Allow requesting low-quality scaling of custom emoji.

ui/text/text.cpp

@@ -1724,13 +1724,12 @@ private:
 								_customEmojiSize = AdjustCustomEmojiSize(st::emojiSize);
 								_customEmojiSkip = (st::emojiSize - _customEmojiSize) / 2;
 							}
-							custom->paint(
-								*_p,
-								x + _customEmojiSkip,
-								y + _customEmojiSkip,
-								_now,
-								_textPalette->spoilerActiveBg->c,
-								_p->inactive());
+							custom->paint(*_p, {
+								.preview = _textPalette->spoilerActiveBg->c,
+								.now = _now,
+								.position = { x + _customEmojiSkip, y + _customEmojiSkip },
+								.paused = _p->inactive(),
+							});
 						}
 					}
 					if (hasSpoiler) {

ui/text/text_block.h

@@ -166,17 +166,24 @@ private:
 
 };
 
+struct CustomEmojiPaintContext {
+	QColor preview;
+	QSize size; // Required only when scaled = true, for path scaling.
+	crl::time now = 0;
+	float64 scale = 0.;
+	QPoint position;
+	bool paused = false;
+	bool scaled = false;
+};
+
 class CustomEmoji {
 public:
 	virtual ~CustomEmoji() = default;
+
 	[[nodiscard]] virtual QString entityData() = 0;
-	virtual void paint(
-		QPainter &p,
-		int x,
-		int y,
-		crl::time now,
-		const QColor &preview,
-		bool paused) = 0;
+
+	using Context = CustomEmojiPaintContext;
+	virtual void paint(QPainter &p, const Context &context) = 0;
 	virtual void unload() = 0;
 
 };

ui/widgets/input_fields.cpp

@@ -1424,13 +1424,14 @@ void CustomEmojiObject::drawObject(
 	if (i == end(_emoji)) {
 		return;
 	}
-	i->second->paint(
-		*painter,
-		int(base::SafeRound(rect.x())) + st::emojiPadding + _skip,
-		int(base::SafeRound(rect.y())) + _skip,
-		_now,
-		st::defaultTextPalette.spoilerActiveBg->c,
-		_paused && _paused());
+	i->second->paint(*painter, {
+		.preview = st::defaultTextPalette.spoilerActiveBg->c,
+		.now = _now,
+		.position = QPoint(
+			int(base::SafeRound(rect.x())) + st::emojiPadding + _skip,
+			int(base::SafeRound(rect.y())) + _skip),
+		.paused = _paused && _paused(),
+	});
 }
 
 void CustomEmojiObject::clear() {