Allow slowing down Animations::Simple globally.

ui/effects/animation_value.cpp

@@ -14,6 +14,7 @@ namespace anim {
 namespace {
 
 rpl::variable<bool> AnimationsDisabled = false;
+int SlowMultiplierMinusOne/* = 0*/;
 
 } // namespace
 
@@ -76,6 +77,16 @@ void SetDisabled(bool disabled) {
 	AnimationsDisabled = disabled;
 }
 
+int SlowMultiplier() {
+	return (SlowMultiplierMinusOne + 1);
+}
+
+void SetSlowMultiplier(int multiplier) {
+	Expects(multiplier > 0);
+
+	SlowMultiplierMinusOne = multiplier - 1;
+}
+
 void DrawStaticLoading(
 		QPainter &p,
 		QRectF rect,

ui/effects/animation_value.h

@@ -351,6 +351,8 @@ QPainterPath path(QPointF (&from)[N]) {
 rpl::producer<bool> Disables();
 bool Disabled();
 void SetDisabled(bool disabled);
+int SlowMultiplier();
+void SetSlowMultiplier(int multiplier); // 1 - default, 10 - slow x10.
 
 void DrawStaticLoading(
 	QPainter &p,

ui/effects/animations.h

@@ -410,7 +410,7 @@ inline void Simple::startPrepared(
 		anim::transition transition) {
 	_data->from = _data->value;
 	_data->delta = to - _data->from;
-	_data->duration = duration;
+	_data->duration = duration * anim::SlowMultiplier();
 	_data->transition = transition;
 	_data->animation.start();
 }