From d2ea65da10c7a4738f65431269f1f3e86098d82c Mon Sep 17 00:00:00 2001
From: N-Shar-ma <bablinaneh@gmail.com>
Date: Mon, 6 Feb 2023 16:54:57 +0530
Subject: [PATCH] compose: Clean code to fix `up` hotkey to edit previous
 message.

This is a follow up to 875ad8e implementing a better approach. We call
`cursor_at_start_of_whitespace_in_compose` from `focus_in_empty_compose`
itself if and when needed.
---
 static/js/compose_state.js | 24 +++++++++++++-----------
 static/js/hotkey.js        |  3 +--
 2 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/static/js/compose_state.js b/static/js/compose_state.js
index d8f5ffaf59..651fdfd18d 100644
--- a/static/js/compose_state.js
+++ b/static/js/compose_state.js
@@ -86,24 +86,26 @@ export const message_content = get_or_set("compose-textarea", true);
 
 const untrimmed_message_content = get_or_set("compose-textarea", true, true);
 
-export function cursor_at_start_of_whitespace_in_compose() {
-    // First check if the compose box is focused.  TODO: Maybe we
-    // should make `consider_start_of_whitespace_message_empty` a
-    // parameter to `focus_in_empty_compose` instead.
-    const focused_element_id = document.activeElement.id;
-    if (focused_element_id !== "compose-textarea") {
-        return false;
-    }
-
+function cursor_at_start_of_whitespace_in_compose() {
     const cursor_position = $("#compose-textarea").caret();
     return message_content() === "" && cursor_position === 0;
 }
 
-export function focus_in_empty_compose() {
+export function focus_in_empty_compose(consider_start_of_whitespace_message_empty = false) {
     // A user trying to press arrow keys in an empty compose is mostly
     // likely trying to navigate messages. This helper function
     // decides whether the compose box is empty for this purpose.
-    if (!composing() || untrimmed_message_content() !== "") {
+    if (!composing()) {
+        return false;
+    }
+
+    // We treat the compose box as empty if it's completely empty, or
+    // if the caller requested, if it contains only whitespace and we're
+    // at the start of te compose box.
+    const treat_compose_as_empty =
+        untrimmed_message_content() === "" ||
+        (consider_start_of_whitespace_message_empty && cursor_at_start_of_whitespace_in_compose());
+    if (!treat_compose_as_empty) {
         return false;
     }
 
diff --git a/static/js/hotkey.js b/static/js/hotkey.js
index 9ec56943f2..af618a7a21 100644
--- a/static/js/hotkey.js
+++ b/static/js/hotkey.js
@@ -732,8 +732,7 @@ export function process_hotkey(e, hotkey) {
             ((event_name === "down_arrow" || event_name === "page_down" || event_name === "end") &&
                 compose_state.focus_in_empty_compose()) ||
             ((event_name === "up_arrow" || event_name === "page_up" || event_name === "home") &&
-                (compose_state.focus_in_empty_compose() ||
-                    compose_state.cursor_at_start_of_whitespace_in_compose()))
+                compose_state.focus_in_empty_compose(true))
         ) {
             compose_actions.cancel();
             // don't return, as we still want it to be picked up by the code below