feat(conversation-viewer): update message rendering with single emoji detection and dynamic font sizing for improved display

meshchatx/src/frontend/components/messages/ConversationViewer.vue

@@ -818,10 +818,11 @@
                                         'markdown-content--outbound-solid':
                                             chatItem.is_outbound && !isThemeOutboundBubble(chatItem),
                                         'markdown-content--inbound': !chatItem.is_outbound,
+                                        'markdown-content--single-emoji': messageMarkdownSingleEmoji(chatItem),
                                     }"
                                     :style="{
                                         'font-family': 'inherit',
-                                        'font-size': (config?.message_font_size || 14) + 'px',
+                                        'font-size': messageMarkdownFontSizePx(chatItem) + 'px',
                                     }"
                                     @click="handleMessageClick"
                                     v-html="renderMarkdown(chatItem.lxmf_message.content)"
@@ -2989,6 +2990,26 @@ export default {
         renderMarkdown(text) {
             return MarkdownRenderer.render(text);
         },
+        messageMarkdownSingleEmoji(chatItem) {
+            const c = chatItem?.lxmf_message?.content;
+            if (!c) {
+                return false;
+            }
+            if (this.getParsedItems(chatItem)?.isOnlyPaperMessage) {
+                return false;
+            }
+            if (this.shouldHideAutoImageCaption(chatItem)) {
+                return false;
+            }
+            return MarkdownRenderer.isSingleEmojiMessage(c);
+        },
+        messageMarkdownFontSizePx(chatItem) {
+            const base = Number(this.config?.message_font_size) || 14;
+            if (this.messageMarkdownSingleEmoji(chatItem)) {
+                return Math.round(base * 2.75);
+            }
+            return base;
+        },
         handleMessageClick(event) {
             const nomadnetLink = event.target.closest(".nomadnet-link");
             if (nomadnetLink) {
@@ -5724,6 +5745,15 @@ export default {
     margin: 0.5rem 0;
 }
 
+.markdown-content--single-emoji {
+    line-height: 1;
+}
+
+.markdown-content--single-emoji :deep(p) {
+    margin: 0;
+    line-height: 1;
+}
+
 .markdown-content :deep(strong) {
     font-weight: 700;
 }

meshchatx/src/frontend/js/MarkdownRenderer.js

@@ -80,6 +80,30 @@ export default class MarkdownRenderer {
         return processed_parts.join("\n");
     }
 
+    /**
+     * True when the body is only a single emoji (after markdown strip), for large bubble rendering.
+     */
+    static isSingleEmojiMessage(raw) {
+        if (raw == null || typeof raw !== "string") {
+            return false;
+        }
+        let plain = MarkdownRenderer.strip(raw);
+        plain = plain.replace(/\s+/g, "");
+        if (!plain) {
+            return false;
+        }
+        if (typeof Intl === "undefined" || typeof Intl.Segmenter !== "function") {
+            return false;
+        }
+        const seg = new Intl.Segmenter(undefined, { granularity: "grapheme" });
+        const clusters = [...seg.segment(plain)].map((s) => s.segment);
+        if (clusters.length !== 1) {
+            return false;
+        }
+        const g = clusters[0];
+        return /\p{Extended_Pictographic}/u.test(g) || /\p{Emoji}/u.test(g);
+    }
+
     /**
      * Strips markdown from text for previews.
      */

tests/frontend/MarkdownRenderer.test.js

@@ -226,6 +226,22 @@ describe("MarkdownRenderer.js", () => {
         });
     });
 
+    describe("isSingleEmojiMessage", () => {
+        it("is true for one emoji and false for text or multiple emojis", () => {
+            expect(MarkdownRenderer.isSingleEmojiMessage("\u{1F600}")).toBe(true);
+            expect(MarkdownRenderer.isSingleEmojiMessage("  \u{1F600}  ")).toBe(true);
+            expect(MarkdownRenderer.isSingleEmojiMessage("**\u{1F600}**")).toBe(true);
+            expect(MarkdownRenderer.isSingleEmojiMessage("\u{1F600}\u{1F600}")).toBe(false);
+            expect(MarkdownRenderer.isSingleEmojiMessage("hi")).toBe(false);
+            expect(MarkdownRenderer.isSingleEmojiMessage("\u{1F600} a")).toBe(false);
+        });
+
+        it("treats ZWJ family and skin tone as a single emoji", () => {
+            expect(MarkdownRenderer.isSingleEmojiMessage("\u{1F468}\u{200D}\u{1F469}\u{200D}\u{1F467}")).toBe(true);
+            expect(MarkdownRenderer.isSingleEmojiMessage("\u{1F44D}\u{1F3FD}")).toBe(true);
+        });
+    });
+
     describe("strip", () => {
         it("strips markdown correctly", () => {
             const md = "# Header\n**Bold** *Italic* `code` ```\nblock\n```";