slidingView: Set current page before starting animation

If animations are disabled, the animation ends when calling play
returns. Therefore, everything has to be set before calling play when
animations can be disabled.

Closes #368

news.d/47.0/fixed-wrong-image-shown-with-animations-disabled

@@ -0,0 +1 @@
+When disabling animations in the OS and using the buttons to change the image, the wrong image was shown, disabling features like zoom.

src/widgets/sliding_view.rs

@@ -356,6 +356,9 @@ mod imp {
             let position_shift = self.position_shift.get() as f32;
             let page_position = page_index as f32;
 
+            // Reset from potential stacked cards animation
+            page.set_opacity(1.);
+
             // reverse page order for RTL languages
             let direction_sign = if self.is_rtl() { -1. } else { 1. };
 
@@ -617,6 +620,8 @@ impl LpSlidingView {
 
                 *self.imp().position_tracking.borrow_mut() =
                     PositionTracking::StackedCards(StackedCards::new(prev_page, backward));
+                // Set current page here as well, to make sure it's set when animation completes for disabled animations
+                self.set_current_page(Some(page));
                 animation.play();
             }
         }
@@ -631,8 +636,8 @@ impl LpSlidingView {
             animation.set_value_from(self.position());
             animation.set_value_to(index as f64 - self.position_shift());
             animation.set_initial_velocity(initial_velocity);
-            animation.play();
             self.set_current_page(Some(page));
+            animation.play();
         } else {
             log::error!("Page not in LpSlidingView {}", page.file().uri());
         }