Added ability to go to top of media panel by clicking on selected tab.

Telegram/SourceFiles/boxes/stickers_box.cpp

@@ -436,6 +436,7 @@ void StickersBox::switchTab() {
 		requestArchivedSets();
 	}
 	if (_tab == newTab) {
+		onScrollToY(0);
 		return;
 	}
 

Telegram/SourceFiles/chat_helpers/tabbed_selector.cpp

@@ -782,6 +782,7 @@ void TabbedSelector::switchTab() {
 	Assert(tab >= 0 && tab < Tab::kCount);
 	auto newTabType = static_cast<SelectorTab>(tab);
 	if (_currentTabType == newTabType) {
+		_scroll->scrollToY(0);
 		return;
 	}
 

Telegram/SourceFiles/ui/widgets/discrete_sliders.cpp

@@ -17,10 +17,8 @@ DiscreteSlider::DiscreteSlider(QWidget *parent) : RpWidget(parent) {
 }
 
 void DiscreteSlider::setActiveSection(int index) {
-	if (_activeIndex != index) {
 	_activeIndex = index;
 	activateCallback();
-	}
 	setSelectedSection(index);
 }