Fix newline rendering in chat messages (#80)

* Fix newline rendering in chat messages

The Text component was not properly rendering newlines in chat messages.
The previous implementation had buggy logic that only rendered <br /> for
empty lines and used an inconsistent mix of spans and divs for non-empty
lines, which didn't create proper line breaks between consecutive text lines.

Changes:
- Render each line in a span with <br /> between consecutive lines
- Remove unused useMemo import and fix React hooks violation
- Simplify logic for better maintainability

This ensures that multi-line messages in chat (and other text content)
display correctly with proper line breaks.

Fixes rendering of newlines in NIP-29 groups and NIP-53 live chat.

* Preserve newlines when sending chat messages

The MentionEditor's serializeContent function was not handling hardBreak
nodes created by Shift+Enter. This caused newlines within messages to be
lost during serialization, even though the editor displayed them correctly.

Changes:
- Add hardBreak node handling in serializeContent
- Preserve newlines (\n) from Shift+Enter keypresses
- Ensure multi-line messages are sent with proper line breaks

With this fix and the previous Text.tsx fix, newlines are now properly:
1. Captured when typing (Shift+Enter creates hardBreak)
2. Preserved when sending (hardBreak serialized as \n)
3. Rendered when displaying (Text component renders \n as <br />)

* Make Enter insert newline on mobile devices

On mobile devices, pressing Enter now inserts a newline (hardBreak) instead
of submitting the message. This provides better UX since mobile keyboards
don't have easy access to Shift+Enter for multiline input.

Behavior:
- Desktop: Enter submits, Shift+Enter inserts newline (unchanged)
- Mobile: Enter inserts newline, Cmd/Ctrl+Enter submits
- Mobile detection: Uses touch support API (ontouchstart or maxTouchPoints)

Users can still submit messages on mobile using:
1. The Send button (primary method)
2. Ctrl+Enter keyboard shortcut (if available)

---------

Co-authored-by: Claude <noreply@anthropic.com>

src/components/editor/MentionEditor.tsx

@@ -584,6 +584,9 @@ export const MentionEditor = forwardRef<
             node.content?.forEach((child: any) => {
               if (child.type === "text") {
                 text += child.text;
+              } else if (child.type === "hardBreak") {
+                // Preserve newlines from Shift+Enter
+                text += "\n";
               } else if (child.type === "mention") {
                 const pubkey = child.attrs?.id;
                 if (pubkey) {
@@ -664,6 +667,9 @@ export const MentionEditor = forwardRef<
 
     // Build extensions array
     const extensions = useMemo(() => {
+      // Detect mobile devices (touch support)
+      const isMobile = "ontouchstart" in window || navigator.maxTouchPoints > 0;
+
       // Custom extension for keyboard shortcuts (runs before suggestion plugins)
       const SubmitShortcut = Extension.create({
         name: "submitShortcut",
@@ -674,10 +680,16 @@ export const MentionEditor = forwardRef<
               handleSubmitRef.current(editor);
               return true;
             },
-            // Plain Enter submits (Shift+Enter handled by hardBreak for newlines)
+            // Plain Enter behavior depends on device
             Enter: ({ editor }) => {
-              handleSubmitRef.current(editor);
-              return true;
+              if (isMobile) {
+                // On mobile, Enter inserts a newline (hardBreak)
+                return editor.commands.setHardBreak();
+              } else {
+                // On desktop, Enter submits the message
+                handleSubmitRef.current(editor);
+                return true;
+              }
             },
           };
         },

src/components/nostr/RichText/Text.tsx

@@ -1,5 +1,4 @@
 import { CommonData } from "applesauce-content/nast";
-import { useMemo } from "react";
 
 interface TextNodeProps {
   node: {
@@ -11,23 +10,22 @@ interface TextNodeProps {
 
 export function Text({ node }: TextNodeProps) {
   const text = node.value;
-  const lines = useMemo(() => text.split("\n"), [text]);
-  if (text.includes("\n")) {
-    return (
-      <>
-        {lines.map((line, idx) =>
-          line.trim().length === 0 ? (
-            <br />
-          ) : idx === 0 || idx === lines.length - 1 ? (
-            <span dir="auto">{line}</span> // FIXME: this should be span or div depnding on context
-          ) : (
-            <div dir="auto" key={idx}>
-              {line}
-            </div>
-          ),
-        )}
-      </>
-    );
+
+  // If no newlines, render as simple span
+  if (!text.includes("\n")) {
+    return <span dir="auto">{text}</span>;
   }
-  return <span dir="auto">{text}</span>;
+
+  // Multi-line text: split and render with <br /> between lines
+  const lines = text.split("\n");
+  return (
+    <>
+      {lines.map((line, idx) => (
+        <span key={idx} dir="auto">
+          {line}
+          {idx < lines.length - 1 && <br />}
+        </span>
+      ))}
+    </>
+  );
 }