Emoji display added to sticker preview. Reading featured sticker sets.

Reading featured sticker sets one by one while scrolling through them,
only when the row was fully visible and the image was already loaded.

Telegram/SourceFiles/layerwidget.h

@@ -133,7 +133,6 @@ class MediaPreviewWidget : public TWidget {
 	Q_OBJECT
 
 public:
-
 	MediaPreviewWidget(QWidget *parent);
 
 	void paintEvent(QPaintEvent *e);
@@ -148,10 +147,10 @@ public:
 	~MediaPreviewWidget();
 
 private:
-
 	QSize currentDimensions() const;
 	QPixmap currentImage() const;
 	void startShow();
+	void fillEmojiString();
 	void resetGifAndCache();
 
 	anim::fvalue a_shown;
@@ -163,6 +162,9 @@ private:
 		return (!_gif || _gif == Media::Clip::BadReader) ? false : true;
 	}
 
+	int _emojiSize;
+	QList<EmojiPtr> _emojiList;
+
 	void clipCallback(Media::Clip::Notification notification);
 
 	enum CacheStatus {