Restore menu item focus for accessibility, fix DropdownMenu.

Re-enable setFocus() in menu item selection for screen reader
support. Save and restore the previously focused widget in
DropdownMenu so that focus returns correctly when the menu hides.

Author: rezabakhshilaktasaraei

ui/widgets/dropdown_menu.cpp

@@ -7,6 +7,7 @@
 #include "ui/widgets/dropdown_menu.h"
 
 #include <QtGui/QtEvents>
+#include <QtWidgets/QApplication>
 
 namespace Ui {
 
@@ -31,6 +32,15 @@ DropdownMenu::DropdownMenu(QWidget *parent, const style::DropdownMenu &st) : Inn
 //}
 
 void DropdownMenu::init() {
+	QObject::connect(
+		qApp,
+		&QApplication::focusChanged,
+		this,
+		[this](QWidget *old, QWidget *now) {
+			if (now && isAncestorOf(now) && old && !isAncestorOf(old)) {
+				_previousFocusWidget = old;
+			}
+		});
 	InnerDropdown::setHiddenCallback([this] { hideFinish(); });
 
 	_menu->resizesFromInner(
@@ -233,6 +243,10 @@ void DropdownMenu::childHiding(DropdownMenu *child) {
 
 void DropdownMenu::hideFinish() {
 	_menu->clearSelection();
+	if (const auto widget = _previousFocusWidget.data()) {
+		widget->setFocus();
+		_previousFocusWidget = nullptr;
+	}
 	if (const auto onstack = _hiddenCallback) {
 		onstack();
 	}

ui/widgets/dropdown_menu.h

@@ -94,6 +94,8 @@ class DropdownMenu : public InnerDropdown {
 
 	SubmenuPointer _activeSubmenu;
 
+	QPointer<QWidget> _previousFocusWidget;
+
 	bool _deleteOnHide = false;
 	bool _triggering = false;
 	bool _deleteLater = false;

ui/widgets/menu/menu_item_base.cpp

@@ -38,9 +38,9 @@ void ItemBase::setSelected(
 		_selected = selected;
 		update();
 		if (selected) {
-			//setFocus();
-			//QAccessibleEvent event(this, QAccessible::Focus);
-			//QAccessible::updateAccessibility(&event);
+			setFocus();
+			QAccessibleEvent event(this, QAccessible::Focus);
+			QAccessible::updateAccessibility(&event);
 		}
 	}
 }