From 8cfbe1ca3fb3389164285b1fb176bed726358fee Mon Sep 17 00:00:00 2001
From: Paul <paulmakles@gmail.com>
Date: Tue, 6 Jul 2021 23:03:29 +0100
Subject: [PATCH] Fluff: Jump to bottom when editing last message in chat. (up
 arrow)

---
 src/lib/eventEmitter.ts                          | 1 +
 src/pages/channels/messaging/MessageArea.tsx     | 8 +++++++-
 src/pages/channels/messaging/MessageRenderer.tsx | 1 +
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/lib/eventEmitter.ts b/src/lib/eventEmitter.ts
index e2881c8d..192bae46 100644
--- a/src/lib/eventEmitter.ts
+++ b/src/lib/eventEmitter.ts
@@ -18,6 +18,7 @@ export function internalEmit(ns: string, event: string, ...args: any[]) {
 // Event structure: namespace/event
 
 /// Event List
+// - MessageArea/jump_to_bottom
 // - MessageRenderer/edit_last
 // - MessageRenderer/edit_message
 // - Intermediate/open_profile
diff --git a/src/pages/channels/messaging/MessageArea.tsx b/src/pages/channels/messaging/MessageArea.tsx
index 2cc14690..23675f4d 100644
--- a/src/pages/channels/messaging/MessageArea.tsx
+++ b/src/pages/channels/messaging/MessageArea.tsx
@@ -12,7 +12,7 @@ import {
 } from "preact/hooks";
 
 import { defer } from "../../../lib/defer";
-import { internalEmit } from "../../../lib/eventEmitter";
+import { internalEmit, internalSubscribe } from "../../../lib/eventEmitter";
 import { SingletonMessageRenderer } from "../../../lib/renderer/Singleton";
 import { RenderState, ScrollState } from "../../../lib/renderer/types";
 
@@ -132,6 +132,12 @@ export function MessageArea({ id }: Props) {
     const atTop = (offset = 0) =>
         ref.current ? ref.current.scrollTop <= offset : false;
 
+    // ? Handle global jump to bottom, e.g. when editing last message in chat.
+    useEffect(() => {
+        return internalSubscribe('MessageArea', 'jump_to_bottom',
+            () => setScrollState({ type: 'ScrollToBottom' }));
+    }, []);
+
     // ? Handle events from renderer.
     useEffect(() => {
         SingletonMessageRenderer.addListener("state", setState);
diff --git a/src/pages/channels/messaging/MessageRenderer.tsx b/src/pages/channels/messaging/MessageRenderer.tsx
index 91856852..d573578b 100644
--- a/src/pages/channels/messaging/MessageRenderer.tsx
+++ b/src/pages/channels/messaging/MessageRenderer.tsx
@@ -60,6 +60,7 @@ function MessageRenderer({ id, state, queue }: Props) {
             for (let i = state.messages.length - 1; i >= 0; i--) {
                 if (state.messages[i].author === userId) {
                     setEditing(state.messages[i]._id);
+                    internalEmit('MessageArea', 'jump_to_bottom');
                     return;
                 }
             }