Convert bunch of utils to TS

src/utils/EventUtils.ts

@@ -0,0 +1,98 @@
+/*
+Copyright 2019 - 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.
+*/
+
+import { Room } from 'matrix-js-sdk/src/models/room';
+import { MatrixEvent, EventStatus } from 'matrix-js-sdk/src/models/event';
+
+import { MatrixClientPeg } from '../MatrixClientPeg';
+import shouldHideEvent from "../shouldHideEvent";
+
+/**
+ * Returns whether an event should allow actions like reply, reactions, edit, etc.
+ * which effectively checks whether it's a regular message that has been sent and that we
+ * can display.
+ *
+ * @param {MatrixEvent} mxEvent The event to check
+ * @returns {boolean} true if actionable
+ */
+export function isContentActionable(mxEvent: MatrixEvent): boolean {
+    const { status: eventStatus } = mxEvent;
+
+    // status is SENT before remote-echo, null after
+    const isSent = !eventStatus || eventStatus === EventStatus.SENT;
+
+    if (isSent && !mxEvent.isRedacted()) {
+        if (mxEvent.getType() === 'm.room.message') {
+            const content = mxEvent.getContent();
+            if (content.msgtype && content.msgtype !== 'm.bad.encrypted' && content.hasOwnProperty('body')) {
+                return true;
+            }
+        } else if (mxEvent.getType() === 'm.sticker') {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+export function canEditContent(mxEvent: MatrixEvent): boolean {
+    if (mxEvent.status === EventStatus.CANCELLED || mxEvent.getType() !== "m.room.message" || mxEvent.isRedacted()) {
+        return false;
+    }
+    const content = mxEvent.getOriginalContent();
+    const {msgtype} = content;
+    return (msgtype === "m.text" || msgtype === "m.emote") &&
+        content.body && typeof content.body === 'string' &&
+        mxEvent.getSender() === MatrixClientPeg.get().getUserId();
+}
+
+export function canEditOwnEvent(mxEvent: MatrixEvent): boolean {
+    // for now we only allow editing
+    // your own events. So this just call through
+    // In the future though, moderators will be able to
+    // edit other people's messages as well but we don't
+    // want findEditableEvent to return other people's events
+    // hence this method.
+    return canEditContent(mxEvent);
+}
+
+const MAX_JUMP_DISTANCE = 100;
+export function findEditableEvent(room: Room, isForward: boolean, fromEventId: string = undefined): MatrixEvent {
+    const liveTimeline = room.getLiveTimeline();
+    const events = liveTimeline.getEvents().concat(room.getPendingEvents());
+    const maxIdx = events.length - 1;
+    const inc = isForward ? 1 : -1;
+    const beginIdx = isForward ? 0 : maxIdx;
+    let endIdx = isForward ? maxIdx : 0;
+    if (!fromEventId) {
+        endIdx = Math.min(Math.max(0, beginIdx + (inc * MAX_JUMP_DISTANCE)), maxIdx);
+    }
+    let foundFromEventId = !fromEventId;
+    for (let i = beginIdx; i !== (endIdx + inc); i += inc) {
+        const e = events[i];
+        // find start event first
+        if (!foundFromEventId && e.getId() === fromEventId) {
+            foundFromEventId = true;
+            // don't look further than MAX_JUMP_DISTANCE events from `fromEventId`
+            // to not iterate potentially 1000nds of events on key up/down
+            endIdx = Math.min(Math.max(0, i + (inc * MAX_JUMP_DISTANCE)), maxIdx);
+        } else if (foundFromEventId && !shouldHideEvent(e) && canEditOwnEvent(e)) {
+            // otherwise look for editable event
+            return e;
+        }
+    }
+}
+