiwyg_composer/utils/selection.ts

@@ -39,3 +39,50 @@ export function isSelectionEmpty(): boolean {
     const selection = document.getSelection();
     return Boolean(selection?.isCollapsed);
 }
+
+export function isCaretAtStart(editor: HTMLElement): boolean {
+    const selection = document.getSelection();
+
+    // No selection or the caret is not at the beginning of the selected element
+    if (!selection || selection.anchorOffset !== 0) {
+        return false;
+    }
+
+    // In case of nested html elements (list, code blocks), we are going through all the first child
+    let child = editor.firstChild;
+    do {
+        if (child === selection.anchorNode) {
+            return true;
+        }
+    } while ((child = child?.firstChild || null));
+
+    return false;
+}
+
+export function isCaretAtEnd(editor: HTMLElement): boolean {
+    const selection = document.getSelection();
+
+    if (!selection) {
+        return false;
+    }
+
+    // When we are cycling across all the timeline message with the keyboard
+    // The caret is on the last text element but focusNode and anchorNode refers to the editor div
+    // In this case, the focusOffset & anchorOffset match the index + 1 of the selected text
+    const isOnLastElement = selection.focusNode === editor && selection.focusOffset === editor.childNodes?.length;
+    if (isOnLastElement) {
+        return true;
+    }
+
+    // In case of nested html elements (list, code blocks), we are going through all the last child
+    // The last child of the editor is always a <br> tag, we skip it
+    let child: ChildNode | null = editor.childNodes.item(editor.childNodes.length - 2);
+    do {
+        if (child === selection.focusNode) {
+            // Checking that the cursor is at end of the selected text
+            return selection.focusOffset === child.textContent?.length;
+        }
+    } while ((child = child.lastChild));
+
+    return false;
+}