message-text: Make emoji-only messages bigger

Cargo.lock

@@ -1001,6 +1001,7 @@ dependencies = [
  "once_cell",
  "qrcode",
  "rand 0.8.4",
+ "regex",
  "secret-service",
  "serde",
  "serde_json",

Cargo.toml

@@ -34,6 +34,7 @@ gst = {version = "0.17", package = "gstreamer"}
 gst_base = {version = "0.17", package = "gstreamer-base"}
 gst_video = {version = "0.17", package = "gstreamer-video"}
 image = {version = "0.23", default-features = false, features=["png"]}
+regex = "1.5.4"
 
 [dependencies.sourceview]
 package = "sourceview5"

data/resources/style.css

@@ -209,6 +209,10 @@ headerbar.flat {
   margin-left: 46px;
 }
 
+.room-history .event-content .emoji {
+  font-size: 3em;
+}
+
 .room-history .event-content .thumbnail {
   border-radius: 6px;
   background-color: @light_3;

src/session/content/room_history/message_row/text.rs

@@ -5,6 +5,8 @@ use html2pango::{
     html_escape, markup_links,
 };
 use matrix_sdk::ruma::events::room::message::{FormattedBody, MessageFormat};
+use once_cell::sync::Lazy;
+use regex::Regex;
 use sourceview::prelude::*;
 
 use crate::session::{
@@ -13,6 +15,21 @@ use crate::session::{
     UserExt,
 };
 
+static EMOJI_REGEX: Lazy<Regex> = Lazy::new(|| {
+    Regex::new(
+        r"(?x)
+        ^
+        [\p{White_Space}\p{Emoji_Component}]*
+        [\p{Emoji}--\p{Decimal_Number}]+
+        [\p{White_Space}\p{Emoji}\p{Emoji_Component}--\p{Decimal_Number}]*
+        $
+        # That string is made of at least one emoji, except digits, possibly more,
+        # possibly with modifiers, possibly with spaces, but nothing else
+        ",
+    )
+    .unwrap()
+});
+
 mod imp {
     use super::*;
     use once_cell::sync::Lazy;
@@ -199,6 +216,10 @@ impl MessageText {
             child
         };
 
+        if EMOJI_REGEX.is_match(text) {
+            child.add_css_class("emoji");
+        }
+
         if use_markup {
             child.set_markup(text);
         } else {